User equipment, network entity, wireless communication system and method using enhanced NR sidelink control message design

Abstract

A user equipment (UE) for a wireless communication system is connected to one or more other UEs in the wireless communication system to perform sidelink communication with the one or more other UEs. The sidelink communication includes one or more sidelink control messages, such as sidelink control information (SCI), to be sent on sidelink resources. The UE identifies the sidelink control message for the UE and decodes the sidelink control message for the UE to obtain control information embedded in the sidelink control message. The UE is preconfigured or configured by the network or base station using a sidelink SL search space in the sidelink resources, such as an SL control resource set or an SL control channel opportunity. The sidelink search space includes one or more search opportunities, at which the UE will perform blind decoding on the sidelink resources.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication systems or networks, and more particularly, to direct communication between network entities such as user equipment (UE) in such wireless communication systems or networks using sidelink communication. Embodiments of the present invention relate to improvements / enhancements to two-level SCI and sidelink control information. Background Art

[0002] FIG1 is a schematic diagram of an example of a terrestrial wireless network 100. As shown in FIG1(a), the wireless network includes a core network 102 and one or more radio access networks RAN1, RAN2, ...RAN N Figure 1(b) shows the radio access network RAN n , the wireless access network may include one or more base stations gNB1 to gNB5, each base station serving a specific area around the base station schematically represented by the corresponding cells 1061 to 1065. The base station is provided to serve users within the cell. The term base station BS refers to a gNB in ​​a 5G network, an eNB in ​​UMTS / LTE / LTE-A / LTE-A Pro or simply a BS in other mobile communication standards. Users can be fixed devices or mobile devices. Mobile or fixed IoT devices connected to the base station or to the user can also access the wireless communication system. Mobile devices or IoT devices may include physical devices, ground vehicles (such as robots or cars), aircraft (such as manned or unmanned aerial vehicles UAV, the latter also known as drones), buildings and other items or devices with embedded electronics, software, sensors, actuators, etc., as well as network connections that enable these devices to collect and exchange data through existing network infrastructure. Figure 1(b) shows an exemplary view of five cells, however, the RAN n More or fewer such cells may be included, and the RAN nAlternatively, only one base station may be included. Figure 1(b) shows two users, UE1 and UE2, also referred to as user equipment (UE), in cell 1062 and served by base station gNB2. Another user, UE3, is shown in cell 1064 served by base station gNB4. Arrows 1081, 1082, and 1083 schematically represent uplink / downlink connections for transmitting data from users UE1, UE2, and UE3 to base stations gNB2 and gNB4, or for transmitting data from base stations gNB2 and gNB4 to users UE1, UE2, and UE3. Furthermore, Figure 1(b) shows two IoT devices 1101 and 1102 in cell 1064, which may be fixed or mobile devices. As schematically indicated by arrow 1121, IoT device 1101 accesses the wireless communication system via base station gNB4 to receive and transmit data. As schematically indicated by arrow 1122, IoT device 1102 accesses the wireless communication system via user UE3. The respective base stations gNB1 to gNB5 may be connected to the core network 102, for example, via an S1 interface, via respective backhaul links 1141 to 1145, which are schematically represented in FIG1(b) by arrows pointing to "core." The core network 102 may be connected to one or more external networks. In addition, some or all of the respective base stations gNB1 to gNB5 may be connected to each other via respective backhaul links 1161 to 1165, for example, via an S1 or X2 interface, or an XN interface in NR, which are schematically represented in FIG1(b) by arrows pointing to "gNBs."

[0003] For data transmission, a physical resource grid can be used. The physical resource grid may include a set of resource elements to which various physical channels and physical signals are mapped. For example, physical channels may include a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and a physical sidelink shared channel (PSSCH) that carry user-specific data (also known as downlink and uplink payload data), a physical broadcast channel (PBCH) that carries, for example, a master information block (MIB) and a system information block (SIB), and a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), and a physical sidelink control channel (PSSCH) that carry, for example, downlink control information (DCI), uplink control information (UCI), and sidelink control information (SCI). For the uplink, physical channels may also include a physical random access channel (PRACH or RACH), which is used by the UE to access the network once it is synchronized and obtains the MIB and SIB. Physical signals may include reference signals or symbols (RS), synchronization signals, etc. The resource grid may include frames or radio frames having a certain duration in the time domain and a given bandwidth in the frequency domain. A frame may have a certain number of subframes of a predetermined length, for example, 1 ms. Each subframe may include one or more time slots of 12 or 14 OFDM symbols, depending on the cyclic prefix (CP) length. A frame may also consist of a smaller number of OFDM symbols, for example when utilizing a shortened transmit time interval (sTTI) or a mini-slot / non-slot-based frame structure that includes only a few OFDM symbols.

[0004] The wireless communication system may be any single-tone or multi-carrier system using frequency division multiplexing, such as an orthogonal frequency division multiplexing (OFDM) system, an orthogonal frequency division multiple access (OFDMA) system, or any other IFFT-based signal with or without CP, such as DFT-s-OFDM. Other waveforms may be used, such as non-orthogonal waveforms for multiple access, such as filter bank multi-carrier (FBMC), generalized frequency division multiplexing (GFDM), or universal filtered multi-carrier (UFMC). The wireless communication system may operate, for example, according to the LTE-Advanced pro standard or the 5G or NR (New Radio) standard.

[0005] The wireless network or communication system depicted in Figure 1 can be a heterogeneous network with different coverage networks, such as a network of macro cells, each macro cell including macro base stations, such as base stations gNB1 to gNB5, and for example a network of small cell base stations (not shown in Figure 1), such as femto or pico base stations.

[0006] In addition to the above-mentioned terrestrial wireless networks, there are also non-terrestrial wireless communication networks, including spaceborne transceivers (such as satellites) and / or airborne transceivers (such as unmanned aircraft systems). Non-terrestrial wireless communication networks or systems can operate in a similar manner to the terrestrial systems described above with reference to FIG1, for example according to the LTE-Advanced Pro standard or the 5G or NR (New Radio) standard.

[0007] In a mobile communication network, for example, in a network as described above with reference to FIG1 , such as an LTE or 5G / NR network, there may be UEs that communicate directly with each other via one or more sidelink SL channels, for example using a PC5 interface. UEs that communicate directly with each other via sidelinks may include vehicles that communicate directly with other vehicles (V2V communication), vehicles that communicate with other entities of a wireless communication network (e.g., roadside entities such as traffic lights, traffic signs, or pedestrians) (V2X communication). Other UEs may not be vehicle-related UEs and may include any of the devices mentioned above. Such devices may also communicate directly with each other (D2D communication) using SL channels.

[0008] When considering two UEs communicating directly with each other via a sidelink, both UEs can be served by the same base station, so that the base station can provide sidelink resource allocation configuration or assistance to the UEs. For example, both UEs can be within the coverage area of ​​a base station, such as one of the base stations depicted in Figure 1. This is called an "in-coverage" scenario. The other scenario is called an "out-of-coverage" scenario. It should be noted that "out-of-coverage" does not mean that the two UEs are not within one of the cells depicted in Figure 1, but rather that these UEs:

[0009] - may not be connected to the base station, e.g. they are not in RRC connected state, so that the UE does not receive any sidelink resource allocation configuration or assistance from the base station, and / or

[0010] - may be connected to a base station, but for one or more reasons, the base station may not provide sidelink resource allocation configuration or assistance to the UE, and / or

[0011] -May connect to base stations that may not support NR V2X services, such as GSM, UMTS, LTE base stations.

[0012] When considering two UEs communicating directly with each other via a sidelink, for example using a PC5 interface, one of the UEs may also be connected to a BS and information may be relayed from the BS to the other UE via the sidelink interface. Relaying can be performed in the same frequency band (in-band relaying) or using another frequency band (out-of-band relaying). In the first case, the communications on the Uu and sidelink may be decoupled using different time slots, as in a time division duplex (TDD) system.

[0013] Figure 2 Figure 1 illustrates an in-coverage scenario in which two UEs are directly communicating with each other, both connected to a base station. The base station gNB has a coverage area schematically represented by circle 200, which generally corresponds to the cell schematically represented in Figure 1. The UEs directly communicating with each other include a first vehicle 202 and a second vehicle 204, both within the coverage area 200 of the base station gNB. Both first and second vehicles 202 and 204 are directly connected to the base station gNB and, in addition, to each other via a PC5 interface. The gNB assists with scheduling and / or interference management of V2V traffic via control signaling over the Uu interface, which is the radio interface between the base station and the UEs. In other words, the gNB provides SL resource allocation configuration or assistance to the UEs, and the gNB allocates resources to be used for V2V communication via the sidelink. This configuration is also known as Mode 1 configuration in NR V2X or Mode 3 configuration in LTE V2X.

[0014] Figure 3 is a schematic diagram of an out-of-coverage scenario, in which the UEs communicating directly with each other are either not connected to the base station, although they may be physically within a cell of the wireless communication network, or some or all of the UEs communicating directly with each other are connected to the base station, but the base station does not provide SL resource allocation configuration or assistance. Three vehicles 206, 208 and 210 are shown, which communicate directly with each other via a side link, for example using a PC5 interface. Scheduling and / or interference management of V2V services are based on algorithms implemented between vehicles. This configuration is also called a Mode 2 configuration in NR V2X, or a Mode 4 configuration in LTE V2X. As mentioned above, Figure 3 The scenario in is an out-of-coverage scenario, which does not mean that the corresponding Mode 2 UE (in NR) or Mode 4 UE (in LTE) is outside the coverage 200 of the base station. Instead, it means that the corresponding Mode 2 UE (in NR) or Mode 4 UE (in LTE) is not served by the base station or is not connected to the base station in the coverage area, or is connected to the base station but does not receive SL resource allocation configuration or assistance from the base station. Therefore, there may be some scenarios in which, in Figure 2 In the coverage area 200 shown in FIG, in addition to the NR Mode 1 or LTE Mode 3 first vehicle 202 and the second vehicle 204, there are also NR Mode 2 or LTE Mode 4 vehicles 206, 208, and 210.

[0015] In the above-mentioned scenario of vehicle user equipment UE, a plurality of such user equipment may form a user equipment group, also referred to as a group for short, and communication within the group or between group members may be performed via a side link interface (such as a PC5 interface) between the user equipment. For example, the above-mentioned scenario using vehicle user equipment may be adopted in the field of the transportation industry, where a plurality of vehicles equipped with vehicle user equipment may be grouped together, for example, by a remote driving application. Other use cases in which a plurality of user equipment may be grouped together for side link communication with each other include, for example, factory automation and power distribution. In the case of factory automation, a plurality of mobile or fixed machines within a factory may be equipped with user equipment and grouped together for side link communication, for example for controlling the operation of the machines, such as motion control of a robot. In the case of power distribution, entities within a distribution network may be equipped with corresponding user equipment, which may be grouped together within a certain area of ​​the system to communicate with each other via side link communication, thereby allowing monitoring of the system and allowing handling of distribution network faults and interruptions.

[0016] Naturally, in the use cases mentioned above, sidelink communication is not limited to communication within a group. Instead, sidelink communication can be performed between any UEs, such as any pair of UEs.

[0017] It should be noted that the information in the previous section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

[0018] Based on the prior art as described above, there may be a need to improve or enhance SCI designs (both single-stage SCI and two-stage SCI designs) for sidelink communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Embodiments of the present invention will now be described in further detail with reference to the following drawings:

[0020] FIG1 shows a schematic diagram of an example of a wireless communication system;

[0021] Figure 2 is a schematic diagram of an in-coverage scenario in which UEs communicating directly with each other are connected to a base station;

[0022] Figure 3 is a schematic diagram of an out-of-coverage scenario, in which UEs communicating directly with each other do not receive SL resource allocation configuration or assistance from the base station;

[0023] Figure 4 shows a flow chart of the first-level SCI blind decoding process;

[0024] Figure 5is a schematic diagram of a wireless communication system, the wireless communication system including a transmitter (such as a base station) and one or more receivers (such as user equipment UE);

[0025] Figure 6 An embodiment of a SL search space information element is shown, which may be used to configure a sidelink UE with a common search space and may be signaled in a SIB;

[0026] Figure 7 An embodiment of a UE-specific search space information element with a search space type of ue-specific is shown;

[0027] Figure 8 An embodiment of the first aspect of the invention is shown which uses a common SL search space or a common set of SL control resources in a common bandwidth portion or resource pool accessible to some or all of the sidelink UEs;

[0028] Figure 9 An embodiment of switching from a common search pool to a UE-specific search pool is shown;

[0029] Figure 10 An embodiment of a first short SCI first level format is shown wherein the timing and frequency of data and control are not identified in the first level;

[0030] Figure 11 An embodiment of a second short SCI first level format is shown, wherein the time and periodicity P for the second level and control can be identified within the first level;

[0031] Figure 12 An embodiment of a first long SCI first level format is shown, wherein the time, frequency and periodicity P for the second level are identified in the first level SCI;

[0032] Figure 13 An embodiment of the long format described above is shown, which has cross-carrier / BWP / resource pool scheduling or second-level SCI and data included in the first-level SCI;

[0033] Figure 14 An embodiment of the second aspect involving periodic reservation and release using a periodic field provided in a first level SCI is shown;

[0034] Figure 15 An embodiment for the PSCCH-config-common information element is shown;

[0035] Figure 16 An embodiment of a PSCCH-config-UE specific information element is shown;

[0036] Figure 17 shows a DMRS pattern for a level 1 SCI type identifying broadcast communications;

[0037] Figure 18 shows a DMRS pattern for a level 1 SCI type identifying unicast communications;

[0038] Figure 19 shows a DMRS pattern for a level 1 SCI type identifying groupcast or multicast communications;

[0039] Figure 20 An embodiment using DMRS shifting in frequency and / or time for different propagation types is shown; and

[0040] Figure 21 An example of a computer system is shown on which the units or modules and steps of the method described according to the present invention can be executed. DETAILED DESCRIPTION

[0041] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings, in which the same or similar elements are designated with the same reference numerals.

