Method and device for coexistence of same channel

Abstract

The invention provides an apparatus and method for co-channel coexistence in a wireless network. In one novel aspect, the UE performs channel access before occupying one or more resources. In one embodiment, the SU UE determines a sensing configuration based on one or more pre-configured conditions, performs channel access based on the sensing configuration, and transmits a cyclic prefix extension signal between a start position of SU transceiving and an end position of successful channel access only when the channel access is successful, otherwise the UE performs a new channel access. In one embodiment, the sensing configuration includes one or more elements including a number of SU resources configured for SU transceiving, a number of sensing slots for channel sensing, a start of the SU resources, a trigger position for channel sensing, and an offset between a cyclic prefix extension start position. In one embodiment, the sensing configuration is based on resource reservation information.

Description

Technical Field

[0001] Embodiments of the present invention relate generally to wireless communications, and more particularly to co-channel coexistence in wireless networks. Background Art

[0002] With the rapid expansion of 5G development and availability around the world, the demand for wireless data services is increasing. For future 5G advanced and 6G wireless communications, spectrum sharing has the potential to meet the growing demand for wireless data services. When spectrum is shared or reused with another radio access technology (RAT) for secondary use (SU), the most critical issue is the harmonious co-channel coexistence between the secondary use and the primary use (PU), and should therefore be the basic prerequisite to ensure that secondary UEs can reuse the spectrum harmoniously with the primary UE. Current wireless networks do not address the differences between primary and secondary users. No steps are taken to ensure co-channel coexistence between users of different RATs for inter-RAT sharing or intra-RAT sharing of secondary UEs.

[0003] Co-channel coexistence in wireless networks requires improvement and enhancement. Summary of the invention

[0004] The present invention provides an apparatus and method for co-existence of channels in a wireless network. In one novel aspect, a secondary use (SU) UE performs channel access before occupying one or more resources. In one embodiment, the SU UE determines a sensing configuration based on one or more pre-configured conditions, performs channel access based on the sensing configuration, and sends a control signal between the end position of successful channel access and the start position of SU transceiver only when the channel access is successful, otherwise the UE performs a new channel access. In one embodiment, the sensing configuration includes one or more elements, which include the number of SU resources configured for SU transceiver, the number of time slots for channel sensing, and the offset between the start of SU resources and the trigger position of channel sensing. In another embodiment, one or more sensing elements are configured by the network or generated by the UE. One or more pre-configured conditions include the frequency range of transceiver resources, parameter set, channel busy rate, feedback information, SU transceiver traffic type, SU transceiver traffic priority, SU transceiver channel access priority level (CAPC), 5G QoS identifier (5QI) and PC5 QoS identifier (PQI). In one embodiment, the sensing configuration is based on resource reservation information. When there is no reservation on the SU resources, a random sensing configuration is determined; when the SU resources are reserved by the UE, a prioritized sensing configuration is determined; when the SU resources are reserved by one or more other UEs, a low prioritized sensing configuration is determined. In one embodiment, the control signal is a cyclic prefix (CP) extension (CPE) or a timing advance (TA). In another embodiment, the determination of the sensing configuration includes selecting a CPE starting position from a set of predefined CPE starting positions.

[0005] This summary is not intended to define the invention. The invention is defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The accompanying drawings illustrate embodiments of the present invention, wherein like reference numerals refer to like components.

[0007] Figure 1 A schematic system diagram is shown describing an example wireless network for co-channel coexistence with primary usage UE and secondary usage UE according to an embodiment of the present invention.

[0008] Figure 2 An exemplary diagram showing co-channel coexistence of UEs of a SU according to an embodiment of the present invention is shown.

[0009] Figure 3 An exemplary diagram is shown of a PU and a SU UE sharing a spectrum with a SU UE performing channel sensing before data transmission and reception according to an embodiment of the present invention.

[0010] Figure 4AAn example diagram is shown of co-channel coexistence considering time slots / symbols shared by a PU and a SU with different channel sensing configurations of the SU according to an embodiment of the present invention.

[0011] Figure 4B An exemplary diagram is shown of different sensing slot configurations for co-channel coexistence taking into account time slots / symbols according to an embodiment of the present invention.

[0012] Figure 5 An example diagram of SU prioritized channel access with reservation according to an embodiment of the present invention is shown.

[0013] Figure 6 An exemplary diagram is shown for performing two-stage channel access before occupying resources to avoid intra-RAT conflicts of SUs according to an embodiment of the present invention.

