Side link time slot structure

Abstract

A User Equipment, UE, for a wireless communication network, such as a 3rd Generation Partnership Project, 3GPP, network is described. The UE is to communicate with one or more further UEs in the wireless communication network over the sidelink SL. The UE is configured or pre-configured with a slot structure that allows transmission to begin at one of a plurality of start symbols during a duration of a slot, the plurality of start symbols comprising a first start symbol and a second start symbol, the first start symbol is an automatic gain control (AGC) symbol and the second start symbol is an AGC symbol and is offset from the first start symbol. And the UE is used for starting transmission at the first start code element or the second start code element. When the UE starts the transmission at the first start symbol, the UE will include an additional AGC symbol in the time slot, the additional AGC symbol being located at a symbol of the time slot corresponding to the second start symbol.

Description

[0001] Specification

[0002] The present invention relates to the field of wireless communication systems or networks, and more particularly, to direct communication between user equipment via a sidelink, for example, communication using resources in licensed or unlicensed spectrum, also referred to as SL or SL-U. Embodiments relate to the use of one or more additional automatic gain control signal AGC symbols in a time slot that allows a user equipment to start transmission at one of two or more start symbols.

[0003] FIG. 1 is a schematic diagram of an example of a terrestrial wireless network 100, as shown in FIG. 1(a), which includes a core network 102 and one or more radio access networks RAN1, RAN2, ……, RAN n . FIG. 1(b) is a schematic diagram of an example of a radio access network RAN n which may include one or more base stations gNB1 to gNB5, each base station serving a specific area around the base station, and these specific areas are schematically represented by corresponding cells 1061 to 1065. The base stations provide services to users within the cells. One or more base stations may provide services to users in authorized and / or unlicensed frequency bands. The term base station BS refers to a gNB in a 5G network, an eNB in UMTS / LTE / LTE-A / LTE-A Pro, or a BS in other mobile communication standards. A user may be a fixed device or a mobile device. The wireless communication system may also be accessed by mobile or fixed IoT devices connected to the base stations or users. Mobile or fixed devices may include physical devices, ground vehicles (such as robots or cars), aerial vehicles (such as manned or unmanned aerial vehicles UAVs, the latter also being referred to as drones), buildings, and other items or devices having network connections in which electronic devices, software, sensors, actuators, etc. are embedded and which enable these devices to collect and exchange data on existing network infrastructures. FIG. 1(b) shows a schematic view of five cells, however, RAN n may include more or fewer cells, and RAN nIt may also include only one base station. Fig. 1(b) shows two users, UE1 and UE2, also known as user equipment or user apparatus, which are located in cell 1062 and served by base station gNB2. Another user UE3 is shown as being located in cell 1064 and served by base station gNB4. Arrows 1081, 1082, and 1083 schematically represent uplink / downlink connections for sending data from users UE1, UE2, and UE3 to base stations gNB2, gNB4 or for sending data from base stations gNB2, gNB4 to users UE1, UE2, UE3. This can be achieved on an authorized frequency band or an unauthorized frequency band. In addition, Fig. 1(b) shows two additional devices 1101 and 1102 in cell 1064, such as IoT devices, which can be fixed devices or mobile devices. Device 1101 accesses the wireless communication system via base station gNB4 to receive and transmit data, as indicated by arrow 1121. Device 1102 accesses the wireless communication system via user UE3, as schematically indicated by arrow 1122. The corresponding base stations gNB1 to gNB5 can be connected to the core network 102, for example, via the S1 interface, via the corresponding backhaul links 1141 to 1145, which are schematically represented by arrows pointing to "core" in Fig. 1(b). The core network 102 can be connected to one or more external networks. The external network can be the Internet or a private network, such as an intranet or any other type of campus network, for example, a private WiFi communication system or a 4G or 5G mobile communication system. In addition, some or all of the corresponding base stations gNB1 to gNB5 can be connected to each other, for example, via the S1 or X2 interface or XN interface in NR, via the corresponding backhaul links 1161 to 1165, which are schematically represented by arrows pointing to gNB in Fig. 1(b). The sidelink channel allows direct communication between UEs, also known as device-to-device D2D communication. The sidelink interface in 3GPP is named PC5.

[0004] For data transmission, a physical resource grid can be used. The physical resource grid can include a set of resource elements to which various physical channels and physical signals are mapped. For example, physical channels can include the Physical Downlink Shared Channel (PDSCH), the Physical Uplink Shared Channel (PUSCH), and the Physical Sidelink Shared Channel (PSSCH) (carrying user-specific data, also referred to as downlink, uplink, sidelink payload data), the Physical Broadcast Channel (PBCH) and the Physical Sidelink Broadcast Channel (PSBCH) (carrying, for example, the Master Information Block (MIB) and one or more System Information Blocks (SIBs), one or more Sidelink Information Blocks (SLIBs) (if supported)), the Physical Downlink Control Channel (PDCCH), the Physical Uplink Control Channel (PUCCH), and the Physical Sidelink Control Channel (PSSCH) (carrying, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and Sidelink Control Information (SCI)), and the Physical Sidelink Feedback Channel (PSFCH) (carrying PC5 feedback responses). The sidelink interface can support two levels of SCI, where the two-level SCI refers to a first control region (also referred to as the first level of SCI) that includes some parts of the SCI, and optionally a second control region (also referred to as the second level of SCI) that includes a second part of the control information.

[0005] For the uplink, the physical channel can further include the Physical Random Access Channel (PRACH or RACH), which is used by the UE to access the network once the UE is synchronized and has obtained the MIB and SIBs. Physical signals can include Reference Signals or Symbols (RS), Synchronization Signals, etc. The resource grid can include a frame or radio frame having a specific duration in the time domain and a given bandwidth in the frequency domain. The frame can have a specific number of subframes of a predefined length (e.g., 1 ms). Depending on the Cyclic Prefix (CP) length, each subframe can include one or more time slots of 12 or 14 OFDM symbols. The frame can also have a smaller number of OFDM symbols, for example, when using a shortened Transmission Time Interval (sTTI) or a mini-slot / non-slot-based frame structure that includes only a few OFDM symbols.

[0006] A wireless communication system can 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 inverse fast Fourier transform (IFFT)-based signal with or without a cyclic prefix (CP), such as discrete Fourier transform spread OFDM (DFT-s-OFDM). Other waveforms can 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 can operate according to 3GPP's LTE, LTE-Advanced, LTE-Advanced Pro, or 5G or 3GPP NR (New Radio), or operate within LTE-U (LTE Unlicensed) or NR-U (New Radio Unlicensed), which are both specified within the LTE and NR specifications.

[0007] The wireless network or communication system depicted in FIG. 1 can be a heterogeneous network with different coverage networks, e.g., a macrocell network (where each macrocell includes a macro base station, such as base stations gNB1 to gNB1) and a small cell base station network (not shown in FIG. 1, such as a femto base station or a pico base station). In addition to the terrestrial wireless networks described above, there are non-terrestrial wireless communication networks (NTN), including spaceborne transceivers such as satellites and / or airborne transceivers such as unmanned aerial vehicle (UAV) systems. The non-terrestrial wireless communication network or system can operate in a similar manner to the terrestrial system described above with reference to FIG. 1, e.g., operate according to LTE-Advanced Pro, or 5G, or 5G-Advanced, or NR (New Radio).

[0008] In a mobile communication network, e.g., in a network similar to the one described above with reference to FIG. 1 (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 (e.g., using the PC5 / PC3 interface or using WiFi Direct). UEs that communicate directly with each other via the sidelink can include vehicles that communicate directly with other vehicles (vehicle-to-vehicle (V2V) communication), and vehicles that communicate with other entities of the wireless communication network (e.g., roadside units (RSUs), roadside entities such as traffic lights, traffic signs, or pedestrians) (vehicle-to-everything (V2X) communication). Depending on the specific network configuration, an RSU can have the functions of a BS or a UE. Other UEs may not be vehicle-related UEs and can include any of the devices mentioned above. These devices can also communicate directly with each other using the SL channel (device-to-device (D2D) communication).

[0009] When considering two UEs communicating directly with each other over the sidelink, the two UEs can be served by the same base station, such that the base station can provide sidelink resource allocation configuration or assistance to the UEs. For example, both UEs may be within the coverage area of the base station, such as one of the base stations depicted in FIG. 1. This is referred to as the "in-coverage" scenario. Another scenario is referred to as the "out-of-coverage" scenario. It should be noted that "out-of-coverage" does not necessarily mean that these two UEs are definitely not within one of the cells depicted in FIG. 1, but rather means that these UEs

[0010] - may not be connected to the base station. For example, they are not in the Radio Resource Control (RRC) connected state, and thus the UEs do not receive any sidelink resource allocation configuration or assistance from the base station, and / or

[0011] - may be connected to the base station, but due to one or more reasons, the base station may not provide sidelink resource allocation configuration or assistance to the UEs, and / or

[0012] - may be connected to a base station that may not support NR V2X services, such as a GSM, UMTS, or LTE base station.

[0013] FIG. 2(a) is a schematic diagram of the in-coverage scenario, where two UEs communicating directly with each other are both connected to a base station. The coverage area of the base station gNB is schematically represented by a circle 200, which generally corresponds to the cell schematically shown in FIG. 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. The two vehicles 202 and 204 are both connected to the base station gNB, and in addition, they are directly connected to each other via the PC5 interface. The gNB assists in the scheduling of V2V traffic and / or interference management through control signaling on the Uu interface, which is the radio interface between the base station and the UE. In other words, the gNB provides SL resource allocation configuration or assistance to the UEs, and the gNB assigns resources for V2V communication via the sidelink. This configuration is also referred to as Mode 1 configuration in NR V2X, or Mode 3 configuration in LTE V2X. Thus, in Mode 1, the SL UE (e.g., UE 202) is connected to the gNB via the Uu interface, and the gNB coordinates the resources of UE 202 for transmission of control and / or data to another UE (e.g., UE 204) via the SL interface (referred to as PC5 in NR).

[0014] Figure 2(b) is a schematic diagram of an out-of-coverage scenario, where the UEs communicating directly with each other are either not connected to the base station, although they may be physically located within the 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 in the figure communicating directly via a sidelink (e.g., using the PC5 interface). The scheduling and / or interference management of V2V traffic is based on an algorithm implemented between the vehicles. This configuration is also referred to as Mode 2 configuration in NR V2X or Mode 4 configuration in LTE V2X. As mentioned above, the scenario in Figure 2(b) is an out-of-coverage scenario, which does not necessarily mean that the corresponding Mode 2 UEs in NR or Mode 4 UEs in LTE are outside the coverage area 200 of the base station. Instead, it means that the corresponding Mode 2 UEs in NR or Mode 4 UEs in LTE are not served by the base station, not connected to the base station in the coverage area, or connected to the base station but do not receive the SL resource allocation configuration or assistance from the base station. Therefore, within the coverage area 200 shown in Figure 2(a), in addition to the NR Mode 1 or LTE Mode 3 UEs 202, 204, there may also be NR Mode 2 or LTE Mode 4 UEs 206, 208, 210. In addition, Figure 2(b) schematically shows an out-of-coverage UE communicating with the network using a relay. For example, UE 210 can communicate with UE 212 via a sidelink, and UE 212 can in turn be connected to the gNB via the Uu interface. Therefore, UE 212 can relay information between the gNB and UE 210. Therefore, the SL UEs (e.g., UE 206 - 210) do not need to have a connection to the gNB and, for example, perform sensing and access resource allocation or random access-based resource allocation when transmitting from UE 206 to UE 208. However, for successful data exchange, a basic configuration needs to be available for UE 206 - 210. This information can be pre-configured or can be configured when the UE is within the coverage area of the gNB. For this purpose, the gNB can provide a basic configuration, such as basic information, which can be transmitted via a broadcast channel, for example, using the System Information Block (SIB). The BS can also assist the Mode 2 UEs in providing basic information on which resource pool (RP) to use, or can act as a synchronization source.

[0015] Although Figures 2(a) and 2(b) illustrate vehicle-mounted UEs, it should be noted that the described in-coverage and out-of-coverage scenarios also apply to non-vehicle-mounted UEs. In other words, any UE (such as a handheld device) communicating directly with another UE using the SL channel may be in-coverage or out-of-coverage.

[0016] In the application scenarios of the in-vehicle user equipment (UE) described above, multiple such user equipments can form a user equipment group, which can also be simply referred to as a group. The communication between members within the group or among the group can be carried out through the sidelink interface (such as the PC5 interface) between the user equipments. For example, the application scenario of using vehicle user equipment described above can be applied to the transportation industry field. In this field, multiple vehicles equipped with vehicle user equipment can be combined together, for example, through remote driving applications. Other use cases where multiple user equipments can be combined for sidelink communication between each other include, for example, factory automation and power distribution. In terms of factory automation, multiple mobile or fixed machines in the factory can be equipped with user equipment and combined together for sidelink communication, for example, to control the operation of the machines, such as the motion control of robots. In terms of power distribution, entities in the power distribution network can be equipped with corresponding user equipment, and these user equipments can be combined together within a specific area of the system to communicate with each other through sidelink communication, so as to achieve the monitoring of the system and handle power distribution network faults and interruptions.

[0017] It should be noted that the information in the above sections is only used to strengthen the understanding of the background of the present invention, and therefore, it may contain information that does not constitute the prior art already known to those of ordinary skill in the art.

