CN119968803A - Monitoring of PDCCH candidates overlapping with LTE CRS in enhanced dynamic spectrum sharing configurations - Google Patents

Abstract

Various techniques are provided for a method in which a process may be performed, the process comprising: determining, by a user equipment, whether a control channel candidate of a first radio access technology overlaps with at least one resource element of a second radio access technology; determining, by the user equipment, whether to process the control channel candidate based on a predetermined criterion associated with the control channel candidate of the first radio access technology; disabling monitoring of the control channel candidate by the user equipment in response to the user equipment determining not to process the control channel candidate; and processing the control channel candidate by the user equipment in response to the user equipment determining to process the control channel candidate.

Description

Monitoring of PDCCH candidates overlapping LTE CRS in enhanced dynamic spectrum sharing configuration

Technical Field

The present description relates to wireless communications.

Background

A communication system may be a facility that enables communication between two or more nodes or devices, such as fixed or mobile communication devices. The signals may be carried on a wired or wireless carrier.

An example of a cellular communication system is an architecture standardized by the third generation partnership project (3 GPP). Recent developments in this field are commonly referred to as Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology. E-UTRA (evolved UMTS terrestrial radio Access) is an air interface for the 3GPP Long Term Evolution (LTE) upgrade path of mobile networks. In LTE, a base station or Access Point (AP), referred to as an enhanced node B (eNB), provides wireless access within a coverage area or cell. In LTE, a mobile device or mobile station is referred to as a User Equipment (UE). LTE has included many improvements or developments. The aspects of LTE are also continually improving.

The 5G New Radio (NR) development is part of an ongoing mobile broadband evolution process for meeting 5G requirements, similar to the early evolution of 3G and 4G wireless networks. In addition to mobile broadband, 5G is also directed to emerging use cases. The goal of 5G is to significantly improve wireless performance, which may include new levels of data rate, latency, reliability, and security. The 5G NR can also be extended to efficiently connect to the large-scale internet of things (IoT) and can provide new mission critical services. For example, ultra-reliable low latency communication (URLLC) devices may require high reliability and very low latency. The 5G NR development may include advanced version 5G, which incorporates advances in multiple-input multiple-output (MIMO) antennas, artificial intelligence, position location, dynamic Spectrum Sharing (DSS), and the like.

Disclosure of Invention

According to example embodiments, an apparatus, system, non-transitory computer readable medium (having stored thereon computer executable program code executable on a computer system), and/or method may perform a process comprising determining, by a user equipment, whether a control channel candidate of a first radio access technology overlaps with at least one resource element of a second radio access technology, determining, by the user equipment, whether to process the control channel candidate based on a predetermined criterion associated with the control channel candidate of the first radio access technology, determining, by the user equipment, to not process the control channel candidate, to enable monitoring of the control channel candidate by the user equipment in response to the user equipment determining, and processing, by the user equipment, the control channel candidate in response to the user equipment determining to process the control channel candidate.

Implementations may include one or more of the following features and/or any combination thereof. For example, the first radio access technology may be a New Radio (NR) radio access technology, the second radio access technology may be a Long Term Evolution (LTE) radio access technology, the control channel candidate for the first radio access technology may be a radio Physical Downlink Control Channel (PDCCH) candidate, and the resource element for the second radio access technology may be an LTE cell specific reference signal (CRS). The determining whether the control channel candidate of the first radio access technology overlaps with at least one resource element of the second radio access technology may include determining whether a PDCCH candidate for the UE on the serving cell overlaps with at least one of an overlap tag and an overlap list. The determination of whether the control channel candidate of the first radio access technology overlaps with a resource element of the second radio access technology may precede the configuration of the overlap list. The predetermined criteria of the control channel candidates may be indicated based on the aggregation level of the control channel candidates being less than the overlap handling threshold. The overlap processing threshold may vary with at least one of cell conditions, and configuration of network devices serving the associated cell. The predetermined criteria for the control channel candidates may be indicated based on the aggregation level of the control channel candidates being less than the overlap handling threshold before configuring the overlap list.

For example, the method may further include determining that the user equipment is configured to process control channel candidates of the first radio access technology that overlap with resource elements of the second radio access technology. The determination of whether to handle control channel candidates of the first radio access technology may also be based on a serving cell search space configuration. The determining of the control channel candidates not to process the first radio access technology may comprise at least one of each search space and each control channel candidate of the first radio access technology of the search space being configured separately. The determination of the control channel candidates not to process the first radio access technology may comprise that each search space is configured to be identical. The determination of whether to process the control channel candidates of the first radio access technology may also be based on an aggregation level of the search space, and the search space may be configured to be the same for a plurality of control channel candidates of the first radio access technology at the aggregation level. The determination of whether to process the control channel candidate of the first radio access technology may also be based on a power difference between the resource element candidate of the first radio access technology and overlapping resource elements of the second radio access technology. The determination of whether to process control channel candidates of the first radio access technology may also be based on a derivation of allowed aggregation levels at the user equipment and the network equipment serving the associated cell.

The details of one or more examples of the embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.

Drawings

Fig. 1 is a block diagram of a wireless network according to an example embodiment.

Fig. 2 illustrates a block diagram of a DSS resource grid according to an example embodiment.

Fig. 3 illustrates a block diagram of a method of operating a user device according to an example embodiment.

Fig. 4 illustrates a block diagram of a method of operating a user device according to an example embodiment.

Figure 5 is a wireless station or wireless node according to an example embodiment (e.g., AP, BS, gNB, RAN node, relay node, UE or user equipment, network node, network entity, DU, CU-CP, a.

