Wireless communication system having specific sidelink frame structure

Abstract

To provide an improved frame structure for sidelink communication for a wireless communication system in which multiple users perform sidelink communication.SOLUTION: A wireless communication system includes one or more base stations and a plurality of user devices. Sidelink communication by the user devices includes one or more sidelink frames each having a control region and a data region, where the control region includes a first control region and a second control region, where the first control region includes basic information regarding sidelink transmission of a packet, and the second control region includes information regarding one or more data transmission resource locations of the packet. The packet transmission uses two or more data transmission resource locations in a single sidelink frame, and the packet is transmitted in data transmission resource locations across one or more subsequent sidelink frames, or multiple versions of the packet are transmitted in data transmission resource locations across one or more subsequent sidelink frames.SELECTED DRAWING: Figure 5a

Description

[Technical field]

[0001] The present application relates to the field of wireless communication networks or systems, and more particularly to sidelink communication of user devices in such communication systems. Embodiments relate to a new radio sidelink frame structure NR SL FS. Further embodiments refer to a communication system, corresponding UE, base station, and method. Preferred embodiments relate to NR V2X-enabled slot aggregation using two-stage SCI. [Background technology]

[0002] FIG. 1 is a schematic diagram of an example of a terrestrial wireless network 100, which includes a core network 102 and one or more radio access networks RAN1, RAN2, ...RAN1, as shown in FIG. 1(a). N FIG. 1(b) shows the radio access network RAN. n 1 is a schematic diagram of an example of a radio access network RAN nmay include one or more base stations gNB1 to gNB5, each serving a particular area surrounding the base station, represented diagrammatically by corresponding cells 1061 to 1065. The base stations are provided to serve users in the cells. The term base station BS refers to gNB in ​​5G networks, eNB in ​​UMTS / LTE / LTE-A / LTE-A Pro, or simply BS in other mobile communication standards. The users may be fixed or mobile devices. The wireless communication system may also be accessed by mobile or fixed IoT devices that connect to the base station or the user. The mobile or IoT devices may be physical devices, ground vehicles such as robots or cars, aerial vehicles such as manned aerial vehicles or unmanned aerial vehicles (UAVs) (the latter also called drones), buildings, as well as other items or devices embedded with electronic circuits, software, sensors, actuators, etc., and network connectivity that allows these devices to collect and exchange data across the existing network infrastructure. FIG. 1(b) shows merely an exemplary diagram of five cells, but the RAN may also include a RAN. n may contain more or fewer such cells, and the RAN nmay include only one base station. Fig. 1(b) shows two users UE1 and UE2, also called user equipment UE, in a cell 1062 and served by a base station gNB2. Another user UE3 is shown in a cell 1064 served by a base station gNB4. Arrows 1081, 1082, and 1083 represent diagrammatically uplink / downlink connections for transmitting data from users UE1, UE2, and UE3 to base stations gNB2, gNB4 or from base stations gNB2, gNB4 to users UE1, UE2, UE3. Furthermore, Fig. 1(b) shows two IoT devices 1101 and 1102 in the cell 1064, which may be fixed or mobile devices. The IoT device 1101 accesses the wireless communication system via base station gNB4 to receive and transmit data, as diagrammatically represented by arrow 1121. The IoT device 1102 accesses the wireless communication system via a user UE3, as represented diagrammatically by the arrow 1122. Each base station gNB1 to gNB5 can be connected to the core network 102, e.g., via an S1 interface, via corresponding backhaul links 1141 to 1145, which are diagrammatically represented in FIG. 1(b) by the arrow pointing to "core". The core network 102 can be connected to one or more external networks. Furthermore, some or all of the respective base stations gNB1 to gNB5 can be connected to each other, e.g., via an S1 or X2 interface, or an XN interface in NR, via corresponding backhaul links 1161 to 1165, which are diagrammatically represented in FIG. 1(b) by the arrow pointing to "gNB".

[0003] A physical resource grid may be used for data transmission. The physical resource grid may comprise a set of resource elements onto which various physical channels and physical signals are mapped. For example, the physical channels may include a physical downlink shared channel, a physical uplink shared channel, and a physical sidelink shared channel (PDSCH, PUSCH, PSSCH) carrying user-specific data also referred to as downlink payload data, uplink payload data, and sidelink payload data, a physical broadcast channel (PBCH) carrying, for example, a master information block (MIB) and a system information block (SIB), a physical downlink control channel, a physical uplink control channel, and a physical sidelink control channel (PDCCH, PUCCH, PSCCH) carrying, for example, downlink control information (DCI), uplink control information (UCI), and sidelink control information (SCI). In the uplink, the physical channels may further include a physical random access channel (PRACH or RACH) used by the UE to access the network after the UE synchronizes and acquires the MIB and SIB. The physical signals may include reference signals or symbols (RS), synchronization signals, etc. The resource grid may comprise a frame or radio frame having a certain duration in the time domain and a given bandwidth in the frequency domain. The frame may have a certain number of subframes with a predefined length. Each subframe may include one or more slots, consisting of 12 or 14 OFDM symbols depending on the cyclic prefix (CP) length. The frame may also consist of fewer OFDM symbols, for example when utilizing a reduced transmission time interval (sTTI) or a minislot / non-slot based frame structure with 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, e.g., DFT-s-OFDM. Other waveforms may be used, such as non-orthogonal waveforms for multiple access, e.g., 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 standard or the NR, i.e., New Radio standard.

[0005] The wireless network or wireless communications system depicted in FIG. 1 may be a heterogeneous network having separate overlapping networks, e.g. a network of macro cells, each macro cell including a macro base station, such as base stations gNB1 to gNB5, and a network of small cell base stations, such as femto base stations or pico base stations (not shown in FIG. 1).