[0018] Based on the above, it may be necessary to improve or enhance the sidelink in a wireless communication system or network.

[0019] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings:

[0020] FIG. 1 is a schematic diagram of an example of a terrestrial wireless network;

[0021] FIG. 2(a) is a schematic diagram of a scenario within the coverage area;

[0022] FIG. 2(b) is a schematic diagram of a scenario outside the coverage area;

[0023] FIG. 3 illustrates two examples of sidelink time slot formats, where FIG. 3(a) illustrates a time slot format with one guard symbol, and FIG. 3(b) illustrates a time slot format with two guard symbols;

[0024] Figure 4 Illustrates multiple time slots with transmissions aligned in the frequency domain;

[0025] Figure 5 Illustrates a scenario where a sidelink UE starts two transmissions in adjacent channels or frequency bands at the unique starting symbol of the time slot structure in FIG. 3(a);

[0026] Figure 6The figure shows a scenario where a sidelink UE starts two transmissions at different starting symbols provided in the time slot structure of Fig. 3(a) in adjacent channels or frequency bands;

[0027] Figure 7 is a schematic diagram of a wireless communication system implementing an embodiment of the present invention, the wireless communication system including a transmitter (such as a base station) and one or more receivers (such as a user equipment UE);

[0028] Figure 8 The figure shows a wireless communication system according to an embodiment of the present invention, the wireless communication system including a user equipment and a base station;

[0029] Fig. 9 shows an embodiment of the present invention including additional AGC symbols in full time slot transmission;

[0030] Figure 10 The figure shows an embodiment of the present invention where transmission starts at the second starting position of a time slot and extends to subsequent time slots having the time slot structure according to Fig. 3(a);

[0031] Figure 11 The figure shows an embodiment similar to Figure 10 except that the time slot structure in the subsequent time slot has a time slot structure including additional AGC symbols;

[0032] Fig. 12 shows an embodiment of the present invention where corresponding transmissions in two frequency bands align DMRS symbols,

[0033] Figure 13 The figure shows an embodiment of the present invention using the time slot structure according to Fig. 3(b), where additional AGC symbols are located before PSFCH symbols; and

[0034] Figure 14 The figure shows an example of a computer system on which units or modules and method steps described according to the method of the present invention can be executed.

[0035] Now, embodiments of the present invention will be described in more detail with reference to the accompanying drawings, in which the same or similar elements are assigned the same reference symbols.

[0036] In a mobile communication system or network, such as those mobile communication systems or networks described above with reference to Fig. 1, for example in an LTE or 5G / NR network, corresponding entities can communicate using one or more frequency bands. A frequency band includes a starting frequency, an ending frequency, and all intermediate frequencies between the starting frequency and the ending frequency. In other words, the starting frequency, the ending frequency, and the intermediate frequencies can define a specific bandwidth, such as 20 MHz. A frequency band can also be referred to as a carrier or subcarrier, a bandwidth part, BWP, a subband, a subchannel, an interleaving, a resource block set (RB-set), etc.

[0037] When using a single frequency band, the communication can be referred to as single-band operation. For example, a UE transmits or receives radio signals to / from another network entity at frequencies within a frequency band (such as a 20 MHz frequency band).

[0038] When using two or more frequency bands, the communication can be referred to as multi-band operation or wideband operation or carrier aggregation operation. These frequency bands can have different bandwidths or the same bandwidth, such as a 20 MHz frequency band. For example, in the case where the frequency bands have the same bandwidth, a UE can transmit or receive radio signals to / from another network entity at frequencies within two or more 20 MHz frequency bands, such that the frequency range of the radio communication can be a multiple of 20 MHz. Two or more frequency bands can be consecutive / adjacent frequency bands or separated parts or all of the frequency bands in the frequency domain.

[0039] Multi-band operation can include frequency bands in licensed spectrum, or frequency bands in unlicensed spectrum, or frequency bands in both licensed and unlicensed spectrum.

[0040] Carrier Aggregation (CA) is an example of using two or more frequency bands in licensed spectrum and / or unlicensed spectrum. It can also be a hybrid combination, such as one or more licensed frequency bands and one or more unlicensed frequency bands. In addition, CA can also be used only for unidirectional aggregation of additional carriers, such as a supplementary carrier, to improve transmission via UL, DL, or SL.

[0041] 5G New Radio (NR) can support operation in unlicensed spectrum, such that single-band operation or multi-band operation can include frequency bands or sub-bands in unlicensed spectrum. Unlicensed spectrum can include frequency bands that potentially coexist with IEEE 802.11, such as frequency bands within the 5 GHz and / or 6 GHz spectrum. For example, due to regulatory requirements, NR-U can support bandwidths that are integer multiples of 20 MHz. The purpose of splitting into sub-bands is to minimize interference to coexisting systems, such as IEEE 802.11 systems, which can use the same nominal bandwidth channels (such as 20 MHz channels) in one or more of the same frequency bands. Other coexisting systems can use sub-bands with different sub-band sizes and nominal frequencies from those of the IEEE 802.11 system described above. For example, unlicensed spectrum can include the 5 GHz frequency band, 6 GHz frequency band, 24 GHz frequency band, or 60 GHz frequency band. Examples of such unlicensed bands include Industrial, Scientific and Medical (ISM) radio frequency bands, which are internationally reserved for the use of radio frequency energy for industrial, scientific, and medical purposes other than telecommunications.

[0042] During operation using an unlicensed subband, listen-before-talk (LBT) can be performed individually for each subband or each resource block set (RB set). This may cause one or more subbands to be busy or occupied due to interference, e.g., from other communication systems coexisting in the same frequency band, such as other public land mobile networks (PLMNs) or systems operating according to the IEEE 802.11 specification or systems operating according to the ETSI broadband radio access network (BRAN) specification. In such cases, the transmitter, whether it is a transmitting gNB or a transmitting UE, can only transmit on subbands that are detected as not busy (also referred to as idle or unoccupied subbands). For example, when performing a transmission spanning more than 20 MHz in the 5 GHz unlicensed operating band, the transmitter (such as a gNB or a UE) performs listen-before-talk (LBT) separately on each subband. Once the LBT result for each subband is obtained, the device (e.g., the gNB in downlink DL or the UE in uplink UL) is allowed to transmit on those subbands determined to be idle or unoccupied, i.e., on the winning subbands. Transmissions are not allowed on occupied, busy, or non-winning subbands.

[0043] To access resources or channels in the unlicensed spectrum, the so-called NR-U channel access will be performed, which requires the use of a channel access procedure that is based on sensing to evaluate whether the channel is available for performing a transmission. The basic unit for sensing can be a sensing time slot with a specific duration, e.g., T sl = 9 μs. If the base station or UE senses the channel within the sensing time slot duration and determines that the power detected for at least a specific time (such as 4 μs) within the sensing time slot duration is less than the energy detection threshold, the sensing time slot duration T sl is considered idle. Otherwise, the sensing time slot duration will be considered busy. In the case where the channel is available or not busy, one or more transmissions can be performed on the channel. The so-called channel occupancy rate refers to one or more transmissions performed by the base station or UE on one or more channels after performing the corresponding channel access procedure. The channel occupancy time (COT) refers to the total time during which the base station or UE and any other base station or UE can share channel occupancy to perform one or more transmissions on the channel after the base station or UE performs the channel access procedure (CAP).

[0044] For communication using sidelink, the corresponding entity (such as an SL-UE) may adopt an SL time slot structure (also referred to as a sidelink frame structure). As shown in Figure 3, Figure 3 illustrates two examples of the time slot structure (also referred to as the time slot format). Figure 3(a) illustrates a time slot format with one guard symbol, and Figure 3(b) illustrates a time slot format with two guard symbols. As can be seen from Figure 3(a), the time slot includes 14 symbols. The first symbol is an automatic gain control (AGC) symbol, followed by two symbols carrying both PSCCH and PSSCH. The fourth symbol is a demodulation reference signal (DMRS) symbol, followed by six PSSCH symbols and another DMRS symbol. The twelfth and thirteenth symbols are also PSSCH symbols, and the last symbol is a guard symbol. Figure 3(b) illustrates a time slot format in which the first symbol is also an AGC symbol, followed by three symbols shared by DMRS, PSCCH, and PSSCH. The fifth symbol is a DMRS symbol, followed by two PSSCH symbols, another DMRS symbol, and then two PSSCH symbols. The eleventh symbol is a guard symbol, followed by another AGC symbol for PSFCH, PSFCH is transmitted in the thirteenth symbol, and then another guard symbol.

[0045] The time slot format according to Figure 3(a) can be used when sending / receiving payload data with feedback is disabled, for example, for blind transmission. Figure 3(b) illustrates a time slot format that can be used in cases where receiver transmission feedback is provided using PSFCH symbols. Therefore, the sidelink frame structure illustrated in Figure 3 includes at least one guard symbol, and the UE uses this guard symbol to switch from the transmit mode (TX) to the receive mode (RX), and vice versa. For example, the time slot in Figure 3(a) may be used by the first UE for transmission, and the last symbol, i.e., the guard symbol, is used by the first UE to switch from the transmit mode to the receive mode, for example, to receive transmissions from another UE in subsequent time slots. In Figure 3(b), the first UE can send payload data and switch from the transmit mode to the receive mode in the first guard symbol in order to receive feedback in the twelfth and thirteenth symbols. As illustrated in Figure 3, although the duration of the guard symbol spans one OFDM symbol, the actual duration may vary according to the subcarrier spacing SCS. In the case of a single-component carrier CC using the CP-OFDM waveform and at least 10 resource blocks, the actual time required for the UE to switch between the transmit and receive modes (i.e., the AGC setting time) may be as follows:

[0046] - For 15 kHz SCS, it is 35 μs,

[0047] - For 30 kHz SCS, it is 35 μs,

[0048] - For 60 kHz SCS, it is 18 μs.

[0049] During the guard symbol, the UE neither sends nor receives any information. As illustrated in Figure 3, the guard symbol may appear at the end of a time slot or before the symbol for the PSFCH, because transmitting the PSFCH in the same time slot requires the UE to switch between transmit / receive modes. In a time slot that can be used for PSSCH transmission, 7 to 14 time slots can be reserved for sidelink operation, where the PSSCH can be transmitted in 5 to 12 symbols. The remaining sidelink symbols can transmit some or all of the control information, such as PSCCH, PSFCH, reference symbols (such as DMRS), AGC, and guard symbols.

[0050] The AGC symbol described above with reference to Figure 3 is used during communication to allow the receiving UE to adjust the gain of its receiver, such as the amplifier in its receiver chain, in order to handle the varying received signal power.

[0051] The sidelink transmissions of different UEs can be performed in different time slots that are aligned in the frequency domain across multiple subchannels. Figure 4 The figure shows multiple time slots with transmissions aligned in the frequency domain. More specifically, three time slots are depicted, called Time Slot 1, Time Slot 2, and Time Slot 3. The corresponding time slot boundaries are schematically illustrated by vertical lines at the start of Time Slot 1, between Time Slot 1 and Time Slot 2, and between Time Slot 2 and Time Slot 3. The first UE (UE1) performs a transmission Tx during the first time slot using the time slot structure described above with reference to Figure 3. 1A The first symbol is an AGC symbol to allow the UE receiving the transmission Tx 1A from UE1 to adjust its receiver. In Time Slot 2, the second UE (UE2) performs two transmissions, a first transmission Tx 2A in the first frequency band or frequency sub - band, and a second transmission Tx 2B in the second frequency band or sub - band. The transmissions can use the time slot structure described above with reference to Figure 3, and the two transmissions are aligned across the frequency band or subchannels in the frequency domain. Similarly, both transmissions include an AGC symbol as the first symbol, such that one or more UEs receiving the transmissions Tx 2A and Tx 2B can adjust the receiver gain. In Time Slot 3, the third UE (UE3) again performs two transmissions Tx 3B and Tx 3C in different sub - bands. Additionally, for these transmissions, the first symbol of the time slot includes an AGC symbol for allowing adjustment of the gain of the corresponding receiving UE to which the transmissions Tx 3B and Tx 3C are directed.

[0052] From Figure 4It can be seen that the transmission starts only at the slot boundary, and the transmitting UE (TX UE) sends an AGC symbol in the first symbol of the slot. The content of the AGC symbol can be a simple copy of the content of the subsequent symbols, which can be a combination of PSCCH and DMRS or PSSCH, depending on whether the slot structure illustrated in Fig. 3(a) or the slot structure illustrated in Fig. 3(b) is used. The AGC symbol at the start of each slot allows all receiving UEs (Rx UEs) to adjust the gain of their receivers, thereby minimizing or reducing quantization noise and preventing saturation of the receiver chain (e.g., at the analog-to-digital converter ADC).

[0053] There may be a situation where the channel currently used by a particular transmitting entity becomes idle, e.g., because the transmitting entity has completed its transmission before the end of the slot. Thus, the time when the channel becomes idle can be any time during the duration of the slot. For example, consider a mini-slot transmission that occupies only a part of the slot. More than one starting symbol position can be configured, which enables the UE to start at a second starting symbol position that may not be aligned with the slot boundary, e.g., start in the middle of a slot or a half-slot. Additionally, the system can support multi-continuous slot transmission (MCSt), which allows aggregating slots and partial slots, e.g., a slot and a mini-slot or a slot and a partial slot, that start at a symbol position different from the first symbol of the slot. In this case, the MCSt transmission can terminate at a symbol position outside the slot boundary, which also enables other UEs to start transmission within any symbol in the slot. Furthermore, when performing sidelink communication in unlicensed spectrum, the currently occupied frequency band, sub-band, or channel can become idle as another device from a system using the same radio access technology (RAT) as the SL-UE or from a system using a different RAT (such as a WiFi or Bluetooth device) completes its transmission, making it possible to acquire the now idle channel at basically any time during the slot.