Detailed Description

Fig. 1 is a block diagram of a wireless network 130 according to an example embodiment. In the wireless network 130 of fig. 1, user equipments 131, 132, 133 and 135 (which may also be referred to as Mobile Stations (MSs) or User Equipments (UEs)) may be connected to (and in communication with) Base Stations (BSs) 134, 136, which Base Stations (BSs) 134, 136 may also be referred to as Access Points (APs), enhanced node BS (enbs), BSs, next generation node BS (gnbs), next generation enhanced node BS (ng-enbs) or network nodes. The terms user equipment and User Equipment (UE) may be used interchangeably. A BS may also include, or may be referred to as, a RAN (radio access network) node, and may include a portion of the BS or a portion of the RAN node, such as (e.g., such as a Centralized Unit (CU) and/or a Distributed Unit (DU) in the case of a split BS). At least a portion of the functionality of a BS (e.g., an Access Point (AP), a Base Station (BS), or a (enhanced) node B (eNB), BS, RAN node) may also be performed by any node, server, or host that may be operatively coupled to a transceiver, such as a remote radio head. BSs (or APs) 134, 136 provide radio coverage in a cell 138, including radio coverage to User Equipments (UEs) 131, 132, 133 and 135. Although only four User Equipment (UE) are shown connected or attached to BSs 134, 136, any number of user equipment may be provided. BSs 134, 136 are also connected to core network 150 via S1 interfaces or NG interfaces 151, 152. This is just one simple example of a wireless network, and other wireless networks may be used.

A base station (e.g., such as BS134, 136) is an example of a Radio Access Network (RAN) node within a wireless network. The BS (or RAN node) may be or may include (or may alternatively be referred to as) for example an Access Point (AP), a gNB, an eNB or part thereof, such as a Centralized Unit (CU) and/or a Distributed Unit (DU) in case of splitting the BS or splitting the gNB, or other network node. For example, a BS (or gNB) may include a Distributed Unit (DU) network entity, such as a gNB distributed unit (gNB-DU), and a Centralized Unit (CU) that may control a plurality of DUs. For example, in some cases, a Centralized Unit (CU) may be split or partitioned into control plane entities, such as a gNB centralized (or central) unit control plane (gNB-CU-CP), and user plane entities, such as a gNB centralized (or central) unit user plane (gNB-CU-UP). For example, CU sub-entities (gNB-CU-CP, gNB-CU-UP) may be provided as different logical entities or different software entities (e.g., as separate or different communication software entities), they may be run or provided on the same hardware or server, in the cloud, etc., or may be provided on different hardware, systems, or servers, e.g., physically separate or run on different systems, hardware, or servers.

As described, in the split configuration of the gNB/BS, the gNB function may be split into DUs and CUs. A Distributed Unit (DU) may provide or establish wireless communication with one or more UEs. Thus, a DU may provide one or more cells and may allow a UE to communicate with and/or establish a connection to the DU in order to receive wireless services, such as allowing the UE to transmit or receive data. A centralized (or Central) Unit (CU) may provide control functions and/or data plane functions for one or more connected DUs, e.g. including control functions such as gNB control of user data transfer, mobility control, radio access network sharing, positioning, session management, etc., except for functions specifically assigned to DUs. A CU may control operation of DUs (e.g., a CU communicates with one or more DUs) through a forward (Fs) interface.

According to an illustrative example, in general, a BS node (e.g., BS, eNB, gNB, CU/DU, etc.) or a Radio Access Network (RAN) may be part of a mobile telecommunications system. The RAN (radio access network) may comprise one or more BSs or RAN nodes implementing radio access technologies, e.g. to allow one or more UEs to have access to a network or core network. Thus, for example, a RAN (RAN node, such as a BS or a gNB) may reside between one or more user equipments or UEs and a core network. According to example embodiments, each RAN node (e.g., BS, eNB, gNB, CU/DU, etc.) or BS may provide one or more wireless communication services for one or more UEs or user equipment, e.g., to allow the UE to have wireless access to the network via the RAN node. Each RAN node or BS may perform or provide wireless communication services, such as, for example, allowing UEs or user equipment to establish wireless connections to the RAN node, and to send data to and/or receive data from one or more UEs. For example, after establishing a connection to the UE, the RAN node (e.g., BS, eNB, gNB, CU/DU, etc.) may forward data received from the network or core network to the UE and/or forward data received from the UE to the network or core network. The RAN node (e.g., BS, eNB, gNB, CU/DU, etc.) may perform a variety of other wireless functions or services, such as, for example, broadcasting control information (e.g., such as system information) to UEs, paging UEs when there is data to be delivered to the UEs, assisting the UEs in switching between cells, scheduling resources for uplink data transmissions from the UE(s) and downlink data transmissions to the UE(s), sending control information configuring one or more UEs, etc. These are several examples of one or more functions that the RAN node or BS may perform. The base station may also be a DU (distributed unit) part of an IAB (integrated access and backhaul) node (also called relay node). The DU facilitates access link connection(s) for the IAB node.

User equipment (user terminals, user Equipment (UE), mobile terminals, handheld wireless devices, etc.) may refer to portable computing devices including wireless mobile communications devices that operate with or without a Subscriber Identity Module (SIM), which may be referred to as a universal SIM, including, but not limited to, mobile Stations (MS), mobile phones, handsets, smartphones, personal Digital Assistants (PDAs), handsets, devices using wireless modems (alarm or measurement devices, etc.), laptop and/or touch screen computers, tablet phones, gaming machines, notebook computers, vehicles, sensors, and multimedia devices, or any other wireless device. It should be understood that the user device may also be (or may include) a nearly exclusive uplink-only device, an example of which is a camera or video camera that loads images or video clips into the network. The user equipment may also be an MT (mobile terminal) part of an IAB (integrated access and backhaul) node (also referred to as a relay node). The MT facilitates a backhaul connection to the IAB node.

