Communication method and user device

Abstract

A communication method applied to a user device (UE) is provided, and includes: obtaining a first indication indicating at least one of possible random access channel (RACH) opportunity (RO) positions, actually transmitted synchronization signal block (SSB) positions, frame-based device (FBE) frame period (FFP) information, and uplink / downlink (UL / DL) modes within the FFP; obtaining a second indication indicating channel occupation time (COT) information; and determining a valid RO for physical RACH (PRACH) transmission based on the first indication and the second indication.

Description

[Technical field]

[0001] [Cross-reference to related applications] This disclosure claims priority to PCT Application No. PCT / CN2019 / 112064, filed October 19, 2019, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present application relates to communication systems, and in particular to communication methods and user devices. [Background technology]

[0003] In frame based equipment (FBE) mode, the determination of random access channel (RACH) occasions (RACH occasions, ROs) and physical RACH (PRACH) transmissions on ROs are open problems. This disclosure provides a method for how a UE determines a valid RO and whether the RO is allowed for PRACH transmission. Summary of the Invention

[0004] Embodiments of the present application provide a communication method and a user device.

[0005] These embodiments provide a communication method applied to a user device (UE), including obtaining a first indication indicating at least one of possible random access channel (RACH) opportunity (RO) positions, actual transmitted synchronization signal block (SSB) positions, frame based device (FBE) frame period (FFP) information, and uplink / downlink (UL / DL) mode within the FFP; obtaining a second indication indicating channel occupation time (COT) information; and determining a valid RO for physical RACH (PRACH) transmission based on the first indication and the second indication.

[0006] These embodiments further provide a communication method applied to a user device (UE), comprising determining to allow PRACH transmission in a random access channel (RACH) opportunity (RO) in an associated frame based device (FBE) frame period (FFP) if the RO is an RO in an associated FFP and satisfies a condition that at least one downlink (DL) signal or channel in the associated FFP has been detected before the RO.

[0007] These embodiments further provide a user device, including a memory having instructions stored thereon and a processor communicatively coupled to the memory, where the instructions, when executed by the processor, cause the processor to perform operations of obtaining a first indication indicative of at least one of possible random access channel (RACH) opportunity (RO) locations, actual transmitted synchronization signal block (SSB) locations, frame based device (FBE) frame period (FFP) information, uplink / downlink (UL / DL) modes within the FFP, obtaining a second indication indicative of channel occupation time (COT) information, and determining an effective RO for physical RACH (PRACH) transmission based on the first indication and the second indication.

[0008] These embodiments further provide a user device, including a memory having instructions stored thereon and a processor communicatively coupled to the memory, where the instructions, when executed by the processor, cause the processor to perform an operation of determining to grant a PRACH transmission at a random access channel (RACH) opportunity (RO) in an associated frame based device (FBE) frame period (FFP) if the RO is a valid RO in an associated FFP and satisfies a condition that at least one downlink (DL) signal or channel in the associated FFP has been detected prior to the RO.

[0009] The embodiments further provide a non-transitory computer-readable medium including instructions that are executed by one or more processors of a user device to perform a communication method, the communication method including obtaining a first indication indicating at least one of possible Random Access Channel (RACH) Opportunity (RO) locations, actual transmitted Synchronization Signal Block (SSB) locations, Frame Based Device (FBE) Frame Periodicity (FFP) information, Uplink / Downlink (UL / DL) modes within the FFP, obtaining a second indication indicating Channel Occupancy Time (COT) information, and determining a valid RO for a Physical RACH (PRACH) transmission based on the first indication and the second indication.

[0010] These embodiments further provide a non-transitory computer-readable medium including instructions that are executed by one or more processors of a user device to perform a communication method, the communication method including determining to allow a PRACH transmission at a random access channel (RACH) opportunity (RO) in an associated frame based device (FBE) frame period (FFP) if the RO is an RO in an associated FFP and satisfies a condition that at least one downlink (DL) signal or channel in the associated FFP has been detected prior to the RO.