[0042] In the above-mentioned wireless communication system or network, sidelink communication can be performed between corresponding network entities, and this sidelink communication includes the transmission of control information using corresponding sidelink control messages (also referred to as sidelink control information SCI). The SCI in LTE contains information about the time-frequency resources to be used for data transmission (also referred to as PSSCH transmission). For example, a resource block or resource pool is specified, that is, a set of resources on which the PSSCH is transmitted. In LTE, the SCI is transmitted in the PSCCH, for example, with each PSSCH. For direct communication between user equipments, such as V2X communication, in LTE, decoding and blind decoding can be direct because the PSCCH is transmitted on certain known resource blocks, which can be configured or pre-configured. According to reference [1], in addition to the time-frequency resources mentioned above, the LTE SCI may include one or more of the following information:

[0043] - a time repetition pattern index TRPI, which indicates the subframe set used for PSSCH transmission,

[0044] -Frequency Hopping Flag,

[0045] - Resource block and frequency hopping resource allocation to indicate the resource blocks indicated by the TRPI within the subframe to be used for PSSCH transmission,

[0046] - Resource allocation fields,

[0047] - an indication of the MCS used for PSSCH, e.g. 5 bits,

[0048] - Group destination ID, e.g. 8 bits, which indicates the UE group to which the SL communication is intended,

[0049] - Timing advance indicator, for example, an 11-bit indicator.

[0050] Therefore, similar to the downlink control information DCI or uplink control information UCI used for communication from a mobile user to a base station using the Uu interface, the SCI provides the necessary control information for the sidelink SL transmission. As mentioned above, the SCI is carried by the PSCCH and enables the receiving sidelink UE to correctly detect and decode the data transmission on the PSSCH and to extract data from the SL-SCH, i.e., from the transport channel (also known as the SL shared channel).

[0051] Like in LTE, direct communication between user equipments, such as V2X communication, is also enabled in NR, so that NR also provides SCI on the physical layer, and in addition, in addition to broadcast communication, which is the only SL communication allowed in LTE, NR also supports unicast and multicast communication on sidelink communication.

[0052] Traditionally, a single-stage SCI design is adopted in LTE. However, the SCI can be divided into several parts, for example, into a first part and into a second part, and this divided SCI is also called a two-stage SCI. The first part of the first stage of the SCI can be decoded by, for example, all sidelink UEs, and the second part or second stage can be decoded by the sidelink UEs intended for the current communication or transmission or addressed by the current SL communication. Two-stage SCI may have advantages over single-stage SCI. For example, in the case where the same SCI size is shared between broadcast, unicast, and multicast or groupcast communications, even though this may reduce the complexity of the decoding process (such as blind decoding), efficiency may be reduced, especially for broadcast communications, because some padding information must be added. Two-stage SCI may be advantageous because the first part or first stage can be used to provide some or more basic information for the sidelink communication, and the second stage or second part of the SCI includes detailed information for decoding data channels, such as the PSSCH that is decoded when the SCI is actually intended for the UE that recognizes the first part of the SCI. Therefore, the SCI size may be different for different broadcast communications, which may result in an increase in the decoding process time when decoding the first part or first level of the SCI.

[0053] To address this issue, a two-step decoding algorithm for the first part or level of the SCI is used. Figure 4A flow chart of a first level SCI blind decoding process is shown. Initially, at S1, a UE that will participate in the sidelink communication may receive specific configuration parameters for the sidelink communication. The UE, which may be referred to as a receiving UE in the context of SL communication, starts blind decoding as indicated at S2 on the first part of the SCI. As indicated at S3, once the pattern has been identified, i.e., once the first part of the SCI or the SCI has been identified as intended for the receiving UE, the receiving UE (as indicated at S4) performs a decoding process for decoding the information from the first level or first part of the SCI. In other words, in order to address the time complexity associated with blind decoding, the above-mentioned two-step decoding algorithm may be employed, in which initially, the first part of the SCI (e.g., the format type) may be, for example, based on different DMRS patterns (see Figure 4 Then, in the second stage (see above Figure 4 In S4), normal decoding can be applied to derive the information embedded in the first part of the SCI that has been identified in the first step.

[0054] A specific parameter may be used to indicate to the receiving UE that the SCI is a two-level SCI, such as the parameter cdm-type, which may be configured using an RRC configuration or reconfiguration message when the receiving UE is in connected mode, or by a system information block SIB when the receiving UE is in idle mode.

[0055] The present invention provides methods for improving SCI designs (both single-stage SCI and two-stage SCI designs) to provide, for example, improvements, eg in terms of flexibility, complexity, forward compatibility, overhead, latency, robustness, reliability.

[0056] The embodiment of the present invention can be shown in FIG. Figure 2 and Figure 3 The depicted embodiment is implemented in a wireless communication system including a base station and a user (such as a mobile terminal or an IoT device). Figure 5 Schematic diagram of a wireless communication system, which includes a transmitter 300 (such as a base station) and one or more receivers 3021 to 302 n (eg, user equipment UE). The transmitter 300 and the receiver 302 may communicate via one or more wireless communication links or channels 304a, 304b, 304c (eg, radio links). The transmitter 300 may include one or more antennas ANT T or an antenna array having a plurality of antenna elements, a signal processor 300a and a transceiver 300b, which are coupled to each other. The receiver 302 includes one or more antennas ANT R or an antenna array having multiple antennas, a signal processor 302a1, 302a nand transceivers 302b1, 302b n , which are coupled to each other. Transmitter 300 and one or more receivers 3021 to 302 n Communication can be performed via corresponding first wireless communication links 304a and 304b (e.g., radio links using a Uu interface), while UE 302 can communicate with each other via a second wireless communication link 304c (e.g., a radio link using a PC5 interface). When the UEs are not served by the base station, are not connected to the base station, for example, they are not in an RRC connected state, or more generally, when the base station does not provide SL resource allocation configuration or assistance, the UEs can communicate with each other via the side link. The system, one or more UEs, and the base station can operate according to the teachings of the present invention described herein.

[0057] User equipment / network entity

[0058] The present invention provides a user equipment UE for a wireless communication system, wherein:

[0059] The UE is to be connected to one or more other UEs in the wireless communication system to perform sidelink communications with the one or more other UEs, wherein the sidelink communications include one or more sidelink control messages, such as sidelink control information (SCI), to be sent on sidelink resources.

[0060] The UE will identify the sidelink control message for the UE by blind decoding,

[0061] The UE is to decode the sidelink control message for the UE to obtain control information embedded in the sidelink control message, and

[0062] The network or base station pre-configures or configures the UE using the side link SL search space in the side link resource, such as the SL control resource set or the SL control channel opportunity, and the side link search space includes one or more search opportunities. At the one or more search opportunities, the UE will perform the blind decoding on the side link resource.

[0063] According to an embodiment, the SL search space includes one or more of a UE-common SL search space and a UE-specific SL search space.

[0064] According to an embodiment, the UE will receive:

[0065] - A broadcast message or a common search space message, such as a system information block (SIB) or a group common control channel, that configures the UE-common SL search space for all UEs or UE groups, or

[0066] - a dedicated message, such as a Radio Resource Control (RRC) message, to configure the UE-specific SL search space for the UE, or

[0067] - A pre-configuration message for configuring the UE to share a common SL search space.

[0068] According to an embodiment, the UE common SL search space identifies one or more of the following:

[0069] - shared SL frequency resources, such as selected subchannels or PRBs, selected resource pools or shared BWPs,

[0070] - A shared band or shared resource to be used for broadcast, unicast or multicast.

[0071] According to an embodiment, the UE common SL search space identifies one or more of the following:

[0072] - a common SL time resource opportunity within a timeslot for timeslot transmission, e.g. at the beginning of said timeslot,

[0073] - a common SL time resource opportunity within a slot for subslot transmission, e.g. at the beginning of each subslot,

[0074] - shared SL time resource opportunity periodicity and / or bitmap slot positions,

[0075] - Common time domain opportunities to be used for broadcast, unicast or multicast.

[0076] According to an embodiment, the UE-specific SL search space identifies one or more of the following:

[0077] - Specific SL frequency resources, such as selected subchannels or PRBs, selected resource pools or shared BWPs,

[0078] - A specific band or specific resource to be used for broadcast, unicast or multicast.

[0079] According to an embodiment, the UE-specific SL search space identifies one or more of the following:

[0080] - a specific SL time resource opportunity within a timeslot for timeslot transmission, e.g. at the beginning of said timeslot,

[0081] - a specific SL time resource opportunity within a time slot for sub-slot transmission, e.g. at the beginning of each sub-slot,

[0082] - specific SL time resource opportunity periodicity and / or bitmap slot positions,

[0083] - A specific time domain opportunity to be used for broadcast, unicast or multicast.

[0084] According to an embodiment, the UE-specific SL search space identifies the search space signaled by the transmitting UE to be used by the receiving UE or receiving UE group, for example using a physical L1 SL control channel, or an intra-data control channel, or an SL-RRC control message.

[0085] According to an embodiment, the SL search space defines the number of symbols in time, such as NsymbSL control resource set, and the number of resource blocks RB, such as NRBSL control resource set, and the position of the resource blocks within the side link resources such as resource pool or SL bandwidth part SL-BWP.

[0086] According to an embodiment, the sidelink control message includes at least a first part, such as a first level, and a second part, such as a second level, and wherein the sidelink search space includes one or more search opportunities, at which the UE will perform the blind decoding to identify the first part of the sidelink control message.

[0087] The present invention provides a network entity for a wireless communication system, the wireless communication comprising one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, the sidelink communication comprising one or more sidelink control messages, such as sidelink control information SCI, to be sent on a sidelink resource, wherein

[0088] The network entity will signal the UE-specific SL search space in the side link resources, such as the SL control resource set, to the receiving UE or the receiving UE group, so as to indicate one or more search opportunities to the receiving UE, at which the receiving UE will perform blind decoding on the side link resources to identify the side link control message for the receiving UE, such as the side link control information SCI.

[0089] According to an embodiment, the network entity is a transmitting user equipment UE, and wherein once the SL communication with the receiving UE using the UE-specific SL search space is completed or interrupted, the transmitting UE will adopt the UE-common SL search space.

[0090] The present invention provides a user equipment UE for a wireless communication system, wherein:

[0091] The UE is to be connected to one or more other UEs in the wireless communication system to perform sidelink communications with the one or more other UEs, wherein the sidelink communications include one or more sidelink control messages, such as sidelink control information (SCI), to be sent on sidelink resources.

[0092] The UE will identify the sidelink control message intended for the UE,

[0093] The UE is to decode the sidelink control message for the UE to obtain control information embedded in the sidelink control message, and

[0094] The information embedded in the sidelink control message indicates the configuration of further messages, the further messages comprising further control information and / or data.

[0095] According to an embodiment, said information embedded in said sidelink control message indicates time and frequency resources to be used for said further message.

[0096] According to an embodiment, the time and frequency resources used for the sidelink control message and the time and frequency resources used for the further message are one or more of:

[0097] - adjacent in the time domain,

[0098] - non-adjacent in the time domain, with or without a time gap between said time and frequency resources used for said sidelink control message and said time and frequency resources used for said further message,

[0099] - adjacent in the frequency domain, such as equal frequency resources or equal subchannel lengths,

[0100] - non-adjacent in the frequency domain, such as different frequency resources or different subchannel lengths,

[0101] - in the same resource pool, or

[0102] -In different resource pools.