In LTE (as an illustrative example), the core network 150 may be referred to as an Evolved Packet Core (EPC), which may include a Mobility Management Entity (MME), which may handle or assist in mobility/handover of user equipment between BSs, one or more gateways, which may forward data and control signals between the BSs and a packet data network or the internet, and other control functions or blocks. Other types of wireless networks, such as 5G (which may be referred to as New Radio (NR)), may also include core networks (which may be referred to as 5GC in 5G/NR, for example).

Further, by way of illustrative example, the various example embodiments or techniques described herein may be applied to various types of user devices or data service types, or may be applied to user devices on which multiple applications may be running, which may be different data service types. New radio (5G) development may support a variety of different applications or a variety of different data service types, such as Machine Type Communication (MTC), enhanced machine type communication (eMTC), large-scale MTC (eMTC), internet of things (IoT) and/or narrowband IoT user equipment, enhanced mobile broadband (eMBB), and ultra-reliable low-latency communication (URLLC). Many of these new 5G (NR) related applications may typically require higher performance than previous wireless networks.

IoT may refer to an ever-growing group of objects that may have internet or network connectivity such that the objects may send and receive information to and from other network devices. For example, many sensor-type applications or devices may monitor physical conditions or states and may send reports to a server or other network device, e.g., when an event occurs. For example, machine type communications (MTC or machine-to-machine communications) may be characterized by fully automatic data generation, exchange, processing, and driving between intelligent machines, whether or not human intervention is involved. The enhanced mobile broadband (eMBB) may support higher data rates than are currently available in LTE.

Ultra-reliable low latency communications (URLLC) are new data service types or new usage scenarios that can be supported for new radio (5G) systems. This enables emerging new applications and services such as industrial automation, autopilot, vehicle security, electronic health services, etc. By way of illustrative example, 3GPP aims at providing connectivity with reliability corresponding to a block error Rate (BLER) of 10-5 and a U-plane (user/data plane) delay of at most 1 ms. Thus, for example, URLLC user equipment/UEs may require significantly lower block error rates and low latency (with or without a requirement for simultaneous high reliability) than other types of user equipment/UEs. Thus, for example, URLLC UE (or URLLC application on a UE) may require a shorter delay than eMBB UE (or eMBB application running on the UE).

Various example embodiments may be applied to a variety of wireless technologies or wireless networks, such as LTE, LTE-a, 5G (new radio (NR)), cmWave and/or mmWave band networks, ioT, MTC, eMTC, mMTC, eMBB, URLLC, etc., or any other wireless network or wireless technology. These exemplary network, technology, or data service types are provided as illustrative examples only.

Example implementations may be directed to Dynamic Spectrum Sharing (DSS) features associated with UEs operating in a serving cell. Spectrum sharing may mean that multiple radio access technologies may share the same spectrum. For example, referring to fig. 1, BS134 may be associated with a first radio access technology and BS136 may be associated with a second radio access technology. Alternatively, BS134 and/or BS136 may be associated with two radio access technologies. For example, two radio access technologies sharing the same spectrum may be LTE (e.g., 4G) and NR (e.g., 5G). The dynamic may indicate that the channel allocation may not be static. Conversely, the channel allocation may vary in time and/or frequency (e.g., from subframe/slot to another subframe/slot). DSS may be an important feature as new radio access technologies are implemented and/or deployed. For example, when deploying 4G-5G Dynamic Spectrum Sharing (DSS), one of the fundamental principles is to reduce the impact on legacy LTE networks. This results in DSS deployment in the low frequency band where the NR has very limited PDCCH resources. Example implementations may enable a UE to support and be configured with two overlapping CRS rate matching modes.

In an example implementation, if DSS features (e.g., reception of NR PDCCH candidates overlapping LTE CRS REs) are supported, the DSS features may be supported by the UE performing channel estimation in the frequency dimension with conventional legacy DMRS patterns (e.g., without changing UE assumptions about PDCCH DMRS RE positions/patterns in symbols used for channel estimation purposes). In an example implementation, assuming that PDCCH and PDCCH-DMRS RE mapping is based on an earlier release (e.g., rel 15) from the UE side, the UE (e.g., rel 18) may support reception of NR PDCCH candidates overlapping LTE CRS REs. Legacy channel estimation hypotheses may be used for channel estimation using the PDCCH-DMRS. Channel estimation is performed only on clean symbol(s), i.e., more than 1 PDCCH symbol duration (more than 1 symbol control resource set), and at least one "clean" symbol does not overlap with LTE CRS REs (this channel estimation option is not applicable to 1 symbol CORESET) may be used for PDCCH-DMRS channel estimation.

Fig. 2 illustrates a block diagram of a DSS resource grid according to an example embodiment. DSS resource grid 205 may include a plurality of blocks (excluding a first column or a first row) representing Resource Elements (REs). In order to demodulate different downlink physical channels, in LTE, the UE may need several channel estimates spread over subcarriers and symbols. Thus, LTE cell-specific reference symbols (LTE-CRS) may be inserted into DSS resource grid 205. LTE-CRS may be mapped to REs in DSS resource grid 205. Blocks of the plurality of blocks of DSS resource grid 205 may include numbers (e.g., 0, 1, 2, 3) corresponding to LTE-CRSs associated with antenna ports (e.g., antenna ports 0 through 3). For example, block 210 includes a number 1 indicating block 210 corresponding to LTE-CRS associated with antenna port 1.

As described above, DSS features associated with UEs operating in a serving cell include spectrum sharing, which means that multiple radio access technologies may share the same spectrum. For example, two radio access technologies sharing the same spectrum may be LTE (e.g., 4G) and NR (e.g., 5G). DSS resource grid 205 includes columns 215 of blocks, where columns 215 of blocks include REs, each of which may be a control channel candidate for a first radio access technology (e.g., NR or 5G). In an example implementation, all blocks of DSS resource grid 205 are REs of a second radio access technology (e.g., LTE or 4G). For example, as described above, if the second radio access technology is LTE, then LTE-CRS may be mapped to REs in DSS resource grid 205 (e.g., block 210).