[0006] In addition to the terrestrial wireless networks described above, there are also non-terrestrial wireless communication networks, including spaceborne transceivers such as satellites and / or airborne transceivers such as unmanned aerial systems. The non-terrestrial wireless communication networks or systems may operate, for example, according to the LTE-Advanced Pro standard, or the 5G standard or the NR, i.e. new radio standard, similar to the terrestrial systems described above with reference to FIG. 1.

[0007] In a mobile communication network, such as a LTE network or a 5G / NR network, as described above with reference to FIG. 1, there may be UEs that communicate directly with each other via one or more sidelink (SL) channels, e.g. using a PC5 interface. The UEs that communicate directly with each other via sidelink may be vehicles that communicate directly with other vehicles (V2V communication), vehicles that communicate with other entities of the wireless communication network, e.g. roadside entities such as traffic lights, traffic signs, or pedestrians (V2X communication). The other UEs may not be vehicle-related UEs and may comprise any of the devices described above. Such devices may also communicate directly with each other (D2D communication) using the SL channels.

[0008] When considering two UEs that communicate directly with each other via sidelink, both UEs may be served by the same base station, which may provide sidelink resource allocation configuration or assistance to them. For example, both UEs may be within the coverage area of ​​a base station, such as one of the base stations depicted in FIG. 1. This is called an "in-coverage" scenario. Another scenario is called an "out-of-coverage" scenario. "Out-of-coverage" does not mean that the two UEs are not in one of the cells depicted in FIG. 1, but rather that the UEs are in one of the cells. - they may not be connected to a base station, e.g. they are not in an RRC connected state, whereby the UE does not receive any sidelink resource allocation configuration or assistance from the base station, and / or - the UE may be connected to a base station, but for one or more reasons the base station may not provide the UE with sidelink resource allocation configuration or assistance; and / or - May be connected to base stations that cannot support NR V2X services, such as GSM base stations, UMTS base stations, LTE base stations, and NR base stations that do not support V2X services. It will be noted that this means

[0009] Yet another scenario is called the "partial coverage" scenario, according to which one of two UEs communicating with each other via sidelink is served by the base station, while the other UE is not served by the base station.

[0010] When considering two UEs communicating directly with each other via sidelink, e.g. PC5, one of the UEs can also be connected to a BS and can relay information from the BS to the other UE via the sidelink interface. The relaying can be performed in the same frequency band (in-band-relay) or using another frequency band (out-of-band relay). In the first case, the communication on Uu and on the sidelink can be separated using different time slots, similar to a time division duplex (TDD) system.

[0011] Figure 2 is a schematic diagram of a situation where two UEs communicating directly with each other are both within the coverage of a base station. The base station gNB has a coverage area, which is represented diagrammatically by a circle 200, which essentially corresponds to the cell represented diagrammatically in Figure 1. The UEs communicating directly with each other include a first vehicle 202 and a second vehicle 204, both of which are within the coverage area 200 of the base station gNB. Both vehicles 202, 204 are connected to the base station gNB, and in addition, they are directly connected to each other via a PC5 interface. Scheduling and / or interference management of V2V traffic is assisted by the gNB via control signaling over the Uu interface, which is the radio interface between the base station and the UEs. The gNB allocates resources used for V2V communication over the sidelink. This configuration is also called Mode 1 configuration in NR V2X or Mode 3 configuration in LTE V2X.

[0012] FIG. 3 is a schematic diagram of a situation where the UEs are not in the coverage of a base station, i.e., the respective UEs that communicate directly with each other may be physically within a cell of the wireless communication network but are not connected to the base station. The three vehicles 206, 208, and 210 are shown in the figure directly connected to each other via sidelinks, for example using a PC5 interface. Scheduling and / or interference management of V2V traffic is based on algorithms implemented between these vehicles. This configuration is also called Mode 2 configuration in NR V2X or Mode 4 configuration in LTE V2X. As mentioned above, the scenario of FIG. 3 being an out-of-coverage scenario does not mean that the respective Mode 4 UE is outside the coverage 200 of the base station, but rather that the respective Mode 4 UE is not served by the base station, is not connected to a 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 a situation where in addition to mode 3 UEs 202, 204, mode 4 UEs 206, 208, 210 are present within the coverage area 200 shown in FIG.

[0013] In the above-mentioned scenario of a vehicular user device UE, a plurality of such user devices may form a user device group, also simply referred to as a group, and communication within the group or between the group members may be performed via a sidelink interface between the user devices, such as a PC5 interface. A plurality of such groups may exist simultaneously within a wireless communication network or within a cell thereof. Although it is stated that communication within the group is performed via sidelink communication, in the case where the group or at least some of its group members are in coverage, this does not exclude that some or all of the group members may also communicate with other entities outside the group, via a base station or via a sidelink. For example, the above-mentioned scenario using a vehicular user device may be used in the transportation industry sector, where a plurality of vehicles equipped with vehicular user devices may be grouped together, for example by a remote driving application.

[0014] Other use cases where multiple user devices can be grouped together to be able to communicate sidelink between each other include, for example, factory automation and power distribution. In the case of factory automation, multiple mobile or fixed machines in a factory can be equipped with user devices and grouped together to be able to communicate sidelink between each other, for example for control of the machine's operation, such as the motion control of a robot. In the case of power distribution, entities in the power distribution grid can be equipped with corresponding user devices and grouped together in certain areas of the system to communicate with each other via sidelink communication, which can enable monitoring of the system and addressing faults and outages in the power distribution grid.

[0015] Of course, in the above mentioned use cases, sidelink communication is not limited to intra-group communication, but rather sidelink communication can take place between any of the UEs, such as any pair of UEs.

