Downlink control information (DCI) retransmission for enhanced two-stage DCI robustness

Abstract

A method involving downlink control information (DCI) retransmission for enhanced two-stage DCI robustness is provided, the method comprising receiving, from a network, a configuration for a multi-stage downlink control information (DCI), the multi-stage DCI comprising a first-stage DCI and at least one second-stage DCI. The method comprises determining that, upon occurrence of a failure to successfully decode the at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission. The method comprises successfully decoding a first-stage DCI transmission from the network for the multi-stage DCI to obtain a first-stage DCI, the first-stage DCI carrying information associated with the at least one second-stage DCI transmission for the multi-stage DCI. The method comprises detecting a failure to successfully decode the at least one second-stage DCI transmission. And the method comprises storing the first-stage DCI, and monitoring for at least one second-stage DCI retransmission from the network for the multi-stage DCI.

Description

Technical Field

[0001] This disclosure generally relates to telecommunications, and more particularly to downlink control information (DCI) in telecommunications systems. Background Technology

[0002] A telecommunications system can be viewed as a facility that enables communication between two or more entities, such as between two user equipments (UEs), between a UE and a base station, between two base stations, or between a UE and a communication network and / or between base stations and network functions of other nodes. A telecommunications system may include a communication network and one or more UEs. A communication session may include, for example, communication using data to carry communications such as voice, video, email, text messages, multimedia, and / or content data. Non-limiting examples of services provided include two-way or multi-way calling, data communication or multimedia services, and access to data network systems such as the Internet.

[0003] In telecommunications systems that include wireless communication networks, at least a portion of a communication session between at least two stations occurs over a wireless link. Examples of wireless communication networks include Public Land Mobile Networks (PLMNs), satellite-based communication networks, and various wireless local area networks, such as Wireless Local Area Networks (WLANs). Some wireless communication networks can be divided into cells and are therefore often referred to as cellular networks.

[0004] Users can access the telecommunications network of a telecommunications system through appropriate communication equipment or terminals. The user's communication equipment may be referred to as user equipment (UE) or user device. The communication equipment is provided with appropriate signal receiving and transmission means for enabling communication, such as access to the communication network or direct communication with other users. The communication equipment can access a carrier provided by, for example, a base station in a cell, and transmit and / or receive communication on that carrier.

[0005] Telecommunications systems have evolved through multiple generations, each bringing advancements in speed, capacity, and functionality. Evolved Packet System (EPS) represents the 4G architecture, which includes Long Term Evolution (LTE) and LTE-Advanced (LTE-A) as its radio access technologies. 5G systems (5GS) are built on EPS, introducing 5G New Radio (5G NR) for enhanced mobile broadband, massive machine-type communications, and ultra-reliable low-latency communications. The future 6G system (6GS) promises to further revolutionize telecommunications with even more advanced capabilities. Telecommunications systems are interconnected, with 5GS designed to interoperate with EPS for seamless service continuity. The 3rd Generation Partnership Project (3GPP) plays a crucial role in developing and maintaining standards for these telecommunications systems, ensuring global interoperability and evolution from Universal Mobile Telecommunications System (UMTS) (3G) to 6G technologies. Summary of the Invention

[0006] The exemplary implementations of this disclosure relate to telecommunications, and more particularly to downlink control information (DCI) in telecommunications systems. This disclosure includes, but is not limited to, the following exemplary implementations.

[0007] Some example implementations provide an apparatus including: at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive configuration for multi-stage downlink control information (DCI) from a network, the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; determine that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, wherein in the second-stage retransmission, only retransmissions of at least one second-stage DCI are monitored, and in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are monitored; successfully decode the first-stage DCI transmission for the multi-stage DCI from the network to obtain a first-stage DCI carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI; detect a failure to successfully decode at least one second-stage DCI transmission; store the first-stage DCI; and monitor at least one second-stage DCI retransmission for the multi-stage DCI from the network.

[0008] Some example implementations provide a method comprising: receiving configuration for multi-stage downlink control information (DCI) from a network, the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; determining that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, wherein in the second-stage retransmission, only retransmissions of at least one second-stage DCI are monitored, and in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are monitored; successfully decoding the first-stage DCI transmission for the multi-stage DCI from the network to obtain a first-stage DCI carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI; detecting a failure to successfully decode at least one second-stage DCI transmission; storing the first-stage DCI; and monitoring at least one second-stage DCI retransmission for the multi-stage DCI from the network.

[0009] Some example implementations provide an apparatus including: at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: transmit to a user equipment (UE) a configuration for multi-stage downlink control information (DCI), the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; determine that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, wherein in the second-stage retransmission, only the retransmission of at least one second-stage DCI is performed, and in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are performed; transmit to the UE a first-stage DCI transmission for the multi-stage DCI, the first-stage DCI transmission carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI; transmit at least one second-stage DCI transmission to the UE; receive from the UE feedback indicating that the UE failed to successfully decode at least one second-stage DCI transmission; and transmit at least one second-stage DCI retransmission for the multi-stage DCI to the UE.

[0010] Some example implementations provide a method comprising: sending configuration to a user equipment (UE) for multi-stage downlink control information (DCI), the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; determining that, in the event of failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, wherein in the second-stage retransmission, only the retransmission of at least one second-stage DCI is performed, and in the full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are performed; sending to the UE a first-stage DCI transmission for the multi-stage DCI, the first-stage DCI transmission carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI; sending at least one second-stage DCI transmission to the UE; receiving from the UE feedback indicating that the UE failed to successfully decode at least one second-stage DCI transmission; and sending at least one second-stage DCI retransmission for the multi-stage DCI to the UE.

[0011] Other example implementations are provided or described for each example method, including: components for performing any example method; a non-transitory computer-readable storage medium containing instructions stored thereon, which, when executed by at least one processor, are configured to cause a computing system to perform any of the example methods; and means including at least one processor and at least one memory, the at least one memory including computer program code, which, together with the at least one processor, causes the means to perform at least any example method.

[0012] These and other features, aspects, and advantages of this disclosure will become apparent from the following detailed description and the accompanying drawings, which are briefly described below. This disclosure includes any combination of two, three, four, or more features or elements set forth in this disclosure, whether or not such features or elements are explicitly combined or otherwise described in the particular example implementations described herein. This disclosure is intended to be read holistically, such that any separable feature or element of this disclosure shall be considered composable in any aspect and example implementation, unless the context of this disclosure expressly provides otherwise.

[0013] Therefore, it should be understood that the content of this invention is provided merely to outline some exemplary implementations in order to provide a basic understanding of some aspects of this disclosure. Consequently, it should be understood that the above-described exemplary implementations are merely examples and should not be construed as limiting the scope or spirit of this disclosure in any way. Other exemplary implementations, aspects, and advantages will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate the principles of some of the described exemplary implementations by way of example. Attached Figure Description

[0014] Therefore, an exemplary implementation of this disclosure has been described in general terms. Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in which: Figure 1 The present disclosure illustrates a telecommunications system comprising one or more Public Land Mobile Networks (PLMNs) coupled to one or more external data networks, according to some example implementations of this disclosure; Figure 2 This illustrates a PLMN based on some example implementations; Figure 3 A method for multi-stage downlink control information (DCI) is shown; Figure 4 This is a diagram illustrating the retransmission process for multi-stage DCI based on some example implementations; Figure 5A , 5B 5C and 5D are flowcharts illustrating the individual steps in a method performed according to various example implementations; Figure 6 It is a flowchart illustrating the various steps in a method implemented according to various examples; and Figure 7 The apparatus is shown according to some example implementations. Detailed Implementation

[0015] Some implementations of this disclosure will now be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, implementations of this disclosure. In fact, various implementations of this disclosure may be embodied in many different forms and should not be construed as limited to the implementations set forth herein; rather, these exemplary implementations are provided so that this disclosure will be thorough and complete and will fully convey the scope of this disclosure to those skilled in the art. The same reference numerals always refer to the same elements. Unless otherwise stated or clearly stated from the context, references to first, second, etc., should not be construed as implying a particular order, but are used only to distinguish one item or operation from another.

