CN117615456A

CN117615456A - Method for enhancing side-uplink communication on unlicensed spectrum

Info

Publication number: CN117615456A
Application number: CN202310947072.6A
Authority: CN
Inventors: 程俊强; 陈滔; 陈暻葳
Original assignee: MediaTek Singapore Pte Ltd
Current assignee: MediaTek Singapore Pte Ltd
Priority date: 2022-08-19
Filing date: 2023-07-31
Publication date: 2024-02-27
Also published as: WO2024036617A1

Abstract

Various solutions are described relating to sidelink communication enhancement over unlicensed spectrum. The device operating in the first transmission mode communicates with the peer device for SL-U communication. The apparatus may determine whether a condition associated with SL-U communication is satisfied. Responsive to the determination, the device remains in the first transmission mode or switches from the first transmission mode to the second transmission mode for SL-U communication.

Description

Method for enhancing side-uplink communication on unlicensed spectrum

Technical Field

The present invention relates generally to mobile communications, and more particularly to Sidelink (SL) communication enhancement over unlicensed spectrum.

Background

Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims listed below and are not admitted to be prior art by inclusion in this section.

Cellular-based vehicular-to-evaluation (V2X), such as Long-Term Evolution (LTE) V2X or New Radio (NR) V2X, is a Radio access technology developed by the third generation partnership project (3rd Generation Partnership Project,3GPP) for supporting advanced vehicle applications. In V2X, a direct radio link (also referred to as a side-link) may be established between two User Equipments (UEs) (e.g., installed on a vehicle). When the UE is within the coverage area of the cellular network, the side-links may operate under the control of the cellular network (e.g., for radio resource allocation). Alternatively, the side links may operate independently, for example, when there is no available cellular network or no available cellular network. In particular, the side-link communication may be performed through a direct communication interface called a PC5 interface.

To meet the growing demand for wireless data services, the use of unlicensed spectrum has become an enhancement to future wireless communication systems (including the fourth generation (4 ^th generation, 4G) LTE or fifth generation (5 ^th Generation, 5G) SL communication in NR). In order to fairly share unlicensed spectrum, a UE operating on unlicensed spectrum needs to perform a channel access procedure (or referred to as listen-before-talk (LBT)) before any transmission on unlicensed spectrum. However, there is a problem in that the channel access procedureMay result in a longer latency for the UE to transmit on the unlicensed spectrum. Another problem with using unlicensed spectrum is that after a UE gains access to a channel on the unlicensed spectrum, the transmission gap may be utilized by other UEs to occupy the channel and interrupt transmission. Furthermore, for legacy SL, one carrier has only one bandwidth part (BWP), which all UEs support. That is, only one BWP configuration is provided for all UEs to perform SL communication, which is inefficient in terms of radio resource utilization.

Thus, there is a need to provide a solution to the above-mentioned problems of side-uplink (SL over unlicensed spectrum, SL-U) communication over unlicensed spectrum.

Disclosure of Invention

The following summary is illustrative only and is not intended to be in any way limiting. That is, the following summary is provided to introduce a selection of concepts, gist, benefits, and advantages of the novel and non-obvious techniques described herein. Selected embodiments will be described further in the detailed description below. Accordingly, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter.

It is an object of the present invention to propose a solution, a concept, a design, a system, a method and a device for SL-U communication enhancement. It is believed that the foregoing problems will be avoided or otherwise alleviated by the practice of one or more of the proposed solutions described herein.

In one aspect, a method involves a device operating in a first transmission mode communicating with a peer device (SL-U). The method also involves the apparatus determining that a condition associated with SL-U communication is satisfied. The method also involves, in response to the determination, the apparatus staying in the first transmission mode or switching from the first transmission mode to the second transmission mode for SL-U communication.

In another aspect, a method involves a device performing a channel access procedure to initialize a channel occupancy time (channel occupancy time, COT) for SL-U communication with a peer device. The method also involves the device maintaining the COT by filling a gap (gap) between two successive transmissions.

In yet another aspect, a method involves an apparatus performing a first SL communication with any one or more of all peer apparatuses according to a first configuration of a common BWP, a common Resource Pool (RP), or a common Resource Block (RB) set. The method also involves the apparatus performing, by the processor, a second SL communication with at least one particular peer device according to a second configuration of the UE-specific BWP, the UE-specific RP, or the UE-specific RB set.

Notably, although the description provided herein is in the context of certain radio access technologies, networks, and network topologies, such as LTE, LTE-Advanced, and LTE-Advanced-Pro-enhanced, 5G, NR, internet of Things (IoT), narrowband Internet of Things (Narrow Band Internet of Things, NB-IoT), industrial Internet of Things (industrial Internet of Things, IIoT), beyond 5G (beyond 5G, b 5G), and sixth generation (6) ^th Generation, 6G), the concepts, schemes, and any variants/derivatives thereof presented by the present invention may be implemented in other types of radio access technologies, networks, and network topologies. Accordingly, the scope of the invention is not limited to the examples described herein.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. It will be appreciated that for clarity of illustration of the concepts of the invention, the drawings are not necessarily to scale, and that certain components may be shown out of scale from the actual implementation.

Fig. 1 is an example scene diagram illustrating transmission mode switching according to an aspect of an embodiment of the present invention.

Fig. 2 is an example scenario diagram illustrating access channel maintenance according to an aspect of an embodiment of the present invention.

Fig. 3 is a block diagram of an example communication system in accordance with an embodiment of the present invention.

FIG. 4 is a flowchart of an example process according to an embodiment of the invention.

Fig. 5 is a flowchart of an example process according to an embodiment of the invention.

FIG. 6 is a flowchart of an example process according to an embodiment of the invention.

