Improving performance of cellular communication in reduced bandwidth

Abstract

To provide a method for achieving improved performance when bandwidth is reduced.SOLUTION: A method includes: receiving an indication of a modification of at least one control channel element structure within an initial set of control resources set for a device; determining at least one modified control channel element structure for at least one aggregation level within the initial set of control resources; monitoring a physical downlink control channel from the initial set of control resources according to the modified control channel element structure; and receiving a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The following exemplary embodiments relate to wireless communications and to improving performance when bandwidth is reduced. [Background technology]

[0002] Cellular communications enable a variety of mobile use cases. Different cellular communication technologies can occur in parallel within a given frequency bandwidth. Also, for example, 5G may have implementations that use narrower bandwidths than usual. For such narrowband use cases, it is beneficial to ensure good performance even with the narrower bandwidth. Summary of the Invention

[0003] The scope of protection sought for various embodiments is defined by the independent claims. The exemplary embodiments and features described herein that do not fall within the scope of the independent claims, if any, should be interpreted as examples that serve to understand various embodiments of the present disclosure.

[0004] According to a first aspect, there is provided an apparatus comprising at least one processor and at least one memory containing computer program code, wherein the at least one memory and the computer program code are configured, using the at least one processor, to cause the apparatus to perform the following: receive an indication of modification of at least one control channel element structure in an initial control resource set configured for the apparatus; determine at least one modified control channel element structure for at least one aggregation level in the initial control resource set; monitor physical downlink control channels from the initial control resource set according to the modified control channel element structure; and receive a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure.

[0005] According to a second aspect, an apparatus is provided, comprising: means for receiving an indication of modification of at least one control channel element structure in an initial control resource set configured for the apparatus; means for determining at least one modified control channel element structure for at least one aggregation level in the initial control resource set; means for monitoring a physical downlink control channel from the initial control resource set according to the modified control channel element structure; and means for receiving a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure.

[0006] According to a third aspect, there is provided a method including: receiving an indication of modification of at least one control channel element structure in an initial control resource set configured for a device; determining at least one modified control channel element structure for at least one aggregation level in the initial control resource set; monitoring a physical downlink control channel from the initial control resource set according to the modified control channel element structure; and receiving a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure.

[0007] According to a fourth aspect, there is provided a computer program comprising instructions to cause a device to at least receive an indication of modification of at least one control channel element structure in an initial control resource set configured for the device; determine at least one modified control channel element structure for at least one aggregation level in the initial control resource set; monitor a physical downlink control channel from the initial control resource set according to the modified control channel element structure; and receive a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure.

[0008] According to a fifth aspect, there is provided a computer program product including instructions to cause a device to at least receive an indication of modification of at least one control channel element structure in an initial control resource set configured for the device; determine at least one modified control channel element structure for at least one aggregation level in the initial control resource set; monitor a physical downlink control channel from the initial control resource set according to the modified control channel element structure; and receive a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure.

[0009] According to a sixth aspect, there is provided a computer program having instructions stored thereon for executing at least: receiving an indication of modification of at least one control channel element structure in an initial control resource set configured for a device; determining at least one modified control channel element structure for at least one aggregation level in the initial control resource set; monitoring physical downlink control channels from the initial control resource set in accordance with the modified control channel element structure; and receiving a physical downlink shared channel in accordance with the physical downlink control channel received via the modified control channel element structure.

[0010] According to a seventh aspect, there is provided a non-transitory computer-readable medium including program instructions for causing a device to at least receive an indication of modification of at least one control channel element structure in an initial control resource set configured for the device; determine at least one modified control channel element structure for at least one aggregation level in the initial control resource set; monitor a physical downlink control channel from the initial control resource set according to the modified control channel element structure; and receive a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure.

[0011] According to an eighth aspect, there is provided a non-transitory computer-readable medium having stored thereon program instructions for performing at least: receiving an indication of modification of at least one control channel element structure in an initial control resource set configured for a device; determining at least one modified control channel element structure for at least one aggregation level in the initial control resource set; monitoring physical downlink control channels from the initial control resource set according to the modified control channel element structure; and receiving a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure.

[0012] According to a ninth aspect, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, using the at least one processor, to cause the apparatus to perform the following: transmit an indication of modification of at least one control channel element structure for at least one aggregation level in an initial control resource set configured by the apparatus; transmit at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level in the initial control resource set; and transmit a physical downlink shared channel in accordance with the at least one physical downlink control channel transmitted via the modified control channel element structure.

[0013] According to a tenth aspect, there is provided an apparatus, comprising: means for transmitting an indication of modification of at least one control channel element structure for at least one aggregation level in an initial control resource set configured by the apparatus; means for transmitting at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level in the initial control resource set; and means for transmitting a physical downlink shared channel according to the at least one physical downlink control channel transmitted via the modified control channel element structure.

[0014] According to an eleventh aspect, there is provided a method, the method including: transmitting an indication of modification of at least one control channel element structure for at least one aggregation level in an initial control resource set configured by an apparatus; transmitting at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level in the initial control resource set; and transmitting a physical downlink shared channel according to the at least one physical downlink control channel transmitted via the modified control channel element structure.

[0015] According to a twelfth aspect, there is provided a computer program comprising instructions to cause an apparatus to at least: transmit an indication of modification of at least one control channel element structure for at least one aggregation level in an initial control resource set configured by the apparatus; transmit at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level in the initial control resource set; and transmit a physical downlink shared channel in accordance with the at least one physical downlink control channel transmitted via the modified control channel element structure.

[0016] According to a thirteenth aspect, there is provided a computer program product including instructions to cause an apparatus to at least: transmit an indication of modification of at least one control channel element structure for at least one aggregation level in an initial control resource set configured by the apparatus; transmit at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level in the initial control resource set; and transmit a physical downlink shared channel in accordance with the at least one physical downlink control channel transmitted via the modified control channel element structure.

[0017] According to a fourteenth aspect, there is provided a computer program having instructions stored thereon for executing at least: transmitting an indication of modification of at least one control channel element structure for at least one aggregation level in an initial control resource set configured by the device; transmitting at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level in the initial control resource set; and transmitting a physical downlink shared channel in accordance with the at least one physical downlink control channel transmitted via the modified control channel element structure.