[0016] As used herein, unless otherwise stated or clearly indicated from the context, an "OR" of a set of operands is an "inclusive OR," meaning it is true if and only if one or more operands are true, not a "XOR" which is false if all operands are true. Thus, for example, "[A] OR [B]" is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Furthermore, the articles "a" and "one" mean "one or more," unless otherwise stated or clearly indicated from the context as singular. Additionally, it should be understood that, unless otherwise stated, the terms "data," "content," "digital content," "information," and similar terms are sometimes used interchangeably. The term "network" can refer to a group of interconnected computers, including clients and servers; and within a network, these computers can be interconnected directly or indirectly by various means, including via one or more switches, routers, gateways, access points, etc.

[0017] This disclosure discusses telecommunications systems and mobile or cellular networks and their user equipment, and while specific terminology may be used, it is broadly applicable to a wide range of technologies. For example, while this disclosure may refer to radio access technologies such as 5G NR and 5G Advanced, it is equally relevant to next-generation radio access technologies such as 6G. The exemplary implementations of this disclosure described herein also refer to Public Land Mobile Networks (PLMNs) and Mobile Network Operators (MNOs), but the exemplary implementations are similarly applicable to Standalone Non-Public Networks (SNPNs).

[0018] While some examples and figures focus on radio access networks (RANs), particularly radio access networks operating according to the 3GPP standards for 5G NR (often referred to as 3GPP access or 3GPP access network), the example implementations are applicable to any type of access network. The applicability of any type of access network includes not only 3GPP access networks but also non-3GPP access networks, such as wired access, untrusted non-3GPP access networks, and trusted non-3GPP access networks, which use Radio Access Gateway Functions (W-AGF), Non-3GPP Interoperability Functions (N3IWF), or Trusted Non-3GPP Gateway Functions (TNGF) to connect to the core network of a mobile or cellular network (e.g., a 5G core network (5GC) or a 6G core network (6GC)).

[0019] Furthermore, the term "circuit system" as used in this application may refer to one or more of the following: (a) a hardware circuit implementation only (such as an implementation in analog and / or digital circuits only) and (b) a combination of hardware circuits and software, such as (if applicable): (i) a combination of (multiple) analog and / or digital hardware circuits with software / firmware and (ii) any part of (multiple) hardware processors having software (including (multiple) digital signal processors), software and (multiple) memories, which work together to enable a device (such as a mobile phone or a server) to perform various functions and (c) (multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or a portion of (multiple) microprocessors, which require software (e.g., firmware) to operate, but may be absent when the software is not required to operate.

[0020] The definition of "circuit system" applies to all uses of the term in this application, including any claim. As yet another example, as used in this application, the term "circuit system" also covers implementations of hardware circuitry or processors (or processors) or a portion thereof, including but not limited to hardware circuitry or processors and their accompanying software and / or firmware. The term "circuit system" also covers, for example (and if applicable to a particular claim element), baseband integrated circuits or processor integrated circuits for mobile devices or similar integrated circuits in servers, cellular network devices, or other computing or networking devices.

[0021] Figure 1Telecommunication system 100 according to various example implementations of this disclosure is illustrated. Examples of suitable telecommunications systems include UMTS, EPS, and 5GS, as well as future 6GS. A telecommunications system (also referred to as a system) typically includes one or more mobile or cellular networks. The one or more mobile or cellular networks can interoperate with each other. As shown, for example, the system includes one or more PLMNs 102 coupled to one or more other external data networks (DNs) 104, particularly including wide area networks (WANs) such as the Internet. As will be understood, a PLMN can be a standalone PLMN including a 5GC, or it can be a non-standalone PLMN including both an evolved packet core (EPC) and a 5GC connected to a RAN. Although the illustrated system includes one or more PLMNs, it should be understood that the system may include one or more non-public networks, or one or more PLMNs and one or more non-public networks.

[0022] Each PLMN 102 includes a core network (CN) 106, such as an EPC, 5GC, or 6GC; and each CN is coupled to one or more RANs 108 implementing one or more Radio Access Technologies (RATs). Examples of these RANs include the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) for 4G LTE, the Next Generation Radio Access Network (NG-RAN) for 5G NR, and the 6G RAN. As used herein, “network equipment” refers to any suitable equipment within the RAN or the core network of a telecommunications system. Examples of suitable network equipment are described in more detail below.

[0023] Examples of RATs include 3GPP radio access technologies such as GSM, CDMA2000 1xEV-DO (HRPD), CDMA2000 1x (1xRTT), UTRA, E-UTRA, 5G NR, 5G Advanced, and 6G. Other examples of RATs include IEEE 802 technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee), and 802.15.6 (WBAN), Bluetooth, Bluetooth Low Energy (BLE), Ultra Wideband (UWB), etc. Generally, RAT can refer to any 2G, 3G, 4G, 5G, 6G, or higher generation RAT and its different versions, as well as any other RAT that can be deployed to interoperate with such a RAT to provide access to CN 106 of the MNO.

[0024] Telecommunication system 100 also includes one or more communication devices, which may be referred to differently as User Equipment (UE) 110, terminal equipment, terminal device, mobile station, etc. The UE is typically a device configured to communicate with network equipment (e.g., access nodes, such as the RAN node of RAN 108) or another UE in the telecommunications system. The UE may be a portable computer (e.g., laptop computer, notebook computer, tablet computer), a mobile phone (e.g., cellular phone, smartphone), a wearable computer (e.g., smartwatch), etc. In other examples, the UE may be an Internet of Things (IoT) device, an Industrial IoT (IIoT) device, a vehicle equipped with Vehicle-to-Everything (V2X) communication technology, etc. In some examples, as referenced by 3GPP, the UE may be a Narrowband IoT (NB-IoT) device, an enhanced machine-type communication (eMTC) device, a RedCap device, an environmental IoT device, etc.

[0025] In operation, these UEs 110 can connect to one or more RAN nodes of RAN 108 according to their specific RAT, thereby accessing a specific CN 106 of PLMN 102, or accessing one or more external data networks 104 (e.g., the Internet) or services provided by the PLMN. External data networks can provide Internet access or third-party services (e.g., services provided by third-party application servers). For example, the International Telecommunication Union (ITU) has categorized 5G mobile network services (e.g., services provided by 5G mobile networks) into three classes: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine-type communications (mMTC) or massive Internet of Things (MIoT).

[0026] In various examples, RAN 108 can be configured to provide one or more macro cells, micro cells, pico cells, femto cells, etc. RAN typically includes one or more RAN nodes that interact with UE 110. In various examples, RAN nodes can be referred to as base stations (BS), access points (AP), base transceiver stations (BTS). Examples of RAN nodes include node B (NB), evolved NB (eNB), macro BS, NB (MNB) or eNB (MeNB), home BS, NB (HNB) or eNB (HeNB), next-generation NB (gNB), enhanced gNB (en-gNB), next-generation eNB (ng-eNB), 6G NB (6gNB), etc. The term “gNB” in 5G NR can correspond to eNB in ​​4G LTE. In addition, next-generation RAN nodes can refer to gNB or ng-eNB. And unless otherwise stated, gNB in ​​5G NR or 6gNB in ​​6G can sometimes be more generally referred to as (6) gNB or more simply as gNB.

[0027] RAN 108 may include some type of network control / management entity responsible for controlling RAN nodes. The network control / management entity and RAN nodes may be separate entities or integrated into a single device. The network control / management entity may include processing circuitry configured to perform various management functions for controlling one or more RAN nodes. The processing circuitry may be associated with memory, computer-readable storage media, or data storage devices, including databases for maintaining information required for the various management functions.