Detailed Description

Examples and implementations of the claimed subject matter are described in detail below. It should be understood, however, that the disclosed examples and implementations are merely illustrative of the claimed subject matter, which is embodied in various forms. This invention may be embodied in many different forms and should not be construed as limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided so that this description will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the following description, well-known features and technical details are omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

SUMMARY

Embodiments in accordance with the present invention relate to various techniques, methods, schemes and/or solutions for SL-U communication enhancement. Many possible solutions may be implemented according to the invention, either individually or in combination. That is, although the following describes the possible solutions separately, two or more of the possible solutions may be implemented in one combination or another.

In the current framework of SL-U communications, devices operating on unlicensed spectrum need to perform a channel access procedure (or LBT) before any transmission on the unlicensed spectrum to facilitate fair sharing on the unlicensed spectrum. However, SL-U communication presents a number of problems. First, the indeterminate duration of the channel access procedure may result in a longer latency for the UE to transmit on the unlicensed spectrum. Second, after a UE gains access to a channel on the unlicensed spectrum, the transmission gap may be utilized by other UEs to occupy the channel and interrupt transmission. Third, the BWP configuration of the legacy SL is that one carrier has only one BWP, which all UEs support. That is, only one BWP configuration is provided for all UEs to perform SL communication, which is inefficient in terms of radio resource utilization. Thus, there is a need to provide a solution to the above-mentioned problems of SL-U communication.

For devices operating on unlicensed spectrum, different transmission methods may be required to simplify the channel access procedure. For example, in some regions (e.g., europe (EU) and China (CN)), ultra-low-power (VLP) operation has been widely used or considered for the important 5/6GHz spectrum. In the european union, the electrical communications committee (electric communications Committee, ECC) decision (20) 01 supports low power indoor (Lower Power Indoor, LPI) and VLP devices at 5925-6425 MHz. VLPs are designated for indoor and outdoor use, maximum equivalent omnidirectional radiation power (maximum equivalent isotropically radiated power, eirp=14 dBm, maximum EIRP density= -8dBm/MHz. At CN, VLP operation at occupied channel bandwidth-5850 MHz is supported, maximum eirp=14 dBm VLPs may be considered as an option to meet specification requirements, similar to the short control signaling mechanism used to simplify channel access and the avoidance of occupied channel bandwidth (occupied channel bandwidth, OCB).

In view of the above, the present invention proposes various schemes related to enhancement of SL-U communication. According to some aspects of the invention, a UE is allowed to switch between a first transmission mode (e.g., standard, STD, mode) and a second transmission mode (e.g., VLP mode) for SL-U communication. In particular, the first transmission mode and the transmission power mode are associated with different maximum transmission power thresholds (e.g., STD:23dbm; vlp:14 dbm), different channel access settings (e.g., channel access procedures with different sensing durations, or no channel access procedures), and/or different resource allocation (resource allocation, RA) settings (e.g., different oversubscription (oversubscription) configurations and/or gap margin (gap margin) configurations with different numbers of allocated radio resources). Furthermore, according to some aspects of the present invention, the UE is allowed to maintain the COT for SL-U communication by filling the gap between two consecutive transmissions. In addition, according to some aspects of the present invention, a plurality of BWPs are supported for SL-U or future SL evolution (SL-evo). In particular, a default or common BWP (or common RP or RB set) may be configured for all UEs, and a UE-specific BWP (or UE-specific RP or RB set) is configured for each link (i.e., PC 5-radio resource control (radio resource control, RRC) connection). Therefore, by applying the scheme of the invention, the performance of SL-U communication and the utilization rate of radio resources can be improved.

Fig. 1 shows an example scenario 100 of transmission mode switching of a scheme according to an embodiment of the invention. Scenario 100 shows an exemplary message sequence diagram for SL-U communication between two UEs 110 and 120. As shown in fig. 1, both UE 110 and UE 120 initially operate in STD mode. The initial transmission mode may be determined based on a pre-configured maximum EIRP and/or a pre-configured maximum EIRP density. For example, if the preconfigured maximum EIRP is less than 14dBm or the preconfigured maximum EIRP density is less than 1dBm/MHz, the initial transmission mode is a VLP mode. Otherwise, the initial transmission mode is the STD mode.

In step 101, while operating in STD mode, UE 110 performs type 1LBT to initialize COT. In step 102, UE 110 transmits data to UE 120 during the obtained COT. In step 103, UE 120 performs type 1LBT to initialize COT while operating in STD mode. In some implementations, type 1LBT may be performed for a sensing duration and may be performed with a mechanism of oversubscription and/or gap margin (e.g., one of oversubscription configuration and gap margin configuration associated with multiple allocated radio resources) to combat potential channel access failure.

In step 104, UE 120 sends data and signal strength feedback (e.g., reference signal received power (reference signal received power, RSRP)) to UE 110 during the obtained COT. Specifically, the signal strength feedback may be sent via SL signaling, such as side-uplink control information (sidelink control information, SCI), a PC5-RRC message, or an additional bit in a PC5 media access control-element (MAC-CE). In step 105, UE 110 derives a side-uplink path loss between UE 110 and UE 120 for further use in power control of UE 110. After power control, it is assumed that the derived power indicator (e.g., transmission power and/or transmission power density) meets the requirements of VLP mode as described above. For example, power control may be performed based on SL pathloss, downlink (DL) pathloss, and/or (pre) configured maximum transmission power. For example, UE 110 may determine the transmission power from a power control (e.g., derived based on the measured SL path loss and/or the (pre) configured maximum transmission power). If the determined transmission power is less than a threshold (e.g., total EIRP power <5 dBm), or the determined transmission power density is less than a threshold (e.g., total EIRP density < -8 dBm/MHz), UE 110 may switch to VLP mode for SL-U communication.