[0054] Figure 5 The figure illustrates a scenario where it is assumed that the sidelink UE performs two transmissions Tx 1A and Tx 1B in adjacent channels or frequency bands 220A and 220B using the slot structure illustrated in Fig. 3(a). 1A and Tx 1B are aligned in the frequency domain to start at the slot boundary, and the initial symbols are AGC symbols 222A, 222B to allow one or more receiving UEs to adjust their receivers accordingly. Assume that the first transmission Tx 1A extends over the full duration of the slot, also referred to herein as a full-slot transmission, while the second transmission Tx 1BIncludes less data to be transmitted and thus terminates before the end of the time slot, leaving a portion of the time slot unused in the second channel 220B. The second transmission Tx 1B Is also referred to herein as partial time slot or sub - time slot transmission. The first transmission Tx 1A Utilizes the full time slot, while the second transmission Tx 1B Utilizes only a portion of the time slot, for example, only the first seven symbols, and is also referred to herein as half - time slot transmission. When considering Figure 5 The scenario where, according to this scenario, the full time slot and the half - time slot are aligned at the start of the time slot, which results in a waste of resources because the UE has to wait for its next transmission to start at the next start of the time slot. This is illustrated in Figure 5 According to which, the second portion of the time slot in the second band 220B is not used, i.e., resources are wasted. Since the UE performing the transmission in Figure 5 Has a COT for the transmission of its half - time slot and may miss its transmission opportunity, for example, in the case where the COT may not be extended to the next full time slot, such scenarios may occur for operations in the unlicensed spectrum.

[0055] To address this situation, it has been agreed to allow the use of additional transmission start times. For example, a time slot can support at least two start symbols, where each of these start symbols can be used for AGC purposes. This essentially means that there is a full time slot structure and a sub - time slot structure that starts at a configured or pre - configured symbol within the time slot, where the first symbol of both structures is used for AGC purposes. Introducing such additional start symbols for AGC purposes results in a more flexible position of the AGC symbol, enabling the UE to start transmission at a specific symbol within the time slot, thus avoiding waste of resources. For example, when considering the above - described situation in the unlicensed spectrum, the additional AGC symbol can enable the UE to better utilize the existing COT and thus increase system efficiency in terms of higher throughput, lower latency, etc. Also, data services with latency constraints according to the packet delay budget PDB can benefit from such additional AGC symbols. Two or more additional start symbols can be provided, and the additional start symbols are provided with corresponding offsets relative to the first start symbol. The first start symbol can be the first symbol in the time slot or a later symbol in the time slot.

[0056] Figure 5The figure shows a time slot structure to be used for transmission in the second frequency band 220B. The time slot structure includes additional AGC symbols 224 in addition to the AGC symbol 222B at the start of the time slot. The two AGC symbols 222B, 224 are the starting positions from which the transmitting UE can start transmission. For example, when considering the case where the second frequency band 220B in the unlicensed spectrum is determined to be occupied at the start of the time slot but is subsequently determined to be idle, the UE does not need to wait until the next time slot boundary to start transmission Tx 1B , but can utilize the additional starting symbol 224 and start its transmission Tx at symbol 224 during the current time slot 1B . Another scenario where this can be applied is when the actual data to be transmitted in the second transmission Tx 1B becomes available at the transmitting UE only at a certain time during the time slot. Additionally, in such a case, the UE can utilize the additional starting symbol 224 and start transmission Tx in the second half of the time slot 1B .

[0057] Figure 6 This situation is shown in more detail. Assume the UE performs two transmissions Tx 1A and Tx 1B . Further assume that in channel 220A, transmission Tx is performed using the time slot structure according to Figure 3 1A , while in channel 220B, the time slot structure can be used for transmission Tx 1B , which has a structure as in Figure 3, but includes, for example, an additional AGC symbol 224 used as a second starting symbol or starting position in the seventh symbol. Thus, in the situation described above, for example, when the channel or data to be transmitted during transmission Tx 1B is not available at the start of the time slot but becomes available at a later time during the time slot, the first part of the time slot in the second frequency band 220B remains unused. However, once the UE becomes aware that the channel or data to be sent is available, a channel access procedure, such as the LBT procedure, can be performed. If it is determined that channel 220B is available, i.e., not occupied by any other transmitting entity, the UE can utilize the additional starting position 224 and start transmission Tx during the second half of the time slot 1BNote that the second starting symbol does not necessarily have to be in the middle of the time slot. For example, in the seventh symbol, it can actually be any symbol within the time slot that is configured or pre-configured (e.g., configured or pre-configured as part of a system or resource configuration). Note that the exact position of the second starting symbol can also depend on the specific time slot structure. For example, it can depend on whether feedback (PSFCH) is enabled for a given time slot or channel / sub-channel / interleaving / RB set, or whether PSFCH is disabled. In a time slot structure where PSFCH is enabled, it can be more efficient to configure or pre-configure the second starting symbol position at an earlier symbol between the first symbol of the time slot and the middle symbol of the time slot, in order to increase the number of data symbols (PSSCH) that can be transmitted in such a time slot. This is because a large number of symbols in a PSFCH-enabled time slot or half time slot are already occupied by two guard symbols, one additional AGC symbol, and the symbols for PSFCH, and thus only allows PSSCH to be transmitted on one or two symbols within the time slot. Also, the first starting symbol does not necessarily have to be the first symbol of the time slot. It is just the symbol in the time slot where the earliest transmission can start. The first starting symbol can also be any other symbol after the first symbol in the time slot.

[0058] However, when configuring other time slot structures with additional starting symbols, the absence of an additional AGC symbol within the time slot structure causes the transmission to start during an ongoing transmission in other sub-bands (e.g., in the middle of the time slot), and this can lead to clipping because the RX UE does not have the possibility to tune its ADC accordingly using an additional AGC symbol, which can result in an improperly adjusted gain control. For example, when considering Figure 6 the UE transmits an initial AGC symbol in the first frequency band 220A, and the receiving UE performs a corresponding AGC adjustment based on this AGC symbol at the start of the time slot. However, in Figure 6 the example, the UE transmits an additional AGC symbol in the middle of the time slot, which allows the receiving UE that knows the additional AGC symbol to also perform an additional gain adjustment in the middle of the time slot according to the additional AGC symbol 224. Without this additional AGC symbol, the RX UE does not have the time and knowledge of the RX power required to properly tune its ADC before receiving PSCCH / PSSCH / DRMS / PSFCH. Therefore, in the case where the received power is too high, the UE may not be able to avoid saturation at its receiver, or in the case where its received power is too low and its RX amplifier is not configured accordingly, it may not be able to decode the data.

[0059] In addition, when using additional starting symbols, there is a first transmission Tx that starts at the beginning of the time slot 1A and a second transmission Tx that starts at the second starting symbol 1BFor a UE, a receiving UE attempting to adjust its receiver gain may not be able to perform the adjustment correctly because the RX UE performs an initial adjustment based on the AGC symbol at the start of the first transmission's time slot in frequency band 220A, but may not be aware of the additional AGC symbol 224, such that the receiving UE does not perform AGC for the second transmission, resulting in a power variation associated with the second transmission Tx 1B Furthermore, in the case where the receiving UE performs additional AGC in response to the AGC symbol 224 for the second transmission, this may result in spikes or peaks in power, leading to saturation of the receiver at the receiving UE.

[0060] In other words, the conventional method described above of simply introducing an additional start time into the time slot to allow the transmitting UE to start its transmission at the time slot boundary (i.e., at the start of the time slot) or at one or more other symbols during the duration of the time slot causes additional problems in the receiving UE, such as the power adjustment problem mentioned, because the receiving UE performs power adjustment only based on the initial AGC symbol in the time slot or after the guard symbol of the PSFCH-enabled time slot, resulting in power variations for different transmissions starting at a later time during the time slot.

[0061] To solve the problems described above that occur when using an additional start time during the time slot, according to the present invention, a sidelink UE that performs transmission using a time slot structure that allows transmission to start at one of a plurality of start symbols during the duration of the time slot and starts transmission at the first start symbol includes an additional AGC symbol at a position corresponding to the second start symbol in the time slot. In other words, depending on the configured or pre-configured additional start symbol position, an additional AGC symbol is introduced into the full time slot structure at the symbol position that is the same as the second start position within the time slot. In other words, according to the method of the present invention, an additional AGC symbol is introduced at the start symbol of the sub-time slot transmission.

[0062] The method of the present invention is advantageous because it avoids the problems described above of transmitting AGC symbols at different times during the time slot duration, where the receiving UE may only consider the first AGC symbol, or when considering two AGC symbols, may cause problems during the receiving phase of the receiving UE, for example due to the situation of the receiver. Providing an additional AGC symbol at the same position as the second start point during the time slot ensures that the receiving UE can adjust its receiving gain, for example, by adjusting the receiving power, and thus avoids saturation (e.g., clipping at the ADC). This is necessary for successful decoding and reception of PSCCH / PSSCH / PSFCH / DMRS.

[0063] Embodiments of the present invention may be implemented in a wireless communication system depicted in FIGS. 1, 2(a), or 2(b), the wireless communication system including a base station and users, such as mobile terminals or IoT devices. Figure 7 is a schematic diagram of a wireless communication system, the wireless communication system including a transmitter 300 (such as a base station) and one or more receivers 302, 304 similar to user equipment UE. The transmitter 300 and the receivers 302, 304 may communicate via one or more wireless communication links or channels 306a, 306b, 308 (such as radio links). The transmitter 300 may include one or more antennas ANT coupled to each other or an antenna array having a plurality of antenna elements, a signal processor 300a, and a transceiver 300b. The receivers 302, 304 include one or more antennas ANTUE coupled to each other or an antenna array having a plurality of antennas, signal processors 302a, 304a, and transceivers 302b, 304b. The base station 300 and the UEs 302, 304 may communicate via corresponding first wireless communication links 306a and 306b (such as radio links using the Uu interface), and the UEs 302, 304 may communicate with each other via a second wireless communication link 308 (such as a radio link using the PC5 or sidelink SL interface). When the UEs are not served by or not connected to the base station, for example, they are not in the RRC connected state, or more generally, when the base station does not provide SL resource allocation configuration or assistance, the UEs may communicate with each other via the sidelink. Figure 7 the system or network, Figure 7 one or more UEs 302, 304 of Figure 7 the base station 300 may operate according to the inventive teachings described herein.

[0064] Transmitting UE

[0065] The present invention provides a user equipment UE for a wireless communication network (such as a 3rd Generation Partnership Project 3GPP network),

[0066] wherein the UE communicates with one or more other UEs via a sidelink SL in the wireless communication network,

[0067] wherein the UE is configured or preconfigured with a time slot structure that allows a transmission to start at one of a plurality of starting symbols during the duration of a time slot, the plurality of starting symbols including a first starting symbol and a second starting symbol, the first starting symbol being an automatic gain control AGC symbol and the second starting symbol being an AGC symbol and offset from the first starting symbol,

[0068] wherein the UE is for starting a transmission at the first starting symbol or at the second starting symbol, and

[0069] Wherein, when the UE starts the transmission at the first starting symbol, the UE will include additional AGC symbols in the time slot, and the additional AGC symbols are located at the symbols in the time slot corresponding to the second starting symbol.

[0070] According to an embodiment, the first starting symbol is at the start of the time slot.

[0071] According to an embodiment, the UE is configured or pre-configured with a time slot structure according to one or more of the following:

[0072] - Each resource pool,

[0073] - Each bandwidth part,

[0074] - Each sub-band,

[0075] - Each sub-band set, for example, each sub-channel, or interleaving in unlicensed spectrum,

[0076] - System-wide configuration, for example, using broadcast messages such as system information block SIB and / or master information block MIB,

[0077] - Each transmission,

[0078] - Each transmission set.

[0079] According to an embodiment, the time slot includes a plurality of symbols, the first starting symbol is the first symbol in the time slot, thereby allowing the transmission to use the entire time slot, and the second starting symbol is the second symbol in the time slot or a symbol offset by one or more symbols from the first symbol, thereby allowing the transmission to use a partial time slot.

[0080] According to an embodiment, the second starting symbol is in the middle of the time slot, for example, at symbol position seven, thereby allowing the transmission to use half of the time slot.

[0081] According to an embodiment, the UE is configured or pre-configured with a time slot structure, and the additional AGC symbols are configured or pre-configured

[0082] - In each time slot within the SL resource pool, or

[0083] - Only in a proper subset of the time slots within the SL resource pool.

[0084] According to an embodiment, the proper subset of the time slots is configured or pre-configured with the following

[0085] - Using a time pattern, such as a bitmap, or

[0086] - Using a periodic pattern, for example, including the periodicity and / or length of the pattern, or

[0087] - Using an asymmetric pattern, or

[0088] - Using a start symbol and / or a periodic offset, or

[0089] - Using a time resource indicator value TRIV, and / or a frequency resource indicator value FRIV, or

[0090] - Depending on whether a specific symbol, such as a physical sidelink feedback channel PSFCH, exists in a time slot.