[0028] Figure 2 An example of a PLMN 102 (such as a 4G LTE, 5G NR, or 6G PLMN) communicating with an external data network 104 of a UE 110 and a telecommunications system 100 is shown. As illustrated, a RAN 108 (e.g., E-UTRAN, NG-RAN, 6G RAN) includes one or more RAN nodes 202 configured to connect one or more UEs to the RAN, thereby accessing a CN 106 (e.g., EPC, 5GC, 6GC). In 4G LTE, the UE, E-UTRAN, and EPC constitute the EPS. Similarly, in 5G NR, the UE, NG-RAN, and 5GC constitute the 5GS. And in 6G, the UE, 6G RAN, and 6GC constitute the 6GS.

[0029] UE 110 typically has a primary cell, referred to as PCell 204, which is usually the cell through which the UE first connects to RAN 108 (or more specifically, RAN node 202 of the RAN). The RAN (typically via PCell) can provide the UE with additional configuration information to enable it to simultaneously connect to additional cells besides PCell; these cells are referred to as the UE's secondary cells or SCells. PCell RAN nodes can be referred to as primary nodes, and SCell RAN nodes can be referred to as secondary nodes. Relatedly, a Primary Cell Group (MCG) refers to a group of serving cells associated with a primary node, and the MCG includes PCells. A Secondary Cell Group (SCG) refers to a group of serving cells associated with a secondary node, and the SCG includes primary cells referred to as Primary-Secondary Cells (PSCells). A Special Cell (SpCell) refers to a PCell of an MCG or a PSCell of an SCG.

[0030] In some implementations, one or more of the above-mentioned cells can refer to carriers, such as in a multi-carrier single-cell scenario, where the UE can have a cell with multiple carriers (e.g., component carriers). In these implementations, for example, a set of carriers can be associated with a cell of a primary node, and this set of carriers can include an anchor carrier or a primary carrier (similar to a PCell). Similarly, a set of carriers can be associated with a cell of a secondary node, and this set of carriers can include an anchor carrier or a primary carrier (similar to a PSCell). In another example implementation, two sets of carriers can be associated with a single cell and / or node.

[0031] In some implementations, the operation of the gNB or other RAN node 202 can be distributed or functionally broken down into components including one or more Remote Radio Headers (RRHs) or Radio Units (RUs) and Baseband Units (BBUs); and in some implementations, the BBU can be broken down into Central Units (CUs) (central nodes) and Distributed Units (DUs) (distributed nodes). A CU can be, for example, a server, host, or node. In some implementations, the RRH / RU and DU can be co-located at a network device. The operation of the gNB or RAN node may also be distributed among multiple servers, hosts, or nodes.

[0032] It should also be understood that the distribution of operations between core network operations and RAN node operations can vary depending on the implementation. For example, 5G or 6G network architectures can be based on so-called CU-DU splitting. One gNB-CU (CU) can control one or more gNB-DUs (DUs). A gNB-CU can control multiple spatially separated gNB-DUs, at least as transport / receive (Tx / Rx) nodes. However, in some example implementations, a gNB-DU may include, for example, the Radio Link Control (RLC), Media Access Control (MAC) layer, and Physical (PHY) layer, while the gNB-CU may include layers above the RLC layer, such as the Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC), and Internet Protocol (IP) layer. Other functional splitting is also possible. Those skilled in the art are expected to be familiar with the Open Systems Interconnection (OSI) model and the functions within each layer.

[0033] In some example implementations, the server or CU can generate a virtual network through which the server communicates with the radio nodes. Typically, virtual networking can involve the process of combining hardware and software network resources and network functions into a single software-based management entity (virtual network). Such a virtual network can provide flexible distribution of operations between the server and the radio head end / node. In practice, any digital signal processing task can be performed in the CU or DU, and the boundaries of responsibility transferred between the CU and DU can be chosen depending on the implementation.

[0034] From the PHY layer's perspective, data and signaling messages can be carried in downlink (DL) and uplink (UL) physical channels. In these channels, the Physical Downlink Control Channel (PDCCH) plays a role in, for example, DL allocation (for the Physical Downlink Shared Channel PDSCH), UL granting (for the Physical Uplink Shared Channel PUSCH), and dedicated operations (such as slot format indication, preemption indication, and power control). The PDCCH can carry downlink control information (DCI), which includes scheduling information for data transmission, such as DL allocation / UL granting for PDSCH / PUSCH, and other control information for one or more UEs.

[0035] In 5G NR, during the generation of the PDCCH, if the DCI format size is less than 12 bits, zero-padding bits can be added until the payload reaches 12 bits. A 24-bit Cyclic Redundancy Check (CRC) can then be calculated and appended to the DCI payload to allow the UE to detect errors in the decoded information. The last 16 bits of the CRC can be masked using an identifier such as a Radio Network Temporary Identifier (RNTI), enabling the UE to identify unicast data and distinguish DCIs with the same payload size but different purposes. After masking, the CRC bits can be interleaved with the payload bits to distribute them evenly, with the interleaver supporting input sizes up to 164 bits, meaning a maximum of 140 payload bits without CRC. The resulting bit sequence can then be encoded using a polar encoder to prevent transmission errors. The encoded output can be further processed by a sub-block interleaver and rate-matched to fit the resource elements (REs) allocated in the PDCCH, ensuring efficient and reliable transmission.

[0036] Each DCI payload bit can be individually scrambled from a scrambling sequence generated from a 31-bit Gold sequence. The scrambling sequence can be initialized using the cell's physical layer cell identifier or using a UE-specific scrambling identifier and a UE-specific cell RNTI (C-RNTI). After the scrambled DCI bit sequence is modulated using Quadrature Phase Shift Keying (QPSK), the complex-valued modulation symbols can be mapped to physical resources in units called Control Channel Elements (CCEs). Each CCE can include six Resource Element Groups (REGs), where a REG can be defined as a Physical Resource Block (PRB) in an Orthogonal Frequency Division Multiplexing (OFDM) symbol, which can include nine REs and three Demodulation Reference Signals (DMRS) REs for the PDCCH payload. For each DCI, 1, 2, 4, 8, or 16 CCEs can be allocated, where the number of CCEs for a DCI can be represented as the Aggregation Level (AL).

[0037] UE 110 can perform blind decoding on a set of PDCCH candidates. The search space (SS) set can be configured for the UE to monitor PDCCH candidates. Various SS set types can exist, including a common SS (CSS) set that can be monitored by a group of UEs in the cell, and a UE-specific SS (USS) set that can be monitored by a single UE. A UE can be configured with up to 10 SS sets, each serving up to four bandwidth portions (BWPs) in the serving cell. SS set configuration provides the UE with the SS set type (CSS set or USS set), the DCI formats(s) to be monitored, the monitoring timing, and the number of PDCCH candidates for each AL in the SS set.

[0038] As mentioned above, due to the interleaver design, the polar encoder supports a maximum DCI size of 164 bits, which (without CRC) results in a maximum of 140 payload bits in 5G NR. However, it has been observed that the DCI payload size reaches its limit, and it is anticipated that 6G will require support for larger DCI payloads. For example, 3GPP Release 18 has specified a DCI format in which a single DCI can be used to schedule multiple cells. However, this DCI format may not be easily scalable, as the 140-bit payload limit may be easily exceeded. Furthermore, multi-cell scheduling can be combined with multi-slot scheduling (introduced in 3GPP Releases 16-17). There may also be other reasons to increase the size of the DCI payload, such as support for multiple-input multiple-output (MIMO), multiple parallel physical shared channels (PxSCH, e.g., PDSCH and / or PUSCH) in a single cell, etc.