[0018] According to a fifteenth aspect, there is provided a non-transitory computer-readable medium including program instructions for causing an apparatus to at least: transmit an indication of modification of at least one control channel element structure for at least one aggregation level in an initial control resource set configured by the apparatus; transmit at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level in the initial control resource set; and transmit a physical downlink shared channel in accordance with the at least one physical downlink control channel transmitted via the modified control channel element structure.

[0019] According to a sixteenth aspect, there is provided a non-transitory computer-readable medium having stored thereon program instructions for performing at least: transmitting an indication of modification of at least one control channel element structure for at least one aggregation level in an initial control resource set configured by the device; transmitting at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level in the initial control resource set; and transmitting a physical downlink shared channel in accordance with the at least one physical downlink control channel transmitted via the modified control channel element structure.

[0020] Exemplary embodiments will now be described in more detail with reference to the embodiments and accompanying drawings. [Brief explanation of the drawings]

[0021] [Figure 1] 1 illustrates an exemplary embodiment of a radio access network. [Figure 2] 1 shows an example of an initial access signal and a channel. [Figure 3A] 1 illustrates an exemplary embodiment of a synchronization raster point. [Figure 3B] 1 illustrates an exemplary embodiment of a DRMS ​​allocation in a PBCH PRB. [Figure 3C] 1 shows an example of a pattern of SS / PBCH blocks, CORESET, and PDSCH multiplexed by TDM. [Figure 4] 10 illustrates an exemplary embodiment of possible PDCCH transmissions for CORESET#0. [Figure 5] 1 shows an example of possible PDCCH candidate sizes for AL8. [Figure 6] 10 illustrates an exemplary embodiment of CORESET with a frequency location option of offset 0 for SS / PBCH. [Figure 7] 10 shows an example of CCE mapping to REG bundles according to physical cell identifiers. [Figure 8] 10 shows an example of CCE mapping to REG bundles according to physical cell identifiers. [Figure 9] 1 illustrates a flowchart in accordance with an exemplary embodiment. [Figure 10] 1 illustrates an exemplary embodiment of an apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0022] The following embodiments are illustrative. Although this specification may refer to "an," "one," or "some" embodiment(s) in several places throughout the text, this does not necessarily mean that each reference refers to the same embodiment(s) or that a particular feature applies only to a single embodiment. Single features of different embodiments may be combined to provide other embodiments.

[0023] As used in this application, the term "circuitry" refers to all of the following: (a) hardware-only circuit implementations, e.g., implementations with only analog and / or digital circuitry, and (b) combinations of circuitry and software (and / or firmware), such as (where applicable): (i) a combination of processor(s) or (ii) processor(s) / software, including digital signal processor(s), software, and portions of memory(s), working in conjunction to cause a device to perform various functions, and (c) circuits, such as, for example, microprocessor(s) or portions of microprocessors, that require software or firmware for operation even when the software or firmware is not physically present. This definition of "circuitry" applies to all uses of the term in this application. As a further example, the term "circuitry," as used in this application, also encompasses an implementation of just a processor(s), or portions of a processor, and its (or their) accompanying software and / or firmware. The term "circuit" also encompasses, for example, a baseband integrated circuit or an application processor integrated circuit for a mobile phone, or similar integrated circuits in a server, cellular network device, or other network device, when applicable to the particular element. The above-described embodiments of circuits may also be considered to be embodiments that provide means for performing embodiments of the methods or processes described herein.

[0024] The techniques and methods described herein may be implemented by various means. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. In a hardware implementation, an apparatus(es) of an embodiment may be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. In the case of firmware or software, implementation may occur via modules (e.g., procedures, functions, etc.) of at least one chipset that performs the functions described herein. Software code may be stored in a memory unit and executed by a processor. The memory unit may be implemented within the processor or external to the processor. In the latter case, it may be communicatively coupled to the processor via any suitable means. Furthermore, the components of the systems described herein may be reconfigured and / or supplemented with additional components to facilitate implementation of various aspects, etc., described in connection therewith, and are not limited to the exact configurations depicted in the provided figures, as will be understood by those skilled in the art.

[0025] The embodiments described herein may be implemented in a communication system such as at least one of the following: Global System for Mobile Communications (GSM) or any other second generation cellular communication system, basic Wideband Code Division Multiple Access (W-CDMA), High Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), Universal Mobile Telecommunications System based on LTE-Advanced (UMTS, 3G), a system based on the IEEE 802.11 standard, a system based on the IEEE 802.15 standard, and / or a fifth generation (5G) mobile or cellular communication system. However, the embodiments are not limited to the systems given as examples, and one skilled in the art may apply the solution to other communication systems provided with the required characteristics.

[0026] Figure 1 shows an example of a simplified system architecture showing some elements and functional entities, which are all logical units and may be implemented differently from those shown. The connections shown in Figure 1 are logical connections, and the actual physical connections may be different. It is clear to those skilled in the art that the system may have functions and structures other than those shown in Figure 1. The example in Figure 1 shows a portion of an exemplary radio access network.

[0027] FIG. 1 illustrates terminal devices 100 and 102 configured to wirelessly connect with an access node (e.g., (e / g)NodeB) 104 that provides the cell over one or more communication channels within the cell. The access node 104 may also be referred to as a node. The physical link from the terminal device to the (e / g)NodeB is referred to as an uplink or reverse link, and the physical link from the (e / g)NodeB to the terminal device is referred to as a downlink or forward link. It should be understood that the (e / g)NodeB or its functionality may be implemented using any node, host, server, or access point, or other entity suitable for such use. While one cell is discussed in this exemplary embodiment, it should be noted that for ease of explanation, in some exemplary embodiments, multiple cells may be provided by one access node.

[0028] A communication system may include two or more (e / g)NodeBs, which may be configured to communicate with each other via wired or wireless links designed for that purpose. These links may be used for signaling purposes. An (e / g)NodeB is a computing device configured to control the radio resources of the communication system to which it is coupled. An (e / g)NodeB may also be referred to as a base station, an access point, or any other type of interface device, including a relay station, operable in a wireless environment. An (e / g)NodeB includes or is coupled to a transceiver. A connection is provided from the transceiver of the (e / g)NodeB to an antenna unit that establishes a bidirectional wireless link to a user device. The antenna unit may include multiple antennas or antenna elements. The (e / g)NodeB is further connected to a core network 110 (CN or Next Generation Core NGC). Depending on the system, the counterpart on the CN side may be a Serving Gateway (S-GW, which routes and forwards user data packets), a Packet Data Network Gateway (P-GW) for providing connectivity of terminal devices (UEs) to external packet data networks, or a Mobile Management Entity (MME), etc.