In step 106, UE 110 switches from STD mode to VLP mode in response to a condition that the derived at least one power indicator is less than at least one threshold (e.g., total EIRP power <5dBm, and/or EIRP density < -8 dBm/MHz). Notably, when operating in VLP mode, UE 110 need not perform any LBT before starting SL-U transmission. That is, UE 110 may directly obtain the COT for SL-U communication. Alternatively, when operating in VLP mode, the UE may need to perform loose LBT (e.g., type 2 LBT) for a smaller sensing duration before starting SL-U transmission, and may perform loose LBT with or without oversubscription and/or gap margin mechanisms (e.g., at least one of oversubscription configuration and gap margin configuration associated with a reduced number of allocated radio resources).

Next, in step 107, UE 110 transmits data and mode information (i.e., information indicating that UE 110 is operating in VLP mode) to UE 120 during the obtained COT. In particular, the mode information may be transmitted through SL signaling (e.g., SCI, PC5-RRC message, or an additional bit in PC 5-MAC-CE). In step 108, in response to the mode information of UE 110 being a condition of a VLP mode different from the mode information of UE 120, UE 120 switches from STD mode to VLP mode. Similarly, when operating in VLP mode, UE 120 may directly acquire COT for SL-U communication without any LBT prior to starting SL-U transmission. In step 109, UE 120 transmits data to UE 110 during the obtained COT.

In some embodiments, each of UE 110 and UE 120 may report whether it supports a VLP mode (e.g., VLP mode only, STD mode and VLP mode all support, or STD mode only) UE capability. For the case where UE 110 or 120 supports both VLP mode and STD mode, it may be further (pre) configured whether UE 110 or 120 is allowed to operate in STD mode or VLP mode.

In some embodiments, the determination and/or switching of STD mode and VLP mode may be configured and/or indicated by the gNB (pre) and the gNB may share mode information to the eligible UE via one additional bit in the RRC and/or MAC-CE and/or physical downlink control channel (physical downlink control channel, PDCCH). Alternatively, the determination and/or switching of STD mode and VLP mode may be configured and/or indicated (pre-) by the group header, and the group header may share mode information to eligible UEs via one additional bit in the PC5-RRC and/or PC5-MAC-CE and/or physical side uplink control channel (physical sidelink control channel, PSCCH) or physical side uplink shared channel (physical sidelink shared channel, PSSCH).

In some embodiments, the determination and/or switching of STD mode and VLP mode may be performed according to some other configuration. For example, mode determination and/or switching may be performed based on hybrid automatic repeat request (hybrid automatic repeat request, HARQ) feedback (e.g., positive feedback (ACK) or negative feedback (NACK)), received signal strength indication (received signal strength indication, RSSI), or RSRP measurements, traffic load, and/or channel access priority class (channel access priority class, cap)/priority of traffic. For example, if a UE operating in VLP mode receives multiple NACK feedback consecutively (e.g., for a (pre) configured duration), N times (consecutively) no feedback is received, and/or no feedback is received for a (pre) configured duration, the UE may determine to switch back to STD mode. If the UE is operating in STD mode and the measured RSSI is less than the (pre) configured threshold (e.g., for a certain duration), the UE may determine to switch to VLP mode.

In some embodiments, the UE may be (pre) configured to report mode information to the gNB via one additional bit in RRC, MAC-CE (i.e., PUSCH), and/or PUCCH. In addition, the UE may be (pre) configured to report the mode information to the group head or anchor UE via one additional bit in the PC5-RRC, MAC-CE and/or first stage SCI (or referred to as first SCI) and/or second stage SCI (or referred to as second SCI). In addition, the UE may be (pre) configured to indicate mode information to other eligible UEs (e.g., receiving UE, COT shared UE and/or other UEs) via one additional bit in the PC5-RRC, MAC-CE and/or the first SCI and/or the second SCI.

In some embodiments, for the case that includes broadcast transmission SL-U communication, if the maximum EIRP and maximum EIRP density of all UE (pre) configurations can meet the VLP mode requirements as described above, the UE may remain operating in VLP mode or switch to VLP mode. Otherwise, the UE operates in STD mode. For the case of a communication comprising multicast transmissions SL-U, the UEs in the group may remain operating in VLP mode or switch to VLP mode if the maximum EIRP and maximum EIRP density of all UE (pre) configurations in the group can meet the requirements of VLP mode. Otherwise, the UEs in the group operate in STD mode. In addition, for the case of multicasting, if SL path loss based power control can be used, the UE can operate in or switch to VLP mode depending on whether the highest derived transmission power and/or highest derived transmission power density after each link power control meets the requirements of VLP mode. If SL path loss based power control cannot be used in case of multicast, the UEs in the (pre) configuration group may be operated in STD mode.