[0091] According to an embodiment, the UE will use additional AGC symbols

[0092] - For all transmissions, or

[0093] - Only for one or more specific transmissions.

[0094] According to an embodiment, the UE is allowed to start at a second start symbol

[0095] - For all transmissions, or

[0096] - Only for one or more specific transmissions.

[0097] According to an embodiment, one or more specific transmissions include one or more of the following:

[0098] - A new transmission,

[0099] - A transmission with a priority exceeding a predetermined threshold,

[0100] - A transmission with a specific latency constraint (such as an ultra-reliable low-latency communication URLLC constraint), e.g., according to the packet delay budget PDB of the transmission,

[0101] - A transmission for which the UE has successfully performed a channel access procedure (such as listen-before-talk LBT) on a subchannel,

[0102] - A transmission including positioning information, which may include, for example, one or more positioning reference symbols PRS,

[0103] - A PSFCH transmission, e.g., an independent PSFCH transmission without data, for sending urgent feedback such as hybrid automatic repeat request HARQ feedback,

[0104] - A transmission of an auxiliary information message AIM or an inter-UE coordination message IuC,

[0105] - A transmission including control information (e.g., a MAC-CE sent within a physical sidelink shared channel PSSCH),

[0106] - includes transmission of one or more additional demodulation reference signals DRMS or channel state information CSI, e.g., for precoding or decoding of multi-input multi-output MIMO transmission,

[0107] - transmission prior to reserved transmission in a subsequent full time slot.

[0108] According to an embodiment,

[0109] the last symbol of the time slot includes a guard symbol, and

[0110] the UE will use the guard symbol for data transmission, e.g., for transmission of physical sidelink shared channel PSSCH, or physical sidelink feedback channel PSFCH, or physical sidelink control channel PSCCH, or demodulation reference signal DMRS,

[0111] - when the UE starts the transmission at the first starting symbol in the current time slot or at the second starting symbol in the current time slot using the additional AGC symbol, and

[0112] - when the UE will also transmit in a subsequent time slot, or at the end of the current time slot, will enter discontinuous reception DRX mode.

[0113] According to an embodiment,

[0114] the first time slot structure is a time slot structure that allows transmission to start at one of the plurality of starting symbols, and the second time slot structure is a time slot structure that allows transmission to start only at the first symbol of the time slot, and

[0115] when the UE starts the transmission at the first starting symbol in the current time slot using the additional AGC symbol and is to perform transmission in a subsequent time slot, the subsequent time slot has the first time slot structure or the second time slot structure, or

[0116] when the UE starts transmission at the second starting symbol in the current time slot and is to perform transmission in a subsequent time slot, the subsequent time slot has

[0117] - the first time slot structure, or

[0118] - the second time slot structure, or

[0119] - a third time slot structure, the third time slot structure allows a first transmission to start at the first starting symbol during the duration of the subsequent time slot, and allows a second transmission to start at a second starting symbol after the first starting symbol during the duration of the subsequent time slot, or

[0120] - A fourth time slot structure that allows the transmission in the current time slot to extend into subsequent time slots without AGC symbols and / or control symbols at the start of the subsequent time slots.

[0121] According to an embodiment,

[0122] The UE will use the first time slot structure and the second time slot structure for transmission,

[0123] The first time slot structure and the second time slot structure use

[0124] - The same frequency, or

[0125] - Different frequencies,

[0126] The frequency is defined as one or more of a subchannel, a set of subchannels, a subband, a set of subbands, an interleaving, a set of resource blocks, an interleaving set, a resource pool, a resource pool set.

[0127] According to an embodiment, the second start symbol and additional AGC are located at one or more symbols, such as DMRS symbols, before a preconfigured or predefined number of symbols in the time slot.

[0128] According to an embodiment,

[0129] The time slot structure includes a predefined number of symbols at the end of the time slot, which are dedicated to receiving transmissions such as feedback transmissions, for example, a first guard symbol, an AGC symbol for the PSFCH, the PSFCH symbol, and a second guard symbol, and

[0130] The second start symbol is offset from the first symbol among the predefined number of symbols, and the UE is to use one or more symbols between the second start symbol and the first symbol among the predefined number of symbols for specific transmissions, for example,

[0131] - Transmission of virtual data for maintaining the channel occupancy time COT after performing listen-before-talk LBT, or

[0132] - Transmission of a predefined reference symbol (e.g., a positioning reference symbol PRS for sidelink positioning) or a reference symbol for channel reconstruction (such as DRMS), or

[0133] - Transmission of channel state information CSI (e.g., CSI reference symbol CSI-RS) for improving multi-input multi-output MIMO channel estimation

[0134] - Transmission of an auxiliary information message AIM or a UE-to-UE coordination message IuC,

[0135] - Transmission including control information (e.g., MAC-CE sent within the PSSCH).

[0136] According to an embodiment, the UE will use one or more symbols between the second starting symbol and the end of the time slot for a specific transmission, for example,

[0137] - a transmission in which the UE has successfully performed LBT on the subchannel,

[0138] - a PSFCH transmission, for example, an independent PSFCH transmission without data, for sending urgent feedback such as HARQ feedback,

[0139] - a transmission of virtual data for maintaining the channel occupancy time (COT) initiated after performing listen-before-talk (LBT), or

[0140] - a transmission of a predefined reference symbol (e.g., a positioning reference symbol (PRS) for sidelink positioning) or a reference symbol for channel reconstruction (such as DRMS), or

[0141] - a transmission of channel state information (CSI) (e.g., a CSI reference symbol (CSI-RS)) for improving multi-input multi-output (MIMO) channel estimation

[0142] - a transmission of an auxiliary information message (AIM) or an inter-UE coordination message (IuC),

[0143] - a transmission including control information (e.g., a MAC-CE sent within a PSSCH).

[0144] According to an embodiment, the UE will perform a specific transmission in a configured or preconfigured resource pool having a PSFCH periodicity greater than one (e.g., two or four).

[0145] According to an embodiment, a first control channel, such as a first PSCCH, is sent at the start of the current time slot, and / or a second control channel, such as a second PSCCH, is sent at the start of a subsequent time slot.

[0146] According to an embodiment, the UE will send control information only in the first control channel (such as the first PSCCH), where the control information includes information about data transmission (including PSSCH and / or PSFCH) extending into a subsequent time slot (e.g., by indicating in the SCI the number of time slots to which the data transmission extends), and whether the subsequent time slot uses a full time slot structure or a partial time slot structure.

[0147] According to an embodiment, the UE will send control information only in the second control channel (such as the second PSCCH), where the control information includes information about data transmission (such as PSFCH) extending into a previous time slot (e.g., by indicating in the SCI the number of previous time slots or partial time slots to which the data transmission extends), and whether the previous time slot uses a full time slot structure or a partial time slot structure.

[0148] According to an embodiment, the first PSCCH and / or the second PSCCH includes one or more of the following:

[0149] - Control information pointing to data (such as PSSCH) transmitted across the current and subsequent time slots,

[0150] - The corresponding first-level sidelink control information SCI, where the first SCI and the second SCI are independent and include corresponding reservation fields pointing to, for example, the primary time slot resource allocation, or are copies of each other,

[0151] - Additional information, such as a sub-time slot indicator indicating a partial time slot belonging to the current resource allocation.

[0152] According to an embodiment, the PSSCH after the first / or second PSCCH includes the corresponding second-level SCI in the PSSCHs of both the current time slot and the subsequent time slot, or includes only one second-level SCI in the PSSCH of one of the current time slot and the subsequent time slot.

[0153] According to an embodiment, the UE will communicate with one or more other UEs via SL using a resource set in the unlicensed spectrum.

[0154] According to an embodiment, when the UE starts transmitting at the second start symbol, the UE will perform a listen-before-talk LBT procedure during one or more symbols before the second start symbol.

[0155] According to an embodiment, the time slot structure allows starting at at least one other start symbol during the duration of the time slot.

[0156] According to an embodiment, the UE is configured with a time slot structure by one or more network entities of the wireless communication system.

[0157] According to an embodiment, the network entities of the wireless communication system include one or more of the following:

[0158] - A base station, such as 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 an integrated access and backhaul IAB node,

[0159] - A roadside unit, RSU,

[0160] - A UE, such as an SL UE, or a master UE, GL-UE or relay UE,

[0161] - A remote radio head,

[0162] - A core network entity, such as an access and mobility management function AMF or a service management function SMF or a mobile edge computing MEC entity,

[0163] - For network slices in the context of NR or 5G core,

[0164] - Any transmit / receive point (TRP) enabling an item or device to communicate using the wireless communication network, the item or device being provided with a network connection to communicate using the wireless communication network.

[0165] According to an embodiment, the UE is preconfigured with a time slot structure, e.g., by hard-coded configuration in the UE.

[0166] Receiving UE

[0167] The present invention provides a user equipment (UE) for a wireless communication network (such as a 3rd Generation Partnership Project 3GPP network),

[0168] wherein the UE will communicate with one or more additional transmitting UEs according to embodiments of the present invention,

[0169] wherein the UE is configured to receive a transmission from a transmitting UE including additional AGC symbols located at symbols corresponding to the second starting symbol of the time slot, and

[0170] wherein the UE will perform a gain control procedure at the additional AGC symbols.

[0171] According to an embodiment, the presence of the additional AGC symbols at the second starting symbol is indicated by one or more of the following

[0172] - Control signaling together with the signaling and / or configuration of the transmission, e.g., an SCI field indicating the additional AGC symbols, or a preconfiguration of a PSFCH indicator indicating the absence of the PSFCH,

[0173] - Resource pool configuration,

[0174] - Configuration,

[0175] - Preconfiguration.

[0176] According to an embodiment, the signaling and / or configuration or preconfiguration is indicated according to one or more of the following

[0177] - Each resource pool,

[0178] - Each bandwidth part,

[0179] - Each subband,

[0180] - Each set of subbands, e.g., each subchannel, or interleaving in unlicensed spectrum,

[0181] - System-wide configuration, e.g., using broadcast messages such as System Information Block SIB and / or Master Information Block MIB,

[0182] - For each transmission,

[0183] - For each transmission set.

[0184] According to an embodiment, signaling and / or configuration is / are indicated by one or more network entities of a wireless communication system.

[0185] According to an embodiment, the network entities of a wireless communication system include one or more of the following:

[0186] - Base stations, such as macro cell base stations, or small cell base stations, or the central unit of a base station, or the distributed unit of a base station, or an integrated access and backhaul IAB node,

[0187] - Road Side Unit, RSU,

[0188] - UEs, such as SL UEs, or master UEs, GL-UEs or relay UEs,

[0189] - Remote radio heads,

[0190] - Core network entities, such as Access and Mobility Management Function AMF or Service Management Function SMF or Mobile Edge Computing MEC entities,

[0191] - Network slices, e.g., in the context of NR or 5G Core,

[0192] - Any Transmission / Reception Point TRP enabling an article or device to communicate using the wireless communication network, the article or device being provided with a network connection to communicate using the wireless communication network.

[0193] According to an embodiment, the pre-configuration is based on hard-coded configuration in the UE.

[0194] According to an embodiment, a first control channel, such as a first PSCCH, is received at the start of the current time slot and / or a second control channel, such as a second PSCCH, is received at the start of a subsequent time slot.

[0195] According to an embodiment, the UE will receive control information only in the first control channel (such as the first PSCCH), where the control information includes information about data transmission (including PSSCH and / or PSFCH) extending into subsequent time slots (e.g., by indicating in the SCI the number of time slots to which the data transmission extends) and whether the subsequent time slots use a full time slot structure or a partial time slot structure.

[0196] According to an embodiment, the UE will accept control information only in a second control channel, such as a second PSCCH, where the control information includes information on whether data transmission (such as a PSFCH) extends into a previous time slot (e.g., by indicating in the SCI the number of previous time slots or partial time slots to which the data transmission extends), and whether the previous time slot uses a full time slot structure or a partial time slot structure.

[0197] System / Network

[0198] The present invention provides a wireless communication system (such as a 3rd Generation Partnership Project 3GPP system), and according to embodiments of the present invention and one or more base stations, the system includes one or more user equipments UE.

[0199] According to an embodiment,

[0200] The UE includes one or more of the following: a power-constrained UE; or a handheld UE, such as a UE used by a pedestrian and referred to as a vulnerable road user VRU; or a pedestrian UE (P-UE); or a wearable or handheld UE used by public safety personnel and first responders and referred to as a public safety UE (PS-UE); or an IoT UE, for example, sensors, actuators, or UEs provided in a campus network for performing repetitive tasks and requiring regular input from a gateway node; or a mobile terminal; or a fixed terminal; or a cellular IoT-UE; or an SL UE or a vehicle-mounted UE; or a vehicle-mounted master UE (GL-UE); or a scheduling UE (S-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 RSU; or a building; or any other item or device having a network connection enabling the item / device to communicate using a wireless communication network, such as a sensor or an actuator; or any other item or device having a network connection enabling the item / device to communicate using a sidelink wireless communication network, such as a sensor or an actuator; or any network entity capable of implementing a sidelink; and

[0201] The base station includes one or more of the following: a macrocell 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 an integrated access and backhaul IAB node; or a roadside unit RSU; or a UE; or an SL UE; or a master UE (GL-UE); or a relay or a remote radio head; or an AMF; or an SMF; or a core network entity; or a mobile edge computing MEC entity; or a network slice in an NR or 5G core environment; or any transmission / reception point TRP enabling an item or device to communicate using a wireless communication network, the item or device being provided with a network connection to communicate using a wireless communication network.