[0029] A terminal device (also referred to as UE, user equipment, user terminal, user device, etc.) represents one type of device to which air interface resources are allocated and assigned. Therefore, any feature described herein with respect to a terminal device may be implemented by a corresponding device, such as a relay node. One example of such a relay node is a Layer 3 relay (self-backhauling relay) to a base station. A relay node may be referred to as an IAB (integrated access and backhaul) node. A relay node may include a MT (mobile termination) portion that facilitates backhaul connection (i.e., the radio link between the IAB node and the parent DU) and a distributed unit (DU) portion that facilitates access link functionality (i.e., the radio link between the IAB node and the UE(s) / child IAB node(s)). A CU (centralized unit) may coordinate DU operations, for example, via an F1AP interface.

[0030] A terminal device may refer to a portable computing device, including a wireless mobile communication device that operates with or without a subscriber identity module (SIM), or an embedded SIM, eSIM, including, but not limited to, the following types of devices: mobile stations (cell phones), smartphones, personal digital assistants (PDAs), handsets, devices that use wireless modems (such as alarms or measurement devices), laptop and / or touchscreen computers, tablets, game consoles, notebooks, and multimedia devices. It should be understood that a user device may be an uplink-only or mostly uplink-only device, an example of which is a camera or video camera that loads images or video clips onto a network. A terminal device may also be a device capable of operating in an Internet of Things (IoT) network, a scenario in which objects are provided with the ability to transfer data over a network without the need for human-to-human or human-to-computer interaction. A terminal device may also utilize the cloud. In some applications, a terminal device may include a small portable device (e.g., a watch, earphones, or glasses) with wireless components, and computations are performed in the cloud. The terminal device (or in some embodiments, the MT portion of the IAB node) is configured to perform one or more of the user equipment functions.

[0031] The various techniques described herein may also be applied to cyber-physical systems (CPS), systems that coordinate computational elements to control physical entities. CPS may enable the implementation and utilization of a large number of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects in various locations. Mobile cyber-physical systems, where the physical system in question has inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices carried by humans or animals.

[0032] Furthermore, although these devices are shown as single entities, various units, processors, and / or memory units (not all of which are shown in FIG. 1) may be implemented.

[0033] 5G will use multiple-input, multiple-output (MIMO) antennas to enable many more base stations or nodes than LTE (the so-called small cell concept), including macro sites that operate in conjunction with smaller stations and employ various radio technologies depending on service needs, use cases, and / or available spectrum. 5G mobile communications will support a wide range of use cases and related applications, such as video streaming, augmented reality, various data sharing methods, and various forms of machine-type applications, such as (massive) machine-type communications (mMTC), e.g., vehicle safety, various sensors, and real-time control. 5G will have multiple air interfaces, including sub-6 GHz, cm-wave, and mm-wave, and is expected to be able to integrate with existing legacy radio access technologies such as LTE. Integration with LTE, at least initially, may be implemented as a system in which macro coverage is provided by LTE and 5G air interface access is obtained from small cells by aggregation to LTE. In other words, 5G is planned to support both inter-RAT interoperability (e.g., LTE-5G) and inter-RI interoperability (inter-air interface interoperability, e.g., sub-6 GHz - cm wave, sub-6 GHz - cm wave - mm wave). One concept expected to be used in 5G networks is network slicing, in which multiple independent and dedicated virtual sub-networks (network instances) can be created within the same infrastructure to carry services with different requirements in latency, reliability, throughput, and mobility. The current solution is particularly suitable for Frequency Range 1, i.e., FR1 (covering sub-6 GHz), especially for sub-1 GHz frequency scenarios, and has a normal cyclic prefix (CP), 15 kHz subcarrier spacing, and frequency division duplexing (FDD). However, this solution can also be extended to other scenarios, such as time division duplexing (TDD).

[0034] The current architecture of LTE networks is fully distributed over the air and fully centralized in the core network. 5G low-latency applications and services may require content to be closer to the air, which could lead to local breakout and multi-access edge computing (MEC). 5G enables analytics and knowledge generation at the source of the data. This approach requires leveraging resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for hosting applications and services. It also has the ability to store and process content closer to the mobile subscriber for faster response times. Edge computing covers a wide range of technologies, such as wireless sensor networks, mobile data acquisition, mobile signature analysis, collaborative, distributed peer-to-peer ad-hoc networking and processing (which can also be classified as local cloud / fog computing and grid / mesh computing), dew computing, mobile edge computing, cloudlets, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and / or latency critical), critical communications (autonomous vehicles, road safety, real-time analytics, time-critical control, healthcare applications), etc.

[0035] The communications system may also communicate with and / or use services provided by other networks, such as the public switched telephone network or the Internet 112. The communications network may also be capable of supporting the use of cloud services, e.g., at least some of the core network operations may be performed as cloud services (this is illustrated in FIG. 1 by "cloud" 114). The communications system may also comprise a central control entity that provides facilities for different operators' networks to cooperate, e.g., in spectrum sharing.

[0036] By utilizing network function virtualization (NFV) and software defined networking (SDN), an edge cloud can be incorporated into the radio access network (RAN). The use of an edge cloud may mean that access node operations are performed at least in part in a server, host, or node operatively coupled to a remote radio head, or a base station comprising radio components. It is also possible that node operations are distributed among multiple servers, nodes, or hosts. Applying a Cloud RAN architecture allows RAN real-time functions to be performed on the RAN side (in a distributed unit, DU 104) and non-real-time functions to be performed in a centralized manner (in a central unit, CU 108).

[0037] It should also be understood that the division of labor between core network operations and base station operations may be different from that in LTE, or may even not exist. Some other technologies that may be used include, for example, big data and all-IP, which may change the way networks are built and managed. 5G (or new radio, NR) networks are designed to support multiple tiers, and MEC servers may be located between the core and base stations or nodeBs (gNBs). It should be understood that MEC is equally applicable to 4G networks.