[0011] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a wireless communication system in some embodiments of the present application. [Diagram 2] 2 is a flow chart of a communication method 200 according to some embodiments of the present disclosure. [Diagram 3] 3 is a flow chart of a communication method 300 according to some embodiments of the present disclosure. [Figure 4]This information is about FFP, COT, SSB location, RO location, and DL / UL mode acquired by the UE. [Diagram 5] FIG. 1 is a schematic diagram illustrating a UE determining a valid RO from all RO locations based on FFP, COT, SSB location, RO location, and DL / UL mode. [Figure 6] 1 is a schematic diagram of a UE determining which available RO (for PRACH transmission) is to be utilized for actual PRACH transmission based on reception / detection of a downlink transmission prior to the available RO in the current FFP; [Figure 7] 1 is a schematic diagram of a UE determining which available RO (for PRACH transmission) is to be utilized for actual PRACH transmission based on reception / detection of a downlink transmission prior to the available RO in the current FFP; [Figure 8] FIG. 8 is a schematic diagram of a user device 800 in accordance with some embodiments of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the drawings, in which like numerals in different drawings represent the same or similar elements unless otherwise indicated. The embodiments set forth in the following description of the exemplary embodiments are not intended to represent all embodiments consistent with the present invention, but are merely illustrative of apparatus and methods consistent with aspects of the present invention as set forth in the appended claims. FIG. 1 illustrates an exemplary wireless communication system in an embodiment of the present application. The wireless communication system includes a base station 120, a user device 140, and a user device 160. The base station 120 is an end node of a wireless communication network. For example, the base station 120 is an evolved Node B (eNB) in an LTE system or a gNB in ​​a 5G wireless system. The base station 120 transmits a wireless signal including system information of the wireless communication system. The user devices within a coverage area 180 around the base station 120 receive the system information. For example, the user device 140 within the coverage area 180 can receive the system information and access a network service via the base station 120.

[0014] Each of the user device 140 and the user device 160 is a mobile terminal in a wireless communication network. For example, the user device 140 or the user device 160 is a smartphone, a network interface card, or a machine-type terminal. As another example, the user device 140 or the user device 160 is a user device in an LTE system or a 5G wireless system. The user device 140 and the user device 160 and the base station 120 each include a communication unit capable of transmitting and receiving wireless signals. The following description describes a scheme for operating the user device 140 in a wireless communication system, and such description also applies to the user device 160.

[0015] When the user device 140 wants to access a network service through the base station 120, the user device 140 may need to receive control signals from the base station 120 to collect system information with coverage 180, such as synchronization and radio resource allocation and scheduling. For example, the user device 140 in a 5G wireless system may need to receive a physical downlink control channel (PDCCH) to know whether data is transmitted to the user device 140 on a physical downlink shared channel. Therefore, the user device 140 needs to detect the PDCCH in the signal transmitted by the base station 120.

[0016] For example, 5G wireless systems use OFDM waveforms for wireless communication. Similar to traditional LTE cellular networks, communication is measured in time frames, with each frame divided into time slots, each slot containing multiple OFDM symbols, and each symbol spanning multiple frequency subcarriers. Resources are defined by time (OFDM symbols) and frequency (subcarriers).

[0017] A PDCCH search space is a set of resources that a user device (e.g., user device 140) may assume as its PDCCH candidates and attempt to search and decode to obtain control information. Without loss of generality, for a user device, an instance in which a PDCCH is configured as a resource to be transmitted (or an instance in which the user device is configured to monitor its PDCCH) is hereafter referred to as a scheduling (or PDCCH) instance. The user device 140 may blindly decode all PDCCH instances in its search space until the user device successfully decodes its PDCCH candidate. Once the PDCCH is successfully decoded, the user device 140 continues to receive and decode data transmitted from the base station on a data channel, such as a physical downlink shared channel (PDSCH). If the user device 140 fails to decode a PDCCH in its search space, the user device 140 assumes that a PDCCH was not transmitted in this scheduling instance and does not decode the PDSCH.

[0018] 5G wireless systems can be deployed at higher frequencies (e.g., 6 GHz and above) where wider bandwidth is available. For example, beamforming (BF) can be used to increase signal strength and reduce interference in wireless systems.

[0019] Below are exemplary explanations of relevant terms in the art.

[0020] Unlicensed Band Unlicensed spectrum is shared spectrum: communication equipment of different communication systems can use this spectrum as long as they meet national or local regulatory requirements for the spectrum and do not need to apply for exclusive spectrum authorization from the government.