[0016] It should be noted that the information in the above section is merely intended to enhance understanding of the background of the present invention, and thus it may contain information that does not constitute prior art already known to those skilled in the art. Summary of the Invention [Problem to be solved by the invention]

[0017] Departing from the above-mentioned prior art, for wireless communication systems in which multiple users can conduct sidelink communication, there may be a need for an improved frame structure for such sidelink communication. [Means for solving the problem]

[0018] Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. [Brief description of the drawings]

[0019] [Figure 1(a)] FIG. 1 is a schematic diagram of an example of a wireless communication system. [Figure 1(b)] FIG. 1 is a schematic diagram of an example of a wireless communication system. [Diagram 2] 1 is a schematic diagram of a situation in which UEs that communicate directly with each other are within the coverage of a base station; [Diagram 3] A diagram showing a scenario in which UEs that communicate directly with each other are not within the coverage of a base station, i.e., are not connected to the base station. [Figure 4] FIG. 2 illustrates an example of a resource pool defined over time and frequency. [Figure 5a]FIG. 13 is an exemplary diagram of a sidelink frame structure to illustrate an embodiment in which a first control region and a second control region are placed in the same timeslot together with a data region. [Figure 5b] FIG. 1 shows a schematic sidelink frame structure to illustrate an embodiment in which the first control region and the second control region are located in different time slots. [Figure 6a] FIG. 5 c illustrates a sidelink frame structure comparable to that shown by FIG. 5 a, in which the first control region is repeated according to an embodiment; [Figure 6b] FIG. 5b illustrates a sidelink frame structure comparable to that of FIG. 5b, in which the first control region is repeated according to a further embodiment; [Figure 7a] FIG. 2 illustrates a schematic diagram of a time frame structure according to an embodiment using another channel, for example PC5-RRC or Uu-RRC. [Figure 7b] FIG. 2 illustrates a schematic diagram of a time frame structure according to an embodiment using another channel, for example PC5-RRC or Uu-RRC. [Figure 7c] FIG. 2 illustrates a schematic diagram of a time frame structure according to an embodiment using another channel, for example PC5-RRC or Uu-RRC. [Figure 8] FIG. 1 illustrates an example of a computer system on which the units or modules and method steps described in accordance with the present technique can be executed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] 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 assigned the same reference numerals.

[0021] The initial Vehicle-to-Everything (V2X) specification was included in Release 14 of the 3GPP® standard. Resource scheduling and allocation have been modified according to V2X requirements, while the original Device-to-Device (D2D) communication standard is used as the basis for the design. Release 15 of the LTE V2X standard (also known as enhanced V2X or eV2X), as well as Release 16 of 3GPP® and the first release of 5G NR V2X, respectively, focus on V2X slot aggregation. NR V2X identifies a set of use cases to be achieved, and one of the main focus areas of these use cases is to guarantee a certain quality of service (QoS) for a given application service.

[0022] According to one aspect, a two-stage sidelink control information (SCI) can be advantageously used. The first stage is used to transmit basic information to the UE, which includes a pointer to a second stage SCI, which is combined with the corresponding data transmission. Another aspect is how to handle slot aggregation for larger capacity transmissions.

[0023] Since the control region is defined for one time slot, an objective is to optimize the use of the control region, particularly for the use of slot aggregation, and to achieve maximum reliability in transmission.

[0024] According to an embodiment (main aspect), a wireless communication system may or may not consist of one or more base stations and a plurality of user equipments UEs configured for sidelink communication (e.g. sidelink transmission), the sidelink communication comprising one or more sidelink frames each having a control region and a data region, the control region comprising a first control region and a second control region, the first control region including basic information regarding the sidelink transmission of a packet and the second control region including information regarding one or more data transmission resource locations of the packet, where the transmission of the packet uses two or more data transmission resource locations in a single sidelink frame and / or the packet is to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames or multiple versions of the packet are to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames.

[0025] With respect to a wireless system, a base station may or may not be present, corresponding to in-coverage or out-of-coverage scenarios, or NR mode 1 and NR mode 2 operation of the UE.

[0026] Regarding slot aggregation, it should be noted that this concept can be used to send larger size packets or to send different redundant versions of the same packet.

[0027] The embodiment of the present invention is based on the principle that a control region can consist of two stages and that a dedicated portion in a time frame can be reserved for the two stages / control regions. The second stage SCI can contain information indicating one or more locations of the data transmission, for example in the same or subsequent timeslots. In particular, in NR V2X applications that depend on slot aggregation, the two-stage SCI is beneficial. This concept allows providing the main information in the SCI whether each data transmission will use aggregated data resources or a single data resource. In the case that multiple data resources are to be aggregated, the transmitted packet spans two or more timeslots. Below is the content of the control information transmitted in the two control regions (in these aggregated slots):

[0028] It should be noted that according to embodiments, one or more subsequent sidelink frames may be located as consecutive or non-consecutive sidelink frames for the transmission of a packet by a given UE, which means, for example, that between two subsequent sidelink frames used for said sidelink transmission, zero, one or more further sidelink frames may be located, where the intervening sidelink frame, if any, may be used by other UEs.

[0029] Two basic cases are distinguished: according to the first case, the first and the second control regions are transmitting using the same sidelink frame, in which case both control regions can also be transmitted together with a part of the data transmission (e.g. the first part of a packet) or together with the first version of the data transmission, for example when a redundant version of the same packet is to be transmitted.

[0030] According to an embodiment, the first control region may include information pointing to a second control region located in the same sidelink frame as well as to a second control region in each of one or more subsequent sidelink frames.

[0031] According to further embodiments, the sidelink transmission made by the UE may use one or more subsequent sidelink frames, the first control region of which is free or to be used by another UE or UEs.

[0032] It should be noted that the control region is free with respect to a particular UE of the communication system. Other UEs are free to use the free first control region, for example for preemption or reservation of resources.