[0038] 5G may utilize satellite communications to enhance or complement 5G service coverage, for example, by providing backhaul, or to enhance or complement service availability in areas without terrestrial coverage. Potential use cases include providing service continuity to machine-to-machine (M2M) or Internet of Things (IoT) devices or vehicle passengers, and / or ensuring service availability for critical communications and / or future rail, maritime, and aviation communications. Satellite communications may utilize geostationary earth orbit (GEO) satellite systems, but may also utilize low earth orbit (LEO) satellite systems, such as megaconstellations (systems in which hundreds of (nano)satellites are deployed). Satellites 106 included in the constellation may host gNBs, or at least a portion of gNBs, that create terrestrial cells. Alternatively, satellites 106 may be used to relay signals from one or more cells to Earth. A terrestrial cell may be created via a terrestrial relay node 104 or by a gNB located on the ground or in a satellite, or a portion of the gNB, e.g., a DU, may reside on a satellite and a portion of the gNB, e.g., a CU, may reside on the ground. Alternatively or additionally, a high-altitude platform station (HAPS) system may be utilized. A HAPS may be understood as a radio station on an object at an altitude of 20 to 50 kilometers and at a fixed point relative to the Earth. Alternatively, a HAPS may move relative to the Earth. For example, broadband access may be provided via a HAPS using lightweight, solar-powered aircraft and airships that operate continuously for several months at an altitude of, e.g., 20 to 25 kilometers.

[0039] It should be noted that the illustrated system is an example of a portion of a radio access system, and that the system may include multiple (e / g)NodeBs, that a terminal device may be able to access multiple radio cells, and that the system may also include other devices such as physical layer relay nodes or other network elements. At least one of the (e / g)nodeBs may be a home (e / g)nodeB. Furthermore, a geographic area of ​​a radio communication system may be provided with multiple radio cells of different types. The radio cells may be macrocells (or umbrella cells), which are large cells typically having diameters of up to tens of kilometers, or smaller cells such as microcells, femtocells, or picocells. The (e / g)NodeB in FIG. 1 may provide any type of these cells. A cellular radio system may be realized as a multi-layer network including several types of cells. In some exemplary embodiments, in a multi-layer network, one access node provides one or more cells of one type, and therefore multiple (e / g)NodeBs are required to provide such a network structure.

[0040] To meet the need to improve the deployment and performance of communication systems, the concept of "Plug and Play" (e / g) NodeB has been introduced. A network that may use "Plug and Play" (e / g) NodeB may include a Home NodeB Gateway, or HNB-GW (not shown in FIG. 1), in addition to a Home (e / g) NodeB (H(e / g)nodeB). The HNB Gateway (HNB-GW), which may be located within an operator's network, may aggregate traffic from multiple HNBs back to the core network.

[0041] 5G may also be used for narrowband operation, i.e., Narrowband New Radio (NB NR) operation. Note that NB NR may also be referred to using other terms, such as NR support in dedicated spectrum below 5 MHz. NB NR may help meet communication needs for, for example, railway, smart grid-related operations, and / or public safety-related operations. For example, in Europe, the Future Railway Mobile Communication System (FRMCS) includes considerations such as an agreement to use NR on 2 x 5.6 MHz FDD (874.4-880 MHz / 919.4-925 MHz) and a smooth transition from GSM-R, which requires parallel operation of GSM-R and NR, expected to last approximately 10 years, with approximately 3.6 MHz available for NR, depending on the number of parallel GSM-R channels required. Additionally, NB NR for smart grids includes the following considerations: 2 x 3 MHz FDD within 900 MHz in the United States. A public safety related scenario has the following consideration: 2 x 3 MHz FDD in Band 28 for Public Protection & Disaster Relief (PPDR) in Europe. In this context of this document, limited spectrum allocations (e.g., less than 5 MHz) are mainly addressed. Note that there may also be other scenarios addressing other limitations such as terminal devices with reduced capabilities, including reduced bandwidth capabilities. The solutions defined for limited spectrum allocations can also support scenarios such as terminal devices with reduced bandwidth capabilities.

[0042] While 5G is designed to operate over 5 MHz channels (at a minimum), it may be beneficial to enable 5G operation over narrower bandwidths to enable such operations. For example, NR deployment in the 900 MHz FRMCS band requires parallel deployment with legacy GSM-R carriers within a 5.6 MHz bandwidth, leaving only approximately 3.6 MHz available for NR. Furthermore, there may be operations where 3 MHz channels are available for NR. Figure 2 shows initial access signals and channels for 5G with 15 kHz subcarrier spacing. In Figure 2, the signals and channels for synchronization signals and physical broadcast channel (PBCH) blocks (SSBs) are shown, including a primary synchronization signal (PSS) 210, a secondary synchronization signal (SSS) 214, and a PBCH 212. Bandwidth 220 is a 0.72 MHz bandwidth containing 48 subcarriers, e.g., four physical resource blocks (PRBs). Bandwidth 222 is a 2.16 MHz bandwidth containing 144 subcarriers, e.g., 12 PRBs. Bandwidth 224 is a 0.72 MHz bandwidth containing 48 subcarriers, e.g., 4 PRBs. Bandwidth 223 containing 127 subcarriers and bandwidth 226 containing 240 subcarriers, e.g., 20 PRBs, are also shown. An SSB contains four OFDM symbols, as shown at 228.

[0043] The important signals and channels shown in Figure 2 are transmitted by an NR base station (gNB), which was not designed for transmission on such narrow channels. During initial cell selection, i.e., initial access, a terminal device searches for the PSS 210 of the SSB on predefined synchronization raster points. In other words, the synchronization raster indicates the frequency location of the synchronization signal block that can be used by the terminal device for system acquisition in the absence of explicit signaling of the synchronization block location. A global synchronization raster is defined for all frequencies. For example, the frequency location of the SS block is defined in 3GPP TS38.101 as SSREF with a corresponding number GSCN. Figure 3A shows an exemplary embodiment of a synchronization raster point 310 below 3 GHz, defined as a cluster of three points.

[0044] Once the PSS 210 and therefore the SSS 214 are detected, the terminal device performs demodulation of the PBCH 212 using a channel estimate calculated from the PBCH demodulation reference set (DMRS). The NR-PBCH DMRS may be mapped to all NR-PBCH symbols at a density of 3 resource elements (REs) / PRB / symbol across the NR-PBCH. The DMRS 330 has the same RE position in all NR-PBCH symbols 320, as shown in Figure 3B, which is a diagram of an example embodiment of DMRS allocation in a PBCH PRB 340 with four different frequency-domain shifts depending on the physical cell ID.