Fig. 2 illustrates an example scenario 200 of access channel maintenance for an arrangement according to an embodiment of the present invention. Scenario 200 illustrates an exemplary time sequence of consecutive SL-U transmissions. As shown in fig. 2, there is no (ACK/NACK) transmission in the symbol (denoted as symbol # 12) of the physical side uplink feedback channel (physical sidelink feedback channel, PSFCH) occasion, and there is a gap between two consecutive transmissions. Specifically, the length of the gap is 4 symbols, including a guard symbol (denoted as symbol # 10) before the PSFCH occasion, an automatic gain control (automatic gain control, AGC) symbol (denoted as symbol # 11) for the PSFCH occasion, a symbol (denoted as symbol # 12) for the PSFCH occasion, and a guard symbol (denoted as symbol # 13) for the end of the slot. Notably, to maintain the COT, the gaps may be filled with cyclic prefix extensions (cyclic prefix extension, CPE), (virtual) data and/or new sequences. For the symbols of the PSFCH occasion (i.e., symbol # 12), the (virtual) data (e.g., PSSCH data) and/or the new sequence (e.g., a predefined sequence, such as a PSFCH class signal) may be transmitted to fill the gap. For the AGC symbol (i.e., symbol # 11), a copy of the PSFCH symbol may be sent. For the guard symbol (i.e., symbol # 10) prior to the PSFCH occasion, the CPE of the AGC symbol may be sent. For the guard symbol at the end of the slot (i.e., symbol # 13), the CPE of the transmission of the next slot may be sent, which may be configured or scheduled by the COT initiator (pre).

In some embodiments, CPE may be sent by the same or another UE between any two consecutive SL transmissions to reduce the gap between the two SL transmissions so that the gap does not exceed 16 microseconds (μs).

In another aspect of the invention, multiple BWPs may be supported for SL communications (e.g., for SL-U or SL-evo). For example, a default BWP (or default RP/RB set) may be (pre) configured to support unicast, multicast and/or broadcast transmissions (e.g. for transmissions for which no PC5-RRC connection is established in idle/inactive state). To save power for the inactive UE, the inactive UE may only listen to the (pre) configured default BWP (or default RP/RB set). The default BWP may be (pre) configured with a first number of RBs or sets of RBs (e.g., only one set of RBs). The default BWP may be (pre) configured as a common BWP for all UEs. In addition, UE-specific BWP (or UE-specific RP/RB set) may be (pre) configured to support unicast, multicast and/or broadcast transmissions (e.g. for transmission after a PC5-RRC connection is established in a connected state), wherein UE capabilities and preferred BWP sizes may be negotiated based on information exchange (e.g. quality of service (quality of service, qoS), cape of traffic, UE capabilities or traffic sizes.

Illustrative embodiments

Fig. 3 illustrates an example communication system 300 having at least two communication devices 310 and 320 in accordance with an embodiment of the invention. Any of communication device 310 and communication device 320 may perform different functions to implement the schemes, techniques, processes, and methods described herein with respect to SL-U communication enhancement, including the scenarios, schemes described above, and processes 400, 500, and 600 described below.

Either of communication device 310 and communication device 320 is part of an electronic device, which may be a UE such as a portable or mobile device, a wearable device, a wireless communication device, or a computing device. For example, any of the communication device 310 and the communication device 320 may be implemented as a smart phone, a smart watch, an electronic control unit (electronic control unit, ECU) in a vehicle, a personal digital assistant, a digital camera, or a computing device such as a tablet computer, a desktop computer, or a notebook computer. Any of the communication device 310 and the communication device 320 may also be part of a machine type device, which may be an IoT device such as a fixed device, a home device, a roadside unit (RSU), a wired communication device, or a computing device. For example, either of the communication device 310 and the communication device 320 may be implemented as a smart thermostat, a smart refrigerator, a smart door lock, a wireless speaker, or a home control center.

In some implementations, any of communication device 310 and communication device 320 may be implemented in the form of one or more integrated-circuit (IC) chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, one or more complex-instruction-set-computing (CISC) processors, one or more reduced-instruction-set computing (RISC) processors. In the various aspects described above, any of the communication apparatus 310 and the communication apparatus 320 may be implemented in or as a UE. Either of communication device 310 and communication device 320 includes at least a portion of the components shown in fig. 3, e.g., processor 312 and processor 322, respectively. Any of the communication devices 310 and 320 further includes one or more other components (e.g., an internal power source, a display device, and/or a user interface device) that are not relevant to the proposed solution of the present invention, and thus, any of the other components of the communication devices 310 and 320 are neither shown in fig. 3 nor described below for the sake of brevity.

In an aspect, any of processor 312 and processor 322 may be implemented in the form of one or more single-core processors, one or more multi-core processors, one or more CISC processors, or one or more RISC processors. That is, even though the singular term "processor" is used herein to refer to the processor 312 and the processor 322, in the present invention, any of the processor 312 and the processor 322 may comprise multiple processors in some embodiments, and a single processor in other embodiments. In another aspect, either of the processor 312 and the processor 322 may be implemented in hardware (and optionally firmware) with electronic components including, for example, but not limited to, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors, and/or one or more varactors configured for a particular purpose in accordance with the invention. In other words, in at least some embodiments, processor 312 and processor 322 are specific target machines that are specifically designed, arranged, and configured to perform specific tasks with respect to SL-U communication enhancement in accordance with various embodiments of the present invention.

In some implementations, the communication device 310 further includes a transceiver 316 coupled to the processor 312. The transceiver 316 is capable of wirelessly transmitting and receiving data. In some implementations, the transceiver 316 is capable of wireless communication with different types of UE/wireless networks of different radio access technologies (radio access technology, RATs). In some implementations, transceiver 316 may be equipped with multiple antenna ports (not shown), e.g., four antenna ports. That is, transceiver 316 may be equipped with multiple transmit antennas and multiple receive antennas for multiple-input multiple-output (MIMO) wireless communications. In some implementations, the communication device 320 further includes a transceiver 326 coupled to the processor 322. The transceiver 326 is capable of wirelessly transmitting and receiving data. In some implementations, the transceiver 326 is capable of wireless communication with different types of UEs/wireless networks of different RATs. In some implementations, the transceiver 326 may be equipped with multiple antenna ports (not shown), such as four antenna ports. That is, the transceiver 326 may be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communication.