[0014] Figure 7 An exemplary flow chart of a co-channel coexistence procedure of a SU UE according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0015] Reference will now be made in detail to some embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0016] Figure 1A schematic system diagram of an example wireless network for co-existence with primary and secondary UEs in the same channel according to an embodiment of the present invention is shown. Wireless network 100 includes multiple communication devices or mobile stations, such as user equipment (UE) 111, 112, 113, 114 and 115, which operate in different RATs. The exemplary mobile device in wireless network 100 has sidelink capability. Sidelink communication involves direct communication between terminal nodes or UEs without data passing through the network. For example, UE 113 communicates directly with UE 114 without a link with a network element. The range of sidelink transmission also supports UE-to-network relay to extend the service range of an eNB, where the inter-coverage UE acts as a relay node between the eNB and the out-of-coverage UE. For example, UE 112 is connected to base station 101 via an access link. UE 112 provides network access to UE 111 out of coverage via sidelink relay. Many UEs are configured as PUs and many UEs are configured as SUs. For example, UE 112 is a cellular user, while UEs 111, 113, 114, and 115 are configured as sidelink users. In one scenario, cellular UEs such as UE 112 are configured as PUs. For example, the sidelink communication used by UEs 111, 113, 114, and 115 is a SU. In other scenarios, the co-channel coexistence method is applicable to licensed bands and unlicensed bands. Mobile devices / UEs with different RATs can also coexist. For example, neighboring UEs 116 and 117 communicate with base station 102 via other RATs (e.g., Wi-Fi) sharing the same licensed or unlicensed band. Neighboring UEs 118 and 119 communicate with base station 103 via other RATs (e.g., NR) sharing the same licensed or unlicensed band. In another scenario, LTE-SUs, such as UEs 111, 113, 114, and 115, are configured as PUs; while NR-SUs, such as 118 and 119, are configured as SUs.

[0017] Base stations such as base station 101 may also be referred to as access points, access terminals, base stations, node Bs, improved node Bs (eNBs), gNBs, or other terms used in the art. A network may be a homogeneous network or a heterogeneous network, and may be deployed in the same frequency or in different frequencies. Base station 101 is an exemplary base station.

[0018] In one novel aspect, SU transceiver occupies one or more resources only in the absence of a PU. The spectrum / resources are (pre)configured to be shared with secondary use (SU). Specifically, for secondary use of spectrum / resources, whenever a secondary UE wants to start transmission on a (pre)configured spectrum / resource where primary use (PU) has been deployed, the secondary UEs should always perform a channel access / sensing process before they can occupy the current time slot to transmit the spectrum / resource. The channel access / sensing process is a sensing-based process that evaluates the availability of the channel for performing transmissions. If the channel is evaluated to be idle during the channel access / sensing duration, the secondary UE can occupy the current time slot and start transmission. Otherwise, the secondary UE cannot start transmission on the current time slot, and they should wait for the next (pre)configured resource for secondary use and perform a channel access / sensing process. In another novel aspect, a two-level and prioritized / deprioritized sensing mechanism can be (pre)configured to avoid conflicts between secondary UEs and prioritized / deprioritized access order. For the case where the side link (SL) is used secondary, the SCI sensing information can be used to find out the resources / time slots reserved by other SL UEs in the same RAT. In addition, in the channel access / sensing process, the energy detection sensing implementation can be performed by different SL UEs. For example, the duration of the sensing time slot, and / or the number of sensing time slots, and / or the trigger time of the first sensing time slot can be (pre) configured by the network or generated by the UE. Through the authorization of the two-level and prioritized / de-prioritized sensing mechanism proposed in the present disclosure, conflicts on resources with or without reservation can be avoided between UEs in secondary use.

[0019] Figure 1 A simplified block diagram of a mobile device / UE operating in an unlicensed band is further described. Take UE 111 as an example. UE 111 has an antenna 125 for sending and receiving radio signals. An RF transceiver circuit 123 coupled to the antenna receives RF signals from the antenna 125, converts them to baseband signals, and sends them to the processor 122. In one embodiment, the RF transceiver may include two RF modules (not shown). The RF transceiver 123 also converts baseband signals received from the processor 122, converts them to RF signals, and sends them to the antenna 125. The processor 122 processes the received baseband signals and calls different functional modules to perform functions in the UE 111. The memory 121 stores program instructions as well as data 126 to control the operation of the UE 111. The antenna 125 sends uplink transmissions to the base station and receives downlink transmissions from the base station.

[0020] UE 111 also includes a set of control modules that perform functional tasks. These control modules can be implemented by circuits, software, firmware, or a combination thereof. Configuration module 191 determines a sensing configuration for secondary use (SU) transceiving in a wireless network, wherein SU transceiving occupies one or more resources only when there is no primary use (PU), and wherein one or more sensing elements of the sensing configuration are determined based on one or more predefined conditions. Sensing module 192 performs a first channel sensing based on the sensing configuration, wherein the channel sensing is successful when all sensed time slots are idle. When the first channel sensing is successful, control module 193 sends a control signal between the end position of the successful first channel sensing and the start position of the SU transceiving, otherwise a second channel sensing is performed on subsequent SU resources. The resource selection module selects resources based on one or more channel access information.