[0021] In order to allow various communication systems that use unlicensed bands for wireless communication to coexist amicably in the spectrum, some countries or regions specify regulatory requirements that must be met when using unlicensed bands. For example, communication devices follow the principle of "Listen Before Talk (LBT)", that is, the device must perform channel sensing before transmitting a signal on the channel. Only if the result of LBT indicates that the channel is idle can the device perform signal transmission; otherwise, the device cannot perform signal transmission. To ensure fairness, once a device successfully occupies a channel, the transmission time cannot exceed the Maximum Channel Occupancy Time (MCOT).

[0022] In an unlicensed carrier, for the channel occupancy time acquired by a base station, the channel occupancy time can be shared with the UE to transmit an uplink signal or an uplink channel. In other words, when the base station shares its channel occupancy time with the UE, the UE can acquire a channel using the LBT mode with a higher priority than that used by the UE itself, thereby acquiring the channel with a higher probability.

[0023] Frame Based Devices (FBE) FBE is a channel access mode for unlicensed bands, in which the initiating device needs to initiate COT at regular intervals. This mode is not supported by LTE LAA, eLAA, or FeLAA.

[0024] Physical Random Access Channel (PRACH) in NRU In unlicensed bands, there is a regulation that for each transmission in the 20MHz band, the actual transmission must guarantee at least 80% of the bandwidth usage. This is also called the occupied channel band (OCB) requirement. For an NRU system with 30Khz subcarrier spacing, if the network configures an initial BWP of 48 RB (i.e., 17.28Mhz bandwidth), the UE will repeatedly utilize Rel.15 PRACH (1 RO = 360Khz bandwidth) in one RO selected by the UE. Therefore, the OCB requirement is not met. To solve this OCB problem, the UE needs to transmit PRACH in ROs of multiple frequency domains, for example, simultaneous transmission in RO#0, RO#1, RO#2, RO#3, or simultaneous transmission in RO#0, RO#3, etc. Note that OCB considers the bandwidth between the lowest and highest frequencies of the transmission, which does not force transmission without gaps in the transmission spectrum. Therefore, transmission in RO#0~RO#3 is equivalent to transmission in RO#0, RO#3.

[0025] Therefore, in FBE mode, the determination of the RO and PRACH transmission on the RO are open problems. The following description provides a method for the UE to determine a valid RO and determine whether the RO is allowed for PRACH transmission.

[0026] 2 is a flow chart of an exemplary communication method 200 in some embodiments of the present application. The method 200 is performed by the user device 140 or the user device 160. The method 200 includes the following steps.

[0027] In step 210, a first indication is obtained indicating at least one of possible Random Access Channel (RACH) Opportunity (RO) positions, actually transmitted synchronization signal BLOCK (SSB) positions, Frame Based Device (FBE) frame period (FFP) information, or uplink / downlink (UL / DL) modes within the FFP.

[0028] At step 230, a second indication is obtained that is indicative of channel occupancy time (COT) information.

[0029] In step 250, a valid RO for a physical RACH (PRACH) transmission is determined based on the first indication and the second indication.

[0030] In one embodiment, the effective RO is: Not being present in the relevant range of the SSSB being transmitted; DL transmission does not overlap or partially overlap with the configured resources At least one of the following conditions is met:

[0031] In one embodiment, the FFP idle portion is the remainder of the FFP and the COT of the FFP.

[0032] In one embodiment, the second indication is included in a particular configuration of cells or is stored based on the system frame number.

[0033] 3 is a flow chart of an exemplary communication method 300 in some embodiments of the present application. The method 300 is performed by the user device 140 or the user device 160. The method 300 includes the following steps.

[0034] In step 310, it is determined that a PRACH transmission is permitted in a random access channel (RACH) opportunity (RO) within an associated frame based device (FBE) frame period (FFP) if the following condition is met: The RO is a valid RO within the relevant FFP; and and at least one downlink (DL) signal or channel in the associated FFP is detected prior to the RO.

[0035] In one embodiment, the DL signal includes at least one of a synchronization signal block (SSB) or a downlink reference signal.

[0036] In one embodiment, the DL channel includes at least one of a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH).