In some implementations, the communication device 310 further includes a memory 314 coupled to the processor 312 and capable of being accessed by the processor 312 and storing data therein. In some implementations, the communication device 320 also includes a memory 324 coupled to the processor 322 and capable of being accessed by the processor 322 and storing data therein. Either of the memory 314 and the memory 324 includes a random-access memory (RAM), such as Dynamic RAM (DRAM), static RAM (SRAM), thyristor RAM (T-RAM), and/or zero-capacitance RAM (Z-RAM). Alternatively, or in addition, either of memory 314 and memory 324 includes a read-only memory (ROM), such as mask ROM, programmable ROM (PROM), erasable programmable ROM (erasable programmable ROM, EPROM), and/or electrically erasable programmable ROM (electrically erasable programmable ROM, EEPROM). Alternatively, or in addition, either of memory 314 and memory 324 includes a Non-volatile random access memory (Non-Volatile Random Access Memory, NVRAM)), such as flash memory, solid state memory, ferroelectric RAM (FeRAM), magnetoresistive RAM (MRAM), and/or phase change memory. Alternatively, either of memory 314 and memory 324 may include a universal integrated circuit card (universal integrated circuit card, UICC).

Each of the communication device 310 and the communication device 320 may be communication entities capable of communicating with each other using various schemes proposed according to the present invention. For illustrative purposes, and not limitation, the following provides a description of the capabilities of communication device 310 as a UE (e.g., UE 110/120) and communication device 320 as a peer UE (e.g., UE 110/120).

According to some aspects of the present invention, processor 312 of communication device 310, implemented in or as a UE, may communicate SL-U with a peer UE in a first transmission mode. In addition, processor 312 may determine that conditions associated with SL-U communications are met. Further, in response to the determination, processor 312 may stay in the first mode or switch from the first transmission mode to the second transmission mode for SL-U communication.

In some implementations, processor 312 may also receive signal strength feedback from peer devices via transceiver 316 and perform power control for SL-U communications based on the signal strength feedback. The condition may be detailed as to whether at least one power indicator derived from the power control is less than at least one threshold associated with the second transmission mode.

In some implementations, the signal strength feedback may include RSRP measured by the peer device during SL-U communications when the peer device is operating in the first transmission mode, and the at least one power indicator may include at least one of a transmission power and a transmission power density.

In some implementations, processor 312 may also receive mode information from the peer device via the transceiver 316 via SL signaling indicating whether the peer device is operating in the first transmission mode or the second transmission mode. The condition may be detailed as mode information indicating that the peer device is operating in the second transmission mode.

In some embodiments, SL signaling may include SCI, PC5-RRC message, or PC5-MAC-CE.

In some implementations, when the device is operating in the first transmission mode, the processor 312 may also perform a first channel access procedure for a first sensing duration via the transceiver 316 before beginning transmission with the peer device. In addition, when the device is operating in the second transmission mode, the processor 312 may perform a second channel access procedure, or not perform any channel access procedure, via the transceiver 316 for a second sensing duration that is less than the first sensing duration prior to beginning transmission with the peer device.

In some implementations, when the device is operating in the first transmission mode, the processor 312 may also perform a first channel access procedure via the transceiver 316 before starting transmission with the peer device. In particular, the first channel access procedure may be performed with at least one of a first oversubscription configuration and a first gap margin configuration associated with a first amount of allocated radio resources. In addition, when the device is operating in the second transmission mode, the processor 312 may perform a second channel access procedure via the transceiver 316 prior to beginning transmission with the peer device, or may not perform any channel access procedure. In particular, the second channel access procedure may be performed with at least one (or none) of a second oversubscription configuration and a second gap margin configuration associated with a second number of allocated radio resources that is less than the first number of allocated radio resources.

In some embodiments, the first transmission mode may be an STD mode and the second transmission mode may be a VLP mode.

In some embodiments, the STD mode may be associated with at least one first threshold of maximum transmission power or maximum transmission power density, the VLP mode may be associated with at least one second threshold of derived transmission power or transmission power density, and the at least one second threshold may be less than the at least one first threshold.

In some embodiments, the SL-U communication in the first transmission mode may be determined based on at least one of a pre-configured maximum transmission power and a pre-configured maximum transmission power density.

According to some aspects of the present invention, processor 312 of communication device 310, implemented in or as a UE, may perform a channel access procedure via transceiver 316 to initialize the COT for SL-U communication with the peer device. In addition, the processor 312 may maintain the COT by filling the gap between two consecutive transmissions.

In some embodiments, filling the gap between two consecutive transmissions comprises: the processor 312 transmits the CPE in one or more guard symbols via the transceiver 316.

In some embodiments, the one or more guard symbols may include at least one of a first guard symbol preceding an AGC symbol of the PSFCH and a second guard symbol at an end of the SL slot.

In some embodiments, filling the gap between two consecutive transmissions comprises: the processor 312 transmits data or a predefined sequence in symbols corresponding to PSFCH occasions without ACK and NACK transmissions via the transceiver 316.

In some implementations, the data can include PSSCH data, and the predefined sequence can include signals of the PSFCH class.

According to some aspects of the present invention, processor 312 of communication device 310, implemented in or as a UE, may conduct a first SL communication with any one or more of all peer devices via transceiver 316 according to a first configuration of a common BWP, a common RP, or a common set of RBs. In addition, processor 312 may conduct a second SL communication with at least one particular peer device via transceiver 316 according to a second configuration of the UE-specific BWP, the UE-specific RP, or the UE-specific RB set.

In some embodiments, the first SL communication may include unicast, multicast, or broadcast transmissions or receptions when no PC5-RRC connection is established with one of all peer devices.