[0039] Another approach already discussed for multi-cell scheduling involves dividing the entire DCI into multiple (typically two) phases, which may be easier to scale for larger payloads, for example, to accommodate more cells (and / or time slots). Several proposals for two-phase DCI (also known as 2-phase DCI) for multi-cell scheduling in 3GPP Release 19 have been introduced. Similarly, numerous proposals for two-phase DCI in 6G have been introduced. In addition to flexible payload delivery, UE power savings also drive the adoption of two-phase DCI. In this regard, the UE 110 can monitor only the first-phase DCI, which can be compact with a light overall monitoring burden, and can indicate the location of the second-phase DCI (i.e., the time-frequency resources in which the second-phase DCI is transmitted) to at least partially avoid blind decoding of the second-phase DCI. This location can be indicated in a variety of different ways, such as by precise location, the area in which the UE will perform blind decoding, etc.

[0040] There are several methods for implementing two-stage DCI. In one method, the first-stage DCI is blindly decoded from the PDCCH, and the first-stage DCI carries information that at least indicates the position of the second-stage DCI in the PDCCH, so that no (or very little) blind search is needed for the second-stage DCI. Figure 3 This method for two-stage DCI is illustrated, where both stages are transmitted on the PDCCH. The total payload for DCI can be split into two parts, one associated with the first-stage DCI and the other with the second-stage DCI. The two payload parts can be encoded separately and then mapped onto the PDCCH.

[0041] In another approach to implementing two-stage DCI, the first-stage DCI can be blindly decoded from the PDCCH, and the first-stage DCI carries information indicating at least the location (or known location) of the second-stage DCI in the PDSCH. Similar to the previous approach, the location of the second-stage DCI can be indicated (or known), so that no (or very little) blind search is required for the second-stage DCI.

[0042] While two-stage DCI allows RAN 108 to overcome some of the issues associated with one-stage DCI, such as limited DCI payload size, two-stage DCI introduces other challenges to be addressed to ensure spectral efficiency is not compromised. In the case of two-stage DCI, UE 110 may need to successfully decode both the first and second DCI stages before being able to attempt to decode any DL data in the DL allocation or transmit it within the UL license.

[0043] Although PDCCH transmissions are encoded to ensure a block error rate (BLER) of no more than 1% under normal channel conditions, the probability of unsuccessful decoding increases with two-stage DCI because performance is determined by the worse of the first and second DCI stage portions. RAN 108 may also be unaware whether the decoding problem is related to the first or second stage DCI, or to UL acknowledgment feedback for PDSCH transmissions to DL or UL power control for UL authorization. Furthermore, the performance of the second stage DCI may be less robust than the first stage DCI because the second stage DCI will typically include a larger payload, resulting in reduced robustness (e.g., coverage) when overhead needs to be reduced. If the RAN must always retransmit both the first and second stage DCIs when the second stage DCI decoding fails, the result could be increased overhead.

[0044] In light of the foregoing, the example implementations of this disclosure provide solutions(s) to better handle retransmissions in multi-stage DCIs without compromising overall spectral efficiency. As described, a multi-stage DCI includes a first-stage DCI and at least one second-stage DCI. A two-stage DCI is an example of a multi-stage DCI that includes only two stages (a first stage and a second stage). However, in other examples, a multi-stage DCI may include more than two stages. Therefore, some example implementations of this disclosure can be described in the context of two-stage DCIs, but it should be understood that these example implementations are more generally applicable to multi-stage DCIs. In any case, a two-stage DCI, and more generally a multi-stage DCI, includes a first-stage DCI and at least one second-stage DCI.

[0045] According to some example implementations, UE 110 can receive configuration for multi-stage DCI from RAN 108 (e.g., RAN node 202), where multi-stage DCI includes a first-stage DCI and at least one second-stage DCI. In some examples, this configuration may include a configuration for second-stage retransmission instead of a full retransmission for the multi-stage DCI when the UE fails to successfully decode the second-stage DCI(s). In some examples, this configuration can be used for both full retransmission and second-stage retransmission. In the case of full retransmission, the UE can monitor (and the RAN can send) retransmissions of both the first-stage DCI and (multiple) second-stage DCI(s). On the other hand, in the case of second-stage retransmission, the UE can monitor (and the RAN can send) only the retransmissions of (multiple) second-stage DCI(s). In this respect, second-stage retransmission can avoid retransmissions of the first-stage DCI, thereby reducing PDCCH overhead.

[0046] In some cases, UE 110 can determine to perform a second-stage retransmission instead of a full retransmission when at least one second-stage DCI transmission fails to be decoded. In some examples, the UE can receive an instruction from RAN 108 indicating that a second-stage retransmission should be performed, and determine to perform the second-stage retransmission based on that instruction. In some of these examples, the instruction can be received via the first DCI or semi-statically via RRC signaling.

[0047] UE 110 can successfully decode a first-stage DCI transmission for multi-stage DCI from RAN 108 to obtain a first-stage DCI, which carries information associated with multiple second-stage DCI transmissions for multi-stage DCI. Depending on the method used to implement multi-stage DCI, this information may include, for example, the location of the multiple second-stage DCI transmissions in the PDCCH or PDSCH. The UE can detect failure to successfully decode the multiple second-stage DCI transmissions. In response, the UE can store the first-stage DCI and monitor for at least one second-stage DCI retransmission from the RAN for multi-stage DCI. In some examples, the UE may also store the multiple second-stage DCI transmissions to combine with the multiple second-stage DCI retransmissions to obtain a combination, which the UE may attempt to decode to obtain the multiple second-stage DCI.

[0048] To further illustrate some example implementations, Figure 4 This diagram illustrates the retransmission process for a two-stage DCI (multi-stage DCI) process, including a first DCI phase and a second DCI phase. As shown, at step 401, UE 110 is in an RRC connection state with PCell 204 provided by RAN node 202 of RAN 108. However, it should be understood that in some example implementations, PCell may refer to the anchor carrier or primary carrier of the cell provided by the RAN node. PCell can be configured for the UE for two-stage DCI in step 402.

[0049] In some examples, this configuration may include one or more resources to provide feedback on decoding either or both of the first DCI phase transmission or the second DCI transmission(s). In this regard, UE 110 may be configured with UL resources to provide feedback on decoding the second DCI phase(s), or the UE may be configured with separate UL resources for both the first DCI phase and the second DCI phase(s). In some examples, the UL resources(s) may be configured as part of a UL transmission in another serving cell. That is, the UL resources(s) may be multiplexed with other control information or data transmitted to the other serving cell.

[0050] UE 110 can be configured to provide feedback to PCell 204 in various ways, such as via ACK / NACK. In some examples, the UL resources(s) used for feedback can be configured as if the UL resources(s) were additional carriers, sometimes referred to as virtual carriers. In this respect, a virtual carrier is a carrier configured for DL ​​Hybrid Automatic Repeat Request (HARQ) ACK / NACK feedback but without transmitting the associated PDSCH data. Instead, DL HARQ ACK / NACK will be used to transmit DCI feedback associated with at least one scheduled cell. Furthermore, in some examples, the mapping of feedback for the DCI phase can be indicated in various ways, such as via 3GPP standards or via the configuration given to the UE at step 402.

[0051] As described above, this configuration can also include a configuration for full retransmission of the second-stage retransmission instead of the two-stage DCI (multi-stage DCI). In the case of full retransmission, the UE can monitor (and PCell 204 can transmit) retransmissions of both the first-stage DCI and (multiple) second-stage DCI, where either or both may be retransmitted using one or more adjusted parameters (e.g., AL, transmission power, etc.). In this case, the UE can make no assumptions about the decoding of the first-stage or second-stage DCI retransmission based on the failure to successfully decode the first / second-stage DCI transmission. On the other hand, in the case of second-stage retransmission, the UE can monitor (and PCell can transmit) only the retransmissions of (multiple) second-stage DCI. In this case, the UE can store the first-stage DCI (which was successfully decoded) in at least one buffer, and may also store (multiple) second-stage DCI transmissions that the UE failed to decode.