[0202] Method

[0203] The present invention provides a method for operating a user equipment UE for a wireless communication network (such as a 3rd Generation Partnership Project 3GPP network), wherein the UE communicates with one or more other UEs in the wireless communication network via a sidelink SL, and the method includes:

[0204] Configuring or pre-configuring the UE with a time slot structure that allows transmissions to start at one of a plurality of starting symbols during the duration of a time slot, the plurality of starting symbols including a first starting symbol and a second starting symbol, the first starting symbol being an automatic gain control AGC symbol and the second starting symbol being an AGC symbol and offset from the first starting symbol,

[0205] Starting a transmission at the first starting symbol or at the second starting symbol by the UE, and

[0206] When the UE starts the transmission at the first starting symbol, including an additional AGC symbol in the time slot by the UE, the additional AGC symbol being located at a symbol in the time slot corresponding to the second starting symbol.

[0207] Computer Program Product

[0208] Embodiments of the present invention provide a computer program product that includes instructions which, when executed by a computer, cause the computer to perform one or more methods in accordance with the present invention.

[0209] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. It should be noted that the aspects or embodiments outlined and described subsequently may be combined such that some or all of the aspects / embodiments are implemented in one embodiment. Additionally, it should be noted that when referring to "resources" in this specification, a resource should be understood to include one or more of the following resources:

[0210] - One or more symbols,

[0211] - One or more time slots or sub-frames or frames,

[0212] - One or more frequencies or carriers or sub-channels or sub-channel groups,

[0213] - One or more interleavings,

[0214] - One or more resource block sets, RB sets,

[0215] - One or more frequency bands, such as an unlicensed sub-band,

[0216] - One or more bandwidth parts,

[0217] - one or more resource pools,

[0218] - one or more LBT sub - bands,

[0219] - one or more spatial resources, e.g., using spatial multiplexing.

[0220] In addition, it should be noted that when referring to "a set of resources" in this specification, a set of resources may include one or more resources, and the definition of resources is as mentioned above. In addition, it should be noted that when referring to "a channel" in this specification, it may refer to the set of resources mentioned above. Therefore, "a channel" may also refer to a sub - channel, a sub - band, a set of RBs, an interleaving, a resource pool, or an SL BWP.

[0221] Figure 8 The figure shows a wireless communication system, such as the wireless communication system described above with reference to FIG. 1, FIG. 2 or Figure 7 the described wireless communication system, e.g., a system or network of the 3rd Generation Partnership Project 3GPP. The wireless communication system includes user equipments 400, 402 operating according to embodiments of the present invention and one or more base stations 404. UE 400 (also referred to as a sidelink UE (SL - UE)) includes one or more antennas 400a and a signal processor 400b for performing one or more operations, e.g., operations related to antenna 400a such as transmitting / receiving data (such as payload data or control data), or UE - to - UE coordination (IUC) messages. UE 400 can communicate with other UEs (such as UE 402) using the sidelink or PC5 interface, as schematically illustrated at 408. UE 402 (also referred to as a sidelink UE (SL - UE)) includes one or more antennas 402a and a signal processor 402b for performing one or more operations, e.g., operations related to antenna 400a such as transmitting / receiving data (e.g., payload data and / or control data) or UE - to - UE coordination (IUC) messages. In addition, UE 400 and / or UE 402 may be connected to a base station or gNB 404. gNB 404 includes one or more antennas 404a for wireless communication with other network entities such as UE 400 and / or UE 402, and also includes a signal processor 404b. When operating in mode 1, UE 400 and UE 402 receive resources allocated by gNB 404 via the Uu interface 412, and these resources will be used by the UEs for communication via the sidelink 408. As mentioned above, when operating in mode 2, UE 400 and / or UE 402 may not have a connection to gNB 404, and the UE performs sensing plus access resource allocation or random - access - based resource allocation before performing a transmission.

[0222] Figure 8The spectrum 414 is further schematically illustrated, such as a radio spectrum including resources for communication within a wireless communication system or network. Resources that can be used for SL communication can include one or more of the following: one or more symbols, one or more time slots or sub-frames or frames, one or more resource blocks (RBs) or frequencies or carriers or sub-channels or groups of sub-channels, one or more frequency bands. As further schematically illustrated, the spectrum 414 includes an authorized spectrum 416 and an unauthorized spectrum 418. The authorized spectrum 416 is a part of the spectrum reserved for a wireless communication system including UEs 400 and 402 and the base station 404. In other words, according to the regulations of regulatory authorities and entities, the resources in the authorized spectrum are only for use by this wireless system. The unauthorized spectrum 418 includes resources that can be used by multiple wireless communication systems, such as by another wireless communication system operating according to the 3GPP standard but by different operators, or by a system using a different radio access technology (RAT) such as WiFi or Bluetooth.

[0223] According to an embodiment, a resource pool 420 (also referred to as a sidelink resource pool, SL-RP) can be provided for sidelink communication, and the UE 400 is configured or pre-configured with the resource pool 420. Although only one resource pool is depicted in the figure, multiple such resource pools can be configured or pre-configured. The resource pool can include only resources from the unauthorized spectrum 418 or only from the licensed spectrum 416, or, as Figure 8 depicted in an embodiment, can include resources from the licensed spectrum 416 and from the unauthorized spectrum 420. According to a further embodiment, carrier aggregation can be used to aggregate resources in the unauthorized spectrum.

[0224] According to an embodiment of the present invention, the UE 400 is configured or pre-configured with a time slot structure that allows transmission to start at one of multiple starting symbols during the duration of a time slot. For example, a time slot structure as described above with reference to FIGS. 3(a) or 3(b) can be adopted, which includes, in addition to the AGC symbol at the start of the time slot, an additional AGC symbol at symbol 7, for example, and the symbol 7 forms a second starting symbol at which the UE can start transmission. Note that embodiments of the present invention are described herein with reference to the use of one additional starting symbol, i.e., the time slot structure includes a first starting symbol and a second starting symbol, both of which are AGC symbols, where the first starting symbol is located at the start of the time slot and the second starting symbol is positioned at an offset from the first starting symbol. Note that the present invention is not limited to using only two starting symbols, but can include more than two starting symbols in a time slot such that the total number of starting symbols can be 3, 4, or more starting symbols. As Figure 8As illustrated in the figure, UE 400 includes a storage device 400c for storing the time slot configuration of the present invention, and the time slot configuration of the present invention allows transmission to start at two or more starting symbols during a time slot, as schematically indicated at 422. The UE 400 can start transmission at the first starting symbol or the second starting symbol, both of which are AGC symbols. As further indicated at 424, the UE 400 starts its transmission at the first starting symbol, and thus, according to the method of the present invention, additional AGC symbols are included in the time slot at a position corresponding to the position of the second starting symbol, as schematically indicated at 426. For example, when considering that a time slot includes multiple symbols, the first starting symbol can be the first symbol in the time slot, allowing the transmission to utilize the entire time slot, while the second starting symbol is the second symbol of the time slot or a symbol offset by one or more symbols from the first symbol, allowing the transmission to utilize a partial sub - time slot. Introducing additional AGC symbols ensures that in the case where another transmission starts at the second starting symbol, in both transmissions, the AGC symbols at the same symbol position are transmitted, thus avoiding the problems described above at the receiver side.

[0225] FIG. 9 illustrates an embodiment according to which, for full - time - slot transmission, additional AGC symbols are included in the middle of the time slot, such as at the seventh symbol of a time slot with a total duration of 14 symbols, so that in the case where a second transmission to be performed by the UE in a different frequency band starts at the second starting symbol, the AGC symbols for the second transmission are aligned with the additional AGC symbols in the first transmission. FIG. 9(a) illustrates an embodiment according to which the UE 400 performs a first transmission Tx 1A in frequency band 220A and a second transmission in a second frequency band 220B. For the first transmission Tx 1A , the full time slot is adopted, while the second transmission Tx 1C only occupies the second half of the time slot. Thus, the scenario in FIG. 9(a) is similar to the scenario described above with reference to Figure 6 . However, according to the method of the present invention, the problems encountered in the prior - art method are avoided by introducing additional AGC symbols 226 into the transmission Tx 1A performed in the first frequency band 220A at the same symbol position as the second starting symbol 224 in the second frequency band 220B. In the embodiment of FIG. 9(a), it is assumed that the second starting symbol 224 is in the middle of the time slot, and at the corresponding position, the first transmission also includes additional AGC symbols 226. Thus, the full - time - slot transmission Tx 1ANow there is an additional AGC symbol 226 in the middle of the time slot, and the position depends on the configuration or pre-configured position of the second start symbol 224. This enables any RX UE to perform AGC adjustment at this symbol during the duration of the time slot, thereby accommodating transmissions that are only performed in the second half of the time slot, such as transmission Tx 1C 。

[0226] FIG. 9(b) shows another embodiment, according to which the first half of the time slot in the second frequency band 220B can be used for additional transmissions Tx that are only in the first half of the time slot 1B ,and then the second start symbol 252 can be used to start the next transmission Tx 1C 。In addition, in such a scenario, an additional AGC symbol 226 is included in the transmission in the first frequency band 220A. For example, in transmissions Tx 1B and Tx 1C share a COT such that transmission Tx 1C does not need to perform LBT, the scenario in FIG. 9(b) can be adopted.

[0227] According to an embodiment, the UE 400 is configured or pre-configured with a time slot structure for a corresponding resource pool (i.e., each resource pool) or for a corresponding BWP (i.e., each BWP), for a corresponding sub-band or set of sub-bands (i.e., each sub-band or each set of sub-bands) (e.g., each sub-channel or interleaving in unlicensed spectrum), or for a corresponding transmission or set of transmissions (i.e., each transmission or each set of transmissions). The UE 400 can be configured with a time slot structure by one or more network entities of a wireless communication system, for example, forming one or more of the following:

[0228] - a base station, such as 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 an integrated access and backhaul IAB node,

[0229] - a roadside unit, RSU,

[0230] - a UE, such as an SL UE, or a master UE, GL-UE or relay UE,

[0231] - a remote radio head,

[0232] - a core network entity, such as an access and mobility management function AMF or a service management function SMF or a mobile edge computing MEC entity,

[0233] - a network slice, such as in an NR or 5G core environment,

[0234] - Any transmit / receive point TRP that enables an article or device to communicate using the wireless communication network, the article or device being provided with a network connection to communicate using the wireless communication network.

[0235] According to other embodiments, the UE 400 may be provided with a slot structure configuration at the time of its manufacture, i.e., it may have a pre-configuration based on a hard-coded configuration. Additionally, when prepared for use with a wireless communication system, the UE may be pre-configured, e.g., it may obtain the slot structure from a SIM inserted into the UE.

[0236] According to an embodiment, the method of the present invention may be used for each slot or only for some slots. For example, according to a resource pool or system configuration, additional AGC symbols may be used in each slot of a sidelink resource pool. However, providing additional AGC symbols may result in a reduction in the number of symbols available for data transmission. Thus, according to an embodiment, the method of the present invention for providing additional AGC symbols may be used only in a suitable subset of the slots within a sidelink resource pool, or only for one or more specific transmissions. When additional AGC symbols are only allowed for a subset of the slots within a resource pool, only some slots command the UE to use the slot structure of the present invention, the slot structure of the present invention using additional AGC symbols that are included in a full-slot transmission at a position corresponding to any additional start symbols allowed for the slot. This enables the UE to use a partial slot or sub-slot for transmission only in such slots such that when a full-slot transmission is also performed in such slots, the slot structure of the present invention is adopted and the additional AGC symbols are introduced into the full-slot transmission, such that the RX UE can perform AGC to adjust its gain at the receiver chain based on the AGC symbols transmitted at the start symbols of the partial transmission. According to an embodiment, a subset of slots may be defined

[0237] - Using a time pattern, such as a bitmap, or

[0238] - Using a periodic pattern, e.g., including the periodicity and / or length of the pattern, or

[0239] - Using an asymmetric pattern, or

[0240] - Using a start symbol and / or a periodic offset, or

[0241] - Using a time resource indicator value TRIV, and / or a frequency resource indicator value FRIV, or

[0242] - Depending on whether a specific symbol, such as a physical sidelink feedback channel PSFCH, is present in the slot.

[0243] As mentioned above, the use of additional AGC symbols, i.e., the use of the time slot structure of the present invention, may be permitted only for one or more specific transmissions. Similarly, according to another embodiment, for all transmissions, or only for one or more specific transmissions, the transmission may start at the second start symbol. The one or more specific transmissions may include one or more of the following:

[0244] - New transmissions,

[0245] - Transmissions with a priority exceeding a predetermined threshold,

[0246] - Transmissions with specific latency constraints (such as ultra-reliable low-latency communication URLLC constraints), e.g., according to the packet delay budget PDB of the transmission,

[0247] - Transmissions for which the UE has successfully performed a channel access procedure (such as listen-before-talk LBT) on a subchannel,

[0248] - Transmissions including positioning information, which may include, for example, one or more positioning reference symbols PRS,

[0249] - PSFCH transmissions, e.g., stand-alone PSFCH transmissions without data, for sending urgent feedback such as hybrid automatic repeat request HARQ feedback,

[0250] - Transmissions of an auxiliary information message AIM or an inter-UE coordination message IuC,

[0251] - Transmissions including control information (e.g., MAC-CE sent within the physical sidelink shared channel PSSCH),

[0252] - Transmissions including one or more additional demodulation reference signals DRMS or channel state information CSI, e.g., for precoding or decoding of multi-input multi-output MIMO transmissions,

[0253] - Transmissions before reserved transmissions in subsequent full time slots.