[0045] A CORESET (Control resource set) is a set of physical resources, e.g., a specific area on the NR downlink resource grid, and a set of parameters used to carry PDCCH / DCI. CORESET includes many parameters configurable by RRC. CORESET#0, for example, carries PDCCH for SIB1 scheduling. However, CORESET#0 cannot be configured by RRC because it is used before an RRC connection is established when a UE initially accesses a cell from IDLE / Inactive. Therefore, CORESET#0 is configured by a separate process and predefined parameters. An example of such predefined parameters and processes is summarized in Table 1 below. However, it should be noted that CORESET#0 may also be referred to as an initial CORESET, i.e., an initial control resource set. CORESETs other than CORESET#0 may each be referred to as a non-initial control resource set. [Table 1]

[0046] The frequency / time resource allocation is given using an index by a master information block (MIB), such as the PBCH. For NR NB, a scenario may include multiplexing pattern 1 shown in Figure 3C, 15 kHz SCS (both SSB and CORESET#0), 24 RBs, and 2 or 3 OFDM symbols (i.e., indexes 0-5), according to Table 2 below. In Figure 3C, pattern 1 shows a TDM multiplexed SS / PBCH block 352, CORESET 354, and PDSCH 356. [Table 2]

[0047] Table 2 shows a set of resource blocks and slot symbols of CORESET for a Type0-PDCCH search space set when the {SS / PBCH block, PDCCH} SCS is {15,15} kHz for a frequency band with a minimum channel bandwidth of 5 MHz or 10 MHz. The terminal device determines the index shown in Table 2, which specifies the CORESET#0 setting, based on the parameter controlResourceSetZero in pdcch-ConfigSIB1 (provided by MIB / PBCH). In other words, the index in Table 2 is selected based on the SSB, and the index is provided in PBCH / MIB. The RB number in Table 2 is the number of RBs in CORESET#0, and the symbol number refers to the number of OFDM symbols in CORESET#0. The offset in Table 2 is the offset between the SSB and CORESET#0. The offset specifies the offset between the lowest RB of CORESET#0 and the lowest RB of the SSB or an RB in a common resource grid that overlaps with the SSB.

[0048] For a Type 0-PDCCH search space set, the maximum number of PDCCH candidates monitored per PDCCH opportunity is shown in Table 3 below. [Table 3]

[0049] Table 3 shows the CCE aggregation levels and the maximum number of PDCCH candidates for each CCE aggregation level of the CSS set configured by searchSpaceSIB1.

[0050] FIG. 4 shows an exemplary embodiment of a possible PDCCH transmission for CORESET#0. Consider both 2-symbol and 3-symbol CORESETs and assume that the number of RBs is 24 in both cases. This may be the minimum number of PRBs supported by CORESET#0. In this exemplary embodiment, the transmission bandwidth is reduced from one side, e.g., from the upper frequency. However, this should not be understood as a limitation, since in some exemplary embodiments, the bandwidth may also be reduced in other ways, such as from both sides. However, CORESET#0 utilizes interleaved mapping between CCEs and REG bundles (size = 6REG). Due to the interleaved mapping, when a 2-symbol CORESET is used, AL8 (aggregation level 8) cannot be transmitted without puncturing if the available bandwidth is less than 4.32 MHz. Also, the minimum bandwidth for AL4 without puncturing is 3.24 MHz, while 1 / 3 of the PRB resources are unused. However, a solution using puncturing other than CCEs is not preferred because terminal devices are expected to average channel estimates within a CCE, which means that the granularity at which puncturing is performed is 6 PRBs, which may be much higher than that of the PBCH. Furthermore, if a 3-symbol CORESET is used, AL8 cannot be transmitted without puncturing if the bandwidth is less than 3.6 MHz. However, at the same time, 20% of the PRB resources may be unused. For AL4, if a 3-symbol CORESET is used, the minimum bandwidth without puncturing is 2.88 MHz. This may result in 50% of the PRB resources being unused. However, a solution using puncturing other than CCEs is not preferred because terminal devices are expected to average channel estimates within a CCE, which means that the granularity at which puncturing is performed is 2 PRBs, which may be much higher than that of the PBCH.In some exemplary embodiments, the PDCCH may occupy only 12, 13, 14, or 15 PRBs, which may be the case, for example, when the carrier is configured to operate according to a 3 MHz channel bandwidth.

[0051] On the other hand, PDCCH detection performance may be degraded by puncturing, and the impact of puncturing on high-AL PDCCH candidates may be significant. For example, in a simulation case where one-sided puncturing of the PBCH is used, additive white Gaussian noise (AWGN) interference is used to mimic GSM-R interference, the gNB does not transmit the PBCH in those GSM-R PRBs, and the terminal device performs detection assuming a perfect, i.e., incorrect, PBCH Tx BW, the terminal device's performance may be significantly degraded. Table 4 below shows the SNR degradation (dSNR) required for sufficient PBCH detection performance for various amounts of PRB puncturing, such as 2, 4, and 6 PRBs. The SNR degradation is calculated relative to the SNR required for sufficient detection performance of the PBCH transmitted in the full BW. [Table 4]

[0052] Depending on the interference power, PBCH detection performance may degrade by more than 5 dB. This may result in terminal devices frequently being unable to access the cell. It should also be noted that in deployment scenarios such as GSM-R reframing, GSM and NR BSs are likely to be co-located, increasing the likelihood of increased GSM power levels. Therefore, there is a need to improve PDCCH performance. An aspect that is useful to address when using only AL4 is how to support the use of more CCEs for a given minimum bandwidth. It is known that the link performance difference between AL4 and AL8 can exceed 3 dB. Another aspect that is useful to address is that AL8, when also used, cannot be used without puncturing. Based on PBCH results, 25% puncturing in a scenario where the terminal device does not know the actual puncturing pattern can exceed 5 dB. Therefore, an advantage associated with the exemplary embodiments described below is that the PDCCH BW can be individually adjusted for each PDCCH candidate while keeping the PDCCH structure unchanged, facilitating optimal PDCCH detection for accurate PBCH detection.