[0052] In some examples, the configuration for Phase 2 retransmissions may include information indicating pre-configured resources, monitoring timings, or periods for Phase 2 DCI retransmissions(s). In other examples, the information indicating pre-configured resources, monitoring timings, or periods may be predefined, such as through 3GPP standards. Specifically, for example, the configuration or 3GPP standard may indicate a time span (e.g., XX slots / symbols) following the Phase 2 DCI transmission(s) in which the UE 110 can monitor(s) Phase 2 DCI retransmission(s). This time span can provide a fixed window of opportunity for(s) Phase 2 DCI retransmission(s). And in some of these examples, the UE may determine one or more monitoring timings within the time span for monitoring(s) Phase 2 DCI retransmission(s).

[0053] Additionally or alternatively, in some examples, the configuration may indicate multiple scheduled cells for Phase 2 DCI retransmissions, which may be the same as or different from the multiple scheduled cells for Phase 2 DCI transmissions. In this respect, the multiple retransmissions for Phase 2 DCI for the SCell may be via PCell 204, and the PCell may use the SCell's cross-cell scheduling to schedule PxSCH resources. This may be useful if feedback regarding the decoding of the multiple Phase 2 DCI transmissions is sent to the PCell. Similar to the PCell indicated above, in some example implementations, the SCell may refer to the carrier of the cell.

[0054] As described above, in some examples, this configuration may include configurations for both full retransmission and second-stage retransmission. In some of these examples, PCell 204 may determine at step 403 whether the scheduling information for data transmission indicated by the two-stage DCI (e.g., DL allocation, UL authorization) will use a full retransmission or a second-stage retransmission. In other words, PCell may determine whether to perform a full retransmission or a second-stage retransmission for a two-stage DCI carrying scheduling information for data transmission between the UE and RAN 108.

[0055] In various examples, PCell 204 can determine whether to perform a full retransmission or a second-stage retransmission based on the type of data transmission, the load on the PCell, etc. The load on the PCell can include, for example, load from DCIs in the PDCCH (e.g., Phase 1 DCI, Phase 2 DCI). As a more specific example, consider again the possibility of providing a time span for (multiple) Phase 2 DCI retransmissions. If the PCell is under high traffic load and is scheduling UE 110 with a best-effort service, the PCell may not want to sacrifice its resources for the UE and instead retain the flexibility to schedule other higher-priority UEs within the time span used for (multiple) Phase 2 DCI retransmissions. In this case, the PCell can determine to perform a full retransmission and wait until after the time span before retransmitting the first DCI. In some cases, the PCell can determine to perform a Phase 2 retransmission.

[0056] PCell 204 may send a first-stage DCI transmission for the two-stage DCI to UE 110 at step 404, carrying scheduling information for data transmission. The first-stage DCI may carry information associated with the (multiple) second-stage DCI transmissions for the two-stage DCI, such as the location of the (multiple) second-stage DCI transmissions. As shown, in some examples where the PCell determines to perform a second-stage retransmission at step 403, the first-stage DCI may also include instructing the UE to perform a second-stage retransmission. In some other examples, the PCell may send the instruction to the UE via RRC signaling.

[0057] PCell 204 may send multiple Phase 2 DCI transmissions to the UE at step 405. In some examples, the multiple Phase 2 DCI transmissions may carry scheduling information for data transmission, such as DL allocation for PDSCH or UL authorization for uplink transmissions.

[0058] UE 110 may determine at step 406 to perform two-stage DCI decoding, such as based on the configuration received by the UE at step 402. The UE may monitor the first-stage DCI transmission and attempt to decode it. If the UE detects that the first-stage DCI transmission has failed to be decoded, the UE may continue monitoring the first-stage DCI. Otherwise, at step 407, the UE may successfully decode the first-stage DCI transmission to obtain the first-stage DCI for the two-stage DCI.

[0059] UE 110 can monitor and attempt to decode (multiple) second-stage DCI transmissions based on information (e.g., location) associated with (multiple) second-stage DCI transmissions (carried by the first-stage DCI). If the UE successfully decodes (multiple) second-stage DCI transmissions to obtain (multiple) second-stage DCIs, the UE can combine the first-stage DCI and (multiple) second-stage DCIs to obtain a two-stage DCI carrying scheduling information for data transmission. When the data transmission is a DL transmission and the scheduling information is a DL allocation for the PDSCH, the UE can attempt to decode the PDSCH. In another example, where the data transmission is a UL transmission and the scheduling information is a UL authorization for the PUSCH, the UE can perform a UL transmission based on the UL authorization.

[0060] As shown in step 408, UE 110 may otherwise detect the failure to successfully decode (multiple) second-stage DCI transmissions. When a full retransmission is to be performed, the UE may continue searching for the first-stage DCI transmissions (and then searching for (multiple) second-stage DCI transmissions based on the information carried in the first-stage DCI). In the illustrated example, on the other hand, the UE may determine at step 409 to perform a second-stage retransmission instead of a full retransmission, such as based on an indication carried in the first-stage DCI at step 404. At step 410, the UE may store the first-stage DCI (successfully decoded) and (multiple) second-stage DCI transmissions in, for example, at least one buffer (e.g., a soft buffer).

[0061] UE 110 can determine feedback regarding the decoding of (multiple) Phase 2 DCI transmissions at step 411, in which case the feedback includes indication of failure to successfully decode (multiple) Phase 2 DCI transmissions (e.g., NACK). The UE can then send the feedback to PCell 204 at step 412 using UL resources, which can be configured to the UE at step 402. The UE can initiate monitoring and decoding of (multiple) Phase 2 DCI retransmissions from PCell at step 413.

[0062] At step 414, PCell 204 can receive and decode feedback (e.g., NACK) from UE 110 on UL resources. Then, at step 415, PCell can send multiple second-stage DCI retransmissions to the UE for two-stage DCI. Similar to the multiple second-stage DCI transmissions, in some examples, the multiple second-stage DCI retransmissions can carry scheduling information for data transmission, such as DL allocation for PDSCH or UL authorization for uplink transmissions. In some examples, when PCell uses inter-cell scheduling for SCell, DCI transmissions / retransmissions can carry scheduling information for SCell. Furthermore, in some examples, PCell can perform one or more adaptations (e.g., power adaptation, link adaptation) for the second-stage DCI retransmissions and / or the channels in which the multiple second-stage DCI retransmissions are transmitted (e.g., PDCCH, PDSCH), which can improve the likelihood of successful decoding at the UE.

[0063] When UE 110 initiates monitoring and decoding of multiple Phase 2 DCI retransmissions, the UE can determine multiple monitoring opportunities (e.g., predefined or indicated in the configuration) within a time span following the multiple Phase 2 DCI transmissions, and monitor the multiple Phase 2 DCI retransmissions within those monitoring opportunities. In some examples, the UE can monitor multiple Phase 2 DCI retransmissions by attempting to decode the location (time-frequency resource) for the multiple Phase 2 DCI transmissions within the multiple monitoring opportunities within a time span following the multiple Phase 2 DCI transmissions.

[0064] UE 110 can detect multiple second-stage DCI retransmissions at step 416. The UE can combine the multiple second-stage DCI transmissions stored at step 410 with the multiple second-stage DCI retransmissions to obtain a combination, which can improve decoding performance. The UE can then attempt to decode the combination accordingly to obtain multiple second-stage DCIs. In some cases, the UE can detect a failure to successfully decode the combination; and in response, the UE can release the first-stage DCI and multiple second-stage DCI transmissions from the buffer. In other cases, the UE can successfully decode the combination. In these other cases, the UE can combine the first-stage DCI and multiple second-stage DCIs to obtain a two-stage DCI carrying scheduling information for data transmission. For example, when the scheduling information includes a DL allocation for a PDSCH that includes DL transmissions, the UE can decode the PDSCH at step 417.