[0103] According to an embodiment, the information embedded in the sidelink control message indicates one or more of the following:

[0104] - the number of symbols in the time domain, such as 1, 2 or 3 symbols in the time domain, or more than 3 symbols in the time domain,

[0105] - Whether the transmission is unicast, multicast or broadcast,

[0106] - indicating a time offset of the further message relative to the sidelink control message, e.g. in case the sidelink control message spans all frequencies of the further message, wherein the time offset may be precoded in a lookup table LUT,

[0107] - a pointer to the physical channel associated with said sidelink control message, such as the PSCCH and / or shared channel PSSCH channel of said further message or the PSFCH channel of said further message.

[0108] According to an embodiment, said information embedded in said sidelink control message is indicative of a periodicity of the sending of said sidelink message and / or said further message.

[0109] According to an embodiment, a predefined value for the periodicity may be provided to signal a single transmission of the sidelink control message and / or the further message without any periodicity, or a release of a previous periodicity.

[0110] According to an embodiment, the information embedded in the first part of the sidelink control message indicates one or more of the following:

[0111] - a priority level of transmission associated with said sidelink control message,

[0112] a new data indicator NDI or a retransmission indicator, which indicates whether the transmission associated with the sidelink control message comprises new data and is a retransmission,

[0113] - retransmission gap, which indicates whether the retransmission is a non-autonomous retransmission, or whether autonomous retransmission is active with a configured retransmission gap,

[0114] - a DMRS pattern for the second part of the sidelink control message,

[0115] - CDM groups and / or ports for the second part of the sidelink control message and a sidelink data channel such as PSSCH,

[0116] -Timing advance indicator.

[0117] According to an embodiment, the sidelink control message comprises a first part of the control information, e.g. a first level SCI, and the further message comprises at least a second part of the control information, e.g. a second level SCI, and / or one or more transmission reservations for the data.

[0118] The present invention provides a network entity for a wireless communication system, the wireless communication comprising one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, the sidelink communication comprising one or more sidelink control messages, such as sidelink control information SCI, to be sent on a sidelink resource, wherein

[0119] The network entity is to signal a sidelink control message to a receiving UE or group of receiving UEs, wherein information embedded in the sidelink control message indicates a configuration of further messages comprising further control information and / or data.

[0120] The present invention provides a user equipment UE for a wireless communication system, wherein

[0121] The UE is to be connected to one or more other UEs in a wireless communication system to perform sidelink communication with the one or more other UEs, wherein the sidelink communication includes one or more sidelink control messages, such as sidelink control information SCI, to be sent on a sidelink resource, the sidelink control message including at least a first part, such as a first level, and a second part, such as a second level.

[0122] The UE will identify the first part of the sidelink control message for the UE by blind decoding,

[0123] The UE is to decode the first portion of the sidelink control message for the UE to obtain control information embedded in the sidelink control message, and

[0124] The UE will identify from the first part of the sidelink control message, for example, a reference signal accompanying the first part of the sidelink control message, for example, a specific demodulation reference signal DMRS pattern.

[0125] The present invention provides a network entity for a wireless communication system, the wireless communication comprising one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, the sidelink communication comprising one or more sidelink control messages to be sent on a sidelink resource, such as sidelink control information SCI, the sidelink control message comprising at least a first part, such as a first level, and a second part, such as a second level, wherein

[0126] The network entity will signal a reference signal, such as a specific demodulation reference signal (DMRS), to a receiving UE or a group of receiving UEs in or together with the first part of the sidelink control message.

[0127] According to an embodiment, the reference signal has a pattern associated with a specific propagation type of the second part of the sidelink control message.

[0128] According to an embodiment, the reference signal has a pattern associated with a specific use case of the second part of the sidelink control message with a specific QoS.

[0129] According to an embodiment, the reference signal is selected from a plurality of reference signals having patterns that are different from each other in one or more of the following aspects:

[0130] - frequency domain,

[0131] - time domain,

[0132] - code domain, such as different orthogonal or quasi-orthogonal coding schemes or code division multiplexing (CDM),

[0133] - Spatial domains, such as different port IDs.

[0134] Each reference signal in the plurality of reference signals is associated with a particular propagation type.

[0135] According to an embodiment, some or all of the plurality of reference signals have unique designs, such as orthogonal or quasi-orthogonal DMRS patterns, to protect the UE from collisions.

[0136] According to an embodiment, the reference signal is a DMRS with a DMRS type 1 configuration.

[0137] According to an embodiment, the first part of the sidelink control message is accompanied by multiple reference signals, such as a specific DMRS pattern.

[0138] According to an embodiment, the same or different reference signals are repeated in the time domain in order to:

[0139] - repeated in every symbol of said first part of said sidelink control message, or

[0140] - repeated in some of said symbols of said first part of said sidelink control message according to a specific pattern.

[0141] According to an embodiment, the repetition rate of the reference signal depends on the speed at which the UE moves, for example, when the UE moves at a first speed, the repetition rate may be higher, and when the UE moves at a second speed, the repetition rate may be lower, the first speed being higher than the second speed.

[0142] The present invention provides a user equipment UE for a wireless communication system, wherein

[0143] The UE is to be connected to one or more other UEs in a wireless communication system to perform sidelink communication with the one or more other UEs, wherein the sidelink communication includes one or more sidelink control messages, such as sidelink control information SCI, to be sent on a sidelink resource, the sidelink control message including at least a first part, such as a first level, and a second part, such as a second level.

[0144] The UE will identify a first portion of a sidelink control message intended for the UE,

[0145] The UE will determine from the first portion of the sidelink control message whether the sidelink control message is intended for the UE.

[0146] According to an embodiment, the UE will not expect, e.g., will not read or will not decode, the second part of the sidelink control message if the first part of the sidelink control message includes:

[0147] a UE ID or a group ID, which may be, for example, one of a UE destination ID, indicating, for example, a unicast communication, or a group ID, which may be, for example, a group destination ID, indicating, for example, a unicast communication, wherein the UE ID or the group ID does not match the ID of the UE,

[0148] - A broadcast ID indicating a non-broadcast type of communication, such as a broadcast flag or a broadcast bit, and including a UE ID or a group ID that does not match the ID of the UE.

[0149] According to an embodiment, the first part of the sidelink control message comprises a broadcast ID and a UE ID or a group ID,

[0150] In a case where the broadcast ID indicates a broadcast type of communication, e.g., a broadcast flag is set to a first value, the UE determines that the second part of the sidelink control message is relevant to the UE and is to expect, e.g., to read or to decode, the second part of the sidelink control message,

[0151] In the case where the broadcast ID indicates a non-broadcast type of communication, for example the broadcast flag is set to a second value, for example when the UE ID or group ID matches the ID of the UE, the UE will determine from the UE ID or group ID whether the second part is related to the UE and will expect, for example will read or will decode, the relevant second part of the sidelink control message.

[0152] According to an embodiment, the UE will expect, e.g., will read or will decode, the second part of the sidelink control message if the first part of the sidelink control message includes:

[0153] - a UE ID or group ID that matches the UE's ID, or

[0154] - A broadcast ID indicating a broadcast type of communication, or not including an ID of any type.

[0155] According to an embodiment, in the case where the sidelink control message can be scrambled using UE ID or group ID or broadcast ID, for example, using CRC scrambling,

[0156] The UE will not expect, e.g., will not read or will not decode, the second part of the sidelink control message if descrambling results in one or more of the following:

[0157] - the broadcast ID indicates a non-broadcast type of communication and the UE ID or group ID does not match the ID of the UE in question, or

[0158] - the UE ID or group ID does not match the ID of the UE, and

[0159] The UE will expect, e.g., will read or will decode, the second part of the sidelink control message if the descrambling produces:

[0160] - a UE ID or group ID that matches the UE's ID, or

[0161] - a broadcast ID indicating a broadcast type of communication, or

[0162] -No ID.

[0163] According to an embodiment, the UE shall implicitly derive the propagation type from the UE ID or group ID or broadcast ID or absence of any ID in the first part of the sidelink control message as follows:

[0164] - in case no ID is present in said first part of said sidelink control message or the broadcast ID is set to broadcast, deriving the propagation type as broadcast,

[0165] - in the case where a groupcast ID or multiple UE IDs are present in the first part of the sidelink control message, deriving the propagation type as multicast,

[0166] - In case a unicast ID is present in said first part of said sidelink control message, deriving the propagation type as unicast.

[0167] According to an embodiment, in case the first part of the sidelink control message includes a broadcast ID indicating a broadcast type of communication, for example in case of a single-stage broadcast, the UE will not expect, for example will not read or will not decode, the second part of the sidelink control message.

[0168] According to an embodiment, the UE will determine whether the sidelink control message is intended for the UE from a source ID in the first part of the sidelink control message, the source ID being the source ID of the originator of the unicast communication or the originator of the multicast communication.

[0169] The present invention provides a network entity for a wireless communication system, the wireless communication comprising one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, the sidelink communication comprising one or more sidelink control messages to be sent on a sidelink resource, such as sidelink control information SCI, the sidelink control message comprising at least a first part, such as a first level, and a second part, such as a second level, wherein

[0170] The network entity is to indicate in the first part of the sidelink control message whether the sidelink control message is intended for a receiving UE.

[0171] According to an embodiment, the UE will derive from information in the first part of the sidelink control message whether the sidelink control message is intended for the UE.

[0172] According to an embodiment, a user equipment or a network comprises:

[0173] One or more of the following: a mobile terminal, or a fixed terminal, or a cellular IoT UE, or a vehicle UE, or an IoT or narrowband IoT NB-IoT device, or a ground vehicle, or an aircraft, or a drone, or a mobile base station, or a roadside unit, or a building, or any other item or device provided with network connectivity that enables the item / device to communicate using the wireless communication network, such as a sensor or actuator, or

[0174] Base station, including one or more of the following: a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or a roadside unit, or a UE, or a remote radio head, or an AMF, or an SMF, or a core network entity, or a network strip such as in the context of NR or 5G core, or any transmission / reception point TRP that enables an item or device to communicate using the wireless communication network, and the item or device is provided with network connectivity for communicating using the wireless communication network.

[0175] system

[0176] The present invention provides a wireless communication system, including: an invented user equipment or an invented network entity.

[0177] According to an embodiment, the wireless communication system includes one or more base stations, wherein the base station includes one or more of the following: a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or a roadside unit, or a UE, or a remote radio head, or an AMF, or an SMF, or a core network entity, or a network strip such as in the context of NR or 5G core, or any sending / receiving point TRP that enables an item or device to communicate using the wireless communication network, and the item or device is provided with network connectivity for communicating using the wireless communication network.

[0178] method

[0179] The present invention provides a method for a wireless communication system, the method comprising:

[0180] connecting the UE to one or more other UEs in the wireless communication system for sidelink communication with the one or more other UEs, the sidelink communication comprising one or more sidelink control messages, such as sidelink control information (SCI), to be sent on sidelink resources,

[0181] identifying, by the UE through blind decoding, a sidelink control message intended for the UE, and

[0182] decoding, by the UE, the sidelink control message for the UE to obtain control information embedded in the sidelink control message, and

[0183] The network or base station pre-configures or configures the UE using the side link SL search space in the side link resources, such as the SL control resource set or the SL control channel opportunity, and the side link search space includes one or more search opportunities. At the one or more search opportunities, the UE will perform blind decoding on the side link resources.

[0184] The present invention provides a method for a wireless communication system, wherein the wireless communication includes one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, wherein the sidelink communication includes one or more sidelink control messages to be sent on sidelink resources, such as sidelink control information (SCI), the method comprising:

[0185] A network entity signals a UE-specific SL search space in the sidelink resources, such as an SL control resource set, to a receiving UE or a group of receiving UEs, so as to indicate one or more search opportunities to the receiving UE, at which the receiving UE will perform blind decoding on the sidelink resources to identify a sidelink control message for the receiving UE, such as sidelink control information SCI.

[0186] The present invention provides a method for a wireless communication system, the method comprising:

[0187] connecting the UE to one or more further UEs in the wireless communication system for sidelink communication with the one or more further UEs, the sidelink communication comprising one or more sidelink control messages, such as sidelink control information (SCI), to be sent on sidelink resources,

[0188] identifying, by the UE through blind decoding, a sidelink control message intended for the UE, and

[0189] decoding, by the UE, the sidelink control message for the UE to obtain control information embedded in the sidelink control message,

[0190] The information embedded in the sidelink control message indicates configuration of an additional message, wherein the additional message includes additional control information and / or data.