[0254] As described above with reference to FIG. 3, the time slot for sidelink communication may provide a guard symbol at the last symbol of the time slot, such as symbol number 13. According to the time slot structure of the present invention, when additional AGC symbols are introduced in the manner described above, the guard symbol can be maintained. However, when considering a transmission that starts at the second start symbol 224 and extends into subsequent time slots, the transmitting UE does not need to switch between transmit / receive modes, such that no guard symbol is required and it can actually be used for data transmission. Thus, depending on the action performed by the UE in the subsequent time slot, the guard symbol at the end of the time slot can be optional. For example, in the case where the UE needs to receive data in a subsequent time slot, it needs to switch to the receive mode and thus requires a guard symbol. On the other hand, in the case where the UE continues the transmission (i.e., the transmission started in the current time slot extends into the subsequent time slot), it can use the symbol at the end of the time slot to transmit additional data, such as PSSCH, PSFCH, PSCCH, or DMRS. Additionally, in the case where the UE switches to the DRX mode (i.e., enters the sleep mode) after the transmission in the current time slot, the UE does not need to switch to the receive mode and thus can use the last symbol to transmit additional data.

[0255] Figure 10 The figure illustrates an embodiment according to which the transmission starts at the second start position 224 at symbol 7 of time slot i and extends into time slot i+1, assuming that the transmission utilizes the time slot structure according to FIG. 3(a). According to the embodiment, instead of using symbol 13 of time slot i as the guard symbol, according to the embodiment, as Figure 10 illustrated, this symbol is also used for data transmission. Figure 11 The figure illustrates an embodiment similar to Figure 10 except that the time slot structure in time slot i+1 is the time slot structure according to the present invention that includes an additional AGC symbol 226 at symbol 7. In other words, Figure 10 The figure illustrates an embodiment in which a partial or sub-time slot starting at the second start symbol 224 is followed by a full time slot transmission, and according to this full time slot transmission, the guard in symbol 13 can be omitted in favor of the transmission of additional data. Figure 11 The figure illustrates a similar embodiment according to which a partial or sub-time slot starting at the second start symbol 224 of time slot i is followed by a full time slot transmission having an additional AGC symbol 226 in the middle of the time slot.

[0256] According to an embodiment of the present invention, the second and any additional start symbols provided in the time slot structure of the present invention, in addition to the first start symbol, may be located at specific positions within the time slot, such as one or more symbols before a predefined symbol. For example, the second start symbol may be located three symbols before the DMRS symbol. The additional AGC symbols included in the full time slot transmission are located at the same symbol as the second start symbol, thereby causing alignment of the predefined symbols in the corresponding frequency band, such as DMRS alignment across frequency bands, frequency sub - bands, or sub - channels. Note that according to embodiments, different DMRS positions are possible, and each time slot may provide more than one or more than two DMRS symbol positions.

[0257] In the following, additional embodiments regarding transmitting transmissions in subsequent time slots in different frequency bands using the method of the present invention are described. FIG. 12 illustrates such an embodiment, where in the first frequency band 220A, a full time slot transmission is performed in the current time slot i, while in the second frequency band 220B, a partial or sub - time slot transmission is performed in the current time slot i. According to the method of the present invention, since the sub - time slot transmission is performed in the frequency band 220B starting from the second start symbol 224, the transmission in the first frequency band 220A includes an additional AGC symbol 226 at the same symbol position as the start symbol 224 in the second frequency band, which is symbol 7 in the depicted embodiment. FIG. 12 illustrates embodiments according to which the corresponding transmissions in the two frequency bands 220A and 220B cause the DMRS symbols to be aligned, i.e., occur in the same symbols in the corresponding time slots. Note that the corresponding transmissions are not necessarily aligned with respect to the DMRS symbols, but rather, the assignment may also be with respect to any other symbol. This alignment is due to the fact that an additional start symbol 224 is provided at a specific position before the DMRS symbol (symbol 10 in FIG. 12(a)), and since the time slot structures in the two frequency bands are the same except that the transmission in the second frequency band 220B starts at symbol 224, and since according to the method of the present invention, an additional AGC symbol 226 is inserted in the transmission in the first frequency band 220A at the same position as symbol 224. The additional AGC symbol is located at the same distance from the DMRS symbol in the transmission in the second frequency band, such that the corresponding desired symbols (here the DMRS symbols) are aligned in the frequency bands.

[0258] Figures 12(a) to 12(d)All embodiments depicted perform a first transmission in a first frequency band 220A covering the entire current time slot i, while a sub-slot transmission is performed in a second frequency band 220B starting only at a second start symbol 224. According to the method of the present invention, the full-slot transmission includes an additional AGC symbol 226 at the same symbol as the second start symbol 224. According to an embodiment, as schematically illustrated in FIG. 12(a), a first portion of the current time slot i in the second frequency band 220B can be used to perform LBT to see if the frequency band 220B is available for transmission.

[0259] In FIG. 12(a), the transmission in the first frequency band 220A is only during the current time slot i and there is no transmission in the subsequent time slot i + 1. In this case, a guard symbol may or may not be used, and in the latter case, an additional PSSCH or other data can be sent there. In the second frequency band 220B, the transmission starting at the second start symbol 224 can extend into the subsequent time slot i + 1, and a full-slot transmission using the time slot structure according to FIG. 3 or a time slot structure including an additional AGC symbol 226 according to an embodiment of the present invention can be employed. In the latter case, i.e., when using the additional AGC symbol 226, an additional transmission (not depicted) can be performed in an additional frequency band in the subsequent time slot as a sub-slot transmission starting at the second start symbol.

[0260] FIG. 12(b) illustrates an embodiment according to which, in the second frequency band 220B, two sub-slot transmissions are performed in the subsequent time slot i + 1 in a similar manner as described above with reference to FIG. 9(b).

[0261] FIG. 12(c) illustrates an embodiment similar to FIG. 12(b), however, an additional transmission is also performed in the first frequency band 220A in the subsequent time slot i + 1. Since the second frequency band 220B sends two sub-slot transmissions in the subsequent time slot i + 1, i.e., corresponding transmissions starting at a first start symbol and the second start symbol 224, the transmission in the first frequency band 220A includes the additional AGC symbol 226 of the present invention.

[0262] FIG. 12(d) illustrates an embodiment according to which, in the first frequency band 220A, in the subsequent time slot i + 1, a sub-slot transmission is performed starting from the second start point 224. In the second frequency band 220B, at the end of the subsequent time slot i + 1, a sub-slot transmission is also performed. For a transmission starting in the current time slot i, assuming that the transmission extends into the subsequent time slot and there is no transmission in the first portion of the subsequent time slot in the first frequency band 220A, it is not necessary to include an AGC symbol at the start of the subsequent time slot, such that the symbols extending from the current time slot to the second time slot form a full-slot transmission having the time slot structure as described above with reference to FIG. 3(a).

[0263] According to the transmissions described above that extend over two or more time slots (also referred to as slot aggregation), the aggregated time slots can be in the same frequency or different frequency bands. For example, there can be a specific gap between two frequencies / sub-channels / sub-bands / interleaves. According to an embodiment, the UE 400 can use a first time slot structure and a second time slot structure for transmission, which in turn uses the same frequency or different frequencies, where the frequency is defined as one or more of a sub-channel, a set of sub-channels, a sub-band, a set of sub-bands, an interleaving, a set of interleavings, a resource pool, a set of resource pools.

[0264] As already described above, according to an embodiment, the basic time slot structure can be as described above with reference to FIG. 3, where an additional start symbol 224 (such as an AGC symbol) can be used for the UE to start its transmission. In this case, according to the method of the present invention, an additional AGC symbol 226 is provided in the full time slot transmission performed in another frequency band at the same time position / similar position as the second start position. According to an embodiment, the additional or second start position can be placed within the time slot at a specific symbol, and the specific symbol has a predefined distance from one or more symbols used to perform the desired transmission (such as providing feedback information or positioning information). Therefore, according to an embodiment, the additional or second start symbol can be located at a symbol before a single symbol or a block of symbols that allows a specific transmission, such as

[0265] - a transmission in which the UE has successfully performed LBT on the sub-channel,

[0266] - a PSFCH transmission, for example, an independent PSFCH transmission without data, for sending urgent feedback such as HARQ feedback,

[0267] - a transmission of virtual data for maintaining the channel occupancy time COT after performing listen-before-talk LBT, or

[0268] - a transmission of a predefined reference symbol (such as a positioning reference symbol PRS for sidelink positioning) or a reference symbol for channel reconstruction (such as DRMS), or

[0269] - a transmission of channel state information CSI (such as a CSI reference symbol CSI-RS) for improving multi-input multi-output MIMO channel estimation

[0270] - a transmission of an auxiliary information message AIM or a UE-to-UE coordination message IuC,

[0271] - a transmission including control information (such as a MAC-CE sent within a PSSCH).

[0272] Figure 13The figure illustrates an embodiment using the time slot structure according to FIG. 3(b), where the additional AGC symbol 226 is located three symbols ahead of the PSFCH block 230, i.e., symbols 10, 11, 12, and 13. Thus, with PSFCH enabled, a sub - time - slot structure can be defined with the last four symbols dedicated to feedback transmission (i.e., for sending feedback to the transmitting UE). These symbols include a guard symbol, the AGC symbol for PSFCH, the actual PSFCH symbol, and an additional guard symbol, where, depending on the transmission in the subsequent time slot, the last symbol 13 can be an optional guard symbol. According to an embodiment, the start symbol 224 is placed at a specific distance from the PSFCH symbol block to allow the transmission of virtual data, such as for reserving the COT initiated after performing LBT. This allows the UE to also use one or more subsequent time slots for its transmission. As mentioned above, according to other embodiments, the symbol block 230 can be used to send reference symbols, such as positioning reference symbols PRS, which can be used for sidelink positioning. Other symbols can also be sent, such as other reference symbols, symbols for channel reconstruction (such as DMRS symbols), or symbols for improving MIMO channel estimation (such as channel state information (CSI) or channel state information reference symbols (CSI - RS)).

[0273] Regarding the use of one or more symbols to perform a specific transmission, such as PSFCH, it should be noted that, according to an embodiment, the symbols for a specific transmission can be configured to be present in each sub - time - slot structure or only in a subset of the sub - time - slots. For example, PSFCH can be present with a specific priority, such as every second or every fourth sub - time - slot.

[0274] According to an embodiment of the present invention, when considering such as Figure 13When combining sub - slots and full - slots shown in the second frequency band 220B of (a), the symbols for transmitting control data (such as PSCCH) can be reduced, thereby increasing resource efficiency by allowing more data symbols (such as PSSCH) to be transmitted. Thus, in this case, only a single PSSCH after the first transmitted AGC symbol is used. Therefore, according to an embodiment, the first PSCCH can be transmitted at the start of the current time - slot, and / or the second PSCCH can be transmitted at the start of a subsequent time - slot. When the UE transmits control information only in the first control channel (such as the first PSCCH), the control information includes information about data transmission (including PSSCH and / or PSFCH) extending into subsequent time - slots (e.g., by indicating in the SCI the number of time - slots to which the data transmission extends), and whether the subsequent time - slot uses a full - slot structure or a partial - slot structure. When the UE transmits control information only in the second control channel (such as the second PSCCH), the control information includes information about data transmission (such as PSFCH) extending into the previous time - slot (e.g., by indicating in the SCI the number of the previous time - slot or partial - slot to which the data transmission extends), and whether the previous time - slot uses a full - slot structure or a partial - slot structure.

[0275] According to other embodiments, each of the sub - slot transmission and the full - slot transmission may include a corresponding PSCCH, as depicted in the embodiment of FIG. 12.

[0276] One or more PSCCHs may include control information pointing to data (such as PSSCH) transmitted across the current and subsequent time - slots. For example, a first - level SCI may be included in each of the first PSCCH and the second PSCCH, where the corresponding first - level SCIs are independent, and the first of the first - level SCIs provides a reservation field pointing to a resource location in a subsequent or following time - slot. According to other embodiments, the first - level SCIs may be the same and may include additional fields, such as a sub - slot indicator indicating that the sub - slot transmission belongs to the current resource allocation. According to further embodiments, a second - level SCI may also be provided in one of the PSSCHs, preferably in one of the full - slot transmissions, or in both PSSCHs.

[0277] So far, embodiments of the transmitting UE have been described, such as Figure 8 the UE 400 in transmits the corresponding transmissions described in different frequency bands 220A, 220B. However, further embodiments of the present invention provide a receiving UE, such as UE 402, which, as indicated at 428, receives a transmission from the transmitting UE 400 including an additional AGC symbol 226 at a symbol of a time - slot corresponding to the second start symbol 224. As indicated at 430, the UE 402 uses the additional AGC symbol 226 to perform a gain - control procedure.

[0278] According to an embodiment, the presence of the additional AGC symbol 226 at the second start symbol is indicated by control signaling together with the configuration of the signaling and / or transmission. For example, it is indicated by an SCI field that indicates the additional AGC symbol 226, or by a pre-configuration of a PSFCH indicator that indicates the absence of the PSFCH. In another embodiment, the SCI includes a field for indicating one or more AGC symbols that allow the receiver to re-tune the AGC and punch the PSSCH accordingly. In a further embodiment, the additional AGC symbol is present only when the PSFCH is not present in the time slot, thus allowing the PSFCH indicator to be reused to indicate the presence of the additional AGC symbol, which means that if the PSFCH indicator is set to false, one or more additional AGC symbols are present in the time slot.