[0033] According to an embodiment, the sidelink transmission uses one or more subsequent sidelink frames, and the information of the first control region transmitted using the first sidelink frame is resent in the first control region of the one or more subsequent sidelink frames, said first control region including information pointing to a second control region in the further one or more subsequent sidelink frames.

[0034] According to further embodiments, the sidelink transmission may use one or more subsequent sidelink frames, the second control field of the one or more subsequent sidelink frames containing information on the data transmission resource location or locations of the respective sidelink frame.

[0035] According to a second case (embodiment), the first control region and the second control region are transmitted using different sidelink frames, e.g. subsequent sidelink frames, where subsequent means located as consecutive or non-consecutive sidelink frames. For example, the first control region is transmitted using a first sidelink frame and the second control region is transmitted using a subsequent second sidelink frame. Here, the first control information may according to the embodiment include information pointing to the second control region in the respective sidelink frame or in the subsequent sidelink frame.

[0036] According to an embodiment, a second control region belonging to a sidelink frame in which the first control region is transmitted is left free by the UE making a given transmission and can be used by another UE or multiple UEs.

[0037] According to an embodiment, the sidelink transmission uses one or more subsequent sidelink frames, each of which comprises a respective second control part or each of which includes information pointing to a data region.

[0038] According to embodiments, the respective first control part is retransmitted in one or more of the subsequent side link frames or each first control part includes information pointing to one or more second control parts in one or more further subsequent side link frames.

[0039] In connection with all the embodiments discussed above, it is noted that according to further embodiments, the first control part may contain information on a destination ID of the RX UE or information on a number of data transmission resource locations and / or a number of sidelink frames used for the data transmission resource locations and / or information pointing to a respective second control part transmitted using a subsequent sidelink frame.

[0040] Embodiments provide a user device UE for a wireless communication system with or without one or more base stations and a plurality of user devices UE configured for sidelink communication, the sidelink communication comprising one or more sidelink frames each having a control region and a data region, the control region comprising a first control region and a second control region, the first control region including basic information regarding a sidelink transmission of a packet and the second control region including information regarding one or more data transmission resource locations of the packet, where the transmission of the packet uses two or more data transmission resource locations in a single sidelink frame and / or the packet is to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames or multiple versions of the packet are to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames.

[0041] An embodiment provides a base station for a wireless communication system having one or more base stations and a plurality of user devices UE configured for sidelink communication, the sidelink communication comprising one or more sidelink frames each having a control region and a data region. The control region comprises a first control region and a second control region, the first control region including basic information regarding a sidelink transmission of a packet and the second control region including information regarding one or more data transmission resource locations of the packet. The transmission of the packet uses two or more data transmission resource locations in a single sidelink frame and / or the packet is to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames or multiple versions of the packet are to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames.

[0042] Embodiments provide a method for sidelink communication in a wireless communication system with or without one or more base stations and multiple user devices UE configured for sidelink communication, the sidelink communication comprising one or more sidelink frames each having a control region and a data region. The control region comprises a first control region and a second control region, the first control region including basic information regarding a sidelink transmission of a packet and the second control region including information regarding one or more data transmission resource locations of the packet. The transmission of the packet uses two or more data transmission resource locations in a single sidelink frame and / or the packet is to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames or multiple versions of the packet are to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames.

[0043] It should be noted that in a given transmission time interval TTI or subframe, the transmitting UE broadcasts sidelink control information SCI in a control channel followed by data in the same subframe. The SCI indicates the resources in the subframe on which the data is transmitted, and the receiving UE listens to the control subchannel so that when it receives the SCI it knows where the data is supposed to be received.

[0044] According to an embodiment (further aspect), a wireless communication system comprises zero, one or more base stations and a plurality of user equipments UEs configured for (sidelink) communication, the (sidelink) communication comprising one or more (sidelink) frames each having a control region and a data region, wherein control information belonging to a first control region is transmitted in the control region as a first control region of the control region, and control information belonging to a second control region is transmitted or partially transmitted using a layer 2 (PC5-) RRC configuration.

[0045] Embodiments of this aspect are based on the insight that information that is typically transmitted using the second control domain (see above) may be transmitted fully or partly via a kind of higher layer signaling sent via the sidelink or PC5 (PC5 Radio Resource Control Configuration also called Sidelink Radio Resource Control Configuration), in this case Layer 2 PC5-RRC configuration.

[0046] It should be noted that "completely" means that only the first control region in a sidelink frame is used, while the complete information belonging to the second control region is transmitted using PC5-RRC. "Partially" means that the first control region and the second control region with a reduced size are used together with the Layer 2 PC5-RRC configuration. This is beneficial, since the reduced size of the second control region (reduced to zero according to the embodiment) allows more resources for data transmission in the respective sidelink frame. As the first control region is used in the respective sidelink frame, it is still possible to direct the respective sidelink communication.

[0047] According to an embodiment, the control information belonging to the second control region is partially transmitted as the second control region of the control region.

[0048] According to an embodiment, the first control region is transmitted using a sidelink frame prior to or together with a sidelink frame used for the sidelink transmission of the packet.

[0049] According to an embodiment, the second control region is transmitted using one or more subsequent time sidelink frames.

[0050] According to the embodiment, the size for transmitting the second control region is gradually reduced. In other words, the amount of control information belonging to the second control region and transmitted using the second control region is reduced and the amount of control information belonging to the second control region and transmitted using the layer 2 PC5-RRC configuration is increased, or vice versa, the amount of control information belonging to the second control region and transmitted using the second control region is increased and the amount of control information belonging to the second control region and transmitted using the layer 2 PC5-RRC configuration is reduced. The respective increase and decrease of the amount of control information belonging to the second control region is performed for the number of one or more subsequent time sidelink frames. For example, the amount of control information sent in the second control region is gradually reduced in each subsequent sidelink frame used for transmission.