[0191] The present invention provides a method for a wireless communication system, wherein the wireless communication includes one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, wherein the sidelink communication includes one or more sidelink control messages to be sent on sidelink resources, such as sidelink control information (SCI), the method comprising:

[0192] A sidelink control message is signaled by a network entity to a receiving UE or group of receiving UEs, wherein information embedded in the sidelink control message indicates configuration of further messages including further control information and / or data.

[0193] The present invention provides a method for a wireless communication system, the method comprising:

[0194] connecting the UE to one or more further UEs in the wireless communication system for sidelink communication with the one or more further UEs, the sidelink communication comprising one or more sidelink control messages, such as sidelink control information (SCI), to be sent on sidelink resources,

[0195] identifying, by the UE through blind decoding, a sidelink control message intended for the UE, and

[0196] decoding, by the UE, the sidelink control message for the UE to obtain control information embedded in the sidelink control message,

[0197] The UE identifies a reference signal accompanying the first part of the sidelink control message from the first part of the sidelink control message, such as a specific demodulation reference signal DMRS pattern.

[0198] The present invention provides a method for a wireless communication system, wherein the wireless communication includes one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, wherein the sidelink communication includes one or more sidelink control messages to be sent on a sidelink resource, such as sidelink control information (SCI), and the sidelink control message includes at least a first part, such as a first level, and a second part, such as a second level. The method includes:

[0199] A reference signal, such as a specific demodulation reference signal (DMRS), is signaled by a network entity to a receiving UE or a group of receiving UEs in or together with the first part of the sidelink control message.

[0200] The present invention provides a method for a wireless communication system, the method comprising:

[0201] connecting the UE to one or more further UEs in the wireless communication system for sidelink communication with the one or more further UEs, the sidelink communication comprising one or more sidelink control messages, such as sidelink control information (SCI), to be sent on sidelink resources,

[0202] identifying, by the UE, a sidelink control message intended for the UE, and

[0203] A determination is made by the UE from the first portion of the sidelink control message whether the sidelink control message is intended for the UE.

[0204] The present invention provides a method for a wireless communication system, wherein the wireless communication includes one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, wherein the sidelink communication includes one or more sidelink control messages to be sent on a sidelink resource, such as sidelink control information (SCI), and the sidelink control message includes at least a first part, such as a first level, and a second part, such as a second level. The method includes:

[0205] A network entity indicates in the first portion of the sidelink control message whether the sidelink control message is intended for a receiving UE.

[0206] Computer program product

[0207] The present invention provides a computer program product comprising instructions which, when executed by a computer, cause the computer to perform one or more methods according to the present invention.

[0208] As mentioned above, embodiments of the present invention provide improvements and enhancements to single-level or two-level sidelink control messages, such as two-level SCI, as they can be employed in NR sidelink communications, such as V2X communications, etc. Below, several aspects of the present invention are described that provide enhancements in terms of flexibility, complexity, forward compatibility, overhead, regulatory impact, latency, and robustness. The aspects described below can be used independently of each other, or some or all of the aspects can be combined. In addition, when referring to the first part of the sidelink control information or the first-level SCI in the following description, this can simply refer to:

[0209] - Sidelink Control Message or SCI, such as Single-Level SCI, or

[0210] - a sidelink control message or SCI comprising at least a first part, e.g., a first level, and a second part, e.g., a second level, or

[0211] - A sidelink control message or SCI comprising a first portion of control information and associated with or immediately followed by a further message comprising at least a second portion of the control information, such as a second level SCI, and / or data to be transmitted.

[0212] First aspect

[0213] According to an embodiment of the first aspect of the present invention, the search space may be configured to indicate to a UE participating in sidelink communication a search opportunity for performing blind decoding in order to identify the first part of the two-stage SCI, as described above. Figure 4 As shown in S2 in Figure 1 . In wireless communication systems and networks, certain resources may be allocated for sidelink communication. These resources are also referred to as resource sets or resource pools. Some of the sidelink resources may be used for control purposes, and a corresponding sidelink control resource set (SL-CORESET) may be identified. Within such an SL-CORESET, one or more search spaces for a receiving UE may be identified.

[0214] According to an embodiment, the search space may be configured for all UEs or a group of UEs using a broadcast message (e.g., a system information block (SIB)) or a group common control channel. According to other embodiments, the receiving UE may receive signaling from the transmitting UE using, for example, a dedicated radio resource control (RRC) message indicating a specific search space to be used by the receiving UE for blind decoding. According to still other embodiments, the UEs participating in the sidelink communication may be preconfigured with the search space using a preconfiguration message.

[0215] Depending on the embodiment, the search space may be used for one, some, or all UEs on a shared SL frequency resource, such as a selected subchannel or PRB, a selected resource pool, or a shared bandwidth portion (BWP). According to other embodiments, the search space to be used by one or more other UEs or groups of UEs (also referred to as a modified search space) may be signaled by a UE (e.g., a transmitting UE in a sidelink communication pair). For example, a transmitting UE performing unicast or multicast communication may signal its specific search space in a physical L1 SL control channel, in a data control channel, or in an SL-RRC control message.

[0216] According to an embodiment of the first aspect of the present invention, as described above, the search space (also referred to as the first-level search space), the sidelink search space or the SL space contains search opportunities at which the sidelink receiver UE performs decoding, such as blind decoding, on the configured sidelink control resources or the sidelink control resource set SL-CORESET. The SL-CORESET may define the number of symbols in time, for example, by defining N_sub-channels-index, e.g. And the number of resource blocks RB, such as The SL control resource set may be configured for all UEs in a common search space message, which may be conveyed in an RRC broadcast message, such as a system information block (SIB) message, such as SIB18, SIB19, SIB20, and SIB26.

[0217] Figure 6 An embodiment of a SL search space information element is shown, which may be used for sidelink UEs with a common search space and may be signaled in a SIB. As an embodiment, Figure 6 It is shown that within the common search space where the receiving UE will perform decoding, four different SCI formats can be used. In addition to the common search space, a second type of SL search space is the UE-specific search space, for which several SCI formats can be provided. The SL search space can be provided for single-level SCI and two-level SCI.

[0218] According to an embodiment, the transmitting UE may receive a UE-specific RRC message for configuring the side link, the UE-specific RRC message indicating that, for example, the transmitting UE will use the following when sending the SCI or the first level SCI to the receiving UE: Figure 6 According to a further embodiment, the sending UE may switch from the UE-common search space to the UE-specific search space as follows:

[0219] 1- If operating in a cell configuration SL with SIB 18 / 19 / 21 / 26, a UE configured for sidelink shall be configured with the common search space.

[0220] 2- If in the aforementioned SIB message, then find the search space (i.e., SL-SearchSpace)

[0221] a. If in SL-SearchSpace, configure the UE search space of the UE common type

[0222] i. Use configured SL search space for broadcast, unicast and multicast

[0223] 3- If UE-specific SL search space is configured via RRC

[0224] a. If the RRC message contains SL-CORESET dedicated to the first level SCI

[0225] i. If the UE has a successful SL unicast or successful SL multicast communication,

[0226] 1. The UE shall signal its configured UE-specific SL-CORESET / SL-SearchSpace in the SL control channel (L1 or SL-RRC).

[0227] According to an embodiment, the UE-specific search space may have a search space type ue-specific in a search space message or information element, such as Figure 7 shown.

[0228] Further embodiments of the first aspect of sidelink search space allocation are described below. When configured or pre-configured, the UE-shared SL search space can be a search space that will be used for UEs, some UEs, or all UEs in a shared SL frequency, such as a selected subchannel or PRB, a selected resource pool, or a shared BWP. The shared frequency band or shared resources can be used for broadcast communications or for unicast / multicast communications.

[0229] On the other hand, in case the UE is configured with a UE-specific SL search space type, i.e., with a UE-specific search space, the UE may, for example, upon successful unicast or multicast transmission, send a modified SL search space to be used by another UE or UE group as a sidelink communication partner. The sending UE may signal its UE-specific SL search space in the physical L1 SL control channel, or in the data control channel, or by using an SL-RRC control message. According to an embodiment, once the communication between the communication partners of the sidelink communication is terminated or interrupted, the sending UE may be required to return to using a common SL search space. The UE-specific SL search space may also be a search space to be used for UEs, some UEs, or all UEs in a specific SL frequency, such as a selected subchannel or PRB, in a selected resource pool, or in a specific BWP. A specific band or specific resource may be used for broadcast communication, or for unicast / multicast communication.

[0230] Figure 8 An embodiment of the first aspect of the present invention is shown, using a common SL search space or a common SL-CORESET in a common bandwidth portion or resource pool accessible to some or all UEs, and in the case where the UE is involved in sidelink communication with a receiving UE, for example for unicast transmission or multicast transmission, the transmitting UE can signal the receiving UE to use the UE-specific search space for the next one or more transmission cycles. Figure 8 Schematically shows a portion of resources 400 in the time domain and frequency domain provided by a wireless communication system or network for side link communication between multiple user equipments, and within the side link resources 400, corresponding resources are used to send control information, which is also referred to as control resources 402. Figure 8 In the embodiment of FIG. 4 , the control resources 402 include a first bandwidth portion or a first resource pool A and a second bandwidth portion or a resource pool C. Within the first portion 404 of the resource pool C, a plurality of common SL search spaces or SSL-CORESETs 406 are defined. For example, when four UEs are considered to perform sidelink communication, namely, UEs 1B, 2B, 1C, and 2C, one or more of the SL search spaces 406 in the first portion 404 of the resource pool C may be used, for example, to identify the SSL-CORESETs 406 in the message or information element described above (see FIG. 4 ). Figure 6 ) configure these UEs. As mentioned above, the common SL search space can be used by the transmitting UE and the receiving UE in the SL communication pair to initially establish SL communication, such as unicast communication or multicast communication, and once established, the transmitting UE can signal to one or more receiving UEs that the UE-specific search space will be used for one or more of the following transmission periods. Figure 8 In the embodiment of FIG. 4 , the UE-specific SL search space for UEs 1B and 2B is within the second portion 408 of resource pool C, and Figure 8 The corresponding UE-specific SL search space 410 is shown, which indicates the search opportunity for the receiving UE, that is, the opportunity at which blind decoding is performed to see whether the sidelink control message for the UE is sent. Therefore, for UE 1B and 2B, the common and UE-specific SL search spaces are within the same resource pool or bandwidth part, that is, within bandwidth part C. However, the common SL search space and the UE-specific SL search space can also be within different bandwidth parts, as shown in FIG. Figure 8 Shown for UE 1C and 2C. The UE-specific SL search space 412 for UE 1C and 2C is in resource pool C, and the common SL search space is in resource pool A.

[0231] Figure 9 An embodiment for switching from the common search pool to the UE-specific search pool is shown. Figure 9 Shown Figure 8 , namely the first segment 404 or resource pool C and resource pool A. Again, segment 404 of resource pool C houses the common SL search space for UEs 1C and 2C. As shown, the corresponding search space 406 is within the corresponding subband of resource pool C. Figure 9 Some common SL search spaces marked with 406a may include signaling pointing to UE-specific SL search spaces in resource pool A, which will be used by the receiving UE for one or more of the following transmission cycles.

[0232] According to an embodiment, the subchannel size in the frequency domain may not be included in the SIB message or RRC message, but only the number of symbols may be identified by these messages, and in such embodiments, the format is such that a fixed number of subchannels are used to provide a common SL search space and / or a UE-specific SL search space.

[0233] In one embodiment, the SL search space may be signaled (via RRC or SIB) indicating the offset from which the SL level 1 SCI starts, for example, via SL-monitoringfrequencysubchannel_offset. In another embodiment, the SL search space may be signaled (via RRC or SIB) indicating the length of the search space in frequency, for example, SL-monitoringfrequencysubchannel_length, such as the number of subchannels / RBs. In yet another embodiment, if the field SL-monitoringfrequencysubchannel_length is not identified, the UE may detect the level 1 subchannel length from, for example, the decoded / detected DMRS.

[0234] Second aspect

[0235] Embodiments of the second aspect provide an SCI or sidelink control message having information embedded therein indicating the configuration of another message. The other message may include additional control information and / or data. Depending on the embodiment, the sidelink control message may include a first portion of control information, such as a first-level SCI, and the other message may include at least a second portion of control information, such as a second-level SCI, and / or data to be transmitted or (multiple) transmission reservations for data to be transmitted.

[0236] Therefore, according to an embodiment, the first level or first part of the SCI can be configured with time and frequency resources for the second part or second level and / or data transmission part of the SCI. For example, the first and second parts, i.e., the side link control message and the other message, can be adjacent or non-adjacent in the time domain, with or without a time gap between the first part and the second part. The first and second parts can use adjacent or non-adjacent frequency resources or subchannels. The first and second parts can be in the same resource pool (see above). Figure 8 , lower part), can also be in different resource pools, that is, distributed across two or more resource pools, as above Figure 8 shown in the upper part of .