In some embodiments, the second SL communication may include unicast, multicast or broadcast transmission or reception after establishing a PC5-RRC connection with at least one particular peer device.

In some embodiments, the UE-specific BWP may be not smaller than the common BWP.

In some embodiments, the common BWP may include a first number of RB sets, and the UE-specific BWP may include a second number of RB sets that is not less than the first number of RB sets.

In some implementations, processor 312 may also listen via transceiver 316 only to the first number of RB sets for the first SL communication.

In some implementations, each of the first SL communication and the second SL communication can include a SL-U communication.

Illustrative Process

FIG. 4 depicts an example process 400 according to an embodiment of the invention. Whether partially or wholly, process 400 represents one aspect of the various designs, concepts, solutions, systems, and methods presented above. More specifically, process 400 may represent various concepts and schemes related to SL-U communications, and more specifically related to transmission mode switching in SL-U communications, in accordance with the present invention. Process 400 represents one aspect of the implementation of the features of communication device 310 and communication device 320. Process 400 includes one or more operations, actions, or functions as illustrated by one or more of steps 410, 420, and 430. Although illustrated as discrete steps, the various steps of process 400 may be divided into additional steps, combined into fewer steps, or deleted as desired. Further, the steps/sub-steps of process 400 may be performed in the order shown in fig. 4, or in other orders. Further, one or more steps/sub-steps of process 400 may be repeatedly performed. Process 400 may be implemented by or in communication device 310 and communication device 320 and any variations thereof. For illustrative purposes only, but not limited thereto, process 400 is described in the context of communication device 310 being implemented as a UE (e.g., UE 110/120), communication device 320 being implemented as a peer UE (e.g., UE 110/120). Process 400 begins at step 410.

At step 410, process 400 involves processor 312 of communication device 310 (implemented in or as a UE) communicating with a peer UE in a SL-U communication in a first transmission mode. Process 400 proceeds from step 410 to step 420.

At step 420, process 400 involves processor 312 determining that a condition associated with SL-U communication is satisfied. Process 400 proceeds from step 420 to step 430.

At step 430, in response to the determination, process 400 involves processor 312 staying in the first transmission mode or switching from the first transmission mode to the second transmission mode for SL-U communication.

In some implementations, process 400 also involves processor 312 receiving signal strength feedback from peer devices via transceiver 316 and performing power control for SL-U communications in accordance with the signal strength feedback. The condition may be detailed as to whether at least one power indicator derived from the power control is less than at least one threshold associated with the second transmission mode. For example, the condition may detail that at least one power indicator derived from the power control is less than at least one threshold associated with the second transmission mode (e.g., transmission power after the power control < 14 dBm), causing the processor 312 to determine to stay in the first transmission mode (e.g., VLP mode) or switch from the first transmission mode to the second transmission mode (e.g., switch from STD mode to VLP mode). Alternatively, the condition may detail that at least one power indicator derived from the power control is greater than or equal to at least one threshold associated with the second transmission mode (e.g., transmission power ≡14dBm after the power control), causing the processor 312 to determine to stay in the first transmission mode (e.g., STD mode) or switch from the first transmission mode to the second transmission mode (e.g., switch from VLP mode to STD mode).

In some implementations, process 400 also involves processor 312 receiving mode information from the peer device via transceiver 316 via SL signaling indicating whether the peer device is operating in the first transmission mode or the second transmission mode. The condition may be detailed as mode information indicating whether the peer device is operating in the first transmission mode or the second transmission mode. For example, the condition may detail information indicating that the peer device is operating in a first transmission mode, causing the processor 312 to determine to stay in the first transmission mode (e.g., STD mode or VLP mode). Alternatively, the condition may detail information indicating that the peer device is operating in the second transmission mode, causing the processor 312 to determine to switch from the first transmission mode to the second transmission mode (e.g., to switch from STD mode to VLP mode, or from VLP mode to STD mode).

In some implementations, when the device is operating in the first transmission mode, the process 400 also involves the processor 312 performing a first channel access procedure for a first sensing duration via the transceiver 316 before beginning transmission with the peer device. In addition, when the device is operating in the second transmission mode, process 400 involves processor 312 performing a second channel access procedure, or not performing any channel access procedure, via transceiver 316 for a second sensing duration that is less than the first sensing duration before beginning transmission with the peer device.

In some implementations, when the device is operating in the first transmission mode, the process 400 also involves the processor 312 performing a first channel access procedure via the transceiver 316 before beginning transmission with the peer device. In particular, the first channel access procedure may be performed with at least one of a first oversubscription configuration and a first gap margin configuration associated with a first amount of allocated radio resources. In addition, when the device is operating in the second transmission mode, process 400 involves processor 312 performing a second channel access procedure via transceiver 316, or not performing any channel access procedure, prior to beginning transmission with the peer device. In particular, the second channel access procedure may be performed with at least one (or none) of a second oversubscription configuration and a second gap margin configuration associated with a second number of allocated radio resources that is less than the first number of allocated radio resources.

In some embodiments, the first transmission mode may be one of an STD mode and a VLP mode, and the second transmission mode may be the other of the STD mode and the VLP mode.

In some embodiments, the STD mode may be associated with at least one of a first threshold of maximum transmission power or maximum transmission power density, the VLP mode may be associated with at least one of a second threshold of derived transmission power or transmission power density, and the at least one second threshold may be less than the at least one first threshold.