[0021] Figure 2An example diagram of co-channel coexistence of UEs of a SU according to an embodiment of the present invention is shown. A wireless network is configured with shared resources, where multiple RATs share the same resources. These resources are configured to be shared or reused by one or more other RATs for SU. In such a scenario, the most critical issue is harmonious co-channel coexistence between UEs for secondary use (secondary UEs) and UEs for primary use (primary UEs). In one novel aspect, a UE operating in a SU performs channel sensing before data transmission and reception. In step 201, the UE determines whether one or more resources are used for a PU 211 or a SU 212. In one embodiment, the resources are preconfigured or dynamically configured as PU resources 211 or SU resources 212. In another embodiment, the type of resource can also be configured as PU, SU, or flexible configuration. Whenever a resource is indicated by signaling or preconfiguration to be shared with a UE for secondary use, the secondary UEs should always perform a channel access / sensing process before they can occupy the resource / time slot. In step 202, the UE operating in the SU determines the channel sensing configuration. The sensing configuration includes one or more sensing elements 220, including the number of SU resources N (N is the number of symbols) configured for the duration of the channel access process, the number of time slots N_sl for channel sensing, and the offset T_offset between the start of the SU resources and the channel sensing trigger position. The sensing element 220 also includes multiple back-off time slots N_bo and a basic unit for sensing T_sl, as well as a mini time slot N_d between successful channel access and data transmission and reception. In one embodiment 221, the wireless network configures one or more sensing elements based on one or more pre-configured conditions. In another embodiment 222, the UE generates one or more sensing elements based on one or more pre-configured conditions. In one embodiment 228, one or more sensing elements are determined based on the corresponding sensing element range. Each sensing element range is pre-configured or determined by the network or UE based on one or more conditions. The UE or the network selects a value within the sensing element range based on one or more conditions. The one or more predetermined conditions include a frequency range of transceiver resources, a parameter set, a channel busy rate, feedback information, a traffic type transmitted and received by the SU, a traffic priority transmitted and received by the SU, a channel access priority category (CAPC) transmitted and received by the SU, a 5G QoS identifier (5QI), and a PC5 QoS identifier (PQI).

[0022] The channel access / sensing procedure may be performed within a (pre)configured duration. For example, the channel access / sensing procedure may be (pre)configured within N symbols at or starting with a (pre)configured / indicated time slot for shared secondary use. The value of N may be (pre)configured by the network or by the UE from the channel access / sensing range / window [N min , N max] Randomly generated, which can be pre-configured by the network or generated by the UE based on one or more conditions, such as frequency range, parameter set, channel busy rate, ACK / NACK feedback information, traffic type / priority, CAPC, 5QI, PQI and resource reservation information.

[0023] Whenever channel access / sensing is initiated / triggered, the UE in secondary use shall perform the channel access / sensing procedure. The channel access / sensing procedure is configured with a sensing time slot. The value of the sensing time slot N_sl is configured by the network or randomly generated by the UE. In one embodiment, the UE selects from the sensing time slot range / window [N s1,min , N s1,max ], which can be configured by the network or generated by the UE. The UE or the network generates the sensing time slot range based on one or more conditions, such as the value of N, the value of T_offset, the duration of the sensing time slot, the frequency range, the parameter set, the channel busy rate, the ACK / NACK feedback information, the traffic type, the traffic priority, CAPC, 5QI, PQI, and the resource reservation information. If all N_sl sensing time slots are sensed to be idle within N symbols, the channel access / sensing process is considered to be successful / idle.

[0024] In the channel access / sensing procedure, the UE in secondary use triggers the channel access / sensing procedure at a specific position within N symbols. The triggering time / position of the channel access / sensing procedure is determined by the parameter T_offset, which is the duration from the start of the configuration / indication time slot for secondary use to the triggering time / position of the channel access / sensing procedure (i.e., the start position of the first sensing time slot). The value of T_offset can be configured by the network or randomly generated by the UE. In one embodiment, the UE selects the value of T_offset from an offset range / window [T_offset] that can be configured by the network or generated by the UE. offset,min , T offset,max In one embodiment, the UE or the network generates the offset range based on one or more conditions, wherein the conditions include the value of N, the duration of the sensing time slot, the frequency range, the parameter set, the channel busy rate, the ACK / NACK feedback information, the traffic type, the traffic priority, the CAPC, the 5QI, the PQI, and the resource reservation information.

[0025] During the channel access / sensing process, the basic unit for sensing is a sensing slot with a (pre)configured duration T_sl based on a parameter set and / or a frequency range. For example, the sensing slot T_sl can be (pre)configured to 9 microseconds or 5 microseconds or other values ​​based on different parameter sets. If the UE in secondary use senses the channel during the sensing slot duration and determines that the detected power of at least T_al within the sensing slot duration is less than the (pre)configured energy detection threshold value XThresh, the sensing slot T_sl is considered to be idle. Otherwise, the sensing slot duration T_sl is considered to be busy. The value of Tal can be (pre)configured for different sensing slot durations T_sl, for example 4 microseconds for a sensing slot of 9 microseconds.

[0026] If the channel access / sensing procedure fails, the secondary UE cannot start transmission on the time slot configured / indicated for secondary use. Instead, the secondary UE shall wait for the next resource configured / indicated for secondary use and perform a (new) channel access / sensing procedure. In addition, the next resource for secondary use is configured taking into account the backoff N_bo time slots. N_bo is the duration of the backoff in time slots from the end of the current time slot where the channel access / sensing failed to the beginning of the time slot where new channel access / sensing can be performed. The value of N_bo is configured by the network or randomly generated by the UE. In one embodiment, the UE selects from the backoff range / window [N bo,min , N bo,max ] In one embodiment, the backoff range is configured by the network or generated by the UE. In one embodiment, the N_bo range is based on one or more conditions, including frequency range, parameter set, channel busy ratio, ACK / NACK feedback information, traffic type / priority, CAPC, 5QI and PQI.