[0279] In yet another embodiment, it is beneficial to allow half time slots only in specific time slots of a resource pool. The reason is that half time slots may lead to an increase in the number of conflicts because legacy UEs may not support half time slots and may not read the control information transmitted there for future reservation. Therefore, they will only learn this information in the subsequent full time slots that result in misbehavior. In addition, the TRIV and FRIV signal future reservations (time slots and frequency ranges, e.g., RB sets). Then, the UE can use the additional AGC only in the time slots and RB sets where another UE has reserved half time slot transmissions, otherwise transmit without the additional AGC symbol. In another embodiment, half time slots can be supported only in time slots that do not contain the PSFCH, and thus, the additional AGC symbol can be sent only in PSFCH-free time slots.

[0280] The presence of the additional AGC symbol 226 can also be indicated by a resource pool configuration, or by a configuration, or by a pre-configuration. The signaling and / or configuration or pre-configuration can indicate to the UE 402 the corresponding resource pool (i.e., each resource pool) or the corresponding BWP (i.e., each BWP), the corresponding subband or subband set (i.e., each subband or each subband set (e.g., each subchannel or interleaving in unlicensed spectrum)) (by a system-wide configuration, e.g., using broadcast messages such as system information block SIB and / or master information block MIB), or the corresponding transmission or transmission set (i.e., each transmission or each transmission set). The UE 402 can receive the signaling and / or configuration from one or more network entities of the wireless communication system, for example, forming one or more of the following:

[0281] - A base station, such as 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 an integrated access and backhaul IAB node,

[0282] - A roadside unit, RSU,

[0283] - A UE, such as a SL UE, or a master UE, GL-UE or relay UE,

[0284] - A remote radio head,

[0285] - A core network entity, such as an access and mobility management function AMF or a service management function SMF or a mobile edge computing MEC entity,

[0286] - A network slice, such as in an NR or 5G core environment,

[0287] - Any transmit / receive point TRP that enables an article or device to communicate using the wireless communication network, the article or device being provided with a network connection to communicate using the wireless communication network.

[0288] According to other embodiments, the UE 402 may be provided with a configuration at the time of its manufacture, i.e., it may have a pre-configuration based on hard-coded configuration. In addition, when prepared for use with a wireless communication system, the UE may be pre-configured, for example, it may obtain a configuration from a SIM inserted into the UE.

[0289] When receiving transmissions from the UE 400 in different channels, the UE 402 may receive a first control channel (such as a first PSCCH) at the start of the current time slot, and / or may receive a second control channel (such as a second PSCCH) at the start of a subsequent time slot. When receiving control information only in the first control channel (such as a first PSCCH), the control information includes information about data transmission (including PSSCH and / or PSFCH) extending into subsequent time slots (e.g., by indicating in the SCI the number of time slots to which the data transmission extends), and whether the subsequent time slot uses a full time slot structure or a partial time slot structure. When receiving control information only in the second control channel (such as a second PSCCH), the control information includes information about data transmission (such as PSFCH) extending into the previous time slot (e.g., by indicating in the SCI the number of previous time slots or partial time slots to which the data transmission extends), and whether the previous time slot uses a full time slot structure or a partial time slot structure.

[0290] Overview

[0291] The embodiments of the present invention have been described in detail above, and each embodiment and aspect can be implemented separately, or two or more embodiments or aspects can be combined for implementation.

[0292] In the above description of embodiments of the present invention, sidelink communication using resources in unlicensed spectrum has been referred to. Note that the present invention is not limited to such embodiments, but rather, the methods of the present invention are equally applicable to systems in which sidelink communication utilizes only resources from licensed spectrum, and also to embodiments in which sidelink communication utilizes resources from both licensed spectrum and unlicensed spectrum. Also in such embodiments, when transmission is allowed to start at a second start symbol during a specific time slot, additional AGC symbols are added at the symbol position corresponding to the second start symbol for transmissions in parallel frequency bands using full or full time slots.

[0293] Furthermore, in the embodiments described above, it has been assumed that the corresponding transmissions performed in different subbands are performed by the same UE. However, it should be noted that according to other embodiments, transmissions may also be performed by different UEs in the same time slot in different frequency bands.

[0294] According to an embodiment, a wireless communication system may include a terrestrial network or a non-terrestrial network, or a network or network segment using an airborne vehicle or a spaceborne vehicle as a receiver, or a combination thereof.

[0295] According to an embodiment of the present invention, a user equipment includes one or more of the following: a power-constrained UE; or a handheld UE, such as a UE used by a pedestrian, referred to as a vulnerable road user (VRU); or a pedestrian UE (P-UE); or a wearable or handheld UE used by public safety personnel and first responders, also referred to as a public safety UE (PS-UE); or an IoT UE, for example, sensors, actuators, or UEs provided in a campus network for performing repetitive tasks and requiring regular input from a gateway node, or a mobile terminal; or a fixed terminal; or a cellular IoT-UE; or a vehicle UE; or a vehicle master (GL) UE; or a sidelink relay; or an IoT or narrowband IoT (NB-IoT); or a wearable device, such as a smartwatch, a fitness tracker, smart glasses; or a ground vehicle; or an aircraft; or a drone; or a mobile base station; or a roadside unit (RSU); or a building; or any other item or device having a network connection enabling the item / device to communicate using a wireless communication network, such as a sensor or an actuator; or any other item or device having a network connection enabling the item / device to communicate using a sidelink wireless communication network, such as a sensor or an actuator; or any network entity capable of implementing a sidelink.

[0296] According to an embodiment of the present invention, the network entity includes one or more of the following: a macro cell base station; a small cell base station; or a central unit of a base station, an integrated access and backhaul IAB node of a base station or a distributed unit of a base station, a roadside unit (RSU), a remote radio head; or an AMF; or an MME; or an SMF; or a core network entity; or a mobile edge computing (MEC) entity; or a network slice in an NR or 5G core environment; or any transmission / reception point TRP, enabling an article or device to communicate using a wireless communication network, where the article or device is provided with a network connection to communicate using the wireless communication network.

[0297] Although some aspects of the described concepts are described in the context of a device, it is evident that these aspects also represent a description of the 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 method steps also represent a description of the corresponding block or article or feature of the corresponding device.

[0298] 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-purpose 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 14 FIG. illustrates an example of a computer system 600. These units or modules and the method steps performed 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 dedicated or general-purpose digital signal processor. The processor 602 is 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 an auxiliary memory 608, such as a hard disk drive and / or a removable storage drive. The auxiliary memory 608 can allow a computer program or other instructions to be loaded into the computer system 600. The computer system 600 can also include a communication interface 610 to allow the transfer of software and data between the computer system 600 and external devices. The communication can employ electrical, electromagnetic, optical, or other signals that can be processed by the communication interface. The communication can use wires or cables, optical fibers, telephone lines, cellular phone links, RF links, and other communication channels 612.

[0299] The terms "computer program medium" and "computer-readable medium" generally refer to tangible storage media such as removable storage units or hard disks installed in hard disk drives. These computer program products are devices for providing software to a computer system 600. The computer program, also known as computer control logic, is stored in the main memory 606 and / or the auxiliary memory 608. The computer program can also be received through the communication interface 610. When the computer program is executed, the computer system 600 is capable of implementing the present invention. In particular, when executed, the computer program enables the processor 602 to implement the present invention, such as any of the methods described herein. Thus, such a computer program can represent the controller of the computer system 600. When implementing the present disclosure using software, the software can be stored in a computer program product and loaded into the computer system 600 using a removable storage drive, an interface (such as the communication interface 610).

[0300] Implementations in hardware or software can be carried out using digital storage media such as cloud storage, floppy disks, DVDs, Blu-rays, CDs, ROMs, PROMs, EPROMs, EEPROMs or flash memories, on which electronically readable control signals are stored that cooperate or are capable of cooperating with a programmable computer system so as to carry out the corresponding methods. Thus, the digital storage media can be computer-readable.

[0301] Some embodiments according to the invention include a data carrier having electronically readable control signals that are capable of cooperating with a programmable computer system so as to carry out one of the methods described herein.

[0302] Generally, embodiments of the present invention can be implemented as a computer program product having program code that, when run on a computer, is for carrying out one of the methods. The program code can be stored, for example, on a machine-readable carrier.

[0303] Other embodiments include a computer program stored on a machine-readable carrier for carrying out one of the methods described herein. In other words, thus, an embodiment of the method of the present invention is a computer program having program code for carrying out one of the methods described herein when run on a computer.

[0304] Accordingly, a further embodiment of the method of the present invention is a data carrier or digital storage medium, or a computer-readable medium, on which a computer program for performing one of the methods described herein is recorded. Accordingly, a further embodiment of the method of the present invention is a data stream or signal sequence representing a computer program for performing one of the methods described herein. The data stream or signal sequence may be configured, for example, to be transmitted via a data communication connection (such as via the Internet). Further embodiments include a processing device, such as a computer or a programmable logic device, which is configured or adapted to perform one of the methods described herein. Further embodiments include a computer on which a computer program for performing one of the methods described herein is installed.

[0305] In some embodiments, a programmable logic device, such as a field programmable gate array, may be used to perform some or all of the functions of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor to perform one of the methods described herein. Generally, these methods are preferably performed by any hardware device.

[0306] The embodiments described above are only for illustrative purposes of the principles of the present invention. It should be understood that modifications and variations of the arrangements and details described herein will be apparent to those skilled in the art. Accordingly, the scope of the present invention is intended to be limited only by the scope of the upcoming patent claims, and not by the specific details presented herein by way of description and explanation of the embodiments.

Claims

1. A user equipment (UE) for a wireless communication network, such as a 3rd Generation Partnership Project (3GPP) network, Among them, wherein the UE communicates with one or more other UEs in the wireless communication network via a sidelink (SL), wherein the UE is configured or pre-configured with a slot structure that allows transmissions to start at one of a plurality of starting symbols during the duration of a slot, the plurality of starting symbols including a first starting symbol and a second starting symbol, the first starting symbol being an Automatic Gain Control (AGC) symbol and the second starting symbol being an AGC symbol and offset from the first starting symbol, wherein the UE is adapted to start a transmission at the first starting symbol or at the second starting symbol, and wherein when the UE starts the transmission at the first starting symbol, the UE will include an additional AGC symbol in the slot at the symbol corresponding to the second starting symbol of the slot.

2. The user equipment according to claim 1, wherein The first starting symbol is at the start of the slot.

3. The user equipment UE according to claim 1 or 2, wherein, The UE is configured or pre-configured with the slot structure according to one or more of the following: - Each resource pool, - Each bandwidth part, - Each subband, - Each set of subbands, e.g., each subchannel, or interleaving in unlicensed spectrum, - System-wide configuration, e.g., using broadcast messages such as System Information Block (SIB) and / or Master Information Block (MIB), - Each transmission, - Each transmission set.

4. The user equipment UE according to any one of the preceding claims, wherein, The slot includes a plurality of symbols, the first starting symbol being the first symbol in the slot, thereby allowing transmissions to use the full slot, and the second starting symbol being the second symbol of the slot or a symbol offset by one or more symbols from the first symbol, thereby allowing transmissions to use a partial slot.

5. The user equipment UE according to claim 4, wherein, The second starting symbol is at the middle of the slot, e.g., at symbol position seven, thereby allowing transmissions to use half of the slot.

6. The user equipment UE according to any one of the preceding claims, wherein, The UE is configured or pre-configured with a slot structure, and the additional AGC symbol is configured or pre-configured - In each slot within the SL resource pool, or - Only in a proper subset of the slots within the SL resource pool.

7. The user equipment UE according to claim 6, wherein, Configuring or pre-configuring the proper subset of the slots - Using a time pattern, such as a bitmap, or - Using a periodic pattern, e.g., including the periodicity and / or length of the pattern, or or - Using an asymmetric pattern, or - Using a starting symbol and / or a periodic offset, or - Using a Time Resource Indicator Value (TRIV) and / or a Frequency Resource Indicator Value (FRIV), or - Depending on whether a specific symbol, such as a Physical Sidelink Feedback Channel (PSFCH), is present in the slot.

8. The user equipment UE according to any one of the preceding claims, wherein, The UE will use the additional AGC symbol - For all transmissions, or - Only for one or more specific transmissions.

9. The UE according to any one of the preceding claims, wherein, The UE is allowed to start at the second starting symbol - For all transmissions, or - Only for one or more specific transmissions.

10. The user equipment UE according to claim 8 or 9, wherein, The one or more specific transmissions include one or more of the following: - A new transmission, - A transmission with a priority exceeding a predetermined threshold, - Transmissions with specific latency constraints such as ultra-reliable low-latency communication (URLLC) constraints, e.g., according to the packet delay budget (PDB) of the transmission, - Transmissions in which the UE has successfully performed a channel access procedure such as listen-before-talk (LBT) on a subchannel, - Transmissions including positioning information, which may include, for example, one or more positioning reference symbols (PRSs), - Physical sidelink feedback channel (PSFCH) transmissions, e.g., stand-alone PSFCH transmissions without data for sending urgent feedback such as hybrid automatic repeat request (HARQ) feedback, - Transmissions of auxiliary information messages (AIM) or inter-UE coordination messages (IuC), - Transmissions including control information, e.g., MAC control element (MAC-CE) sent within the physical sidelink shared channel (PSSCH), - Transmissions including one or more additional demodulation reference signals (DRSs) or channel state information (CSI), e.g., for precoding or decoding in multiple-input multiple-output (MIMO) transmissions, - Transmissions before reserved transmissions in subsequent full time slots.