FIG. 5 depicts an example process 500 according to an embodiment of the invention. Whether partially or wholly, process 500 represents one aspect of the various designs, concepts, solutions, systems, and methods presented above. More specifically, process 500 may represent various concepts and schemes related to SL-U communications, and more specifically to access channel maintenance in SL-U communications, in accordance with the present invention. Process 500 represents one aspect of the implementation of the features of communication device 310 and communication device 320. Process 500 includes one or more operations, actions, or functions as illustrated by one or more of steps 510 and 520. Although illustrated as discrete steps, the various steps of process 500 may be divided into additional steps, combined into fewer steps, or deleted as desired. Further, the steps/sub-steps of process 500 may be performed in the order shown in FIG. 5, or in other orders. Further, one or more steps/sub-steps of process 500 may be repeatedly performed. Process 500 may be implemented by or in communication device 310 and communication device 320 and any variations thereof. For illustrative purposes only, but not limited thereto, process 500 is described in the context of communication device 310 being implemented as a UE (e.g., UE 110/120), communication device 320 being implemented as a peer UE (e.g., UE 110/120). Process 500 begins at step 510.

At step 510, process 500 involves processor 312 of communication device 310 (implemented in or as a UE) performing a channel access procedure via transceiver 316 to initialize a COT for SL-U communication with a peer device. Process 500 proceeds from step 510 to step 520.

At step 520, process 500 involves processor 312 maintaining the COT by filling in the gap between two consecutive transmissions.

FIG. 6 depicts an example process 600 according to an embodiment of the invention. Whether partially or wholly, process 600 represents one aspect of the various designs, concepts, solutions, systems, and methods presented above. More specifically, process 600 may represent various concepts and schemes in connection with SL-U communications, and more specifically in connection with supporting multiple BWPs for SL-U or SL-evo communications in accordance with the invention. Process 600 represents one aspect of the implementation of the features of communication device 310 and communication device 320. Process 600 includes one or more operations, actions, or functions as shown in one or more of steps 610 and 620. Although illustrated as discrete steps, the various steps of process 600 may be divided into additional steps, combined into fewer steps, or eliminated, as desired. Further, the steps/sub-steps of process 600 may be performed in the order shown in fig. 6, or in other orders. Further, one or more steps/sub-steps of process 600 may be repeatedly performed. Process 600 may be implemented by or in communication device 310 and communication device 320 and any variations thereof. For illustrative purposes only, but not limited thereto, process 600 is described in the context of communication device 310 being implemented as a UE (e.g., UE 110/120), communication device 320 being implemented as a peer UE (e.g., UE 110/120). Process 600 begins at step 610.

At step 610, process 600 involves processor 312 of communication device 310 (implemented in or as a UE) conducting a first SL communication with any one or more of all peer devices via transceiver 316 according to a first configuration of a common BWP, a common RP, or a common set of RBs. Process 600 proceeds from step 610 to step 620.

At step 620, process 600 involves processor 312 conducting a second SL communication with at least one particular peer device via transceiver 316 according to a second configuration of the UE-specific BWP, the UE-specific RP, or the UE-specific RB set.

In some embodiments, the UE-specific BWP may be not smaller than the common BWP, and may or may not overlap between the UE-specific BWP and the common BWP.

In some implementations, the process 600 also involves the processor 312 listening via the transceiver 316 only to the first number of RB sets for the first SL communication.

Supplementary description

The subject matter described in this disclosure is sometimes illustrated as being comprised within or connected to various other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Thus, any two components in this disclosure that are combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being "operably connected," or "operably coupled," to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being "operably coupled," to each other to achieve the desired functionality. Specific examples of operably coupled include, but are not limited to, physically mateable and/or physically interactable components and/or wirelessly interactable components and/or logically interactable components.

Furthermore, those of skill in the art may translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application with respect to the use of essentially any of the plural and/or singular terms in the present invention. For clarity, various singular/plural permutations may be explicitly set forth in this disclosure.

Furthermore, it will be understood by those within the art that, in general, terms used in the specification and claims (e.g., the bodies of the appended claims) are often intended as "open" terms, e.g., the term "comprising" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," etc. It will be further understood by those with skill in the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an", e.g., "a" and/or "an" should be interpreted to mean "at least one" and "one or more", as well as for the use of the indefinite articles used to introduce a claim recitation. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number, and the bare recitation of "two recitations," without other modifiers, for example, means at least two recitations or two or more recitations. Further, in those instances where a similar convention of "at least one of A, B and C, etc." is used, such a construction is intended in general in the sense one having skill in the art would understand the convention, such as "a system having at least one of A, B and C" would include, but not be limited to, a system having only a, only B, only C, A and B together, a and C together, B and C together, and/or A, B and C together, etc. In other cases where a convention similar to "at least one of A, B or C, etc." is used, in general such a construction would be intended in the sense one having skill in the art would understand the convention, for example, "a system having at least one of A, B or C" would include but not be limited to a system having only a, only B, only C, A and B together, a and C together, B and C together, and/or A, B and C together, etc. It should also be appreciated by those skilled in the art that virtually any conjunctive and/or phrase representing two or more alternative terms, whether in the specification, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "a or B" will be understood to include the possibilities of "a" or "B" or "a and B".

From the foregoing, it will be appreciated that various embodiments of the invention have been described herein for purposes of illustration, and that various modifications may be made without deviating from the scope and spirit of the invention. Therefore, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

1. A method of side-uplink communication enhancement over unlicensed spectrum, comprising:

the processor of the device communicates with the peer device in a first transmission mode on a side-uplink over an unlicensed spectrum;

the processor determining that conditions relating to side-uplink communications over the unlicensed spectrum are satisfied; and

responsive to the determination, the processor stays in the first transmission mode or switches from the first transmission mode to a second transmission mode for side-uplink communications over the unlicensed spectrum.