[0027] In one embodiment, a control signal is sent between the end position of successful channel sensing and the start position of SU transceiver. In one embodiment, the control signal is selected from one or more of control CP extension (CPE), timing advance (TA), data message and other control messages. The control signal is used to align the boundary between the channel access / sensing success position and the data transmission position. The secondary UE can start transmission on the subsequent Nd symbols (i.e., mini-slots) shared in the secondary used time slot, where N_d can be (pre)configured based on, for example, the primary used RAT type.

[0028] In one embodiment 230, the SU performs channel sensing based on reservation information, which includes SU resource reservations made by the UE and by one or more other UEs. When applicable, one or more sensing elements 220 and corresponding sensing ranges 230 are selected based on the reservation information. If the resource reservation information can be used for secondary use (e.g., sidelink technology), the secondary UE will send / receive resource reservation information to / from other secondary UEs. If there is no resource reservation information (e.g., before the resources used for initial transmission), the secondary UE should perform a fair / random channel access / sensing process using a random trigger time / position of the channel access / sensing process (i.e., T_offset) and a random number of sensing slots, i.e., N_sl as described above. If the resources / timeslots (pre) configured / indicated for secondary use are reserved by the secondary UE, the secondary UE can perform prioritized channel access / sensing before the reserved resources / timeslots. For example, the triggering time / position T_offset of the channel access / sensing process of the priority channel access / sensing process may be (pre)configured by the network or by the UE according to the offset range / window [T offset,min,s ,T offset,max,s In addition, the number of sensing time slots N_sl in the priority channel access / sensing process can be (pre)configured by the network or by the UE from the sensing time slot range / window [N sl,min,s ,N sl,max,s ] is randomly generated from a smaller value of ]. For other secondary UEs that have not reserved resources / time slots, if they want to occupy resources / time slots reserved by another secondary UE, they should perform low-priority channel access / sensing. For example, the triggering time / position T_offset of the low-priority channel access / sensing process can be (pre)configured by the network or by the UE according to the offset range / window [T offset,min,l ,T offset,max,l In addition, the number of sensing time slots N_sl in the low priority channel access / sensing process can be (pre)configured by the network or by the UE from the sensing time slot range / window [N sl,min,l ,N sl,max,l The smaller value of the offset range / window, and / or the smaller value of the sensing time slot range / window, and / or the larger value of the offset range / window, and / or the larger value of the sensing time slot range / window may be (pre)configured by the network or generated by the UE to ensure prioritized or low-prioritized channel access / sensing according to the resource reservation information.

[0029] Once the UE determines the sensing configuration, the UE performs channel sensing in step 203. The SU UE performs data transmission and reception only when the channel access / sensing procedure is successful.

[0030] Figure 3An example diagram of a PU and a SU UE sharing spectrum with a SU UE performing channel sensing prior to data transmission and reception according to an embodiment of the present invention is shown. UE 301 (PU UE) is a UE operating with a PU with an exemplary transmission 310. UEs 302 and 303 (SU UEs) are UEs operating with SUs with exemplary transmissions 320 and 330, respectively. UEs 301, 302, and 303 share the same resources. Exemplary resource slots / resources 311, 312, 313, 314, and 315 are shared resources configured in a wireless network. In one embodiment, a PU UE occupies resources without a channel access procedure, while a SU UE occupies resources only when channel access is successful. As an example, slots 311, 312, and 314 are used by PU UE 301. SU UEs 302 and 303 perform channel access for slots 311 and 312 before they occupy the slots. Since the resource is used by the PU UE 301, channel access of both UE 302 and 303 fails. In one embodiment, the resource is configured by the network as PU or SU. In another embodiment, the resource is configured as PU, SU or flexible. Subsequently, both UE 302 and 303 perform channel access for time slot 313. UE 303 successfully performs channel access and sends a control signal when the channel successfully ends. UE 303 performs data transceiving 331 on resource 313. UE 302 detects the control signal from UE 302 when performing channel access and fails the channel access. In one embodiment, the SU UE reserves another resource. In step 341, UE 303 reserves future resource 315. UE 303 sends a message about the reservation to other UEs (e.g., UE 302). In one embodiment, UE 302 skips the channel access process for resource 315 after receiving the reservation message from UE 303. UE 303 performs prioritized channel access on resource 315 and sends a signal. UE 303 performs data transmission 332 on resource 315 .