[0053] In an exemplary embodiment, a terminal device may be instructed to monitor a common search space (CSS) in a specific manner. This method may include monitoring a PDCCH with a modified CCE structure for at least one AL, such as AL8, in addition to monitoring all candidates for AL4, AL8, and / or AL16. In this exemplary embodiment, the modified CCE structure corresponds to a punctured PDCCH for a given AL, while in some other exemplary embodiments, the modified CCE structure may correspond to a non-interleaved CCE structure. In still other exemplary embodiments, the modified CCE structure may correspond to a new aggregation level, such as level 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, or 15 (in addition to aggregation levels 1, 2, 4, 8, and 16 supported by new radio). The new aggregation levels may be used with a non-interleaved CCE structure. In yet another exemplary embodiment, the terminal device may perform PDCCH monitoring for SIB1 using only the modified CCE structure, in which case the terminal device operates in a special band. The punctured candidates may be formed in a predefined manner, such as puncturing from the last CCE or the first CCE. Furthermore, the outermost CCE from the highest or lowest PRB may be punctured at a granularity of 1 PRB, in which case the size of the corresponding REG bundle decreases accordingly, while the size of the other REG bundles remains unchanged. The modified CCE structure may also depend on the determined channel bandwidth. For example, one modified CCE structure may be applied to a 3 MHz channel bandwidth (CBW), while another modified CCE structure may be applied to a 5 MHz CBW. Furthermore, a combination of the above-mentioned predefined methods may also be used for the punctured candidates. It should also be noted that the punctured PDCCH, which is punctured in a predefined manner, is punctured in frequency in relation to the CCE. It should also be noted that the determined channel bandwidth may be understood as the channel bandwidth determined to be available. This determination may be made in any suitable manner, for example, by a terminal device.Therefore, in general, the modified CCE structure may depend on the channel bandwidth.

[0054] Figure 5 shows an example of possible PDCCH candidate sizes for AL8. However, note that in the 3 MHz exemplary embodiment, the modified structure can already be applied to AL4. In Figure 5, the CCE indices are shown as numbers according to the legacy CCE-to-REG mapping for a CORESET size of 24 PRBs. In this exemplary embodiment, the CORESET size is 2 OFDM symbols x 24 PRBs. The empty CCEs 520 are punctured REGs. For CORESET sizes greater than 24, the valid CCE indices for the punctured PDCCH candidate are [x, x+2, x+4,..., x+M], where x is the first CCE index given by the hash function and M / 2 is the number of CCEs in the PDCCH candidate.

[0055] Furthermore, the actual PDCCH structure may need to be configured for the terminal device so that the terminal device and the access node, such as the gNB, have a common understanding. For example, reserved bits may be used in the PBCH, or unnecessary bits may be reinterpreted. For example, it may be assumed that the NR NB is limited to {SS / PBCH block, PDCCH} combinations of {15,15} kHz, in which case the 5th bit of kSSB is not required, i.e., the PBCH physical layer bit

number

[0056] In one exemplary embodiment, the signaling solution defined above may only be applied when monitoring the PDCCH for SIB1, and in other situations, such as CORESET#0, the terminal device becomes aware of the actual puncturing based on SIB1 or other higher layer signaling. Based on the actual puncturing, the terminal device may then optimize the PDCCH monitoring, including the PDCCH puncturing pattern, according to the actual Tx BW setting. However, it should be noted that in some other exemplary embodiments, the modified CCE structure may always be applied to CORESET#0.

[0057] The maximum number of PDCCH candidates monitored per PDCCH opportunity is shown in Table 5 below. Table 5 shows the CCE aggregation level and the maximum number of PDCCH candidates per CCE aggregation level for the CSS set configured by searchSpaceSIB1. In this exemplary embodiment, it is assumed that the maximum number of PDCCH candidates per CCE aggregation level is maintained, but the CCE structure among the candidates is changed in a predefined manner. The numbers in parentheses represent the different shares between the legacy structure and the new structure (e.g., [3] + [1]). [Table 5]

[0058] The relative frequency locations of the CORESET and SS / PBCH blocks are specified on the PBCH. This is done by offsets that may be provided in tables and by the quantity k signaled on the PBCH. SSB The offset is from the lowest RB index of CORESET to the lowest RB index of the common RB that overlaps with the first RB of the corresponding SS / PBCH block, and k SSB provides the location of the SS / PBCH relative to the common RB grid, which is the common resource block

number

[0059] If CORESET occupies 24 RBs with a 15 kHz SCS, the offset can have the value 0, 2, or 4. SSBWhen aligning the SS / PBCH block with common RBs, the offset may position CORESET symmetrically with respect to the SS / PBCH block, or align the lower / upper frequency edges of CORESET with the lower / upper frequency edges of the PBCH, respectively, as shown in Figure 6. Figure 6 shows CORESET with a frequency location option 610 with an offset of 0 for the SS / PBCH when aligned with common RBs. The PSS, SSS, and PBCH are shown in Figure 6. Bandwidth 630 is a 0.72 MHz bandwidth containing 48 subcarriers, e.g., 4 PRBs. Bandwidth 632 is a 2.16 MHz bandwidth containing 144 subcarriers, e.g., 12 PRBs. Bandwidth 634 is a 0.72 MHz bandwidth containing 48 subcarriers, e.g., 4 PRBs. Bandwidth 223 containing 127 subcarriers and bandwidth 636 containing 240 subcarriers, e.g., 20 PRBs, are also shown. The SSB includes four OFDM symbols, as shown at 638.

[0060] CCE mapping to REG bundles depends on the physical cell identifier, as shown in Figures 7 and 8. Note that for some cell IDs, CCE puncturing for PDCCH candidates may begin to occur at a narrower BW than for other cell IDs. Therefore, in some exemplary embodiments, a subset of cell IDs may be used, e.g., for wide-area cells in an NB NR deployment. Alternatively, non-interleaved mapping may be used for some cell IDs. For non-interleaved mapping, CCEs are mapped to REG bundles in ascending order of CCE and REG bundle index. Correspondingly, asymmetric mapping from higher PRBs may be used with a CORESET offset of 0, with lower PRBs aligned with SS / PBCH blocks. Because asymmetric puncturing from lower PRBs may not be supported, limiting asymmetric puncturing to only puncturing from higher PRBs saves signaling state for other purposes, which may be beneficial as signaling state may be scarce.