[0051] According to an embodiment, the second control region is transmitted using a sidelink frame prior to or together with the sidelink transmission of the packet.

[0052] According to an embodiment, the first control region includes information pointing to the second control region or pointing to information belonging to the second control region that is transmitted or partially transmitted using a layer 2 PC5-RRC configuration. Alternatively, the information belonging to the second control region that is transmitted or partially transmitted as the second control region of the control region includes information pointing to the second control region or pointing to information belonging to the second control region that is transmitted or partially transmitted using a layer 2 PC5-RRC configuration and / or the second control region includes information regarding one or more data transmission resource locations of the packet.

[0053] According to embodiments, the transmission of a packet uses more than one data transmission resource location within a single sidelink frame and / or the packet is to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames, or multiple versions of a packet are to be transmitted in the data transmission resource locations across one or more subsequent sidelink frames.

[0054] According to further embodiments, the principles discussed above of using RRC configurations may be applied to communications between a base station and a UE.

[0055] Therefore, an embodiment provides a communication system, wherein the control information is control information transmitted by one or more base stations, where information belonging to a second control domain is transmitted using an RRC configuration over a Uu link rather than an RRC configuration over a PC5 link.

[0056] Another embodiment provides a user device UE for a wireless communication system with or without one or more base stations and a plurality of user devices UE configured for (sidelink) communication, the (sidelink) communication comprising one or more (sidelink) frames each having a control region and a data region, the control information belonging to a first control region being transmitted in the control region as a first control region of the control region and the control information belonging to a second control region being transmitted or partially transmitted using a layer 2 PC5-RRC configuration (generally RRC).

[0057] Another embodiment provides a base station for a wireless communication system having one or more base stations and a plurality of user devices UE configured for (sidelink) communication comprising one or more (sidelink) frames each having a control region and a data region, where control information belonging to a first control region is transmitted in the control region as a first control region of the control region and control information belonging to a second control region is transmitted or partially transmitted using a layer 2 (PC5-) RRC configuration.

[0058] Another embodiment provides a method for wireless (sidelink) communication in a wireless communication system with or without one or more base stations and a plurality of user devices UE configured for (sidelink) communication, the (sidelink) communication comprising one or more sidelink frames each having a control region and a data region, where control information belonging to a first control region is transmitted in the control region as a first control region of the control region and control information belonging to a second control region is transmitted or partially transmitted using a layer 2 (PC5-) RRC configuration.

[0059] With respect to all the embodiments / aspects discussed above, it should be mentioned that according to an embodiment, the UE may comprise one or more of 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 terrestrial base station vehicle, or an air vehicle, or a drone, or a mobile base station, or a roadside unit, or a building, or any other item or device with network connectivity enabling an item / device to communicate using a wireless communication network, such as a sensor or an actuator, and the base station comprises one or more of a macro cell base station, or a small cell base station, or a base station central unit, or a base station distributed unit, or a roadside unit, or a UE, or a remote radio head, or an AMF, or an SMF, or a core network unit, or a network slice as found in the context of NR or 5G Core, or any transmit / receive point TRP enabling an item or device with network connectivity to communicate using a wireless communication network to communicate using a wireless communication network.

[0060] According to an embodiment, a sidelink frame comprises a transmission time interval, i.e. a regular interval for which a device has reserved resources, such as a sidelink subframe, TTI, slot and / or minislot.

[0061] With regard to the methods mentioned above, it should be noted that these methods may be computer-implemented, and therefore in one embodiment reference is made to a computer program for carrying out instructions defined by the methods discussed above.

[0062] It should be noted that all the optional features discussed above, which have been fully discussed in the context of a communication system, may also be used in a corresponding device (UE or BS) or in a corresponding method.

[0063] In the following, the embodiments will be discussed in detail with reference to the accompanying drawings. The discussion is made assuming the case where the transmitted data packet needs to span multiple time slots. In this case, the first stage informs the RX UE about the number of upcoming retransmissions and the location of the second stage SCI corresponding to each of the retransmissions. The second stage contains information about the retransmission resource location, where the second stage SCI and data are contained in the same time slot. The inventors propose the following methods to utilize the control region in the two-stage SCI model, which are appropriately depicted in the diagrams of Figures 5a to 7.

[0064] According to a basic embodiment, the control channel comprises a first control region and a second control region, as illustrated for example by Fig. 5a.

[0065] Figure 5a shows a design of a frame structure 1, for example used in NR V2X. Figure 5 shows six time frames marked t1 to t6. Within each time frame t1 to t6, three parts are shown: two control regions 10c1 and 10c2 and a data region 12d. In other words, this means that for each time frame / sidelink frame, a control region 10c and a data region 12d are present in every timeslot. The control region 10c is divided to accommodate the two stages 10c1 and 10c2 of the transmitted SCI.

[0066] The sidelink structure 1 may contain resource portions having, for example, a time domain (frames t1 to t6) as well as a frequency domain (along which the control portions 10c1, 10c2 and the data portion 12d are arranged), which may also be called subchannels defined within a bandwidth portion (BWP).

[0067] As already indicated, a distinction is made between the case where a data packet can be transmitted in the data region within a single timeslot without timeslot aggregation (SOTA) and the case where it can be transmitted in different timeslots, where, with respect to FIG. 5a, there is timeslot aggregation and the first stage SCI 10C1 and the second stage SCI 10C2 transmit in the same timeslot, e.g. t1.