[0065] As described above, the solutions(s) of some example implementations of this disclosure can provide numerous advantages. For example, given the potential performance differences between first-stage DCI transmission and(s) of second-stage DCI transmission, the solution can compensate for performance issues in second-stage DCI transmission without increasing the overhead of first-stage DCI transmission. The solutions(s) can also allow RAN 108 to selectively determine when to apply a full retransmission or a second-stage retransmission per timeslot, such as when network load is low.

[0066] Figures 5A to 5D This is a flowchart illustrating various steps in method 500 according to various example implementations. The method includes receiving configuration for multi-stage downlink control information (DCI) from the network, the multi-stage DCI including a first-stage DCI and at least one second-stage DCI, such as... Figure 5AAs shown in box 502. The method includes determining that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, as shown in box 504. In a second-stage retransmission, only the retransmission of at least one second-stage DCI is monitored, and in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are monitored. The method includes successfully decoding a first-stage DCI transmission from the network for a multi-stage DCI to obtain a first-stage DCI carrying information associated with at least one second-stage DCI transmission for a multi-stage DCI, as shown in box 506. The method includes detecting a failure to successfully decode at least one second-stage DCI transmission, as shown in box 508. The method includes storing the first-stage DCI, as shown in box 510. And the method includes monitoring at least one second-stage DCI retransmission from the network for a multi-stage DCI, as shown in box 512.

[0067] In some examples, this configuration indicates at least one scheduled cell for at least one Phase 2 DCI retransmission. In some of these examples, the at least one scheduled cell may be the same as or different from the at least one scheduled cell for at least one Phase 2 DCI transmission.

[0068] In some examples, this configuration is for both full retransmission of multi-stage DCI and second-stage retransmission of multi-stage DCI.

[0069] In some examples, method 500 also includes receiving an instruction from the network indicating that a second-stage retransmission should be performed. And in some of these examples, the determination at box 504 is based on the received instruction.

[0070] In some examples, the instruction is received via radio resource control signaling or Phase 1 DCI.

[0071] In some examples, the configuration instructs uplink resources to provide feedback regarding the decoding of at least one Phase 2 DCI transmission. In some of these examples, the method also includes using resources to send feedback to the network indicating that decoding of at least one Phase 2 DCI transmission was unsuccessful.

[0072] In some examples, method 500 further includes determining one or more monitoring opportunities within a time span following at least one second-stage DCI transmission, during which at least one second-stage DCI retransmission is monitored at box 512. And in some of these examples, the time span is predefined or indicated in the configuration.

[0073] In some examples, method 500 also includes storing at least one second-stage DCI transport, such as Figure 5BAs shown in box 514. In some of these examples, the method further includes combining at least one stored second-stage DCI transmission and at least one second-stage DCI retransmission to obtain a combination, as shown in box 516. The method also includes attempting to decode the combination to obtain at least one second-stage DCI, as shown in box 518.

[0074] In some examples, method 500 also includes successful decoding of the combination, such as Figure 5C As shown in box 520. In some of these examples, the method further includes combining a first-stage DCI and at least one second-stage DCI to obtain a multi-stage DCI, which carries scheduling information for data transmission, as shown in box 522.

[0075] In some examples, method 500 also includes detecting a failure to successfully decode the combination, such as Figure 5D As shown in box 524. In some of these examples, the method further includes releasing a first-stage DCI and at least one second-stage DCI transmission from at least one buffer, the first-stage DCI and at least one second-stage DCI transmission being stored in at least one buffer, as shown in box 526.

[0076] Figure 6 This is a flowchart illustrating various steps in method 600 according to various example implementations. The method includes sending configuration to a user equipment (UE) for multi-stage downlink control information (DCI), the multi-stage DCI including a first-stage DCI and at least one second-stage DCI, as shown in box 602. The method includes determining that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, as shown in box 604. In a second-stage retransmission, only the retransmission of at least one second-stage DCI is performed, whereas in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are performed. The method includes sending a first-stage DCI transmission for the multi-stage DCI to the UE, the first-stage DCI transmission carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI, as shown in box 606. The method includes sending at least one second-stage DCI transmission to the UE, as shown in box 608. The method includes receiving feedback from the UE indicating that the UE failed to successfully decode at least one second-stage DCI transmission, as shown in box 610. The method also includes sending at least one second-stage DCI retransmission to the UE for the multi-stage DCI, as shown in box 612.

[0077] In some examples, this configuration indicates at least one scheduled cell for at least one Phase 2 DCI retransmission. In some of these examples, the at least one scheduled cell may be the same as or different from the at least one scheduled cell for at least one Phase 2 DCI transmission.

[0078] In some examples, at box 604, the second-stage retransmission is determined to be performed based on at least one of the data transmission type or the load on the cell.

[0079] In some examples, this configuration is for both full retransmission of multi-stage DCI and second-stage retransmission of multi-stage DCI.

[0080] In some examples, method 600 also includes sending an indication to the UE that a second-stage retransmission should be performed.

[0081] In some examples, the instruction is sent via radio resource control signaling or Phase 1 DCI.

[0082] In some examples, this configuration instructs uplink resources for the UE to provide feedback, and at box 610 the feedback is received from the UE using resources.

[0083] In some examples, at box 612, at least one second-stage DCI retransmission is sent during at least one monitoring opportunity within a time span following at least one second-stage DCI transmission, and the UE will monitor at least one second-stage DCI retransmission during at least one monitoring opportunity. In some of these examples, the time span is predefined or indicated in the configuration.

[0084] According to the example implementations of this disclosure, the telecommunications system 100 or PLMN 102 and its components (such as UE 110, CN 106, RAN 108 and / or RAN node 202) can be implemented by various parts. Components used to implement the system and its components can include hardware, firmware, software, or combinations thereof. In some instances, one or more devices can be configured to act as or otherwise implement the system and its components shown and described herein. In examples involving more than one device, the respective devices can be connected to or otherwise communicate with each other in a variety of different ways, such as directly or indirectly via wired or wireless networks.

[0085] Based on some example implementations, regarding Figures 5A to 5D At least some of the described methods 500 can be performed by means including components for performing functions corresponding to the steps of the method. Similarly, regarding Figure 6At least some of the methods in the described method 600 can be performed by means including components for performing functions corresponding to the steps of the method. Examples of suitable means may include user equipment, user terminal, etc. Other examples of suitable means may include RAN nodes (e.g., ng-eNB, gNB, gNB-DU, gNB-CU) or any suitable means such as a server, host, or node.

[0086] Figure 7 An apparatus 700 is shown according to some example implementations of the present disclosure, wherein components for performing various operations include separate hardware or hardware directed by one or more computer programs from a computer-readable storage medium or other memory, such as computer memory. The apparatus may include one or more of each of a plurality of components, such as a processing circuitry system 702 connected to a computer-readable storage medium or other memory 704.

[0087] The processing circuit system 702 may be configured individually by one or more processors or in combination with one or more computer-readable storage media. A processing circuit system is generally any computer hardware capable of processing information such as data, computer programs, computer code, and / or other suitable electronic information. A processing circuit system consists of a collection of electronic circuits, some of which may be packaged as integrated circuits or multiple interconnected integrated circuits (integrated circuits are sometimes more commonly referred to as “chips”). The processing circuit system may be configured to execute computer programs, which may be stored on the processing circuit system or otherwise stored in memory 704 (of the same or another device).