[0237] According to further embodiments, for example in the case where the first level spans all frequencies of the second level, i.e., the first level or first part of the SCI occupies the same frequency as the second part of the SCI / data, a time offset between the first part and the second part of the SCI / data may be configured and precoded in the lookup table LUT. In addition, according to further embodiments, a pointer to a physical channel associated with the first level may be identified so as to identify, for example, a control channel (e.g., PSCCH) and / or a data channel (e.g., PSSCH) in a further message, or to identify only a control channel (e.g., PSCCH) or only a data channel (e.g., Physical Sidelink Feedback Channel (PSFCH)) in a further message.

[0238] In several embodiments of the second aspect below, more specifically, several embodiments designed for the first level or first part of the SCI are described in detail. In order to reduce the blind decoding work of the SL UE, the above-mentioned two-level SCI decoding can be adopted, and according to the second aspect of the present invention, the first level of the SCI is designed to configure additional messages, such as the second level or the second part and / or the PSSCH containing data associated with the SL transmission. According to the embodiment, the time and frequency resources for the second level are configured, and the information can be encoded implicitly or explicitly. The format or configuration to be used for the second part can be communicated for the receiving UE in the UE-common SL space or the UE-specific SL search space as described above with reference to the first aspect.

[0239] According to embodiments of the second aspect, the following different formats may be used:

[0240] format_i_i

[0241] - Equal frequency resources / subchannel lengths and / or adjacent time domain resources for level 1 and 2 SCI and PSSCH (no time gap)

[0242] format_i_j

[0243] - Equal frequency resources / subchannel lengths and / or non-contiguous time domain resources for level 1 and 2 SCI and PSSCH (no time gap)

[0244] format_j_i

[0245] - Different frequency resources / subchannel lengths with adjacent time domain resources (1st and 2nd level SCI and PSSCH (no time gap))

[0246] Format_j_j

[0247] - Different frequency resources / subchannel lengths with:

[0248] ● Non-adjacent time domain resources (1st and 2nd level SCI and PSSCH (no time gap))

[0249] ●Cross-pool / cross-carrier / cross-BWP

[0250] Scheduling within the same resource pool or across resource pools

[0251] According to an embodiment, one or more of the above formats may provide a multi-UE multiplexing method, such as using CDM, etc., to reduce interference in the control channel. The above formats may have one symbol, two symbols, or three symbols in the time domain, however, according to another embodiment, more than three symbols may also be provided.

[0252] The above format can be used for unicast communication, multicast communication and / or broadcast communication, and in any format, fields can be provided to introduce time and frequency positions, as well as fields to introduce transmission periodicity. However, the present invention is not limited to formats that include this information, and on the contrary, simpler formats that do not include time / frequency positions and / or periodicity can be provided.

[0253] In the following, embodiments for implementing the above-mentioned format are described in more detail.

[0254] Sidelink first-level SCI short format 1: for example, SCI-1st_format_i_i

[0255] The format according to this embodiment may not have information about the time and frequency resource allocation of the second level, because the time allocation of SCI and PSCCH, the first and second levels or parts of data are adjacent. In addition, the frequency allocation, that is, the number of subchannels allocated for data and the second level SCI can be the same. The number of used subchannels can be tracked by the number of subchannels occupied by the first level. Therefore, the first level decoding can identify the length of the used subchannels in the frequency domain, for example by blind decoding or by DMRS scanning. In addition, a periodic indicator (e.g., an indicator) can be provided to indicate periodic or aperiodic transmission, or to indicate resource release. The periodic field can convey periodic information, which will be described in detail below.

[0256] In an embodiment, the search space field may be signaled via SIB / RRC as described above with reference to the first aspect, and may not give the subchannel size in frequency but only identify the number of symbols.

[0257] Therefore, the length of stage 1 can be identified using DMRS scanning, for example.The DMRS length decoded / identified by the RX UE can also indicate the length of stage 1 in frequency.

[0258] The format according to this embodiment can identify the following items:

[0259]

[0260] In this format, the time domain and frequency domain have a size of 0 bits, ie, are not sent or are not part of the SCI message.

[0261] Figure 10 An embodiment of a first short SCI first level format is shown where the time and frequency of data and control are not identified in the first level. Figure 10 Sidelink resources 400 for transmitting sidelink control messages and data are shown. Figure 10In the embodiment depicted in FIG, the SCI and data for a first UE 1 are transmitted in two subchannels, and the corresponding SCI and data for a second UE 2 are transmitted in four or three subchannels 416. Each transmission for a corresponding UE includes first-level SCI 418 and second-level SCI 420, which may also include data to be transmitted by UE 1 to a receiving UE via a sidelink. The first-level SCI 418 of the SCI, along with the associated data, is contiguous with the second-level SCI, i.e., the time offset (T-offset) and frequency offset (F-offset) are zero or null, such that the time offset field in the first-level SCI is set to zero. Therefore, the format described above does not require the inclusion of any bits for time offset or frequency offset. Consequently, the format is reduced in size because the offsets mentioned above do not need to be explicitly indicated; instead, by definition, format_i_i has a null or zero time offset and frequency offset, which is recognized by the receiving UE, thereby recognizing that the second-level SCI and data immediately follow the duration of the first-level SCI in the same frequency band.

[0262] In this format, the duration of the transmission may be signaled in advance to all UEs using an RRC / SIB message.

[0263] Sidelink first-level SCI short format 2: for example, SCI-1st_format_i_j

[0264] The format according to this embodiment involves allocating a first-level SCI to identify control or data with a time offset T. Therefore, in addition to the short format 1 described above, the format of this embodiment may include a longer periodicity field, for example, having more than one bit, in order to take into account additional resources reserved for transmission. Similar to the format_i_i described above, the periodicity field can be set to zero, meaning that no periodic reservation of transmission resources is required, or that a previously made reservation can be released.

[0265] According to another embodiment, as described in more detail below with respect to periodicity, the UE may reserve periodic or aperiodic resources for transmission. For example, the UE may decide to transmit the first-level SCI every period P, or the UE may decide to transmit one first-level SCI every period at the beginning of periodic transmission, or the UE may decide to occasionally transmit a refreshed first-level SCI.

[0266] The first level SCI or the first part of the SCI may indicate the following items:

[0267]

[0268] Figure 11 An embodiment of a second short SCI first level format is shown, where the timing and periodicity P for the second level and control can be identified within the first level. Figure 11 Similar to Figure 10 4. The sidelink resources 400 are shown in FIG. 4, between which two subchannels 414 are used by UE1 and subchannel 416 is used by UE2. According to an embodiment, as described with reference to UE1, the first-level SCI 418 may indicate a time offset (T-offset) of T1, which specifies the distance along the time domain between the first-level SCI 420 and the associated second-level SCI or data 420. In addition, the first-level SCI 418 transmitted by UE1 indicates a specific periodicity P1, which indicates that the second-level SCI and data 420 may be repeated at a specific periodicity and at a specific time interval. Figure 11 In the example depicted in , the periodic indication second level SCI and data 420 is repeated once after the second level SCI and data. With respect to UE2, a similar approach is described, however, between the two occurrences of the second level SCI and data, the first level SCI is also sent.

[0269] According to another embodiment, the short format may also include the sub-channel SC length in the frequency allocation field.

[0270] In this embodiment, the time domain resource allocation may include more than one bit so that the offset time duration may be quantized and used as follows:

[0271] Slot 1 (Sl1): 1 slot,

[0272] Slot 2 (Sl2): 2 slots,

[0273] Time slot 4 (Sl4): 4 time slots.

[0274] Sidelink level 1 SCI long format 1: for example SCI-1st_format_j_i

[0275] According to this embodiment, a long format for the first level SCI is supported so that, for example, more information about the DMRS pattern associated with the second level or data can be provided. The DMRS pattern can be used by a receiving UE to decode the second level SCI and data.

[0276] The format according to this embodiment may include a field for frequency domain resources, and this field may include a frequency domain resource allocation offset (F-offset) and a frequency domain resource allocation channel length (F-length).

[0277] F-offset can indicate an offset relative to the start of a resource pool subchannel (e.g., relative to subchannel zero) or relative to the start of a subchannel where the first-level SCI is located. For example, if the first-level SCI does not span the entire subchannel and is not spanned by the second-level SCI, and if the first-level and second-level SCIs overlap in the time domain, F-offset can have a negative value. F-offset can indicate the starting point of the data.

[0278] F-length may indicate the sub-channel length of the second level in the data, which may always be possible.

[0279] The format according to this embodiment may indicate the following items:

[0280]

[0281]

[0282] In one embodiment, there may be a field for Slot_duration that identifies the slot duration, for example, as the number of symbols. The slot duration may depend on, for example, the subcarrier spacing (SCS) or the frequency range (FR1 < 6 / 7 GHz or FR2 > 7 GHz). The slot duration may be one or more bits that quantify the possible slot durations, for example, for a 2-bit Slot_duration: 00 means 14 symbols, 01 means 7 symbols, 10 means 4 symbols, and 11 means 2 symbols. The slot duration may also be indicated in any other format in the Level 1 SCI.

[0283] In addition, in one embodiment, an Aggregated_slot / or slot_aggregation field may be provided to indicate the number of aggregated slots of data using a single control channel. For example, for a 2-bit Aggregated_slot / or slot_aggregation field, 00 means 1 slot transmission, 01 means 2 slots aggregated transmission, 10 means 4 slots aggregated transmission, etc. Other indication formats within the first level of the SCI may also be used.

[0284] Figure 12 An embodiment of the first long SCI first level format is shown, where the time, frequency and periodicity P for the second level are identified in the first level SCI. Figure 10 and Figure 11 In a similar way, Figure 12 Also shown are side link resources 400 used by UE1 to send data to a receiving UE. Figure 12, the left-hand portion of FIG, shows a first-level SCI 418a occupying two subchannels F=2SC. The first-level SCI 418a further signals to the receiving UE that the second-level SCI and data 420a are provided with a time offset, T-offset=T1, i.e., the first and second-level SCIs are not adjacent, and also with a frequency offset, F-offset being signaled as +1 and -2, thereby indicating to the receiving UE that the second-level SCI and data 420a have an F-length of five subchannels (F-length=5SC), and that, relative to the subchannels occupied by the first-level SCI 418a, the second-level SCI 420a spans two subchannels before the starting subchannel of the first-level SCI and uses additional subchannels after the end of the first-level SCI.

[0285] Figure 12 4 shows another example of a format for this embodiment, according to which the first-level SCI 418a, the second-level SCI, and the data 420b are adjacent in time and frequency. More specifically, the first-level SCI 418b signals to the receiving UE that the F-offset is zero, the T-offset is -1 and 0, and the F-length is two subchannels. In other words, based on this information, the UE receiving the transmission from UE1 determines from the first-level SCI 418b that the second-level SCI and the data 42b immediately follow the first-level SCI in the first subband, and that the first-level SCI and the second-level SCI overlap in the second subband, as shown in FIG. Figure 12 shown.

[0286] Figure 12 , further embodiment of a format according to the present embodiment is described, which comprises a first level 418c and a second level SCI and data 420c, which are similar to the above-described SCI levels 418b and 420, except that the time offset is zero for both sub-bands, i.e., in the second sub-band, which is not covered by the first SCI, the second SCI starts as soon as the first level SCI ends.

[0287] Sidelink level 1 SCI long format 2: e.g. SCI-1st_format_j_j

[0288] The format according to this embodiment allows cross-scheduling for different SL resource pools, SL BWPs including resource pools, and SL carriers in a multi-carrier scenario. This format defines fields including resource pool ID, BWP ID, or carrier ID. Based on the aforementioned IDs, the receiving UE can calculate the frequency domain resource allocation offset (F-offset) and frequency domain resource allocation signal length (F-length).

[0289] The format according to this embodiment can signal the following information in the first stage.

[0290]

[0291]

[0292] Figure 13 An embodiment of the above-mentioned long format is shown, which has cross-carrier / BWP / resource pool scheduling or second-level SCI and data included in the first-level SCI. Figure 13 A first example is shown where the first level SCI 418a and the second level SCI and data 420a are in the same resource pool 422, and this may be signaled by the first level SCI 418a in the manner described above. Figure 13 Another embodiment is shown in which the first-level SCI 418b indicates that the second-level SCI and data 420b use resources from different resource pools, namely resource pool 424. In the depicted embodiment, the information in the first SCI 418b indicates that the F-length of the second-level SCI and data is three subchannels, F-length = 3SC, and further, a frequency offset (i.e., F-offset) is signaled, and the offset is selected so that the subchannels used by the second level are within the second resource pool 424 or within the second bandwidth portion. In addition, a time offset is also signaled, T-offset = T2.