[0061] Table 6 below shows an example of a puncturing function defined based on the invalid {SS / PBCH block, PDCCH} SCS combination {15, 30} for the considered (NR NB) frequency band. In this example, the desired function is achieved by selecting the desired row based on the MIB, and the additional columns indicate how the CCE structure of the predefined CCE is constructed. For example, puncturing the CCE / CCE + outermost RB. In this example, index 5 indicates symmetric puncturing centered on the CORESET. In other examples, asymmetric puncturing, which punctures the CCE / RB from the highest frequency, can be assumed. Table 6 shows the set of resource blocks and slot symbols of CORESET for the Type 0-PDCCH search space set when the {SS / PBCH block, PDCCH} SCS is {15, 30} kHz for frequency bands with a minimum channel bandwidth of 5 MHz or 10 MHz. [Table 6-1] [Table 6-2]

[0062] Alternatively, puncturing may be defined in terms of the REG bundle index, in which case punctured AL16 may also be supported, as shown in Table 7. [Table 7-1] [Table 7-2]

[0063] In one exemplary embodiment, signaling occurs on downlink RF channels 919.4-925 MHz for FRMCS. In this exemplary embodiment, there are only six valid synchronization raster points: N={768,769}, M={1,2,3}. Furthermore, because only SSB-CORESET#0 offsets 0 and 4 are applicable, in the CORESET#0 configuration table, only configuration indexes 0, 2, 3, and 5 are applicable, resulting in 12 unusable entries. In the CORESET#0 setting, four entries are possible as shown in Table 8 below. [Table 8]

[0064] Thus, in an exemplary embodiment, the signaling to the terminal device may be such that there are separate tables defined for the 2-symbol and 3-symbol CORESET#0 configurations. The selection of which table to apply may be provided by reinterpreting the subCarrierSpacingCommon field of the MIB (PBCH) or the fifth (MSB) of kSSB. This selection may also be provided via a reserved field in the MIB. Table 9 below shows the set of resource blocks and slot symbols of CORESET for a Type0-PDCCH search space set when {SS / PBCH block, PDCCH} SCS is {15,15} kHz for a frequency band with a minimum channel bandwidth of 5 MHz when the number of symbols is equal to 2 (subCarrierSpacingCommon=0). [Table 9-1] [Table 9-2]

[0065] Table 10 shows the set of resource blocks and slot symbols of CORESET for Type0-PDCCH search space set when {SS / PBCH block, PDCCH} SCS is {15,15} kHz for a frequency band with a minimum channel bandwidth of 5 MHz when the number of symbols is equal to 3 (subCarrierSpacingCommon=1). [Table 10-1] [Table 10-2]

[0066] In an alternative exemplary embodiment, unique tables may be defined for 0 and 4 RB offsets, with a 2-symbol setting and a 3-symbol setting within the same table for each offset (0 or 4). The selection of which table to select may be provided, for example, by subCarrierSpacingCommon. The selection may also be based on the synchronization raster position: if the terminal device detects a PSS on a synchronization raster point according to N=768, it determines the offset and corresponding table to be 0. Alternatively, if the terminal device detects a PSS on a synchronization raster point according to N=769, it determines the offset and corresponding table to be 4. The selection may also be provided via a reinterpreted / reserved field in the MIB.

[0067] FIG. 9 shows a flowchart according to an exemplary embodiment. In S1, a terminal device receives an SSB from a specific band. Next, in S2, the terminal device determines at least one modified CCE structure for at least one AL in CORESET#0. Next, in S3, the terminal device monitors the PDCCH from CORESET#0 according to the modified CCE structure. Finally, in S4, the terminal device receives SIB-1 according to the PDCCH received via the modified CCE structure. In some exemplary embodiments, the gNB may specify when to transmit the PDCCH for SIB-1. In other words, the terminal device may not always receive a Type-0 PDCCH and, as a result, may not always receive SIB-1 received via a non-existent PDSCH. It should also be noted that the modified CCE structure may be used to increase the number of PRBs or CCEs transmitted for the PDCCH within the total number of available PRBs, which may be less than 24 PRBs. Furthermore, it should be noted that the mechanism for receiving SIB1 is a mechanism for receiving a physical downlink shared channel (PDSCH), and the same mechanism can also be used to receive other system information (SIB-x) and paging. Thus, in general, a terminal device can receive a PDSCH in S4, which can be transmitted by an access node such as a gNB.

[0068] The exemplary embodiments described above have advantages such as requiring only minor changes in implementation, e.g., avoiding changes to the interleaving pattern and thus allowing fine-granularity bandwidth adjustment, such as up to 1 PRB or even less, thereby maximizing PDCCH performance. Furthermore, the exemplary embodiments described above can be performed without additional signaling overhead. The PDCCH monitoring load of the UE can remain unchanged, and the PDCCH hash function can also remain unchanged. The exemplary embodiments described above are straightforward from the gNB's perspective, since only puncturing and appropriate MIB indications are required. It should also be noted that in the context of this document, a table may be understood as a lookup table of values ​​from which the correct settings and / or values ​​can be determined. This table may be pre-determined, i.e., an existing table or any other suitable table. Furthermore, this table may be a table associated with a CORESET, such as an initial CORESET.

[0069] 10 illustrates an apparatus 1000, which may be an apparatus such as a terminal device or an apparatus included in a terminal device, according to an exemplary embodiment. The apparatus 1000 includes a processor 1010. The processor 1010 interprets computer program instructions and processes data. The processor 1010 may include one or more programmable processors. The processor 1010 may include programmable hardware with embedded firmware, or alternatively or additionally, may include one or more application-specific integrated circuits (ASICs).

[0070] The processor 1010 is coupled to the memory 1020. The processor is configured to read and write data from and to the memory 1020. The memory 1020 may comprise one or more memory units. The memory units may be volatile or nonvolatile. It should be noted that in some demonstrative embodiments, there may be one or more units of nonvolatile memory and one or more units of volatile memory, or one or more units of nonvolatile memory, or one or more units of volatile memory. The volatile memory may be, for example, RAM, DRAM, or SDRAM. The nonvolatile memory may be, for example, ROM, PROM, EEPROM, flash memory, optical storage, or magnetic storage. In general, memory may be referred to as a non-transitory computer-readable medium. The memory 1020 stores computer-readable instructions that are executed by the processor 1010. For example, the non-volatile memory stores the computer-readable instructions, and the processor 1010 executes the instructions using the volatile memory for temporary storage of data and / or instructions.

[0071] The computer-readable instructions may be pre-stored in memory 1020, or alternatively or additionally, may be received by the device via an electromagnetic carrier signal and / or copied from a physical entity such as a computer program product. Execution of the computer-readable instructions causes device 1000 to perform the functions described above.

[0072] In the context of this document, a "memory" or "computer-readable medium" may be any non-transitory medium or means that can contain, store, communicate, propagate, or transport instructions used by or in connection with an instruction execution system, apparatus, or device, e.g., a computer.

[0073] The device 1000 further comprises or is connected to an input unit 1030. The input unit 1030 comprises one or more interfaces for receiving user input. The one or more interfaces may comprise, for example, one or more motion and / or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons, and one or more touch detection units. Furthermore, the input unit 1030 may comprise an interface to which external devices may be connected.