[0088] Depending on the specific implementation, the processing circuitry system 702 may include multiple processors, a multi-core processor, or some other type of processor, such as a central processing unit, a graphics processing unit, a tensor processing unit, or an accelerator. Furthermore, the processing circuitry system may be implemented using multiple heterogeneous processor systems, where the main processor resides on a single chip along with one or more auxiliary processors. As another illustrative example, the processing circuitry system may be a symmetric multiprocessor system containing multiple processors of the same type. In yet another example, the processing circuitry system may be embodied as or otherwise include one or more application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), etc. Therefore, while the processing circuitry system may be able to execute a computer program to perform one or more functions, the various examples of processing circuitry systems may be able to perform one or more functions without the assistance of a computer program. In any case, the processing circuitry system may be appropriately programmed to perform functions or operations according to the exemplary implementations of this disclosure.

[0089] Memory 704 is typically any computer hardware capable of temporarily and / or permanently storing information (e.g., data, computer programs, instructions 706 (e.g., computer-readable program code), and / or other suitable information). Memory may include volatile and / or non-volatile memory and may be fixed or removable. Examples of suitable memory include recording media, random access memory (RAM), read-only memory (ROM), hard disk drives, flash memory, thumb drives, removable computer disks, optical disks, or some combination thereof.

[0090] Memory 704 is a non-transitory device capable of storing information. An example of a suitable memory is a computer-readable storage medium, which is distinguishable from a computer-readable transmission medium capable of carrying information from one location to another. Examples of suitable computer-readable transmission media include electronic carrier signals, telecommunication signals, or some combination thereof. As used herein, the term "non-transitory" is a limitation on the medium itself (i.e., tangible, not signaling), not a limitation on the persistence of data storage (e.g., RAM and ROM). As used herein, a computer-readable medium generally refers to a computer-readable storage medium or a computer-readable transmission medium. A computer-readable medium is any entity or device capable of storing and carrying information such as one or more computer programs or portions thereof.

[0091] In addition to memory 704 (e.g., a computer-readable storage medium), processing circuitry 702 may also be connected to one or more interfaces for displaying, transmitting, and / or receiving information. Interfaces may include communication interface 708 and / or one or more user interfaces. Communication interfaces may be configured to transmit and / or receive information, such as to and / or from other devices(s), networks(s), etc. Communication interfaces may be configured to transmit and / or receive information via physical (wired) and / or wireless communication links. Examples of suitable communication interfaces include network interface controllers (NICs), wireless NICs (WNICs), etc.

[0092] The user interface may include a display 710 and / or one or more user input interfaces 712. The display may be configured to present or otherwise display information to a user; suitable examples include liquid crystal displays (LCDs), light-emitting diode (LED) displays, organic LED (OLED) displays, active-matrix OLEDs (AMOLEDs), etc. The user input interface may be wired or wireless and may be configured to receive information from the user into the device, such as for processing, storage, and / or display. Suitable examples of the user input interface include microphones, image or video capture devices, keyboards or keypads, joysticks, touch-sensitive surfaces (separate from or integrated into the touchscreen), biometric sensors, etc. The user interface may also include one or more interfaces for communicating with peripheral devices such as printers, scanners, etc.

[0093] The processing circuitry 702 executes instructions 706 or stores instructions in memory 704, supporting combinations of operations for implementing exemplary implementations of this disclosure. In this way, apparatus 700 may include at least one processing circuitry and at least one memory coupled to the at least one processing circuitry, wherein the at least one processing circuitry is configured to execute instructions stored in the at least one memory. It will also be understood that one or more functions, and combinations thereof, may be implemented by a dedicated hardware-based computer system and / or processing circuitry system, or a combination of dedicated hardware and program code instructions, performing the specified functions.

[0094] Some example implementations of this disclosure can also be executed as a computer process defined by one or more computer programs or portions thereof. Example implementations of this disclosure can be executed by executing at least a portion of a computer program including instructions. The computer program can be in source code form, object code form, or some intermediate form. The computer program can be stored in a computer-readable medium readable by a computer, processing circuitry system, or other suitable means. As mentioned above, for example, the computer program can be stored in memory such as a computer-readable storage medium. Additionally or alternatively, for example, the computer program can be stored in a computer-readable transmission medium. The coding of software used to perform the example implementations of this disclosure is entirely within the scope of those skilled in the art.

[0095] As will be understood, any suitable instructions may be loaded from memory or a computer-readable medium (e.g., a computer-readable storage medium, a computer-readable transmission medium) onto a computer, processor, processing circuitry system, or other programmable means to produce a particular machine, such that the particular machine becomes a component for implementing the functions specified herein. Instructions may also be stored in a computer-readable medium that can direct a computer, processor, processing circuitry system, or other programmable means to operate in a particular manner to produce a particular machine or a particular article of manufacture. In some examples, instructions stored in a computer-readable medium can produce an article of manufacture, wherein the article of manufacture becomes a component for implementing the functions described herein. Instructions may be retrieved from a computer-readable medium and loaded onto a computer, processor, processing circuitry system, or other programmable means to configure the computer, processor, processing circuitry system, or other programmable means to perform operations to be performed on or by the computer, processor, processing circuitry system, or other programmable means.

[0096] The retrieval, loading, and execution of instructions, including program code instructions, can be performed sequentially, such that one instruction is retrieved, loaded, and executed at a time. In some example implementations, retrieval, loading, and / or execution can be performed in parallel, such that multiple instructions are retrieved, loaded, and / or executed together. The execution of program code instructions can produce computer-implemented processes, such that the instructions, executed by a computer, processor, processing circuitry system, or other programmable device, provide operations for implementing the functions described herein.

[0097] Benefiting from the teachings presented in the foregoing description and associated drawings, those skilled in the art to which this disclosure pertains will conceive of numerous modifications and other implementations of the disclosure set forth herein. Therefore, it should be understood that this disclosure is not limited to the specific implementations disclosed, and that modifications and other implementations are intended to be included within the scope of the appended claims. Furthermore, although the foregoing description and associated drawings describe exemplary implementations in the context of certain example combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions may be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, combinations of elements and / or functions different from those explicitly described above are also contemplated as being set forth in some of the appended claims. Although specific terminology is used herein, it is used only in a general and descriptive sense and not for limiting purposes.

[0098] Furthermore, various implementations of this disclosure can be described with reference to the following entries, and their features can be combined in any reasonable manner.

[0099] Item 1. An apparatus comprising: at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive configuration for multi-stage downlink control information (DCI) from a network, the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; determine that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, wherein in the second-stage retransmission, only retransmission of at least one second-stage DCI is monitored, and in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are monitored; successfully decode the first-stage DCI transmission for the multi-stage DCI from the network to obtain a first-stage DCI carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI; detect a failure to successfully decode at least one second-stage DCI transmission; store the first-stage DCI; and monitor at least one second-stage DCI retransmission for the multi-stage DCI from the network.

[0100] Item 2. The apparatus according to Item 1, wherein the configuration indicates at least one scheduling cell for at least one second-stage DCI retransmission, and wherein the at least one scheduling cell is the same as or different from at least one scheduling cell for at least one second-stage DCI transmission.

[0101] Item 3. The apparatus according to Item 1 or 2, wherein the configuration is for both full retransmission of multi-stage DCI and second-stage retransmission of multi-stage DCI.

[0102] Item 4. An apparatus according to any one of items 1 to 3, wherein when an instruction is executed by at least one processor, the apparatus also receives from the network an instruction to retransmit an instruction to be executed in a second phase, and wherein the determination is based on the received instruction.

[0103] Item 5. The apparatus according to Item 4, wherein the indication is received via radio resource control signaling or first-stage DCI.

[0104] Item 6. An apparatus according to any one of items 1 to 5, wherein an uplink resource is configured to provide feedback on decoding at least one second-stage DCI transmission, and wherein the instruction, when executed by at least one processor, causes the apparatus to further: use the resources to send feedback to the network indicating that at least one second-stage DCI transmission was not successfully decoded.