In an example implementation, the control channel candidates of the first radio access technology (e.g., each block of columns 215 of blocks) may overlap with at least one resource element of the second radio access technology (e.g., any block of DSS resource grid 205). For example, block 220 of DSS resource grid 205 may be a resource element of the second radio access technology. For example, block 220 of DSS resource grid 205 may be associated with LTE-CRS, and column 215 of the block may be radio Physical Downlink Control Channel (PDCCH) candidate(s). Accordingly, block 220 of DSS resource grid 205 may be a control channel candidate for the first radio access technology that overlaps with at least one resource element of the second radio access technology. For example, block 220 of DSS resource grid 205 may be PDCCH candidate(s) overlapping LTE-CRS resource elements. The PDCCH candidate(s) overlapping with LTE-CRS are sometimes referred to as NR PDCCH collisions with LTE-CRS.

For PDCCH monitoring, NR uses PDCCH blind decoding principles like LTE, i.e. the UE performs a Cyclic Redundancy Check (CRC), where the CRC bits can be masked with an identifier (RNTI) known to the user. The UE may be configured with multiple PDCCH candidates for each monitoring occasion, where the UE attempts to find one or more PDCCHs with predefined RNTIs. The UE attempts to decode each PDCCH candidate for the monitoring occasion and determines whether a PDCCH is actually transmitted to it on a particular PDCCH candidate based on an RNTI mask CRC check.

The PDCCH candidates may be transmitted via resources defined by CORESET (control resource set). In the time domain CORESET is configured with a duration of 1, 2 or 3 OFDM symbols. CORESET may be divided into Resource Element Groups (REGs), each REG may include 12 subcarriers in frequency and may include 1 OFDM symbol in time. Each REG carrying PDCCH may carry its own DMRS, with 3 of the 12 subcarriers of the REG carrying PDCCH DMRS.

The PDCCH candidates may include a number L of Control Channel Elements (CCEs), each CCE containing 6 REGs. The number L is called the Aggregation Level (AL), L ε {1,2,4,8,16}. The AL used for transmission of the downlink control DCI may be selected by the gNB based on channel quality to ensure the required reliability of the DCI.

A CCE may include one or more REG bundles, which are a set of adjacent REGs with common precoding in frequency and time. Two options for CCE-to-REG construction are supported. For example, the first option may be an interleaved CCE-to-REG mapping and the second option may be a non-interleaved CCE-to-REG mapping.

The goal of the interleaved mapping is to achieve frequency diversity within the CCEs. For non-interleaved mapping, REG bundle size 6 is selected for achieving good channel estimation performance. The REG beam size may be configured separately for each CORESET.

Depending on the extent of overlap of NR PDCCH candidates with LTE-CRS, some PDCCH candidates (e.g., some aggregation levels) may not be useful, or it may be beneficial to prioritize LTE-CRS over PDCCH, PDCCH over LTE-CRS, or both on the same REs. NR UE PDCCH receiver implementations may play a role in the transmission on conflicting REs (CRS, PDCCH, or both superimposed) having the greatest significance.

The PDCCH search space configuration may provide 0,1, 2,3, 4, 5, 6, or 8 PDCCH candidates for the UE to monitor for each aggregation level (1, 2,4, 8, 16). Further, the UE may be equipped with a certain total number of PDCCH candidates to set an upper limit for the total number of PDCCH candidates the search space may be configured with. This upper limit is sometimes referred to as the PDCCH Blind Decoding (BD) budget of the UE. monitoringSlotPeriodictyAndOffset may indicate a time position of a PDCCH candidate to be monitored. This can be illustrated in code sample 1.

Code sample 1

NrofCandidates may represent the number of PDCCH candidates for each aggregation level. The number of candidates and the aggregation level may be applied to all control channel formats unless a specific value is specified or a format specific value is provided (see SEARCHSPACETYPE interior). This field may indicate the number of candidates and the aggregation level to be used on the linked scheduling cells if configured in SEARCHSPACE across carrier scheduling cells.

As described above, the UE may be configured to process PDCCH candidates overlapping with LTE CRS REs (e.g., monitor PDCCH candidates). The gNB does not signal to the UE information about what is to be sent on resource elements of PDCCH/PDCH-DMRS and LTE CRS collisions. A problem may be that for some configurations and for some receiver types, the UE cannot correctly receive PDCCH candidates for certain aggregation levels, no matter how good the received signal conditions the UE experiences. The search space configuration may result in PDCCH candidates sometimes overlapping LTE CRS symbols, and not overlapping LTE CRS symbols at some other times. A problem may be that if these known non-decodable PDCCH candidates are assumed to be processed, they unnecessarily consume the PDCCH blind decoding budget of the UE's PDCCH receiver. Furthermore, useless PDCCH blind decoding may increase false positive probabilities because when no PDCCH is transmitted, any processed PDCCH has a small probability of being misinterpreted as a valid PDCCH (where a CRC check may be found to be positive even though the corresponding PDCCH is not transmitted by the gNB). For example, a false positive may result in unnecessary transmission or reception attempts at the UE. It makes sense to minimize these events by the system design.

Example implementations may address these and other issues using a UE configured to process NR PDCCHs overlapping with LTE CRSs by determining whether to process (e.g., monitor) particular PDCCH candidates based on a configuration and overlapping with LTE CRSs. An advantage of the disclosed (and similar) example implementations may be that based on this procedure, the UE may be configured to skip PDCCH candidates that do not meet predetermined criteria. This will ease the UE PDCCH monitoring burden and minimize the number of false positive detections.