[0068] According to an embodiment, the first stage / first control area 10c1 may contain basic information, for example regarding the destination ID of the RX UE. Furthermore, according to an embodiment, the control area 10c1 may contain a pointer pointing to the second control area 10c2 or, among other things, to one or more second control areas 10c2 arranged in a subsequent timeslot, in this case timeslots t3 and t5. This pointer is indicated by the reference number 14p1. According to an embodiment, the second stage / second control area 10c2 may contain information regarding the data transmission resource location of the packet. This may also include a pointer 14p2 pointing to the respective data area 12d. Since slot aggregation is preferably used for the transmission of the packet, the information contained by 10c2 may include one or more pointers 14p2 pointing to multiple data areas 12d of multiple timeslots t1, t3 and t5. Of course, it should be noted that the pointer 14p2 of the control area 10c2 transmitted using time slot t3 simply contains a pointer to the data portion 12d of t3 and optionally t5. In other words, starting from the assumption that slot aggregation is used, this means that the second stage 10c2 contains information about the retransmission resource location.

[0069] Below, this principle is discussed in detail, including optional elements.

[0070] The first stage SCI 10c1, the first one of the second stage SCIs 10c2 and the first transmission 12d are located in the same timeslot, in this case timeslot t1. In this case there is no prior reservation of said (sidelink) transmission. The RX UE will become aware of the transmission via the first stage SCI 10c1, which points to the first one of the second stage SCIs 10c2, which points to the first transmission 12d of data belonging to time frame t1. In the timeslot t3 for the second transmission, the control area of ​​the first stage SCI (i.e. 10c1) remains free and can be used by other UEs wanting to reserve a future transmission. The second stage SCI 10c2 at t3 pointing to the data 12d at t3 occupies the remaining part of the timeslot.

[0071] It should be noted that data region 12d and control regions 10c1 and 10c2 of, for example, time frames t2 or t4 or t6 are also free and therefore may be used by other UEs. It is also possible that time frames t2, t4, and t6 are used by a transmission in a consecutive manner, in which case data region 12d and control regions 10c1 and 10c2 are used for the transmission of the same packet.

[0072] With respect to FIG. 5b, another basic embodiment is where the first stage SCI and the second stage SCI (ie, 10c1 and 10c2) can be transmitted in different time slots (eg, t1 and t2).

[0073] As shown, a first control region 10c1 is transmitted in time frame t1, while a second control region 10c2 is transmitted in time frame t2. A data region 12d is transmitted in the same time frame t2. Further data in the data region 12d is transmitted during time frames t4 and t6. For example, each frame t4 and t6 may also comprise a respective second control portion 10c2.

[0074] As can be seen, the first stage 10c1 and the second stage 10c2 are transmitted in different time slots t1 and t2, while the second control area 10c2 is also transmitted during t4 and t6. According to an embodiment, the first stage 10c1 contains basic information and a pointer 14p1, which points to the second control area 10c2, for example, in the time frames t2, t4 and t6, respectively. The second stage can contain information about retransmission resource location, as indicated by a second pointer 14p2. This pointer 14p2 can point to the respective data area 12d, for example, in the time frames t2, t4 and t6, respectively.

[0075] In the following, details of this embodiment using different time slots for the first and second stage SCIs are discussed. As mentioned, the first stage SCI is sent only once initially in one time slot, followed by the first of the second stage SCIs and the first transmission in the following time slot (e.g. directly or with other frames in between). In this case, the first stage SCI 10c1 serves as a resource reservation for the upcoming retransmission. The time slot used to send the first stage SCI occupies only the control area of ​​the first stage SCI 10c1, while the remaining control (10c2) and data areas 12d can be used by other UEs or remain free. The first stage SCI 10c1 points to the second stage SCI 10c2 in time frame t2 (i.e., pointer 14p1). This corresponds to the retransmission in future slots t2 to t6. Future slots used for sidelink transmissions, in this case slots t2, t4, and t6, respectively, according to an embodiment, accommodate only a second stage SCI 10c2 and corresponding data 12d. Note that the second stage SCI points to the respective data portion 12d of each time frame t2, t4, t6.

[0076] FIG. 6a shows another variation based generally on the variation discussed in the context of FIG. 5a, where the first stage SCI 10c1 is sent multiple times on time slots t1, t3, where the second stage SCI 10c2 and data retransmissions 12d occur. This means that each frame t1, t3, and t5 includes all three regions: control region 1 10c1, control region 2 10c2, and data region 12d. This approach is beneficial when the RX UE misses the first of the first stage SCIs 10c1 (i.e., time frame t1). If the RX UE misses the first instance of the first stage SCI, it can decode the first stage SCI 10c1 in a later transmission instance (e.g., time frame t3) rather than losing the transmission entirely. This adds redundancy to the first stage SCI 10c1, allowing the RX UE to receive the packet.

[0077] It should be noted that according to an embodiment, the first stage SCI 10c1 (for example at t1) can point to the respective subsequent second stage SCI 10c2 (for example at t1, t3 and t5) or according to a further embodiment can also point to the first stage SCI of a subsequent frame, for example 10c1 at t3 or t5. According to a preferred variant, the first instance of the first stage SCI should indicate that there is a repetition in the upcoming timeslot. This allows the transmission to be dropped for other important transmissions, for example to perform another high priority reception or transmission. Alternatively, each second stage SCI 10c1 can point to a subsequent time frame, for example 10c1 at t3, 10c2 at t3 or 12d at t3.

[0078] Fig. 6b shows another embodiment substantially following the approach discussed in the context of Fig. 5b. In this case, the first stage SCI 10c1 is sent in advance at a first time (i.e., time frame t1) and is repeated beyond the retransmission period (i.e., time frame t5). Note that not all time frames are pointed to by the control region 10c1 sent in advance of the respective time frame, as shown for time frame t3. In other words, 10c1 at t1 points to 10c2 at t2 and 10c2 at t4, i.e., pointer 14p1 (and, for example, 10c2 at t6 as well as 10c1 at t5, as indicated by pointer 14p1'), and 10c1 at t5 points to 10c2 at t6.