[0293] According to an embodiment, a CRC of, for example, 16 bits or 24 bits may be added to any of the above formats, preferably to the above long SCI first level format.

[0294] According to further embodiments, one or more of the above formats may provide multi-UE multiplexing, eg via CDM, in order to reduce interference in the control channel.

[0295] According to some further embodiments, one or more of the above formats may include a destination ID, such as a UE ID, a group ID, or a broadcast ID, scrambled with a CRC of the format, so as to allow the receiving UE to identify from the format of the first-level SCI whether the communication is a unicast communication, a groupcast communication, or a broadcast communication performed by the transmitting UE.

[0296] Periodicity

[0297] As mentioned above, according to another embodiment of the second aspect of the present invention, the first-level SCI may indicate periodicity. Periodicity can be indicated by a variable number of bits and can be provided to assist in sensing and reservation mechanisms in the side link. The periodicity field (also referred to as the persistence field) is signaled using the first-level SCI. When the periodicity field indicates 0, this may mean that a single short transmission occurs without any periodicity, or that the previously set periodicity and associated resources that have been reserved are released. Periodicity can be indicated according to each quantized value indicated for each lookup table entry.

[0298] Once the reservation is relinquished, ie once the periodicity indicates a value of eg 0, the released resources can be used by other UEs.

[0299] According to an embodiment, for a 1-bit periodicity field, a 2-bit periodicity field, a 3-bit periodicity field, and an X-bit periodicity field, the periodicity may be signaled as shown in the following table.

[0300] 1st digit:

[0301]

[0302] 2-digit:

[0303]

[0304] 3-digit:

[0305]

[0306]

[0307] X position

[0308]

[0309] in:

[0310] Time slot 1: Each time slot is reserved

[0311] Time slot 2: every two time slots are reserved

[0312] Slot 4: Every 4 slots are reserved

[0313] Slot 5: Every 5 slots are reserved

[0314] Slot 8: Every 8th slot is reserved, and

[0315] Any other combination, e.g. a 4-bit field can quantize 16 different durations / periodicities, and an 8-bit field can quantize 256 different durations / periodicities.

[0316] Figure 14An embodiment of a second aspect involving periodic reservation and release using a periodic field provided in a first-level SCI is shown. Again, a sidelink resource 400 to be used for sidelink communication between user equipments is schematically shown at 400, and it is assumed that a first UE transmitting SCI and data to a receiving UE provides first and second level SCI and data in two adjacent subchannels (F=2SC). The first-level SCI 418a to the first-level SCI 418c indicate a time offset, T-offset=1T=0, i.e., the second level 420a to 420c follows the first-level SCI in time. The first-level SCI also includes a periodic field with a value of "01", which signals to the receiving UE that the second-level resources are reserved with a period of 1, also known as a quantization period. The fourth-level SCI 418d includes a periodic field with a value of "00", which means that one transmission occurs, or the resources reserved for the second level so far are released.

[0317] Figure 14 Another example is shown for the second UE 2, where the first level SCI 418e indicates a time offset T1 between the first level 418e and the second level SCI 420e. In addition, the periodicity field indicates a value of "00", which means that the transmission is a one-time transmission.

[0318] According to another embodiment, the periodicity field can be used in the first-level SCI to indicate all upcoming occurrences of second-level SCI and data associated with the first level. Data or second-level SCI can appear once per periodicity. In this embodiment, when a receiving UE receives one first-level SCI, such as the first transmitted first-level SCI, the first-level SCI will be decoded once by the receiving UE, and the UE does not expect any additional first-level SCI for subsequent data transmissions.

[0319] According to an embodiment, a transmitting UE may transmit multiple first-level SCIs to reduce sensing ambiguity at a receiving UE in the event that decoding of the first-level SCI that was transmitted is unsuccessful. For example, a receiving UE that does not correctly decode any retransmission of the first-level SCI may rely on information for further decoding of the second-level data and control obtained from the first transmission of the first-level SCI.

[0320] The third aspect

[0321] According to embodiments of the third aspect of the present invention, the first level of SCI may be accompanied by a specific reference signal, such as a DMRS, having a specific pattern and / or location. For example, the first level of SCI or the first part of SCI may be accompanied by a DMRS to indicate the cast type of the associated second level of SCI to the receiving UE according to an embodiment. According to other embodiments, the first level of SCI or the first part of SCI may be accompanied by a DMRS pattern associated with a specific use case of a specific QoS with the second part of the sidelink control message.

[0322] The DMRS design or pattern can be such that the receiving UE is protected from collisions with other UEs. The DMRS design can be associated with different first SCI formats for conveying specific information, such as the size of the first-level SCI in the time and frequency domains, such as the length of the DMRS in frequency is the length of the first level, except that the length in frequency is not conveyed in the search space.

[0323] Thus, according to embodiments of the third aspect, a receiving UE may identify a reference signal, such as the aforementioned demodulation reference signal (DMRS) pattern, from the first part of a sidelink control message. A transmitting UE or another network entity (e.g., a gNB) involved in the SL communication may signal to the receiving UE or group of receiving UEs, in or together with the first part of the sidelink control message, the reference signal selected to convey information to the receiving UE.

[0324] According to an embodiment, the DMRS defined in Rel-15 NR Uu can be considered as the starting point for NR sidelink DMRS design. In Rel-15 NR Uu, two types of DMRS configurations are defined for both PUSCH and PDSCH, namely Type 1 and Type 2 DMRS configurations. These types start with one or two symbols and, depending on the configuration type, are optionally followed by up to three additional DMRS symbols. Considering the number of DMRS symbols required to achieve sufficient performance in low SNR conditions, DMRS Type 1 ensures a sufficient number of DMRS REs per PRB, and according to an embodiment, DMRS Type 1 is the preferred PSCCH DMRS structure for first-level SCI. The DMRS structure for first-level SCI can be received via higher layer signaling, for example by providing the parameter "SL-DMRS-configure-type", or it can be received through the Master Information Block MIB or the System Information Block SIB. According to further embodiments, other parameters such as DMRS position and DMRS maximum length can be configured in a similar manner. Although this configuration only considers one layer, it should be noted that the present invention is not limited to this one layer configuration, but is equally applicable to multi-layer configurations.

[0325] According to an embodiment, in order to reduce the blind decoding processing time of the receiving UE when identifying the first level of SCI, the DMRS mode can be selected depending on the selected subcarrier frequency mapping, the selected subcarrier time mapping, orthogonal or quasi-orthogonal codes or different code generators or code division multiplexing CDM.

[0326] In the case where the UE is configured by a higher signaling message or broadcast information (such as SIB), the position of the DMRS for different modes can be calculated as described in more detail below. The higher signaling message can be SIB 18 / 19 / 21 / 26 defined for LTE-V2X or another newly defined SIB for NR V2X. According to other embodiments, the DMRS can be defined by an information element named PSCCH-config, which can be used to configure UE-specific PSCCH parameters per bandwidth part, and Figure 15 An embodiment of this PSCCH-config-common information element is shown. Figure 15 Among the information elements depicted in

[0065] , SL-dmrs_control_type_x or SL-dmrs_control_type_y_x may include all positions in time and / or frequency, SL-dmrs_control_type_1 may be used for broadcast, and SL-dmrs_control_type_2_1 / SL-dmrs_control_2_2 may be used for unicast and / or multicast.

[0327] Figure 16 An embodiment of the PSCCH-config-UE specific information element is shown, also for the common PSCCH where SL-controlResourceSetToAddModList or SL-controlResourceSetToRelaseModList allows the UE to add or release search spaces from a specific search space. The DMRS type is the same as before, and if the additionalV2XDMRS field is present, the UE enables the DMRS mode per subcarrier spacing. This applies to all formats of the PSCCH. This also includes the possibility of having denser DMRS for high-speed scenarios, as described in detail below.

[0328] Depending on the embodiment, different DMRS patterns may be based on different time / frequency. For example, a particular DMRS pattern may identify a propagation type. In other words, the DMRS may have a pattern associated with a particular propagation type of the second portion of the sidelink control message. Depending on the embodiment, the DMRS may be selected from a plurality of reference signals, such as DMR, having patterns that differ from one another, such that each of the plurality of DMRSs is associated with a particular propagation type. The DMRSs may differ in one or more of the following aspects:

[0329] - frequency domain,

[0330] - time domain,

[0331] - code domain, such as different orthogonal or quasi-orthogonal coding schemes or code division multiplexing (CDM),

[0332] - Spatial domains, such as different port IDs.

[0333] Figure 17 、 Figure 18 and Figure 19 An embodiment of DMRS patterns for different first-level SCI types, i.e., spreading types, is shown, with the first-level SCI transmitted in one symbol, such as the second symbol. In the depicted embodiment, the spreading type can be identified by a DMRS pattern having DMRSs located in three subchannels in the second symbol, separated by two subchannels in the frequency domain. To distinguish the spreading type, the DMRS pattern has a specific frequency offset from the beginning of the PRB.

[0334] Figure 17 The DMRS pattern for the level 1 SCI type identifying broadcast communications is shown. The location of the DMRS in time or frequency is set by upper layers, for example, by the parameter SL-dmrs_control_type_xx. Figure 17 DMRS pattern 430 is shown, which has DMRS_1, DMRS_2, and DMRS_3 located in three subchannels in second symbol 432, separated in the frequency domain by two subchannels 4341 and 4342. DMRS pattern 430 has a frequency offset 436a of three subchannels in the frequency domain, indicating broadcast communication. The UE recognizes from DMRS pattern 430 and offset 436a that the propagation type of the first-level SCI is broadcast.

[0335] Figure 18 The DMRS pattern for the level 1 SCI type identifying unicast communication is shown. The position of the DMRS in time or frequency is set by upper layers, for example, by the parameter SL-dmrs_control_type_xx. Figure 18 Shown with Figure 17 The same DMRS pattern 430 is used, but with a frequency offset 436b of two subchannels in the frequency domain, indicating unicast communication. The UE recognizes from the DMRS pattern 430 and the offset 436b that the propagation type of the first-level SCI is unicast.

[0336] Figure 19 The DMRS pattern for the level 1 SCI type identifying multicast or groupcast communication is shown. The position of the DMRS in time or frequency is set by upper layers, for example, by the parameter SL-dmrs_control_type_xx. Figure 19 Shown with Figure 17 or Figure 18 The same DMRS pattern 430 is used, but the DMRS pattern has a frequency offset 436c of one subchannel in the frequency domain, indicating multicast or groupcast communication. The UE recognizes from the DMRS pattern 430 and the offset 436c that the propagation type of the first-level SCI is multicast or groupcast.

[0337] The location in time and frequency may be configured using any field, such as the SIB / RRC fields SL-dmrs_control_type_1, SL-dmrs_control_type_2_1 / 2, or any other field defined by upper layer parameters in RRC and / or SIB.

[0338] According to another embodiment, as briefly mentioned above, the DMRS pattern can be different in the coding domain and the spatial domain (antenna port). For example, the DMRS can be based on code division multiplexing (CDM). Variable or configurable DMRS patterns for data demodulation can be supported. For example, the configuration can support frontload DMRS patterns. The frontload DMRS can be mapped on one or two adjacent OFDM symbols. According to other embodiments, the DMRS can be configured for the latter part of the time slot.

[0339] DMRS configuration can be up to the maximum number of PT-RS ports. For example, for single-user MIMO, SU-MIMO, eight orthogonal DL DMRS patterns can be supported, such as using configuration type 1, and for multi-user MIMO, MU-MIMO, a maximum of 12 orthogonal DL DMRS ports can be supported, such as using configuration type 2. For CP-OFDM, NR can support a common DMRS structure for DL ​​and UL, and the DMRS positions and DMRS patterns can be the same or different.

[0340] The DMRSs for the respective links can be configured to be orthogonal or quasi-orthogonal to each other. For DL ​​DMRS port multiplexing, FDM including comp, CDM including OCC and cyclic shift, and TDM are considered. In other words, some or all of the multiple reference signals can have unique designs, such as orthogonal or quasi-orthogonal DMRS patterns, which allows the receiving UE to be protected from collisions.

[0341] The PN sequences supported in 3GPP can be used to generate DMRS parameters, for example by considering configuration type 1 for PUSCH as described in reference [2]. This identifies the location in time and frequency in order to generate a transmission-specific DMRS that identifies whether the transmission is for broadcast, unicast or multicast.