Fig. 3 illustrates a block diagram of a method of operating a user device according to an example embodiment. In example implementations, the UE may include hardware and/or software configured to enable processing of NR PDCCHs overlapping with LTE CRSs (e.g., see discussion above). The UE may be configured to determine whether to process (monitor) a particular PDCCH candidate based on the configuration and overlap with the LTE CRS. The example implementation of fig. 3 may involve one monitoring occasion and one search space. In alternative (or additional) implementations, fig. 3 may relate to one monitoring occasion and associated search space. In the implementation described with respect to fig. 3, the UE may follow a serial order for processing all configured PDCCH candidates for a given monitoring occasion. However, in alternative or additional implementations, parallel processing may be applied.

As shown in fig. 3, in step S305, an NR PDCCH configuration and an LTE CRS pattern configuration are received. For example, an NR PDCCH configuration may be received (e.g., signaled) from a network device configured to serve a cell using a first radio access technology (e.g., NR or 5G). For example, the LTE CRS pattern configuration may be received (e.g., signaled) from a network device configured to serve the cell using a second radio access technology (e.g., LTE or 4G). For example, the NR PDCCH configuration and LTE CRS pattern configuration may be received (e.g., signaled) from a network device configured to serve a cell using two radio access technologies.

In step S310, the next PDCCH candidate is selected. In an example implementation, one PDCCH candidate may be selected (e.g., to be blind decoded). The PDCCH candidates may have predefined aggregation levels and cover predefined CCEs. For example, referring to fig. 2, each block in column 215 of blocks of dss resource grid 205 may represent a PDCCH candidate. The blocks of column 215 of blocks may be a subset of PDCCH candidates. In other words, other columns of the block of DSS resource grid 205 may represent PDCCH candidates. The subset of PDCCH candidates may be sequentially selected (refer to 11-0 or 0-11 of fig. 2). Thus, the next PDCCH candidate may be the next consecutive candidate of the subset of PDCCH candidates.

In step S315, it is determined whether the PDCCH candidate overlaps with the LTE CRS. In response to determining that the PDCCH candidate overlaps the LTE CRS, processing continues to step S325. In response to determining that the PDCCH candidate does not overlap the LTE CRS, processing continues to step S330. For example, a PDCCH candidate for a UE is considered to overlap with an LTE CRS if at least one RE of the PDCCH candidate on the serving cell overlaps with at least one RE of the LTE-CRS (e.g., identified with an overlap tag such as LTE-CRS-ToMatchAround) or any RE on an overlap list in the LTE-RS (e.g., LTE-CRS-PATTERNLISTS). This determination may be made separately for each PDCCH monitoring occasion.

In step S320, it is determined whether the PDCCH candidate is to be processed. In response to determining that the PDCCH candidate is to be processed, processing continues to step S325. In response to determining not to process the PDCCH candidate, processing continues to step S330. For example, whether to process the PDCCH candidate is based on predetermined criteria associated with the PDCCH candidate. For example, the predetermined criteria may be an aggregation level of PDCCH candidates, signal quality, a configured power level difference between LTE-CRS and PDCCH symbols or resource elements, and/or a degree of overlap with LTE CRS resource elements. The predetermined criterion may be a combination of two or more criteria.

For example, the determination of whether to process overlapping PDCCH candidates may be based on a Search Space (SS) configuration. The search space configuration may be based on a DSS resource grid (e.g., DSS resource grid 205). The criteria for determining whether to process overlapping PDCCH candidates may be configured separately for each search space and/or for each PDCCH candidate of a search space. In an example embodiment, this configuration may be generic for all search spaces. In an example embodiment, the PDCCH processing criteria may be configured separately for each Aggregation Level (AL) of the search space (e.g., all PDCCH candidates for that aggregation level are common). For example, the criterion may be an AL threshold. For example, all PDCCH candidates of AL.gtoreq.n (or > n) will be processed. Alternatively, all candidates for AL.ltoreq.n (or < n) are not processed.

In an example implementation, different configurations/thresholds (e.g., predetermined criteria) may be used for different degrees of overlap. For example, for a set of multi-symbol PDCCH candidates with 1 symbol overlap (all PDCCH candidates in one SS have the same number of symbols), there is a different threshold than when there is 2 symbol overlap. The overlap threshold may be in the form of frequency (e.g., N PRBs or N Control Channel Elements (CCEs) of PDCCH candidates overlap with LTE CRS REs). If the NR carrier is wider than the LTE-at-root carrier and the LTE CRS symbols may only partially overlap the PDCCH in frequency, an overlap threshold in frequency is applicable.

Additionally or alternatively, PDCCH processing conditions (e.g., predetermined criteria) may be based on a predefined power difference between the superimposed (NR) PDCCH and the LTE CRS. For example, if the PDCCH power is below a particular threshold (e.g., 3 dB) relative to the LTE CRS power, then particular PDCCH candidates with particular ALs may be discarded (not processed).

In an example embodiment, the determination of whether to process PDCCH candidates may be based on implicit derivation of allowed ALs at the UE and the gNB. For example, if implicitly derived by the UE, the implicit derivation may be based on the AL used in the Common Search Space (CSS). The implicit derivation may be decoded during the RRC connection establishment procedure. In this case, the gNB may know which PDCCH AL UE was decoded correctly (PDSCH HARQ feedback received for DL grant and UL transmission received for PUSCH grant) and establish the smallest set of ALs for robustly scheduling the UE in SSs overlapping with LTE CRS.

The possible RRC may be illustrated in code sample 2.

Code sample 2

CrsOverlapProcessingThreshold (the name of this information element is exemplary) may be an aggregation level threshold for monitoring PDCCH candidates when the candidates overlap with LTE CRS. Furthermore, if at least one RE of a PDCCH candidate for a UE on a serving cell overlaps with at least one RE of LTE-CRS-ToMatchAround or LTE-CRS-PATTERNLIST and the UE does not support the overlapping technique, the UE does not need to monitor the PDCCH candidate.