[0079] Fig. 7a shows another variant of how the control information can be transmitted. In this case, the control information is transmitted partly via timeslot t1 as discussed above and partly via higher layer signaling using the RRC configuration, e.g., the level 2 PC5-RRC configuration. The PC5 RRC configuration is, for example, to be sent only in case of unicast communication and is piggybacked on the PSSCH. Within each timeslot, at least a data area 12d is defined, and only some timeslots have a reserved / used control area 10c. The control area 10c may only accommodate the first control area 10c1 or may accommodate both 10c1 and 10c2. Optionally, a control area 10c2 with, for example, a reduced size (including a reduction to zero) can be used. This second control area 10c2 is indicated by a dashed line.

[0080] According to an embodiment, the control information is transmitted using at least the first region 10c1 and the PC5 RRC configuration. Depending on the implementation or current requirements, the control part 10c2 or parts of the control part 10c2 can also be used. For example, the control part 10c1 carries the first stage SCI information 10c1, while the second stage SCI information is delivered entirely to the PC5 RRC configuration or partially to the region 10c2.

[0081] When comparing this embodiment of Fig. 7a, which uses an RRC configuration, e.g. PC5-RRC, for the transmission of control information, it should be noted that one of the main assumptions is that the frame structure must consist of a control area 10c and a data area 12d. In the case where data-only timeslots or a standalone PSSCH are present, the approach shown by Fig. 7a can be used. Here, different variants can be distinguished.

[0082] According to the embodiment, initial control information is sent on the first stage of the SCI 10c1 in the previous manner (i.e. the embodiment of Fig. 5b or Fig. 6b) or in the same timeslot as the data to be transmitted (i.e. the embodiment of Fig. 5a or Fig. 6a). The first stage SCI 10c1 is sent on timeslot t1 in which the control region is defined. The remaining control information is UE specific and can be sent via PC5-RRC to each individual RX UE to handle the data sent in the standalone PSSCH timeslot.

[0083] According to another embodiment of Fig. 7b, initial control information is sent on the first stage of the SCI 10c1 in the previous manner (i.e. the embodiment of Fig. 5b or Fig. 6b) or in the same timeslot as the data to be transmitted (i.e. the embodiment of Fig. 5a or Fig. 6a). The remaining control information can be sent on the second stage SCI 10c2, but to reduce the size of the second stage SCI 10c2, it is also possible that the global parameters used are sent on PC5-RRC. In this case, the timeslot defines the control region.

[0084] According to an embodiment starting from this second case, it is also possible that the size of the second stage SCI 10c2 gradually decreases over the retransmissions, e.g. 10c2 at t3 has a reduced size compared to 10c2 at t1. The remaining information can then be sent via PC5-RRC. By the end of the retransmissions, data can be sent without the second stage SCI (on a standalone PSSCH) as shown by time frame t5 in Figure 7c.

[0085] According to an embodiment, the base station can use the principles discussed above. In this case, the RRC configuration is so-called Uu-RRC, where the time frame structure does not belong to the sidelink time frame structure used for the above embodiment, but is used for the uplink or downlink between the base station and the UE. In this case, the base station also sends detailed information about the data transmission directly to the RX UE via Uu-RRC. However, it is beneficial to send the first stage SCI 10c1, since other UEs can be aware of upcoming / ongoing transmissions, which is important when both Mode 1 and Mode 2 UEs share the same resource pool.

[0086] Therefore, another embodiment provides a communication system comprising one or more base stations and a plurality of UEs, the communication comprising one or more frames each having a control region and a data region, where control information belonging to a first control region is transmitted in the control region as a first control region of the control region and where control information belonging to a second control region is transmitted or partially transmitted using Uu-RRC.

[0087] Further examples related to the above embodiment are discussed below.

[0088] In some of the above described embodiments, reference is made to the respective vehicles being in a connected mode, also referred to as a Mode 1 or Mode 3 configuration, or to the vehicles being in an idle mode, also referred to as a Mode 2 or Mode 4 configuration. However, the present invention is not limited to V2V or V2X communications, but is also applicable to any device-to-device communications, for example non-vehicle mobile or fixed users conducting sidelink communications, for example via a PC5 interface, and in such scenarios the above described aspects of the present invention may be used.

[0089] According to an embodiment, the wireless communications system may include a terrestrial network, or a non-terrestrial network, or a network or segment of a network using an airborne or spaceborne vehicle as a receiver, or a combination thereof.

[0090] According to an embodiment, the receiver may comprise one or more of a mobile or fixed terminal, an IoT device, a ground vehicle, an air vehicle, a drone, a structure, or any other item or device with network connectivity that allows the item / device to communicate using a wireless communication system, such as a sensor or actuator. According to an embodiment, the transmitter may comprise one or more of a macrocell base station, or a small cell base station, or a spaceborne vehicle, such as a satellite vehicle or a space vehicle, or an airborne vehicle, such as an unmanned aircraft system (UAS), e.g., a tethered UAS, a lighter than air UAS (LTA), a heavier than air UAS (HTA), and a high altitude UAS platform (HAP), or any transmit / receive point (TRP) that allows an item or device with network connectivity to communicate using a wireless communication system.

[0091] It should be noted that the above embodiments are applicable to vehicle communication systems, e.g., V2X, as found in the context of cellular (e.g., 3G, 4G, 5G, or beyond) or ad-hoc communication networks.

[0092] Although some aspects of the described concepts have been described in the context of an apparatus, it will be apparent that these aspects also represent a description of a corresponding method, where a block or device corresponds to a method step or feature of a method step, and 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.