11. The user equipment (UE) according to any one of the preceding claims, wherein the last symbol of the time slot includes a guard symbol, and the UE will use the guard symbol for data transmission, e.g., for transmission of the physical sidelink shared channel (PSSCH), or the physical sidelink feedback channel (PSFCH), or the physical sidelink control channel (PSCCH), or the demodulation reference signal (DMRS), - when the UE starts the transmission at the first start symbol or the second start symbol in the current time slot using the additional AGC symbol, and - when the UE will also transmit in a subsequent time slot or will enter the discontinuous reception (DRX) mode at the end of the current time slot.

12. The user equipment (UE) according to any one of the preceding claims, wherein the first time slot structure is a time slot structure that allows the transmission to start at one of the multiple start symbols, and the second time slot structure is a time slot structure that allows the transmission to start only at the first symbol of the time slot, and when the UE starts the transmission at the first start symbol in the current time slot using the additional AGC symbol and is to perform a transmission in a subsequent time slot, the subsequent time slot has the first time slot structure or the second time slot structure, or when the UE starts the transmission at the second start symbol in the current time slot and is to perform a transmission in a subsequent time slot, the subsequent time slot has - the first time slot structure, or - the second time slot structure, or - a third time slot structure that allows a first transmission to start at the first start symbol during the duration of the subsequent time slot and allows a second transmission to start at a second start symbol after the first start symbol during the duration of the subsequent time slot, or - a fourth time slot structure that allows the transmission in the current time slot to extend into the subsequent time slot without an AGC symbol and / or a control symbol at the start of the subsequent time slot.

13. The user equipment (UE) according to any one of the preceding claims, wherein The UE will perform transmissions using a first time slot structure and a second time slot structure. The first time slot structure and the second time slot structure use - the same frequency, or - different frequencies, where the frequency is defined as one or more of a subchannel, a set of subchannels, a subband, a set of subbands, an interleaving, a set of resource blocks, an interleaving set, a resource pool, a resource pool set.

14. The user equipment UE according to any one of the preceding claims, wherein, The second starting symbol and the additional AGC are located one or more symbols before a predefined symbol or a preconfigured number of symbols in the time slot, such as a DMRS symbol.

15. The user equipment UE according to any one of the preceding claims, wherein the time slot structure includes a predefined number of symbols at the end of the time slot, the symbols being dedicated to receiving transmissions such as feedback transmissions, for example, a first guard symbol, an AGC symbol for the PSFCH, the PSFCH symbol, and a second guard symbol, and the second starting symbol is offset from the first symbol among the predefined number of symbols, and the UE is to use one or more symbols between the second starting symbol and the first symbol among the predefined number of symbols for a specific transmission, for example, - transmission of virtual data for maintaining the channel occupancy time COT after performing listen-before-talk LBT, or - transmission of a predefined reference symbol, such as a positioning reference symbol PRS for sidelink positioning or a reference symbol for channel reconstruction such as DRMS, or - transmission of channel state information CSI, such as a CSI reference symbol CSI-RS, for improving multi-input multi-output MIMO channel estimation - transmission of an auxiliary information message AIM or an inter-UE coordination message IuC, - transmission including control information, such as a MAC-CE sent within the PSSCH.

16. The user equipment UE according to any one of the preceding claims, wherein the UE will use one or more symbols between the second starting symbol and the end of the time slot for a specific transmission, for example, - transmission in which the UE has successfully performed LBT on the subchannel, - PSFCH transmission, for example, an independent PSFCH transmission without data, for sending urgent feedback such as HARQ feedback, - transmission of virtual data for maintaining the channel occupancy time COT after performing listen-before-talk LBT, or - transmission of a predefined reference symbol, such as a positioning reference symbol PRS for sidelink positioning or a reference symbol for channel reconstruction such as DRMS, or - transmission of channel state information CSI, such as a CSI reference symbol CSI-RS, for improving multi-input multi-output MIMO channel estimation - transmission of an auxiliary information message AIM or an inter-UE coordination message IuC, - transmission including control information, such as a MAC-CE sent within the PSSCH.

17. The user equipment UE according to claim 16, wherein, The UE is to perform the specific transmission in a configured or preconfigured resource pool having a PSFCH periodicity greater than one, such as two or four.

18. The user equipment UE according to any one of the preceding claims, wherein, A first control channel, such as a first PSCCH, is sent at the start of the current time slot and / or a second control channel, such as a second PSCCH, is sent at the start of the subsequent time slot.

19. The user equipment UE according to claim 18, wherein, The UE will transmit control information only on the first control channel, such as the first PSCCH, where the control information includes information about data transmission including the PSSCH and / or PSFCH extending into the subsequent time slot, for example, by indicating in the SCI the number of time slots to which the data transmission extends, and the control information includes information about whether the subsequent time slot uses a full time slot structure or a partial time slot structure.

20. The user equipment UE according to claim 18, wherein, The UE will transmit control information only on the second control channel, such as the second PSCCH, where the control information includes information about data transmission, such as the PSSCH, extending into the previous time slot, for example, by indicating in the SCI the number of previous time slots or partial time slots to which the data transmission extends, and the control information includes information about whether the previous time slot uses a full time slot structure or a partial time slot structure.

21. The user equipment UE according to claim 18, wherein, The first PSCCH and / or the second PSCCH includes one or more of the following: - Control information pointing to data such as the PSSCH transmitted across the current and subsequent time slots, - Corresponding first-level sidelink control information SCI, where the first SCI and the second SCI are independent and include, for example, corresponding reservation fields pointing to the primary time slot resource allocation, or are copies of each other, - Additional information, such as a sub-time slot indicator indicating the partial time slot belonging to the current resource allocation.

22. The user equipment UE according to claim 19, wherein, The PSSCH after the first / or second PSCCH includes the corresponding second-level SCI in the PSSCHs of both the current time slot and the subsequent time slot, or includes only one second-level SCI in the PSSCH of one of the current time slot and the subsequent time slot.

23. The user equipment UE according to any one of the preceding claims, wherein, The UE will communicate with the one or more other UEs via the SL using a resource set in the unlicensed spectrum.

24. The user equipment UE according to claim 23, wherein, When the UE starts the transmission at the second start symbol, the UE will perform a listen-before-talk LBT procedure during one or more symbols before the second start symbol.

25. The user equipment UE according to any one of the preceding claims, wherein, The time slot structure allows for starting at at least one other start symbol during the duration of the time slot.

26. The user equipment UE according to any one of the preceding claims, wherein, The UE is configured with the time slot structure by one or more network entities of the wireless communication system.

27. The user equipment UE according to claim 26, wherein, The network entities of the wireless communication system include one or more of the following: - Base stations, such as macro cell base stations, or small cell base stations, or the central unit of a base station, or the distributed unit of a base station, or an integrated access and backhaul IAB node, - Roadside units, RSU, - UEs, such as SL UEs, or master UEs, GL-UEs or relay UEs, - Remote radio heads, - Core network entities, such as access and mobility management functions AMF or service management functions SMF or mobile edge computing MEC entities, - Network slices, such as in the NR or 5G core environment, - Any transmit / receive point TRP enabling an article or device to communicate using the wireless communication network, where the article or device is provided with a network connection to communicate using the wireless communication network.

28. The user equipment UE according to any one of claims 1 to 25, wherein, The UE is pre-configured with the time slot structure, for example, based on hard-coded configuration in the UE.

29. A user equipment UE for a wireless communication network such as a 3rd Generation Partnership Project 3GPP network, Among them, wherein the UE is for communicating with one or more additional UEs according to any one of the preceding claims, wherein the UE is for receiving a transmission including additional AGC symbols from a transmitting UE, the additional AGC symbols being at the symbols of the time slot corresponding to the second start symbol, and wherein the UE will perform a gain control procedure at the additional AGC symbols.

30. The UE according to claim 29, wherein The presence of additional AGC symbols at the second start symbol is indicated by one or more of the following: - Control signaling together with the signaling and / or configuration of the transmission, e.g., an SCI field indicating the additional AGC symbols, or a pre-configuration of a PSFCH indicator indicating the absence of the PSFCH, - Resource pool configuration, - Configuration, - Pre-configuration.

31. The user equipment UE according to claim 30, wherein, The signaling and / or the configuration or the pre-configuration is indicated according to one or more of the following: - Each resource pool, - Each bandwidth part, - Each sub-band, - Each set of sub-bands, e.g., each sub-channel, or interleaving in unlicensed spectrum, - System-wide configuration, e.g., using broadcast messages such as System Information Block SIB and / or Master Information Block MIB, - Each transmission, - Each transmission set.

32. The user equipment UE according to claim 30 or 31, wherein, The signaling and / or the configuration is indicated by one or more network entities of the wireless communication system.

33. The user equipment UE according to claim 32, wherein, The network entities of the wireless communication system include one or more of the following: - Base stations, such as macro cell base stations, or small cell base stations, or the central unit of a base station, or the distributed unit of a base station, or an Integrated Access and Backhaul IAB node, - Road Side Unit, RSU, - UEs, such as SL UEs, or master UEs, GL-UEs or relay UEs, - Remote radio heads, - Core network entities, such as Access and Mobility Management Function AMF or Service Management Function SMF or Mobile Edge Computing MEC entities, - Network slices such as in an NR or 5G core environment, - Any Transmission / Reception Point TRP enabling an article or device to communicate using the wireless communication network, the article or device being provided with a network connection to communicate using the wireless communication network.

34. The user equipment UE according to claim 30 or 31, wherein, The pre-configuration is based on a hard-coded configuration in the UE.

35. The user equipment UE according to any one of claims 29 to 24, wherein, Receiving a first control channel such as a first PSCCH at the start of the current time slot, and / or receiving a second control channel such as a second PSCCH at the start of the subsequent time slot.

36. The user equipment UE according to claim 35, wherein, The UE will receive control information only in the first control channel such as the first PSCCH, wherein the control information includes information about data transmission including PSSCH and / or PSFCH extending into the subsequent time slot, e.g., by indicating in the SCI the number of time slots to which the data transmission extends, and the control information includes information about whether the subsequent time slot uses a full time slot structure or a partial time slot structure.

37. The user equipment UE according to claim 35, wherein, The UE will receive control information only on the second control channel, such as the second PSCCH, where the control information includes information about data transmission, such as on the PSSCH, extending into the previous time slot, for example, by indicating in the SCI the number of previous time slots or partial time slots to which the data transmission is extended, and the control information includes information about whether the previous time slot uses a full time slot structure or a partial time slot structure.

38. A wireless communication system, such as a 3rd Generation Partnership Project 3GPP system, comprises one or more user equipments UE and one or more base stations according to any one of the preceding claims.

39. The user equipment UE according to claim 38, wherein the UE comprises one or more of the following: a power-constrained UE; or a handheld UE, such as a UE used by a pedestrian and referred to as a vulnerable road user VRU; or a pedestrian UE, P-UE; or a wearable or handheld UE used by public safety personnel and first responders and referred to as a public safety UE, PS-UE; or an IoT UE, e.g., a sensor, actuator, or UE provided in a campus network for performing repetitive tasks and requiring periodic input from a gateway node; or a mobile terminal; or a fixed terminal; or a cellular loT-UE; or an SL UE or a vehicle-mounted UE; or a vehicle-mounted master UE, GL-UE; or a scheduling UE, S-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 RSU; or a building; or any other item or device having a network connection enabling the item / device to communicate using a wireless communication network, such as a sensor or an actuator; or any other item or device having a network connection enabling the item / device to communicate using a sidelink wireless communication network, such as a sensor or an actuator; or any network entity capable of implementing a sidelink; and the base station comprises one or more of the following: a macrocell 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 an integrated access and backhaul IAB node; or a roadside unit RSU; or a UE; or an SL UE; or a master UE, GL-UE; or a relay or a remote radio head; or an AMF; or an SMF; or a core network entity; or a mobile edge computing MEC entity; or a network slice in an NR or 5G core environment; or any transmission / reception point TRP enabling an item or device to communicate using a wireless communication network, the item or device being provided with a network connection to communicate using a wireless communication network.

40. A method for operating a user equipment UE for a wireless communication network such as a 3rd Generation Partnership Project 3GPP network, wherein, The UE communicates with one or more other UEs in the wireless communication network via a sidelink SL, the method comprising: configuring or pre-configuring the UE with a time slot structure allowing transmission to start at one of a plurality of starting symbols during the duration of a time slot, the plurality of starting symbols including a first starting symbol and a second starting symbol, the first starting symbol being an automatic gain control AGC symbol and the second starting symbol being an AGC symbol and offset from the first starting symbol, The transmission is started by the UE at the first starting symbol or at the second starting symbol, and when the UE starts the transmission at the first starting symbol, the UE includes an additional AGC symbol in the time slot, and the additional AGC symbol is located at the symbol of the time slot corresponding to the second starting symbol.

41. A non-transitory computer program product, comprising a computer-readable medium storing instructions that, when executed on a computer, perform the method according to claim 40.

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