In an example implementation, the UE may support implicit derivation of AL for reliable scheduling. For example, NR UEs in idle mode are unaware of CRS RM mode used by LTE cells of DSS cells. The NR UE is aware that it is handling a NR DSS cell only after entering connected mode and when its capabilities are known. At this stage, the gNB will configure the UE to LTE CRS RM mode. To achieve this, the UE must decode several PDCCH allocations on the CSS. If the UE is already able to decode these ALs without it knowing that LTE CRS is present, the UE may proceed to decode at least these ALs. Typically, a single AL is statically configured for use until UE feedback (e.g., CSI reports) is available to perform PDCCH link adaptation. Thus, after the UE has successfully transitioned to connected mode, the gNB may infer at least some ALs that the UE is able to properly decode in the presence of LTE CRS.

In step S325, the PDCCH candidate is processed. For example, if Downlink Control Information (DCI) is actually transmitted to the UE using the PDCCH candidate, the UE may attempt to decode the PDCCH candidate to obtain the DCI (blind decoding of the PDCCH candidate may be a process in which the UE traverses all configured PDCCH candidates and attempts to decode them in order to determine whether any PDCCH candidates are used to transmit the PDCCH). In step S330, the PDCCH candidates are not processed. For example, the UE may skip processing of the PDCCH candidates and/or disable monitoring of the PDCCH candidates.

In step S335, it is determined whether monitoring is completed. In response to determining that the monitoring is complete, the process ends and/or the monitoring is complete. In response to determining that the monitoring is not completed, the process returns to step S310. For example, referring to fig. 3, if all PDCCH candidates configured for the search space in step S310 are determined to be processed (and then also processed) or not processed, the monitoring is completed. Otherwise, the monitoring may not be complete.

Example 1 fig. 4 is a block diagram of a method of operating a user device according to an example embodiment. As shown in fig. 4, in step S405, it is determined by the user equipment whether the control channel candidate of the first radio access technology overlaps with at least one resource element of the second radio access technology. In step S410, it is determined by the user equipment whether to process a control channel candidate of the first radio access technology based on a predetermined criterion associated with the control channel candidate. In step S415, monitoring of control channel candidates by the user equipment is disabled in response to the user equipment determining not to process the control channel candidates. In step S420, the control channel candidate is processed by the user equipment in response to the user equipment determining to process the control channel candidate.

Example 2. The method of example 1, wherein the first radio access technology may be a New Radio (NR) radio access technology, the second radio access technology may be a Long Term Evolution (LTE) radio access technology, the control channel candidate for the first radio access technology may be a radio Physical Downlink Control Channel (PDCCH) candidate, and the resource element for the second radio access technology may be an LTE cell specific reference signal (CRS).

Example 3. The method of example 1, wherein the determination of whether the control channel candidate of the first radio access technology overlaps with at least one resource element of the second radio access technology may include determining whether a PDCCH candidate for the UE on the serving cell overlaps with at least one of an overlap tag and an overlap list.

Example 4. The method of example 1, wherein the determination of whether the control channel candidate of the first radio access technology overlaps with a resource element of the second radio access technology may precede the configuration of the overlap list.

Example 5. The method of example 1, wherein the predetermined criteria for the control channel candidates may be indicated based on the aggregation level of the control channel candidates being less than an overlap handling threshold.

Example 6. The method of example 5, wherein the overlap handling threshold may vary with at least one of cell conditions, and configuration of network devices serving the associated cell.

Example 7. The method of example 1, wherein the predetermined criteria for the control channel candidates may be indicated based on the aggregation level of the control channel candidates being less than an overlap handling threshold before configuring the overlap list.

Example 8 the method of example 1 may further include determining that the user equipment is configured to process control channel candidates of the first radio access technology that overlap with resource elements of the second radio access technology.

Example 9. The method of example 1, wherein the determination of whether to process control channel candidates for the first radio access technology may further be based on a serving cell search space configuration.

Example 10. The method of example 9, wherein the determining of the control channel candidates not to process the first radio access technology may include at least one of each search space, and each control channel candidate of the first radio access technology of the search space, being configured separately.

Example 11. The method of example 9, wherein the determining of the control channel candidates not to process the first radio access technology may include each search space being configured to be the same.

Example 12. The method of example 1, wherein the determination of whether to process the control channel candidates for the first radio access technology may further be based on an aggregation level of the search space, and the search space may be configured to be the same for a plurality of control channel candidates for the first radio access technology at the aggregation level.

Example 13. The method of example 1, wherein the determination of whether to process the control channel candidate of the first radio access technology may further be based on a power difference between the resource element candidate of the first radio access technology and overlapping resource elements of the second radio access technology.

Example 14. The method of example 1, wherein the determination of whether to process control channel candidates for the first radio access technology may further be based on a derivation of allowed aggregation levels at the user equipment and network equipment serving the associated cell.

Example 15. A non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, are configured to cause a computing system to perform the method of any of examples 1 to 14.

Example 16. An apparatus comprising means for performing the method of any of examples 1 to 14.

Example 17. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform the method of any one of examples 1 to 14.

Fig. 5 is a block diagram of a wireless station 500 or wireless node or network node 500 according to an example embodiment. According to example embodiments, the wireless node or wireless station or network node 500 may include, for example, one or more of AP, BS, gNB, RAN nodes, relay nodes, UEs or user equipment, network nodes, network entities, DUs, CU-CPs, CU-UP, or other nodes.

The wireless station 500 may include, for example, one or more (e.g., two as shown in fig. 5) Radio Frequency (RF) or wireless transceivers 502A, 502B, each of which includes a transmitter to transmit signals and a receiver to receive signals. The wireless station also includes a processor or control unit/entity (controller) 504 that executes instructions or software and controls the transmission and reception of signals, and a memory 506 that stores data and/or instructions.