[0342] For example, according to Rel-15 New Radio, DMRS resource mapping is performed as follows:

[0343]

[0344] in,

[0345] w t (l′),w f (l′) and Δ are given in Tables 7.4.1.1.2-1 and 7.4.1.1.2-2 of reference [2].

[0346] k represents the frequency domain position,

[0347] l represents the time domain position,

[0348] r(.) is the sequence generation method, and

[0349] μ and P are the subcarrier spacing index (numerology) and the number of layers or antenna ports, respectively.

[0350] The embodiments of the third aspect adopt the above items to provide additional degrees of freedom for determining the DMRS pattern corresponding to the different broadcast communication (e.g., broadcast, unicast, or group / multicast) at the first level SCI. Examples of deterministic DMRS patterns obtained according to this embodiment are indicated in the table below, however, other patterns are not excluded. The parameters P, CDM group, k', l' and Δ given in Table 3 are configured as follows:

[0351] - Higher layer signaling in connected mode, i.e. RRC,

[0352] - or, SIB in idle mode.

[0353]

[0354] Table: Illustrative examples of CDM modes and DMRS parameters for different propagation types

[0355] According to another embodiment of the third aspect, the DMRS pattern may be repeated in the time domain, for example in a user scenario where the user is moving rapidly. For example, when considering a high-speed scenario, for example, at a relative speed of 500 km / h, the coherence time may be less than the symbol duration of the upper band frequency of FR1. For example, at fc = 3.6 GHz, the symbol duration may be 0.005 ms, with a subcarrier spacing of 30 kHz, so that more DMRS signals may be required to perform channel estimation, for example as described in reference [3].

[0356] To address this issue, according to an embodiment, a DMRS pattern may be mapped to one or more symbols of the first-level SCI. For example, the DMRS may be mapped to each symbol of the first-level SCI based on a specific time pattern algorithm corresponding to the propagation type of communication. According to other embodiments, a specific pattern for mapping the DMRS to the first-level SCI may be employed. Figure 20 An embodiment using DMRS shifting in frequency and / or time for different propagation types is shown.

[0357] According to an embodiment, DMRS symbols may be provided only in a subset of PSCCH symbols in the time domain, such that all DMRS symbols or a subset of DMRS symbols may be in the first level SCI associated with the PSCCH. In another embodiment, different numbers of symbols may be provided for the PSCCH, such as 1, 2, 3, 4 and up to 14 symbols, wherein all symbols may be associated with different DMRS configurations. In yet another embodiment, different DMRS configurations may be applied in case more than one DMRS symbol is used in the first level SCI in the PSCCH. In yet another embodiment, the density of DMRS time symbols may be increased, for example using Figure 15 The additional field “additional V2X DMRS” is shown, for example for high-speed scenarios.

[0358] The fourth aspect

[0359] According to an embodiment of the fourth aspect of the present invention, a receiving UE may determine from the first part of a sidelink control message whether the sidelink message is intended for the UE. A transmitting UE or another network entity (such as a gNB) involved in SL communication may signal to a receiving UE or a group of receiving UEs in the first part of the sidelink control message or together with the first part whether the sidelink message is intended for the receiving UE. For example, this may be signaled by identifying the transmitted propagation type associated with the SCI in the first-level SCI or the first part of the sidelink control message.

[0360] For example, the receiving UE does not expect the second part of the sidelink, i.e., the second part is not intended for the UE, and the UE will not perform decoding on the second part, etc., for example in the following cases:

[0361] - the first part of the sidelink message includes a broadcast ID, such as a broadcast flag or broadcast bit for identification of the type of communication, or

[0362] - the first part of the sidelink message does not include a broadcast ID and does not include any UE destination ID indicating, for example, a unicast communication or a group destination ID indicating, for example, a multicast communication, or

[0363] - The UE destination ID or group destination ID in the first part of the sidelink message does not match the UE's ID.

[0364] On the other hand, in case the first part of the sidelink message includes a UE destination ID or a group destination ID that matches the ID of the UE and does not include a broadcast ID, the UE may expect a second part of the sidelink, i.e., process the second part, e.g., decode it and use the information and / or data provided therein.

[0365] According to other embodiments, the sidelink control message with the UE destination ID or group destination ID or broadcast ID may be scrambled, for example, using CRC scrambling, and the UE does not expect the second portion of the sidelink if descrambling results in one or more of the following:

[0366] - a broadcast ID, such as a broadcast flag or broadcast bit, or

[0367] - has neither a Broadcast ID nor any UE Destination ID nor any Group Destination ID, or

[0368] - the UE destination ID or group destination ID does not match the UE's ID, and

[0369] On the other hand, in case the UE destination ID or group destination ID generated by descrambling matches the UE's ID and does not include the broadcast ID, the UE may expect the second part of the sidelink.

[0370] Thus, depending on the embodiment, the type of transmission can be signaled via the destination ID, either directly in the first level SCI or scrambled with the SCI of the destination ID via CRC, as described above. The transmission type unicast or multicast can be derived from the group destination ID or UE destination ID, while the transmission type broadcast can be derived from a flag specified in the configuration or from a configuration that does not include any group destination ID or UE destination ID, i.e., the first part or first level SCI is defined without any destination ID.

[0371] Thus, embodiments of the fourth aspect of the present invention provide a first-level SCI design that allows for implicit broadcast type identification in combination with a destination ID. As described above, the use of two-level SCI enables the UE to derive from the information included in the first-level SCI whether the SCI is relevant to the UE or intended for the UE, i.e., whether the UE expects the second-part SCI. In the case where the second-part is intended for the UE, the second-level SCI plus the location and frequency / time domain of the additional associated data can be provided, as described above with reference to the first, second, and third aspects of the present invention.

[0372] According to an embodiment, in order to enable the UE to derive its relevance to the UE from the first-level SCI, i.e., the relevance of the associated second-level SCI, a unique identifier can be used. For example, as described with reference to the third aspect, the propagation type can be derived from the DMRS associated with the first-level SCI. According to a fourth aspect, embodiments allow the propagation type to be derived from the source ID and / or destination ID, or from the absence of source and destination IDs. The source ID identification is valid for at least unicast and multicast. The source ID here refers to the initiator of the unicast communication. If the UE is still in RRC connected mode and has not experienced a radio link failure or handover, the source ID is used to identify the ongoing communication in the first level. This eliminates the need for redundant information to be sent as a broadcast indicator. The source ID here refers to the initiator of the multicast communication (group leader). If the UE is still in RRC connected mode and has not experienced a radio link failure or handover, the source ID is used to identify the ongoing communication in the first level. This eliminates the need for redundant information to be sent as a broadcast indicator. This is only updated when the group leader changes.

[0373] For example, unicast or multicast can be derived from the group destination ID or UE destination ID included in the first-level SCI. On the other hand, broadcast can be derived from a flag or bit included in the first-level SCI, or from the absence of any destination ID in the first-level SCI, i.e., the first-level SCI includes neither a group destination ID nor a UE destination ID, which means that the communication is a broadcast. This can be achieved by sending the first-level SCI with a format that is reduced by removing the corresponding destination ID. According to other embodiments, different formats can be provided for the first-level SCI, one with a destination ID and another without a destination ID, the latter indicating a broadcast.

[0374] Therefore, according to an embodiment, unicast communications can be identified by including the destination ID of the UE to which the unicast communication is directed in the first-level SCI. According to another embodiment, the source ID can be used to identify ongoing unicast communications. The source ID here refers to the initiator of the unicast communication. If the UE is still in RRC connected mode and has not experienced a radio link failure or handover, the source ID is used to identify the ongoing communication in the first level. This eliminates the need to send redundant information such as broadcast indicators.

[0375] According to an embodiment, the multicast communication may be identified by a plurality of destination IDs identifying the UEs involved in the multicast communication, or by a group destination ID identifying the group of UEs involved in the multicast communication. According to other embodiments, the source ID may be used as an identification of the multicast communication, for example in the case where the source ID is the group leader of the multicast communication. The source ID here refers to the initiator of the multicast communication (group leader / group leader). If the UE is still in RRC connected mode and has not experienced a radio link failure or handover, the source ID is used to identify the ongoing communication in the first level. This saves redundant information from being sent like a broadcast indicator. This will only be updated when the group leader changes. Note: This will not work in the case of dynamic groups

[0376] According to an embodiment, a broadcast may be identified by the absence of any destination UE ID or group destination ID, i.e. the absence of any destination ID within the first level SCI. To this end, according to an embodiment, another format of the first level SCI may be adopted, which format has no destination ID. According to other embodiments, the broadcast may be derived from the length of the first level SCI, which is shorter when compared to the first level SCI including the destination ID. According to further embodiments, a broadcast specific ID, or a specific pattern or flag may be used to identify the first level SCI as being associated with a broadcast communication. According to an embodiment, the method is used in case the destination ID is conveyed in the first level SCI or is scrambled with the CRC of the first level CSI. According to an embodiment, a flag indicating broadcast or non-broadcast may be provided.

[0377] The receiving UE may implicitly derive information about the propagation type from the received first-level SCI, more specifically from the missing group destination ID or the missing UE destination ID or from the broadcast indication flag.

[0378] In case the UE destination ID or the group destination ID is included in the first level SCI, only the UEs for which the unicast communication or multicast communication is intended (ie, the UEs with the matching ID) can read or decode the second level SCI.

[0379] According to an embodiment, the broadcast ID may include a plurality of bits, for example, 8 bits, consistent with the group destination ID, or a 1-bit indication may be used to indicate the broadcast and other bit fields may be used for other information.

[0380] According to further embodiments, the UE does not expect, e.g., does not read or decode, the second part of the sidelink control message if:

[0381] - the first part of the sidelink control message includes a broadcast ID, such as a broadcast flag or a broadcast bit, indicating a non-broadcast type of communication, and does not include a UE ID, such as a UE destination ID, indicating, for example, a unicast communication, or a group ID, such as a group destination ID, indicating, for example, a multicast communication, or

[0382] - The UE ID or group ID in the first part of the sidelink control message does not match the UE's ID.

[0383] On the other hand, the UE may desire to, for example, read or decode the second part of the sidelink control message in the event that the first part of the sidelink control message includes:

[0384] - a UE ID or group ID that matches the UE's ID, or

[0385] - A broadcast ID indicating a broadcast type of communication, or not including an ID of any type.

[0386] According to an embodiment, the first part of the sidelink control message includes a broadcast ID and a UE ID or a group ID, so that in the case where the broadcast ID indicates a broadcast type of communication, for example, the broadcast flag is set to a first value, the UE determines that the second part of the sidelink control message is related to the UE and will expect, for example, will read or will decode the second part of the sidelink control message, and, in the case where the broadcast ID indicates a non-broadcast type of communication, for example, the broadcast flag is set to a second value, for example, when the UEID or group ID matches the ID of the UE, the UE will determine from the UE ID or group ID whether the second part is a related UE, and will expect, for example, will read or will decode the relevant second part of the sidelink control message.

[0387] According to another embodiment, the sidelink control message with the UE ID or group ID or broadcast ID may be scrambled, for example, using CRC scrambling. The UE is not expected to, for example, not read or decode, the second part of the sidelink control message if the scrambling results in one or more of the following:

[0388] - a broadcast ID indicating a non-broadcast type of communication, and a UE ID or group ID that does not match the UE's ID, or

[0389] - a UE ID or group ID that does not match the UE's ID, and

[0390] On the other hand, the UE may desire, for example, to read or decode the second part of the sidelink control message where the scrambling results in:

[0391] - a UE ID or group ID that matches the UE's ID, or

[0392] - a broadcast ID indicating the broadcast type of communication, or

[0393] -No ID.

[0394] According to an embodiment, the UE may derive, for example implicitly, the broadcast type from the absence of the UE ID or group ID or broadcast ID or any ID in the first part of the sidelink notification message as follows:

[0395] - in case no ID is present in the first part of the Sidelink Control message or the Broadcast ID is set to Broadcast, then it is Broadcast,

[0396] - In case there is a groupcast ID or multiple UE IDs in the first part of the sidelink control message, it is multicast,

[0397] - In case there is a unicast ID in the first part of the sidelink control message, then it is unicast.

[0398] According to other embodiments, the broadcast may be a signal-level broadcast, e.g., all information is included in a single message. In such embodiments, there is no second part of the sidelink control message, and if the first part of the sidelink control message includes a broadcast ID indicating a broadcast type of communication, the UE does not expect, e.g., does not read or decode, the second part of the sidelink control message.

[0399] Overview

[0400] The embodiments of the present invention have been described in detail above, and the corresponding embodiments and aspects can be implemented individually, or two or more embodiments can be implemented in combination. It should be noted that depending on different transmission / reception, such as unicast, groupcast, and multicast, the UE can have multiple destination L1 / L2 IDs and / or multiple source L1 / L2 IDs.