[0031] Figure 4AAn example diagram of co-channel coexistence of time slots / symbols shared by PU and SU with different channel sensing configurations of SU according to an embodiment of the present invention is shown. For exemplary case 1 401, LTE-SL is the primary use (PU) and NR-SL (402) is the secondary use (SU). The resources / time slots are (pre) configured / indicated for LTE-SL or shared with NR-SL, denoted as SU resources. For exemplary case 2 402, cellular communication is the primary use and SL is the secondary use. The resources / time slots are configured / indicated for cellular communication (e.g., DL, marked as "D" or UL), or flexible "F", or shared with secondary use, marked as "SU". For the resources / time slots (pre) configured / indicated for secondary use in both cases, one example is that the resources / time slots can be occupied for primary use. In another embodiment, if there is no transmission from the primary UE, the resources / time slots can be occupied for secondary use. If the secondary UE intends to start transmission on a resource / time slot (pre-) configured for secondary use, the secondary UE shall perform a channel access / sensing process to evaluate whether the resource / time slot is idle or busy. For PU symbol 410, all symbols are used for transceiving. For SU symbol 411, the channel access / process is configured within the first symbol of the time slot for secondary use, i.e., N=1. In other embodiments, the last symbol of the SU time slot is configured for channel sensing. If the channel access / process is successful, the other thirteen symbols in the time slot can be used for data transmission by the secondary UE. Specifically, as in example 420, the channel access / sensing process adopts the first symbol of the SU time slot, as in 411, and uses the first symbol for channel sensing. As an example, seven sensing time slots are configured, each with a time period. The seven sensing time slots occupy the time of the first symbol of the SU time slot, and the trigger time is located at the beginning of the first symbol. For case A, as shown in 431, 432 and 433, there is no transmission from the primary UE 431 on the time slot for secondary use. In this case, for UE1 in secondary use 432, the channel access / sensing process consists of two sensing slots, i.e., N_sl=2. For UE2 in secondary use 433, the channel access / sensing process consists of four sensing slots, i.e., N_sl=4. Since there is no transmission from the primary UE, the secondary UE1 will sense that the channel is idle within two sensing slots. Therefore, the channel access / sensing process of the secondary UE1 succeeds after two sensing slots, and the secondary UE1 will use the (pre) configured CP extension to align the boundary between the channel access / sensing success position (i.e., the end position of the second sensing slot in the first symbol) and the data transmission position (i.e., the start position of the second symbol in the slot). Then, the secondary UE1 can start transmission on the subsequent 13 symbols in the current slot.In other cases, if the primary use is a cellular communication system, the last few symbols can be (pre) configured for traditional PUCCH transmission. For the secondary UE2 in case A, when it encounters the CP extension from UE1, its channel access / sensing process will fail. Therefore, the secondary UE2 cannot send on the next thirteen symbols in the time slot, and it should wait for the next time slot (pre) configured / indicated for secondary use and perform a (new) channel access / sensing process. For another example, as shown in case B in 441, 442 and 443, the resources / time slots (pre) configured / indicated for secondary use are occupied by the UE in the primary use through transmission (441). In this case, UE1 and UE2 in the secondary uses 442 and 443, respectively, will sense that the channel is busy during their channel access / sensing processes, so neither UE1 nor UE2 can start their transmission on this resource / time slot. Instead, both UE1 and UE2 should wait for the next resource / time slot (pre) configured / indicated for secondary use and perform a (new) channel access / sensing process.

[0032] Figure 4BAn example diagram of different sensing slot configurations for co-channel coexistence considering slots / symbols according to an embodiment of the present invention is shown. In one embodiment, one or more sensing symbols used for channel sensing are the first N symbols of a SU slot. In another embodiment, one or more sensing symbols used for channel sensing are the last N symbols of a PU slot adjacent to a SU slot. As an example configuration 405, LTE-SL is PU and NR-SL is SU, and in configuration 406, cellular communication is PU and SL is SU. 460 shows an expanded view of two adjacent slots of PU 461 and SU slot 462, each with 14 symbols. 470 is an example sensing symbol, which can be the first N symbols of SU 462 or the last N symbols of PU 461. In one example, each sensing symbol has multiple sensing slots as in 471. If channel sensing is successful, a SU symbol for SU control and / or data transceiver follows. In one configuration 481, the first symbol of the SU time slot is configured for channel sensing, and when the channel sensing is successful, the remaining 13 symbols are used for SU control and / or data transceiving. In another configuration 482, the first three symbols of the SU time slot are configured for channel sensing, and when the channel sensing is successful, the remaining 11 symbols are used for SU control and / or data transceiving. In configuration 483, the last symbol of the adjacent PU time slot is used for channel sensing. If the channel sensing is successful, the symbol in the SU time slot is used for SU control and / or data transceiving. In this configuration, the last symbol of the SU time slot is used for channel sensing for subsequent SU transceiving. In configuration 484, the last two symbols of the adjacent PU time slot are used for channel sensing. If the channel sensing is successful, the symbol in the SU time slot is used for SU control and / or data transceiving. In this configuration, the last two symbols of the SU time slot are used for channel sensing for subsequent SU transceiving. In another embodiment, the number of sensing symbols in different time slots is configured with different values. The number of sensing symbols is preconfigured or dynamically determined based on one or more factors, including channel conditions, traffic type, reservation status, and other UE metrics and / or configurations. As an example, in configuration 485, the last two symbols of adjacent PU time slots are used for channel sensing. If channel sensing is successful, the symbols in the SU time slot are used for SU control and / or data transceiver. In this configuration, the last symbol of the SU time slot is used for channel sensing for subsequent SU transceiver.