The processor 504 may also make decisions or determinations, generate frames, packets, or messages for transmission, decode received frames or messages for further processing, and perform other tasks or functions described herein. For example, the processor 504, which may be a baseband processor, may generate messages, packets, frames, or other signals for transmission via the wireless transceivers 502A and/or 502B. The processor 504 may control transmission of signals or messages through the wireless network and may control reception of signals or messages, etc., via the wireless network (e.g., after being down-converted by the wireless transceiver 502A/502B). The processor 504 may be programmable and capable of executing software or other instructions stored in memory or on other computer media to perform the various tasks and functions described above, such as one or more of the tasks or methods described above. For example, the processor 504 may be (or may include) hardware, programmable logic, a programmable processor executing software or firmware, and/or any combination of these. For example, using other terminology, the processor 504 and the transceivers 502A/502B may together be considered a wireless transmitter/receiver system.

Further, referring to fig. 5, a controller (or processor) 508 may execute software and instructions and may provide overall control for the station 500, and may provide control for other systems not shown in fig. 5, such as controlling input/output devices (e.g., displays, keypads), and/or may execute software for one or more applications that may be provided on the wireless station 500, such as email programs, audio/video applications, word processors, voice over IP applications, or other applications or software.

Further, a storage medium may be provided that includes stored instructions that, when executed by a controller or processor, may cause the processor 504 or other controller or processor to perform one or more of the functions or tasks described above.

According to another example embodiment, the RF or wireless transceiver(s) 502A/502B may receive signals or data and/or transmit or send signals or data. The processor 504 (and possibly the transceivers 502A/502B) may control the RF or wireless transceivers 502A or 502B to receive, transmit, broadcast, or transmit signals or data.

However, the exemplary embodiments are not limited to the system given as an example, and a person skilled in the art may apply the solution to other communication systems. Another example of a suitable communication system is a 5G system. It is assumed that the network architecture in 5G will be very similar to that of LTE-advanced. The 5G may use multiple-input multiple-output (MIMO) antennas, more base stations or nodes than LTE (so-called small cell concept), including macro sites operating in cooperation with smaller base stations, and may employ various radio technologies for better coverage and enhanced data rates.

It should be appreciated that future networks will likely utilize Network Function Virtualization (NFV), a network architecture concept that proposes to virtualize network node functions as "building blocks" or entities that may be operatively connected or linked together to provide services. A Virtualized Network Function (VNF) may comprise one or more virtual machines that run computer program code using standard or generic type servers instead of custom hardware. Cloud computing or data storage may also be utilized. In radio communications, this may mean that node operations may be performed at least in part in a server, host, or node operatively coupled to a remote radio head. Node operations may also be distributed among multiple servers, nodes, or hosts. It should also be appreciated that the division of labor between core network operation and base station operation may be different from LTE, or even non-existent.

Example embodiments of the various techniques described herein may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Example embodiments may be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. Embodiments may also be provided on a computer-readable medium or a computer-readable storage medium, which may be a non-transitory medium. Embodiments of the various techniques may also include embodiments provided via transitory signals or media, and/or program and/or software embodiments downloadable via the internet or other network(s) (wired and/or wireless network). Further, embodiments may be provided via Machine Type Communication (MTC) or via internet of things (IOT).

A computer program may be in source code form, object code form, or in some intermediate form and may be stored in some carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers include, for example, recording media, computer memory, read-only memory, electro-optical and/or electronic carrier signals, telecommunications signals, and software distribution packages. The computer program may be executed in a single electronic digital computer or may be distributed among multiple computers, depending on the processing power required.

Further, example embodiments of the various techniques described herein may use a network physical system (CPS) (a system that causes computing elements controlling physical entities to cooperate). CPS may implement and utilize a multitude of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects at different locations. A mobile network physical system, in which the physical system in question has an inherent mobility, is a sub-class of network physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals. The popularity of smartphones has increased interest in the field of mobile network physical systems. Accordingly, various embodiments of the techniques described herein may be provided by one or more of these techniques.

A computer program, such as the computer program(s) described above, can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit or portion thereof suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.

The method steps may be performed by one or more programmable processors executing a computer program or portion of a computer program to perform functions by operating on input data and generating output. Method steps may also be performed by, and apparatus may be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer, chip or chipset. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. Elements of a computer may include at least one processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer can also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data (e.g., magnetic, magneto-optical disks, or optical disks). Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices, magnetic disks, e.g., internal hard disks or removable disks, magneto-optical disks, and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

To provide for interaction with a user, embodiments can be implemented on a computer having a display device (e.g., a Cathode Ray Tube (CRT) or Liquid Crystal Display (LCD) monitor) for displaying information to the user and a user interface (such as a keyboard and a pointing device, e.g., a mouse or a trackball) by which the user can provide input to the computer. Other types of devices may also be used to provide interaction with the user, for example, feedback provided to the user may be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback, and input from the user may be received in any form, including acoustic, speech, or tactile input.

Example embodiments may be implemented in a computing system that includes a back-end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front-end component, e.g., a client computer having a graphical user interface or a web browser through which a user can interact with an embodiment, or any combination of such back-end, middleware, or front-end components. The components may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a Local Area Network (LAN) and a Wide Area Network (WAN), such as the internet.

While certain features of the described embodiments have been illustrated as described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the various embodiments.

Claims (30)

1. An apparatus, comprising:

at least one processor, and

At least one memory including computer program code;

the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

determining, by the user equipment, whether a control channel candidate of the first radio access technology overlaps with at least one resource element of the second radio access technology;

determining, by the user equipment, whether to process the control channel candidate based on a predetermined criterion associated with the control channel candidate of the first radio access technology;

Enabling monitoring of the control channel candidates by the user equipment in response to the user equipment determining not to process the control channel candidates, and

The control channel candidates are processed by the user equipment in response to the user equipment determining to process the control channel candidates.

2. The device of claim 1, wherein

The first radio access technology is a New Radio (NR) radio access technology,

The second radio access technology is a Long Term Evolution (LTE) radio access technology,

The control channel candidate of the first radio access technology is a radio Physical Downlink Control Channel (PDCCH) candidate, and

The resource element of the second radio access technology is an LTE cell-specific reference signal (CRS).