[0074] The device 1000 also comprises an output unit 1040. The output unit comprises or is connected to one or more displays capable of rendering visual content, such as a light-emitting diode (LED) display, a liquid crystal display (LCD), and a liquid crystal on silicon (LCoS) display. The output unit 1040 further comprises one or more audio outputs. The one or more audio outputs may be, for example, a loudspeaker or a set of headphones.

[0075] The device 1000 may further comprise a connectivity unit 1050. The connectivity unit 1050 allows for wired and / or wireless connectivity to external networks. The connectivity unit 1050 may comprise one or more antennas and one or more receivers that may be integrated into the device 1000 or to which the device 1000 may be connected. The connectivity unit 1050 may comprise an integrated circuit or set of integrated circuits that provide wireless communication capabilities for the device 1000. Alternatively, the wireless connection may be a hardwired application specific integrated circuit (ASIC).

[0076] It should be noted that the apparatus 1000 may further comprise various components not shown in Figure 10. The various components may be hardware components and / or software components.

[0077] Although the present disclosure has been described above with reference to examples according to the accompanying drawings, it is clear that the present disclosure is not limited thereto and can be modified in several ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly and are intended to illustrate, not limit, the embodiments. It will be obvious to those skilled in the art that with the advancement of technology, the concept of the present invention can be realized in various ways. Furthermore, it will be obvious to those skilled in the art that the described embodiments can be combined with other embodiments in various ways, although not necessarily.

Claims

1. 1. An apparatus comprising at least one processor and at least one memory containing computer program code, the at least one memory and the computer program code configured to, using the at least one processor, cause the apparatus to: receiving an indication of a modification of at least one control channel element structure within an initial control resource set configured for the device; determining the at least one modified control channel element structure for at least one aggregation level within the initial control resource set; monitoring physical downlink control channels from the initial control resource set according to the modified control channel element structure; receiving a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure; The device is configured to cause the device to execute the following steps.

2. The apparatus of claim 1 , wherein the modified control channel element structure corresponds to a punctured physical downlink control channel for the at least one aggregation level.

3. The apparatus of claim 2 , wherein the punctured physical downlink control channel is obtained by puncturing from the last and / or first control channel element.

4. 10. An apparatus according to any one of the preceding claims, wherein the modified control channel element structure corresponds to a non-interleaved control channel element structure and / or a new aggregation level.

5. The apparatus according to any one of claims 2 to 4, wherein one or more control channel elements from the highest or lowest physical resource block are punctured with a granularity of one physical resource block.

6. 10. An apparatus according to any one of the preceding claims, wherein the modified control channel element structure is dependent on the channel bandwidth.

7. 10. The apparatus of claim 9, wherein one or more bits included in a physical broadcast channel are used to configure the physical downlink control channel, the configuration indicating the modified control channel element structure to be used.

8. 10. The apparatus of claim 1, wherein the configuration of the puncturing of the physical downlink control channel is based on a table associated with the initial control resource set.

9. 10. An apparatus according to any one of the preceding claims, wherein the apparatus is further adapted to monitor a particular frequency band and to receive a synchronization signal block from the particular frequency band for the physical downlink control channel.

10. 10. The apparatus of claim 1, wherein the apparatus is a terminal device, the terminal device detecting at least a Type 0 physical downlink control channel using the modified control channel element structure.

11. 1. An apparatus comprising at least one processor and at least one memory containing computer program code, the at least one memory and the computer program code configured to, using the at least one processor, cause the apparatus to: transmitting an indication of a modification of at least one control channel element structure for at least one aggregation level within an initial control resource set configured by the device; transmitting at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level within the initial control resource set; transmitting a physical downlink shared channel according to the transmitted at least one physical downlink control channel; The device is configured to cause the device to execute the following steps.

12. The apparatus of claim 11 , wherein the modified control channel element structure corresponds to a punctured physical downlink control channel for the at least one aggregation level.

13. The apparatus of claim 12 , wherein the punctured physical downlink control channel is obtained by puncturing from the last and / or first control channel element.

14. The apparatus according to any one of claims 11 to 13, wherein the modified control channel element structure corresponds to a non-interleaved control channel element structure and / or a new aggregation level.

15. The apparatus according to any one of claims 12 to 14, wherein one or more control channel elements from the highest or lowest physical resource block are punctured with a granularity of one physical resource block.

16. The apparatus of any one of claims 11 to 15, wherein the modified control channel element structure is dependent on the channel bandwidth.

17. 17. The apparatus of claim 11, wherein one or more bits included in a physical broadcast channel are used to configure the physical downlink control channel, the configuration indicating the modified control channel element structure to be used.

18. The apparatus according to any one of claims 11 to 17, wherein the configuration of the puncturing of the physical downlink control channel is based on a table associated with the initial control resource set.

19. 1. A method comprising: receiving an indication of a modification of at least one control channel element structure within an initial control resource set configured for the device; determining at least one modified control channel element structure for at least one aggregation level within the initial control resource set; and monitoring physical downlink control channels from the initial control resource set according to the modified control channel element structure; receiving a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure; The method comprising:

20. 1. A method comprising: transmitting an indication of a modification of at least one control channel element structure for at least one aggregation level within an initial control resource set configured by the device; transmitting at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level within the initial control resource set; transmitting a physical downlink shared channel according to the at least one physical downlink control channel transmitted via the modified control channel element structure; The method comprising:

21. A non-transitory computer-readable medium containing program instructions, the program instructions causing an apparatus to at least: receiving an indication of a modification of at least one control channel element structure within an initial control resource set configured for the device; determining at least one modified control channel element structure for at least one aggregation level within the initial control resource set; and monitoring physical downlink control channels from the initial control resource set according to the modified control channel element structure; receiving a physical downlink shared channel according to the physical downlink control channel received via the modified control channel element structure; The non-transitory computer-readable medium is adapted to execute the above.

22. A non-transitory computer-readable medium containing program instructions, the program instructions causing an apparatus to at least: transmitting an indication of a modification of at least one control channel element structure for at least one aggregation level within an initial control resource set configured by the device; transmitting at least one physical downlink control channel having the at least one modified control channel element structure for the at least one aggregation level within the initial control resource set; transmitting a physical downlink shared channel according to the at least one physical downlink control channel transmitted via the modified control channel element structure; The non-transitory computer-readable medium is adapted to execute the above.

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