[0033] Figure 5An example diagram of SU prioritized channel access with reservation according to an embodiment of the present invention is shown. Two secondary UE pairs (UE 501 and UE 502) with SL pair 1 (SL-1) and SL pair 2 (SL-2), respectively, will start transmission on the resources / time slots configured / indicated for secondary use (SU551, 552, 553, 554 and 555). If there is no resource reservation information that can be used, for example, at SU 551, 552 and 553, SL-1 and SL-2 should perform a random / fair channel access / sensing process. Channel accesses 581, 582 and 583 of UE501 and channel accesses 591, 592 and 593 of UE 502 are random channel processes with corresponding random sensing configurations. Exemplary configuration 500 is for channel sensing configured with seven symbols. Channel access 593 configured as a random sensing configuration is successful, and transmission control 571 is performed. When the channel access is successful, the UE 502 performs data transceiving 561 at the resource 553. In one embodiment, at step 550, the UE 502 reserves future resources 555 through a control message. In one embodiment, a multi-level sensing configuration is used for SU channel access. In one embodiment, the sensing configuration has priority 510, random 520, and low priority 530. For SL-1 or SL-2, the prioritized channel access / sensing process (510) is configured by the network or generated by SL-1 or SL-2, where T_offset=0 and N_sl=3. Random channel access 520 is configured with T_offset=1 and N_sl=5. Low-priority channel access 530 is configured with T_offset=2 and N_sl=5. At 553, after SL-2 successfully performs channel access / sensing, SL-2 will send resource reservation information to other secondary UEs. UE 502 may then perform a prioritized channel access / sensing procedure before starting transmission on the reserved resources / time slots (i.e., 555). Since UE 502 has reserved resources 555, only UE 501 performs the failed channel access 584. With the resource reservation information sent from SL-2, SL-1 should perform a low-priority channel access / sensing procedure before it can start transmission on the resources / time slots reserved / occupied by SL-2 (i.e., SU5 in the figure). For UE 501, the low-priority channel access / sensing procedure is (pre)configured by the network or generated by SL-2 with T_offset=2 and N_sl=5. For channel access / sensing of reserved resources / time slots, different levels of prioritized or low-priority channel access / sensing may be configured by the network or generated by the UE to ensure priority access for the UE that reserved the corresponding resources. When there is a UE with priority configuration 510 and another UE with random configuration 521, the channel sensing for random configuration 521 fails.When there is a UE with random configuration (522) and another with low-prioritization configuration 530, channel sensing for random configuration 522 is successful. After the prioritized channel access 595 is successful, UE 502 sends a control message 572 and performs SU transceiving 562. UE 501 can perform low-prioritization channel 585 at resource 555. If channel access 595 is performed, channel access 585 will fail. For the case where the resource reserved UE (i.e., SL-2) does not start transmission on the reserved resources (i.e., resources 555), if the low-prioritization channel access / sensing performed by SL-1 is successful, other secondary UEs (i.e., UE 501) can start transmission on the reserved resources.

[0034] In one embodiment, the shared spectrum may be an unlicensed spectrum. In this case, if the secondary UE operates in a very low power (e.g., 14 dBm) mode, the secondary UE may be (pre) configured to start transmission on a resource / time slot where the channel access / sensing process is not performed. In another embodiment, the resource / time slot after successful channel access / sensing may be shared with other UEs as (pre) configured, i.e., COT sharing. In this case, as long as they have packets to send or as long as a communication group is established, the UEs that want to access the shared COT (COT sharing UEs) should first send their buffer status information / report (BSR). Then for the UE that successfully completes the channel access / sensing (COT initiating UE), it can send COT sharing information to other UEs. In addition, the COT initiating UE may also send channel access / sensing authorization information (e.g., trigger time and / or sensing time slot number, etc.) to the COT sharing UE based on one or more conditions, wherein the one or more conditions include BSR, traffic priority, CAPC, 5QI of the COT sharing UE, PQI of the COT sharing UE, channel busy rate, ACK / NACK feedback.

[0035] Figure 6 An example diagram for performing two-stage channel access before occupying resources to avoid intra-RAT conflicts of SU according to an embodiment of the present invention is shown. In one embodiment, multiple CPE starting positions are configured within the symbol used to sense the slot-level channel to better avoid intra-cell conflicts outside the channel occupation time (COT). In the case where the secondary use is a sidelink technology, the secondary UE can perform channel access / sensing on multiple channels. In this case, the control signal can be (pre) configured to be sent on a subchannel. For example, the control signal can be (pre) configured on a fixed subchannel or on each subchannel.

[0036] For the sidelink operating in the unlicensed spectrum, the following two operations (mode 1 operation and mode 2 operation) are proposed in the present disclosure. For mode 1 operation, SCI sensing, i.e., gNB scheduling on SL resources, is not required. However, LBT sensing is required on the UE side. This means that resource selection / reservation at the gNB is decoupled from LBT sensing at the UE. In essence, there is a timeline impact because the introduction of LBT sensing depends on reserved or non-reserved transmissions. For transmissions on non-reserved resources, such as the first transmission of periodic traffic or the initial transmission of non-periodic traffic, in addition to considering the LBT time at the UE and the existing processing time, resource selection / reservation at the gNB should also leave additional time. Therefore, the timeline for mode 1 may be affected. In addition, the gNB may need to know LBT-related information (e.g., maximum LBT time) to correctly allocate resources. For transmissions on reserved resources, the gNB may need to leave enough / no gaps between reserved resources during resource selection for potential LBT operations. Therefore, it may also require some LBT-related information at the gNB reported by the UE for correct resource selection to avoid invalid resource allocation.