[0093] The various elements and features of the invention can be implemented in the form of hardware using analog and / or digital circuits, in the form of software, through the execution of instructions by one or more general-purpose or special-purpose processors, or as a combination of hardware and software. For example, embodiments of the invention can be implemented in the environment of a computer system or another processing system. FIG. 8 shows an example of a computer system 600. The units or modules as well as the steps of the methods implemented by these units can be executed on one or more computer systems 600. The computer system 600 includes one or more processors 602, such as a special-purpose digital signal processor or a general-purpose digital signal processor. The processors 602 are connected to a communication infrastructure 604, such as a bus or a network. The computer system 600 includes a main memory 606, such as a random access memory (RAM), and a secondary memory 608, such as a hard disk drive and / or a removable storage drive. The secondary memory 608 can allow computer programs or other instructions to be loaded into the computer system 600. The computer system 600 can further include a communication interface 610 that allows software and data to be transferred between the computer system 600 and external devices. The communications may be in the form of electronic, electromagnetic, optical, or other signals capable of being handled by the communications interface and may use wire or cable, fiber optics, phone lines, cellular phone links, RF links, and other communications channels 612.

[0094] The terms "computer program medium" and "computer readable medium" are used to generally refer to tangible storage media, such as a removable storage unit or a hard disk installed in a hard disk drive. These computer program products are a means for providing software to the computer system 600. Computer programs, also referred to as computer control logic, are stored in the main memory 606 and / or the secondary memory 608. The computer programs may be received via the communication interface 610. The computer programs, when executed, enable the computer system 600 to implement the present invention. In particular, the computer programs, when executed, enable the processor 602 to implement the processes of the present invention, such as any of the methods described herein. Such computer programs may thus represent the controller of the computer system 600. When the present disclosure is implemented using software, the software may be stored in the computer program product and loaded into the computer system 600 using an interface, such as a removable storage drive, the communication interface 610.

[0095] The implementation in the form of hardware or software may be implemented using a digital storage medium, such as a cloud storage, floppy disk, DVD, Blu-ray, CD, ROM, PROM, EPROM, EEPROM, or flash memory, on which electronically readable control signals are stored that cooperate (or can cooperate) with a programmable computer system so that the respective method is implemented. Thus, the digital storage medium may be computer readable.

[0096] Some embodiments according to the invention comprise a data carrier having electronically readable control signals capable of cooperating with a programmable computer system to cause one of the methods described herein to be performed.

[0097] In general, embodiments of the present invention can be implemented as a computer program product comprising program code operable to perform one of the methods when the computer program product is executed on a computer. The program code may for example be stored on a machine readable carrier.

[0098] 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.

[0099] 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 for performing one of the methods described herein, i.e. having recorded thereon a computer program for performing one of the methods described herein. A further embodiment of the inventive method is therefore a data stream or a sequence of signals representing a computer program for performing one of the methods described herein. The data stream or sequence of signals can for example be configured to be transferred via a data communication connection, for example via the Internet. A further embodiment comprises a processing means, for example a computer or a programmable logic device, configured 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.

[0100] In some embodiments, a programmable logic device (e.g., a field programmable gate array) may be used to implement some or all of the functionality of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor to implement one of the methods described herein. In general, the methods are preferably implemented by any hardware apparatus.

[0101] The above-described embodiments are merely illustrative of the principles of the present invention. It will be understood that modifications and variations of the arrangements and details described herein will be apparent to those skilled in the art. It is therefore intended to be limited only by the scope of the claims which follow, and not by the specific details presented in the description and illustration of the embodiments herein.

[0102] List of acronyms and symbols V2X Vehicle to Everything 3GPP(registered trademark) 3rd Generation Partnership Project D2D Device to Device ITS Intelligent Transport Services FR1, FR2 frequency range specification BS base station eNB Evolved Node B (3G base station) UE User Equipment SL Side Link V2V Vehicle to Vehicle SCS Subcarrier Spacing RB Resource Block PSCCH Physical Sidelink Control Channel PSSCH Physical Sidelink Shared Channel TTI Transmission Time Interval SCI Sidelink Control Information DCI Downlink Control Information CP Cyclic Prefix BWP Bandwidth Part CORESET Control resource set USS UE specific search space CSS common search space RP Resource Pool M1 Mode 1 M2 Mode 2 M3 Mode 3 (LTE V2X) M4 Mode 4 (LTE V2X) [Explanation of symbols]

[0103] 1 Frame structure, side link structure 10c Control Region 10c1 first control region, first stage, control portion, first stage SCI, control region 1, second stage SCI, first region, first stage SCI information 10c2 second control region, second stage, second control portion, second stage SCI, control, control region 2 12d data area, data portion, first transmission, data, data retransmission 14p1 Reference number, pointer 14p1' pointer 14p2 Second Pointer 600 Computer Systems 602 Processor 604 Communication Infrastructure 606 Main Memory 608 Secondary Memory 610 Communication Interface 612 Communication Channels t1 time frame, time slot t2 time frame, time slot t3 time slot, time frame t4 time frame, slots t5 time slot, time frame t6 timeframe, slots

Claims

[Claim 1] 1. A wireless communication system comprising: a plurality of user equipments UE configured for sidelink communication, the sidelink communication comprises one or more sidelink frames, each having a control region and a data region; the control region comprises a first control region and a second control region, the first control region and the second control region being defined in the frequency domain and the time domain, the first control region differing in frequency and / or time from the second control region, the first control region containing basic information regarding sidelink transmission of a packet, and the second control region containing information regarding one or more data transmission resource locations of the packet; wherein transmission of the packet uses two or more data transmission resource locations in a single sidelink frame and / or the packet is to be transmitted in data transmission resource locations over one or more subsequent sidelink frames, or multiple versions of the packet are to be transmitted in data transmission resource locations over one or more subsequent sidelink frames.

Images