[0401] Embodiments of the present invention have been described above in detail with reference to sidelink communication using the PC5 interface. However, the present invention is not limited to the use of the PC5 interface. Any other interface that allows direct communication between one or more UEs may be employed, such as an interface according to the IEEE 802.11p standard, the IEEE 802.15.4 standard (Zigbee), or the like.

[0402] In some of the above embodiments, reference has been made to a corresponding vehicle in a mode in which SL resource allocation configuration or assistance is provided by a base station (e.g., connected mode, also known as NR mode 1 or LTE mode 3 configuration), or a vehicle in a mode in which SL resource allocation configuration or assistance is not provided by a base station (e.g., idle mode, also known as NR mode 2 or LTE mode 4 configuration). However, the present invention is not limited to V2V communication or V2X communication, but it is also applicable to any device-to-device communication, such as a non-vehicle mobile user or a fixed user performing sidelink communication via a PC5 interface. Likewise, in such scenarios, the above-mentioned aspects of the invention may be adopted.

[0403] Depending on the embodiment, the wireless communication system may include a terrestrial network, or a non-terrestrial network, or a network or network segment using airborne vehicles or spaceborne vehicles as receivers, or a combination thereof.

[0404] According to an embodiment, the receiver may include one or more of the following: a mobile or fixed terminal, an IoT device, a ground vehicle, an aircraft, a drone, a building, or any other item or device with a network connection, enabling the item / device to communicate using a wireless communication network, such as a sensor or actuator. According to an embodiment, the transmitter may include one or more of the following: a macrocell base station, or a small cell base station, or a satellite-borne vehicle (such as a satellite or a spacecraft), or an airborne vehicle (such as an unmanned aerial system (UAS), such as a tethered UAS, a lighter-than-air UAS (LTA), a heavier-than-air UAS (HTA), and a high-altitude UAS platform (HAP)), or any transmission / reception point (TRP) that enables an item or device with a network connection to communicate using a wireless communication system.

[0405] Although some aspects of the described concepts have been described in the context of an apparatus, it is clear that these aspects also represent a description of a corresponding method, where a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.

[0406] The various elements and features of the present invention can be implemented in hardware using analog and / or digital circuits, in software by executing instructions by one or more general or special purpose processors, or as a combination of hardware and software. For example, embodiments of the present invention can be implemented in the environment of a computer system or another processing system. Figure 21An example of a computer system 500 is shown. The units or modules and the steps of the methods performed by these units can be executed on one or more computer systems 500. The computer system 500 includes one or more processors 502, such as special-purpose or general-purpose digital signal processors. The processor 502 is connected to a communication infrastructure 504, such as a bus or network. The computer system 500 includes a main memory 506 (e.g., random access memory (RAM)) and a secondary memory 508 (e.g., a hard drive and / or a removable storage drive). The secondary memory 508 can allow computer programs or other instructions to be loaded into the computer system 500. The computer system 500 can also include a communication interface 510 to allow software and data to be transferred between the computer system 500 and external devices. Communication can be in the form of electronic, electromagnetic, optical or other signals that can be processed by the communication interface. Communication can use wires or cables, optical fibers, telephone lines, cellular phone links, RF links and other communication channels 512.

[0407] The terms "computer program medium" and "computer-readable medium" are generally used to refer to tangible storage media, such as a removable storage unit or a hard disk installed in a hard drive. These computer program products are components for providing software to the computer system 500. Computer programs (also referred to as computer control logic) are stored in the main memory 506 and / or the secondary memory 508. The computer program can also be received via the communication interface 510. When executed, the computer program enables the computer system 500 to implement the present invention. In particular, when executed, the computer program enables the processor 502 to implement the process of the present invention, such as any of the methods described herein. Accordingly, this computer program can represent a controller of the computer system 500. In the case of using software to implement the present disclosure, the software can be stored in a computer program product and loaded into the computer system 500 using a removable storage drive or an interface (such as the communication interface 510).

[0408] The implementation in hardware or software may be performed using a digital storage medium, such as cloud storage, floppy disk, DVD, Blu-ray, CD, ROM, PROM, EPROM, EEPROM or flash memory, on which electronically readable control signals are stored, which cooperate (or are capable of cooperating) with a programmable computer system to perform the corresponding method. The digital storage medium may thus be computer readable.

[0409] Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0410] Generally, embodiments of the present invention can be implemented as a computer program product with a program code, wherein the program code is operative for performing one of the methods when the computer program product runs on a computer. The program code may, for example, be stored on a machine-readable carrier.

[0411] Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier. In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0412] A further embodiment of the inventive method is therefore a data carrier (or a digital storage medium, or a computer-readable medium) comprising a computer program recorded thereon for performing one of the methods described herein. A further embodiment of the inventive method is therefore a data stream or a signal sequence representing the computer program for performing one of the methods described herein. The data stream or signal sequence can, for example, be configured to be transmitted via a data communication connection (for example via the Internet). A further embodiment comprises a processing unit, such as a computer or a programmable logic device, which is configured to or adapted to perform one of the methods described herein. A further embodiment comprises a computer having installed thereon a computer program for performing one of the methods described herein.

[0413] In some embodiments, a programmable logic device (e.g., a field programmable gate array) can be used to perform some or all of the functions of the method described herein. In some embodiments, the field programmable gate array can collaborate with a microprocessor to perform one of the methods described herein. Typically, the method is preferably performed by any hardware device.

[0414] The above embodiments are intended to illustrate the principles of the present invention only. It should be understood that modifications and variations of the arrangements and details described herein will be readily apparent to those skilled in the art. Accordingly, it is intended that the present invention be limited solely by the scope of the following patent claims and not by the specific details presented through the description and explanation of the embodiments herein.

[0415] List of abbreviations and symbols

[0416]

[0417] References

[0418] [1]3GPP TS 36.213, "E-UTRA; Physical layer procedures (Release 15)", V15.6.0, June 2019

[0419] [2]3GPP TS 36.211,“E-UTRA;Physical channels and modulation(Release15)”,V15.6.0,June 2019

[0420] [3]T.S.Rappaport,Wireless Communications,Prentice Hall,2002

[0421] [4]RAN1#97Chairman’s Notes Chairman’s Notes,3GPP TSG RAN WG1#97,May2019

[0422] [5]TR 38.885 3GPP TR 38.885,“NR Study on Vehicle-to-everything”,V16.0.0,March 2019.

[0423] [6]R1-1907924 3GPP TDoc R1-1907924,“Feature lead summary#4for7.2.4.1Physical layer structure for sidelink”,Samsung,3GPP RAN1#97,May 2019

[0424] [7]RP-190984 3GPP TDoc RP-190984,“Revised WID on 5G V2X with NRsidelink”,LG Electronics,Huawei,3GPP RAN#84,June 2019.

[0425] [8]3GPP TS23.303,“Proximity-based services(ProSe);Stage 2(Release15)”,V15.0.0,June 2017

Claims

1. A user equipment UE for a wireless communication system, wherein The UE is to be connected to one or more other UEs in the wireless communication system to perform sidelink communications with the one or more other UEs, the sidelink communications comprising one or more sidelink control messages to be sent on sidelink resources, The UE will identify the sidelink control message intended for the UE, The UE is to decode the sidelink control message for the UE to obtain control information embedded in the sidelink control message, said information embedded in said sidelink control message indicating a configuration of a further message, said further message comprising further control information and / or data, said information embedded in said sidelink control message indicates a periodicity of transmission of said sidelink message and / or said further message, and The predefined value for the periodicity signals a single transmission of the sidelink control message and / or the further message without any periodicity, or a release of a previous periodicity.

2. The user equipment according to claim 1, wherein The information embedded in the sidelink control message indicates time and frequency resources to be used for the further message.

3. The user equipment according to claim 2, wherein: The time and frequency resources used for the sidelink control message and the time and frequency resources used for the further message are one or more of: - adjacent in the time domain, - non-adjacent in the time domain, with or without a time gap between said time and frequency resources used for said sidelink control message and said time and frequency resources used for said further message, - adjacent in the frequency domain, - are not adjacent in the frequency domain, - in the same resource pool, or -In different resource pools.

4. The user equipment according to claim 1, wherein: The information embedded in the sidelink control message indicates one or more of the following: - the number of symbols in the time domain, - Whether the transmission is unicast, multicast or broadcast, - indicating a time offset of said further message relative to said sidelink control message, - A pointer to the physical channel associated with the sidelink control message. The user equipment according to claim 1 , wherein: The information embedded in the first part of the sidelink control message indicates one or more of the following: - a priority level of transmission associated with said sidelink control message, a new data indicator NDI or a retransmission indicator, which indicates whether the transmission associated with the sidelink control message comprises new data and is a retransmission, - retransmission gap, which indicates whether the retransmission is a non-autonomous retransmission, or whether autonomous retransmission is active with a configured retransmission gap, - a DMRS pattern for the second part of the sidelink control message, - CDM groups and / or ports for the second part of the sidelink control message and a sidelink data channel such as PSSCH, -Timing Advance Indicator, -Reservation periodicity. The user equipment according to claim 1 , wherein: The sidelink control message includes a first portion of the control information, And the further message comprises at least the second part of the control information, and / or one or more transmission reservations for the data.

7. The user equipment according to claim 1, wherein: The UE will derive from information in the first part of the sidelink control message whether the sidelink control message is intended for the UE.

8. The user equipment according to claim 1, comprising: One or more of the following: a mobile terminal, or a fixed terminal, or a cellular IoT UE, or a vehicle UE, or an IoT or narrowband IoT NB-IoT device, or a ground vehicle, or an aircraft, or a drone, or a mobile base station, or a roadside unit, or a building, or any other item or device provided with network connectivity that enables the item / device to communicate using the wireless communication system, or Base station, including one or more of the following: a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or a roadside unit, or a UE, or a remote radio head, or an AMF, or an SMF, or a core network entity, or a network strip such as in the context of NR or 5G core, or any transmission / reception point TRP that enables an item or device to communicate using the wireless communication system, and the item or device is provided with network connectivity for communicating using the wireless communication system.

9. A network entity for a wireless communication system, the wireless communication comprising one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, the sidelink communication comprising one or more sidelink control messages to be sent on a sidelink resource, wherein The network entity will signal a sidelink control message to a receiving UE or a group of receiving UEs, wherein information embedded in the sidelink control message indicating configuration of further messages, the further messages comprising further control information and / or data, said information embedded in said sidelink control message indicates a periodicity of transmission of said sidelink message and / or said further message, and The predefined value for the periodicity signals a single transmission of the sidelink control message and / or the further message without any periodicity, or a release of a previous periodicity.

10. A wireless communication system, comprising the user equipment according to claim 1 or the network entity according to claim 9.

11. The wireless communication system according to claim 10 comprises one or more base stations, wherein the base stations comprise one or more of the following: a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or a roadside unit, or a UE, or a remote radio head, or an AMF, or an SMF, or a core network entity, or a network strip such as in the context of NR or 5G core, or any transmission / reception point TRP that enables an item or device to communicate using the wireless communication system, and the item or device is provided with network connectivity for communicating using the wireless communication system.

12. A method for a wireless communication system, the method comprising: connecting the UE to one or more further UEs in the wireless communication system for sidelink communications with the one or more further UEs, the sidelink communications comprising one or more sidelink control messages to be sent on sidelink resources, identifying, by the UE through blind decoding, a sidelink control message intended for the UE, and decoding, by the UE, the sidelink control message for the UE to obtain control information embedded in the sidelink control message, wherein the information embedded in the sidelink control message indicates configuration of a further message, the further message comprising further control information and / or data, wherein the information embedded in the sidelink control message indicates a periodicity of transmission of the sidelink message and / or the further message, and Therein, the predefined value for the periodicity signals a single transmission of the sidelink control message and / or the further message without any periodicity, or a release of a previous periodicity.

13. A method for a wireless communication system, the wireless communication comprising one or more UEs to be connected to one or more other UEs for sidelink communication with the one or more other UEs, the sidelink communication comprising one or more sidelink control messages to be sent on a sidelink resource, the method comprising: signaling, by a network entity, a sidelink control message to a receiving UE or group of receiving UEs, wherein information embedded in the sidelink control message indicates configuration of further messages, the further messages comprising further control information and / or data, wherein the information embedded in the sidelink control message indicates a periodicity of transmission of the sidelink message and / or the further message, and Therein, the predefined value for the periodicity signals a single transmission of the sidelink control message and / or the further message without any periodicity, or a release of a previous periodicity.

14. A non-transitory computer program product comprising a computer-readable medium storing instructions which, when executed on a computer, perform the method according to claim 12 or 13.

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