[0037] For Mode 2 operation, SCI sensing and LBT sensing for resource reservation occur at the same UE. Therefore, LBT information (e.g., LBT access type, CW adjustment) can be available at the device. Similar to Mode 1 operation, the Mode 2 sensing / selection mechanism may have some time impact depending on the traffic. For transmissions on non-reserved resources, such as the first transmission of periodic traffic or the first transmission of non-periodic traffic, the UE can first perform LBT and then determine the selection window for resource selection based on the LBT success time. In this case, there may be a gap between the LBT success timing and the resources selected for transmission. This gap can be handled by delayed sensing or CP extension. Determining the starting point of the selection window based on the LBT success timing can avoid invalid resource selection. Alternatively, the UE can perform resource selection first and then perform LBT. In this case, in addition to considering the processing time T1, the starting point of the resource selection window should also consider the LBT operation time. For transmissions on reserved resources, the UE may have to determine the time of the LBT operation based on the timing of the reserved resources for transmission. That is, the LBT operation is performed on the reserved resources (ie, performed some time earlier than the reserved resources are used for transmission) taking into account the LBT counter and potential LBT failures.

[0038] In one embodiment, sensing slot-level channel access and multiple CPE starting positions can better avoid intra-cell conflicts outside the COT. UE1 with transmission 610 and UE2 with transmission 620 both perform type 1 channel access 611 and 621, respectively. Both type 1 CAs are successful. Delay durations 612 and 622 for UE1 and UE2, respectively. After the LBT process, short LBT 613 and 623 are then performed on UE1 and UE2, respectively. As shown in the figure, LBT 613 and 623 are both successful. If there is no sensing slot-level channel access after a successful LBT, UE1 and UE2 will have an intra-cell conflict. In one embodiment, the first symbol of the 14-symbol slot 601 is used for sensing slot-level channel access. In one embodiment 602, the first seven slots are used for slot-level channel access. In one embodiment, a multi-length CPE is configured, which is sent after the sensing slot. In one embodiment, the UE selects a CPE from multiple configured CPEs and performs channel access. The UE selects the CPE randomly and / or based on one or more preconfigured conditions, including the frequency range of the transceiver resources, the parameter set, the channel busy rate, the feedback information, the type of traffic transmitted and received by the SU, the traffic priority transmitted and received by the SU, the channel access priority level (CAPC) transmitted and received by the SU, the PQI and the 5QI. In another embodiment, the CPE selection is determined by the network. In yet another embodiment, the UE selects the sensing time slot length for channel access. The UE selects the sensing time slot length randomly and / or based on the preconfigured conditions as described above. In one embodiment, the CPE and the sensing time slot length are configured independently. In another embodiment, the CPE or the sensing time slot length is configured, and another parameter is derived based on the configured CPE or the sensing time slot length. As an example, UE1 is configured with a larger CPE 616 or a shorter length sensing time slot 615 (compared to the sensing time slot 625). Channel access of the sensing time slot 615 of UE1 is successful, while channel access of UE2 fails. UE1 performs transmission 617 and UE2 does not transmit and waits for the next available resource. UE2 does not transmit after failing channel sensing at 625 ( 627 ).

[0039] Figure 7An exemplary flow chart of a co-channel coexistence process of a SU UE according to an embodiment of the present invention is shown. In step 701, the UE determines a sensing configuration for secondary use (SU) transceiving in a wireless network, wherein the SU transceiving occupies one or more resources only when there is no primary use (PU), and wherein one or more sensing elements of the sensing configuration are determined based on one or more predefined conditions. In step 702, the UE performs a first channel sensing based on the sensing configuration, wherein the channel sensing is successful when all sensed time slots are idle. In step 703, when the first channel sensing is successful, the UE sends a fill signal between the end position of the successful first channel sensing and the start position of the SU transceiving, otherwise a second channel sensing is performed on subsequent SU resources using back-off. In step 704, the UE selects a resource based on one or more channel access information.

[0040] Although the present invention has been described in conjunction with certain specific embodiments for guiding purposes, the present invention is not limited thereto. Therefore, various modifications, adaptations and combinations of the various features of the described embodiments may be practiced without departing from the scope of the present invention as set forth in the claims.

Claims

1. A method comprising: determining, by a user equipment, a sensing configuration for a secondary-use SU transceiver in a wireless network, wherein the SU transceiver occupies one or more resources only when a primary-use PU is not present, and wherein one or more sensing elements of the sensing configuration are determined based on one or more predefined conditions; performing a first channel sensing based on the sensing configuration, wherein the channel sensing is successful when all sensed time slots are idle; When the first channel sensing is successful, sending a padding signal between the end position of the successful first channel sensing and the start position of the SU transceiver, otherwise performing a second channel sensing on subsequent SU resources using backoff; and A resource is selected based on the one or more channel access information.

2. The method according to claim 1, characterized in that The sensing configuration including one or more sensing elements includes: a channel access procedure starting position, a channel access procedure duration, a number of sensing time slots used for channel sensing, and an offset between the start of the channel access procedure starting position and a trigger position for the channel sensing.