[0105] Item 7. An apparatus according to any one of items 1 to 6, wherein the instructions, when executed by at least one processor, cause the apparatus to further: determine one or more monitoring opportunities within a time span following at least one second-stage DCI transmission, monitor at least one second-stage DCI retransmission during the one or more monitoring opportunities, and wherein the time span is predefined or indicated in a configuration.

[0106] Item 8. An apparatus according to any one of items 1 to 7, wherein the instructions, when executed by at least one processor, cause the apparatus to further: store at least one second-stage DCI transmission; combine the stored at least one second-stage DCI transmission and at least one second-stage DCI retransmission to obtain a combination; and attempt to decode the combination to obtain at least one second-stage DCI.

[0107] Item 9. The apparatus according to Item 8, wherein the instructions, when executed by at least one processor, cause the apparatus to at least: successfully decode the combination; and combine the first-stage DCI and at least one second-stage DCI to obtain a multi-stage DCI, the multi-stage DCI carrying scheduling information for data transmission.

[0108] Item 10. The apparatus according to Item 8 or 9, wherein the instructions, when executed by at least one processor, cause the apparatus to further: detect failure to successfully decode the combination; and release a first-stage DCI and at least one second-stage DCI transmission from at least one buffer, the first-stage DCI and at least one second-stage DCI transmission being stored in at least one buffer.

[0109] Item 11. A method comprising: receiving from a network a configuration for multi-stage downlink control information (DCI), the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; determining that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, wherein in the second-stage retransmission, only retransmission of at least one second-stage DCI is monitored, and in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are monitored; successfully decoding the first-stage DCI transmission for the multi-stage DCI from the network to obtain a first-stage DCI carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI; detecting a failure to successfully decode at least one second-stage DCI transmission; storing the first-stage DCI; and monitoring at least one second-stage DCI retransmission for the multi-stage DCI from the network.

[0110] Item 12. An apparatus comprising: at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: transmit to a user equipment (UE) a configuration for multi-stage downlink control information (DCI), the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; determine that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, wherein in the second-stage retransmission, only a retransmission of at least one second-stage DCI is performed, and in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are performed; transmit to the UE a first-stage DCI transmission for the multi-stage DCI, the first-stage DCI transmission carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI; transmit at least one second-stage DCI transmission to the UE; receive from the UE feedback indicating that the UE failed to successfully decode at least one second-stage DCI transmission; and transmit at least one second-stage DCI retransmission for the multi-stage DCI to the UE.

[0111] Item 13. The apparatus according to Item 12, wherein the configuration indicates at least one scheduling cell for at least one second-stage DCI retransmission, and wherein the at least one scheduling cell is the same as or different from at least one scheduling cell for at least one second-stage DCI transmission.

[0112] Item 14. The apparatus according to Item 12 or 13, wherein the second-stage retransmission is determined to be performed based on at least one of the type of data transmission or the load on the cell.

[0113] Item 15. An apparatus according to any one of Items 12 to 14, wherein the configuration is for both full retransmission of multi-stage DCI and second-stage retransmission of multi-stage DCI.

[0114] Item 16. An apparatus according to any one of items 12 to 15, wherein when the instruction is executed by at least one processor, the apparatus also sends to the UE an instruction indicating that a second-stage retransmission is to be performed.

[0115] Item 17. The apparatus according to Item 16, wherein the indication is transmitted via radio resource control signaling or first-stage DCI.

[0116] Item 18. An apparatus according to any one of items 12 to 17, wherein the configuration indicates uplink resources for the UE to provide feedback, and the feedback is received from the UE using resources.

[0117] Item 19. An apparatus according to any one of Items 12 to 18, wherein at least one second-stage DCI retransmission is transmitted at at least one monitoring time within a time span following at least one second-stage DCI transmission, the UE will monitor at least one second-stage DCI retransmission at at least one monitoring time, and wherein the time span is predefined or indicated in a configuration.

[0118] Item 20. A method comprising: sending to a user equipment (UE) a configuration for multi-stage downlink control information (DCI), the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; determining that, in the event of a failure to successfully decode at least one second-stage DCI transmission, a second-stage retransmission will be performed instead of a full retransmission, wherein in the second-stage retransmission, only a retransmission of at least one second-stage DCI is performed, and in a full retransmission, retransmissions of both the first-stage DCI and at least one second-stage DCI are performed; sending to the UE a first-stage DCI transmission for the multi-stage DCI, the first-stage DCI transmission carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI; sending at least one second-stage DCI transmission to the UE; receiving from the UE feedback indicating that the UE failed to successfully decode at least one second-stage DCI transmission; and sending to the UE a retransmission of at least one second-stage DCI for the multi-stage DCI.

Claims

1. A device for communication, comprising: At least one processor, and At least one memory stores instructions that, when executed by the at least one processor, cause the device to at least: Receive configuration for multi-stage downlink control information (DCI) from the network, the multi-stage DCI including a first-stage DCI and at least one second-stage DCI; In the event that at least one second-stage DCI transmission fails to be decoded, a second-stage retransmission will be performed instead of a full retransmission. In the second-stage retransmission, only the retransmission of the at least one second-stage DCI is monitored, while in the full retransmission, the retransmission of both the first-stage DCI and the at least one second-stage DCI is monitored. Successfully decode a first-stage DCI transmission for multi-stage DCI from the network to obtain a first-stage DCI, the first-stage DCI carrying information associated with at least one second-stage DCI transmission for the multi-stage DCI. Failure to successfully decode at least one second-stage DCI transmission was detected; Store the first stage DCI; as well as Monitor at least one second-stage DCI retransmission from the network for the multi-stage DCI.

2. The apparatus of claim 1, wherein the configuration indicates at least one scheduling cell for the at least one second-stage DCI retransmission, and wherein the at least one scheduling cell is the same as or different from at least one scheduling cell for the at least one second-stage DCI transmission.

3. The apparatus according to claim 1 or 2, wherein the configuration is for both full retransmission of multi-stage DCI and second-stage retransmission of multi-stage DCI.

4. The apparatus of claim 1 or 2, wherein the instruction, when executed by the at least one processor, causes the apparatus to also receive from the network an instruction to perform a second phase retransmission, and wherein the determination is based on the received instruction.

5. The apparatus of claim 4, wherein the instruction is received via radio resource control signaling or the first-phase DCI.

6. The apparatus of claim 1 or 2, wherein the configuration instructs uplink resources to provide feedback regarding the decoding of the at least one second-stage DCI transmission, and The instructions, when executed by the at least one processor, cause the device to also: use the resources to send feedback to the network indicating that the at least one second-stage DCI transmission was not successfully decoded.

7. The apparatus of claim 1 or 2, wherein the instructions, when executed by the at least one processor, cause the apparatus to further: determine one or more monitoring opportunities within a time span following the at least one second-stage DCI transmission, and monitor the at least one second-stage DCI retransmission during the one or more monitoring opportunities, and The time span is either predefined or indicated in the configuration.

8. The apparatus according to claim 1 or 2, wherein the instructions, when executed by the at least one processor, cause the apparatus to further: Store the at least one second-stage DCI transmission; Combine the stored at least one second-stage DCI transmission and the at least one second-stage DCI retransmission to obtain a combination; and Attempt to decode the combination to obtain at least one second-stage DCI.

9. The apparatus of claim 8, wherein the instructions, when executed by the at least one processor, cause the apparatus to further: Successfully decoded the combination; and The first-stage DCI and the at least one second-stage DCI are combined to obtain the multi-stage DCI, which carries scheduling information for data transmission.

10. The apparatus of claim 8, wherein the instructions, when executed by the at least one processor, cause the apparatus to further: The combination was not successfully decoded; and Release the first-stage DCI and the at least one second-stage DCI transmission from at least one buffer, wherein the first-stage DCI and the at least one second-stage DCI transmission are stored in the at least one buffer.

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