3. The apparatus of claim 1 or claim 2, wherein the determination of whether a control channel candidate of a first radio access technology overlaps with at least one resource element of a second radio access technology comprises determining whether the control channel candidate for the user equipment on a serving cell overlaps with at least one of an overlap tag and an overlap list.

4. The apparatus of any of claims 1-3, wherein the determination of whether the control channel candidate of a first radio access technology overlaps with a resource element of a second radio access technology is prior to configuring an overlap list.

5. The apparatus according to any of claims 1-4, wherein the predetermined criteria of the control channel candidates are indicated based on an aggregation level of the control channel candidates being less than an overlap handling threshold.

6. The apparatus of claim 5, wherein the overlap processing threshold varies with at least one of cell conditions and configuration of network devices serving the associated cell.

7. The apparatus according to any of claims 1 to 6, wherein the predetermined criteria of the control channel candidates are indicated based on an aggregation level of the control channel candidates being less than an overlap handling threshold before configuring an overlap list.

8. The apparatus of any of claims 1 to 7, further comprising computer program code configured to cause the apparatus to:

A determination is made that the user equipment is configured to process control channel candidates of the first radio access technology that overlap with the resource elements of the second radio access technology.

9. The apparatus according to any of claims 1-8, wherein the determination of whether to process the control channel candidates of the first radio access technology is further based on a serving cell search space configuration.

10. The apparatus of claim 9, wherein the determination of the control channel candidates not to process the first radio access technology comprises at least one of each search space, and each of the control channel candidates of the first radio access technology for the search space, being configured separately.

11. The apparatus of claim 9, wherein the determination of the control channel candidates not to process the first radio access technology comprises each search space being configured to be identical.

12. The device of any one of claims 1 to 11, wherein

The determination of whether to process the control channel candidates of the first radio access technology is also based on an aggregation level of a search space, and

The search space is configured to be the same for a plurality of control channel candidates of the first radio access technology at the aggregation level.

13. The apparatus according to any of claims 1 to 12, wherein the determination of whether to process the control channel candidate for the first radio access technology is further based on a power difference between the resource element candidate for the first radio access technology and the overlapping resource element of the second radio access technology.

14. The apparatus according to any of claims 1 to 13, wherein the determination of whether to process the control channel candidates of the first radio access technology is further based on a derivation of allowed aggregation levels at the user equipment and network equipment serving the associated cell.

15. A method, comprising:

determining, by the user equipment, whether a control channel candidate of the first radio access technology overlaps with at least one resource element of the second radio access technology;

determining, by the user equipment, whether to process the control channel candidate based on a predetermined criterion associated with the control channel candidate of the first radio access technology;

Enabling monitoring of the control channel candidates by the user equipment in response to the user equipment determining not to process the control channel candidates, and

The control channel candidates are processed by the user equipment in response to the user equipment determining to process the control channel candidates.

16. The method of claim 15, wherein

The first radio access technology is a New Radio (NR) radio access technology,

The second radio access technology is a Long Term Evolution (LTE) radio access technology,

The control channel candidate of the first radio access technology is a radio Physical Downlink Control Channel (PDCCH) candidate, and

The resource element of the second radio access technology is an LTE cell-specific reference signal (CRS).

17. The method according to claim 15 or claim 16, wherein the determination of whether a control channel candidate of a first radio access technology overlaps with at least one resource element of a second radio access technology comprises determining whether the control channel candidate for the user equipment on a serving cell overlaps with at least one of an overlap tag and an overlap list.

18. The method according to any of claims 15 to 17, wherein the determination of whether the control channel candidate of a first radio access technology overlaps with a resource element of a second radio access technology is prior to configuring an overlap list.

19. The method of claims 15 to 18, wherein the predetermined criteria of the control channel candidates are indicated based on an aggregation level of the control channel candidates being less than an overlap handling threshold.

20. The method of claim 15 to claim 19, wherein the overlap processing threshold varies with at least one of cell conditions and configuration of network devices serving the associated cell.

21. The method of claim 15 to claim 20, wherein the predetermined criteria of the control channel candidates are indicated based on an aggregation level of the control channel candidates being less than an overlap handling threshold before configuring an overlap list.

22. The method of claim 15 to claim 21, further comprising:

A determination is made that the user equipment is configured to process control channel candidates of the first radio access technology that overlap with the resource elements of the second radio access technology.

23. The method of claim 15-claim 22, wherein the determination of whether to process the control channel candidates of the first radio access technology is further based on a serving cell search space configuration.

24. The method of claim 23, wherein the determination of the control channel candidates not to process the first radio access technology comprises at least one of each search space, and each of the control channel candidates of the first radio access technology for the search space, being configured separately.

25. The method of claim 23, wherein the determining of the control channel candidates not to process the first radio access technology comprises each search space being configured to be identical.

26. The method of claim 15 to claim 25, wherein

The determination of whether to process the control channel candidates of the first radio access technology is also based on an aggregation level of a search space, and

The search space is configured to be the same for a plurality of control channel candidates of the first radio access technology at the aggregation level.

27. The method of claim 15-26, wherein the determination of whether to process the control channel candidate for the first radio access technology is further based on a power difference between the resource element candidate for the first radio access technology and the overlapping resource element of the second radio access technology.

28. The method according to claim 15-27, wherein the determination of whether to process the control channel candidates of the first radio access technology is further based on a derivation of allowed aggregation levels at the user equipment and network equipment serving the associated cell.

29. A non-transitory computer-readable storage medium comprising instructions stored thereon, which when executed by at least one processor are configured to cause a computing system to perform the method of any of claims 15 to 28.

30. An apparatus comprising means for performing the method of any one of claims 15 to 28.