3. The method according to claim 2, characterized in that The wireless network is configured with the one or more sensing elements.

4. The method according to claim 2, characterized in that The user equipment generates the one or more sensing elements.

5. The method according to claim 2, characterized in that The one or more predefined conditions include the frequency range of the transceiver resources, parameter set, channel busy rate, feedback information, the type of traffic sent and received by the SU, the priority of the traffic sent and received by the SU, the channel access priority category CAPC sent and received by the SU, the 5G service quality identifier and the PC5 service quality identifier.

6. The method according to claim 2, characterized in that The one or more sensing elements are determined based on the corresponding sensing element range.

7. The method according to claim 6, characterized in that Based on the one or more predefined conditions, the user equipment generates or the wireless network configures the one or more sensing element ranges.

8. The method according to claim 2, characterized in that Further including: When the first channel sensing is successful, reserving one or more future SU resources; A control message indicating reservation information for the one or more future SU resources is transmitted to other SU resource users.

9. The method according to claim 8, characterized in that The channel sensing configuration is determined based on reservation information, wherein the reservation information includes SU resource reservations made by the user equipment and by one or more other user equipments.

10. The method according to claim 9, characterized in that The one or more predefined conditions of the SU resource include the reservation information of the SU resource, wherein a random sensing configuration is determined when the SU resource is not reserved, a prioritized sensing configuration is determined when the user equipment reserves the SU resource, and a low priority sensing configuration is determined when one or more other user equipments reserve the SU resource.

11. The method according to claim 10, characterized in that The prioritized sensing configuration configures a smaller number of sensing slots, a smaller value of offset, and a priority selection of specific resources.

12. The method according to claim 10, characterized in that The low-prioritized sensing configuration configures a larger number of sensing slots, a larger value of offset, and a low priority selection of specific resources.

13. The method according to claim 1, characterized in that The fill signal is a cyclic prefix extension (CPE) or a timing advance.

14. The method according to claim 1, wherein: The determining the sensing configuration includes selecting a CPE start position from a set of predefined CPE start positions.

15. The method according to claim 1, wherein: The SU is used for sidelink transceiving, and wherein the user equipment performs channel sensing on a plurality of channels.

16. The method according to claim 1, wherein: The method also includes determining that one or more resources are SU resources based on a predefined configuration or a message indication, and wherein the resources are configured as resource types including PU resources, SU resources, and flexible resources.

17. The method according to claim 1, wherein: The channel access information includes a CAPC value, a contention window size, a random backoff counter, an expected channel access duration, and a channel access result.

18. The method of claim 1, wherein: Based on the channel access duration, SU resources are selected as non-reserved resources to determine the starting position of the selection window, and the non-reserved resources are used for the first transmission of the periodic service or the initial transmission of the non-periodic service selected by the base station gNB of mode 1 or the UE of mode 2.

19. The method according to claim 1, wherein: Based on one or more factors including the location of the reserved resources, the expected channel access duration and the gap offset, the SU is selected as the reserved resource to determine the triggering position of the channel access process, and wherein the reserved resources are used for the non-first transmission of the periodic traffic or the retransmission of the non-periodic traffic selected by the base station gNB of mode 1 or the UE of mode 2.

20. A user equipment comprising: A transceiver for sending and receiving radio frequency signals in a wireless network; a configuration module that determines a sensing configuration for a secondary-use SU transceiver in a wireless network, wherein the SU transceiver occupies one or more resources only when a primary-use PU is not present, and wherein one or more sensing elements of the sensing configuration are determined based on one or more predefined conditions; a sensing module, configured to perform first channel sensing based on the sensing configuration, wherein the channel sensing is successful when all sensed time slots are idle; and The control module sends a filling signal between the end position of the successful first channel sensing and the start position of the SU transceiver when the first channel sensing is successful, otherwise, a backoff is used to perform a second channel sensing on subsequent SU resources.

21. The user equipment of claim 20, wherein: The sensing configuration including one or more sensing elements includes: a channel access procedure starting position, a channel access procedure duration, a number of sensing time slots used for channel sensing, and an offset between the start of the channel access procedure starting position and a trigger position for the channel sensing.

22. The user equipment of claim 20, wherein: The one or more predefined conditions include the frequency range of the transceiver resources, the parameter set, the channel busy rate, the feedback information, the type of traffic sent and received by the SU, the priority of the traffic sent and received by the SU, the channel access priority category sent and received by the SU, the 5G service quality identifier and the PC5 service quality identifier.

23. The user equipment of claim 20, wherein: The control module further reserves one or more future SU resources when the first channel sensing succeeds; and transmits a control message indicating reservation information for the one or more future SU resources to other SU resource users.

24. The user equipment of claim 23, wherein: The channel sensing configuration is determined based on reservation information, wherein the reservation information includes SU resource reservations made by the user equipment and by one or more other user equipments.

25. The user equipment of claim 24, wherein: The one or more predefined conditions of the SU resource include the reservation information of the SU resource, wherein a random sensing configuration is determined when the SU resource is not reserved, a prioritized sensing configuration is determined when the user equipment reserves the SU resource, and a low priority sensing configuration is determined when one or more other user equipments reserve the SU resource.

Images