[0037] In one embodiment, the method 300 further includes performing an LBT type for transmitting the PRACH to the authorized RO.

[0038] In one embodiment, the LBT type is dictated by a particular configuration of the cell (eg, SIB1) or is pre-configured.

[0039] In one embodiment, the LBT type is Category 1, Category 2, or Category 4.

[0040] The following are examples that may be implemented according to some embodiments of the present application. These examples may be employed in 5G NR unlicensed band communication.

[0041] Example 1 FIG. 4 illustrates obtaining information related to FFP, COT, SSB location, RO location, and DL / UL mode by a UE in one embodiment.

[0042] As shown in Figure 4, when the UE receives information about the FFP and COT information, the UE can subtract the COT from the FFP to obtain the FFP idle part. Note that, when the UE receives the SSB location, DL / UL mode, and RO location, the UE can know the relative locations of these resources, as shown in Figure 4.

[0043] In the next step, the UE determines a valid RO from all RO positions, so that the RO does not overlap with the resources configured for downlink transmission and SSB transmission, and the valid RO does not overlap with the FFP idle part, as shown in Figure 5, which shows that the UE determines a valid RO from all RO positions based on FFP, COT, SSB position, RO position, and DL / UL mode.

[0044] Example 2 When the UE determines a valid RO and the UE wants to transmit PRACH in the valid RO, the UE checks whether there is any downlink transmission in the time period from the current FFP to the valid RO, and determines whether the valid RO is used for actual PRACH transmission. The downlink transmission may be any DL transmission, such as SSB, PDCCH, PDSCH, or downlink reference signal. If DL transmission is detected, all valid ROs after the valid RO until the end of the FFP are determined as ROs that can transmit PRACH.

[0045] FIG. 6 shows that the UE determines which available RO (for PRACH) is to be utilized for the actual PRACH transmission based on reception / detection of a previous downlink transmission of the available RO (for PRACH) in the current FFP.

[0046] FIG. 7 shows that the UE determines which available RO (for PRACH) is to be utilized for the actual PRACH transmission based on reception / detection of a previous downlink transmission of the available RO (for PRACH) in the current FFP.

[0047] As shown in Figures 6 and 7, when the UE performs PRACH transmission, it can use the LBT type (e.g., LBT category 1, category 2, gap is 16us or 25us) that the UE notifies in a specific configuration of the cell. In other embodiments, the LBT type may be preset, and the gap may be preset.

[0048] 8 is a schematic diagram of an exemplary user device 800 according to some embodiments of the present application. The user device 800 includes a memory 810, a processor 820, a storage 830, an I / O interface 840, and a communication unit 850. One or more of these elements of the user device 800 may be included to perform any of the embodiments of the communication method as described above. The user device 140 or the user device 160 shown in FIG. 1 may be configured as the user device 800.

[0049] The processor 820 includes any suitable type of general-purpose or special-purpose microprocessor, digital signal processor, or microcontroller. The processor 820 may be one of the processors of the user device 140 or the user device 160. The memory 810 and the storage 830 may include any suitable type of mass storage configured to store any type of information that the processor 820 may need to operate. The memory 810 and the storage 830 may be volatile or non-volatile, magnetic, semiconductor, tape, optical, removable, non-removable, or other type of storage device or computer-readable medium of tangible (i.e., non-transitory) nature, including, but not limited to, read-only memory (ROM), flash memory, dynamic random access memory (RAM), and static RAM. The memory 810 and / or the storage 830 may be configured to store one or more programs executed by the processor 820 to perform any of the embodiments of the communication method disclosed herein.

[0050] The memory 810 and / or the storage 830 may be further configured to store information and data used by the processor 820.

[0051] The I / O interface 840 may be configured to enable communication between the user device 800 and other devices. For example, the I / O interface 840 may receive a signal from another apparatus (e.g., a base station) that includes system configuration information for the user device 800. The I / O interface 840 may also output data for transmission statistics to other devices.

[0052] The communication unit 850 may include one or more cellular communication modules, such as, for example, communication modules for a 5G wireless system, Long Term Evolution (LTE), High Speed ​​Packet Access (HSPA), Wideband Code Division Multiple Access (WCDMA), and / or Global System for Mobile Communications (GSM).