2. The method of side-uplink communication enhancement over unlicensed spectrum according to claim 1, further comprising:

the processor receives signal strength feedback from the peer to peer device and

the processor performs power control for side-uplink communications on the unlicensed spectrum in accordance with the signal strength feedback;

Wherein the condition details whether at least one power indicator derived from the power control is less than at least one threshold associated with the second transmission mode.

3. The method of side-uplink communication enhancement over an unlicensed spectrum of claim 2, wherein the signal strength feedback comprises a reference signal received power measured by the peer to peer device during side-uplink communication over the unlicensed spectrum, and at least one power indicator comprises at least one of a transmission power and a transmission power density.

4. The method of side-uplink communication enhancement over unlicensed spectrum according to claim 1, further comprising:

the device receives mode information from the peer device via side-uplink signaling to indicate whether the peer device is operating in the first transmission mode or the second transmission mode,

wherein the condition details that the mode information indicates whether the peer device is operating in the first transmission mode or the second transmission mode.

5. The method of sidelink communication enhancement over an unlicensed spectrum of claim 4, wherein the sidelink signaling comprises sidelink control information, a PC 5-radio resource control message, or a PC 5-medium access control-control unit.

6. The method of side-uplink communication enhancement over unlicensed spectrum according to claim 1, further comprising:

when the device is operating in the first transmission mode, the processor performs a first channel access procedure for a first sensing duration before beginning transmission with the peer device; and

when the device is operating in the second transmission mode, the processor performs a second channel access procedure, or does not perform any channel access procedure, for a second sensing duration less than the first sensing duration before beginning transmission with the peer device.

7. The method of side-uplink communication enhancement over unlicensed spectrum according to claim 1, further comprising:

when the device is operating in the first transmission mode, the processor performs a first channel access procedure prior to starting transmission with the peer device, wherein the first channel access procedure is performed with at least one of a first oversubscription configuration and a first gap margin configuration associated with a first amount of allocated radio resources; and

when the apparatus is operating in the second transmission mode, the processor performs a second channel access procedure or does not perform any channel access procedure prior to starting transmission with the peer to peer apparatus, wherein the second channel access procedure is performed with or without at least one of a second oversubscription configuration and a second gap margin configuration associated with a second number of allocated radio resources that is less than the first number of allocated radio resources.

8. The method of side-uplink communication enhancement over unlicensed spectrum according to claim 1, wherein the first transmission mode is one of a standard mode and an ultra-low power consumption mode, and the second transmission mode is the other of the standard mode and the ultra-low power consumption mode.

9. The method of unlicensed spectrum side-uplink communication enhancement according to claim 8, wherein the standard mode is associated with at least one first threshold of maximum transmission power or maximum transmission power density, the ultra-low power consumption mode is associated with at least one second threshold of derived transmission power or transmission power density, and the at least one second threshold is less than the at least one first threshold.

10. A method of side-uplink communication enhancement over unlicensed spectrum, comprising:

the processor of the device performs a channel access procedure to initialize a channel occupation time for side-link communication with the peer device over the unlicensed spectrum; and

the processor maintains the channel occupancy time by filling a gap between two consecutive transmissions.

11. The method for enhancing sidelink communication over an unlicensed spectrum of claim 10, wherein the step of filling a gap between two consecutive transmissions comprises:

The processor transmits a cyclic prefix extension in one or more guard symbols.

12. The method of side-uplink communication enhancement over unlicensed spectrum of claim 11, wherein the one or more guard symbols comprise at least one of a first guard symbol preceding an automatic gain control symbol of a physical side-uplink feedback channel and a second guard symbol at an end of a side-uplink slot.

13. The method for enhancing sidelink communication over an unlicensed spectrum of claim 10, wherein the step of filling a gap between two consecutive transmissions comprises:

the processor transmits data or a predefined sequence in symbols corresponding to physical side uplink feedback channel occasions with no positive feedback and no negative feedback transmission.

14. The method of side-uplink communication enhancement over unlicensed spectrum according to claim 13, wherein the data comprises physical side-uplink shared channel data and the predefined sequence comprises a physical side-uplink feedback channel class of signal.

15. A method of side-uplink communication enhancement over unlicensed spectrum, comprising:

the processor of the apparatus performs a first side uplink communication with any one or more of the all peer to peer apparatuses according to a first configuration of the common bandwidth portion, the common resource pool, the common resource block set; and

The processor is configured to perform second-side uplink communications with at least one particular peer device in accordance with a second configuration of the user equipment-specific bandwidth portion, the user equipment-specific resource pool, and the user equipment-specific set of resource blocks.

16. The method of unlicensed spectrum sidelink communication enhancement according to claim 15, wherein the first sidelink communication comprises unicast, multicast or broadcast transmission or reception when no PC 5-radio resource connection is established with one of all peer devices.

17. The method of unlicensed spectrum sidelink communication enhancement according to claim 15, wherein the second sidelink communication comprises unicast, multicast or broadcast transmission or reception after establishing a PC 5-radio resource connection with at least one specific peer device.

18. The method of side-uplink communication enhancement over unlicensed spectrum according to claim 15, wherein the user equipment specific bandwidth portion is not less than the common bandwidth portion, wherein the user equipment specific bandwidth portion and the common bandwidth portion overlap or do not overlap.

19. The method of side-uplink communication enhancement over unlicensed spectrum according to claim 15, wherein the common bandwidth portion comprises a first number of resource blocks or a set of resource blocks, and the user equipment-specific bandwidth portion comprises a second number of resource blocks or a set of resource blocks that is not less than the first number of resource blocks or the set of resource blocks.

20. The method of side-uplink communication enhancement over an unlicensed spectrum of claim 19, wherein the processor listens only to the first number or set of resource blocks for the first side-uplink communication.