[0053] The processor 820 is configured to obtain a first indication indicating at least one of possible random access channel (RACH) opportunity (RO) locations, actual transmitted synchronization signal block (SSB) locations, frame based device (FBE) frame period (FFP) information, uplink / downlink (UL / DL) mode within the FFP, obtain a second indication indicating channel occupation time (COT) information, and determine a valid RO for physical RACH (PRACH) transmission based on the first indication and the second indication.

[0054] In one embodiment, the valid RO satisfies at least one of the following: not existing within a predefined range associated with the transmitted SSSB; the DL transmission does not overlap or overlap with configured resources; and does not enter an FFP idle portion.

[0055] In one embodiment, the FFP idle portion is the remainder of the FFP and the COT of the FFP.

[0056] In one embodiment, the second indication is included in a particular configuration of cells or is stored based on the system frame number.

[0057] The processor 820 is further configured to determine to allow a PRACH transmission at a random access channel (RACH) opportunity (RO) in an associated frame based device (FBE) frame period (FFP) if the RO is an RO in an associated FFP and satisfies a condition that at least one downlink (DL) signal or channel in the associated FFP has been detected before the RO.

[0058] In one embodiment, the DL signal includes at least one of a synchronization signal block (SSB) or a downlink reference signal.

[0059] In one embodiment, the DL channel includes at least one of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH).

[0060] In an embodiment, the processor 820 is further configured to perform an LBT type for transmitting the PRACH to the allowed RO.

[0061] In one embodiment, the LBT type is dictated or pre-configured by the particular configuration of the cell.

[0062] In one embodiment, the particular configuration of cells includes SIB1.

[0063] In one embodiment, the LBT type is Category 1, Category 2, or Category 4.

[0064] Another aspect of the present disclosure provides a non-transitory computer readable medium storing instructions that, when executed, cause one or more processors to perform a method consistent with the embodiments disclosed herein. The computer readable medium may include volatile or non-volatile, magnetic, semiconductor, tape, optical, removable, non-removable, or other types of computer readable media or computer readable storage devices. For example, as disclosed, the computer readable medium may be a storage device or memory module having computer instructions stored thereon. In some embodiments, the computer readable medium may be an optical disk or flash drive having computer instructions stored thereon.

[0065] It should be understood that the present disclosure is not limited to the exact construction described above and illustrated in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of this application is intended to be limited only by the appended claims.

Claims

1. A communication method applied to a user device UE, comprising: Obtaining a first indication indicating at least one of possible random access channel (RACH) opportunity (RO) positions, actual transmitted synchronization signal block (SSB) positions, frame-based device (FBE) frame period (FFP) information, and uplink UL / downlink DL mode in the FFP; obtaining a second indication indicative of channel occupation time (COT) information of the FFP; determining an effective RO for a Physical Random Access Channel (PRACH) transmission based on the first indication and the second indication; The effective RO is not being within a predetermined range associated with the transmitted SSB; DL transmissions do not overlap or partially overlap with configured resources; and At the same time, it also satisfies the following: A communication method comprising:

2. The FFP idle portion is the remaining portion between the FFP and the COT of the FFP.

2. The communication method according to claim 1 .

3. The second indication is stored in association with a particular configuration of cells or with a system frame number.

3. The communication method according to claim 1 or 2.

4. A memory having instructions stored therein; a processor communicatively coupled to the memory; The instructions, when executed by the processor, cause the processor to: Obtain a first indication indicating at least one of possible random access channel (RACH) opportunity (RO) positions, actual transmitted synchronization signal block (SSB) positions, frame based device (FBE) frame period (FFP) information, and uplink UL / downlink DL mode in the FFP; Obtaining a second indication indicative of channel occupation time (COT) information of the FFP; performing an operation of determining an effective RO for a physical random access channel (PRACH) transmission based on the first indication and the second indication; The effective RO is not being within a predetermined range associated with the transmitted SSB; DL transmissions do not overlap or partially overlap with configured resources; and At the same time, it also satisfies the following: A user device comprising:

5. The FFP idle portion is the remainder of the FFP and the COT of the FFP.

5. The user device of claim 4.

6. The second indication is stored in association with a particular configuration of cells or with a system frame number. A user device according to claim 4 or 5.

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