Sub-band full-duplex random access method and device

Abstract

The present disclosure describes methods, systems, and devices for configuring and transmitting physical random access channel (PRACH) transmissions, particularly at random access channel opportunities (RO) of uplink (UL) subbands. A method includes performing, by a user equipment (UE), a PRACH transmission to a base station by obtaining, by the UE, an RO configuration of an RO; determining, by the UE, whether the RO is valid for a UL subband based on a set of predefined rules, where the UL subband includes at least one downlink (DL) symbol or at least one flexible symbol and occupies a portion of a frequency domain resource of the at least one DL symbol or the at least one flexible symbol; and in response to determining that the RO is valid, transmitting, by the UE, a PRACH transmission at the RO to a base station.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications. In particular, the present disclosure relates to methods and apparatus for sub-band full-duplex (SBFD) random access. Background Art

[0002] Wireless communication technology is moving the world towards an increasingly connected and networked society. High-speed and low-latency wireless communications rely on efficient network resource management and allocation between user devices and wireless access network nodes (including but not limited to base stations). The next-generation network is expected to provide high-speed, low-latency and ultra-reliable communication capabilities and meet the needs of different industries and users.

[0003] In some existing wireless communication schemes, uplink (UL) symbols or time slots may be configured / scheduled for transmitting data or control information from a user equipment to a base station; and downlink (DL) symbols or time slots may be configured / scheduled for transmitting data or control information from a base station to a UE. In some existing schemes, UL symbols / time slots are fewer and / or discontinuous compared to DL symbols / time slots, resulting in relatively poor performance in terms of timeliness and / or edge coverage of UL transmissions, which may be due to the absence of more continuous UL symbols / time slots.

[0004] The present disclosure describes various embodiments of configuration / utilization of UL subbands for sub-band full-duplex (SBFD) random access, which solves at least one of the above-mentioned problems / issues and improves the performance of wireless communications, especially the performance of uplink transmission of data / control information. Summary of the invention

[0005] This document relates to methods, systems and devices for wireless communications, and more specifically, to configuring and transmitting physical random access channel (PRACH) transmissions, particularly at random access channel opportunities (RO) in UL subbands. Various embodiments of the present disclosure can improve resource utilization efficiency and enhance latency performance of wireless communications.

[0006] In one embodiment, the present disclosure describes a method for wireless communication. The method includes performing, by a user equipment (UE), a physical random access channel (PRACH) transmission to a base station in the following manner: obtaining, by the UE, a random access channel opportunity (RO) configuration of a RO; determining, by the UE based on a set of predefined rules, whether the RO is valid for an uplink (UL) subband, wherein the UL subband includes at least one downlink (DL) symbol or at least one flexible symbol and occupies a portion of a frequency domain resource of at least one DL symbol or at least one flexible symbol; and in response to determining that the RO is valid, transmitting, by the UE, a PRACH transmission to the base station at the RO.

[0007] In one embodiment, the present disclosure describes a method for wireless communication. The method includes receiving, by a base station, a physical random access channel (PRACH) transmission from a user equipment (UE) in the following manner: configuring, by the base station, a random access channel opportunity (RO) configuration of the UE; determining, by the base station based on a set of predefined rules, whether the RO is valid for a UL subband, wherein the UL subband includes at least one downlink (DL) symbol or at least one flexible symbol and occupies a portion of a frequency domain resource of at least one DL symbol or at least one flexible symbol; and in response to determining that the RO is valid, receiving, by the base station, a PRACH transmission from the UE at the RO.

[0008] In some other embodiments, the apparatus for wireless communication may include a memory storing instructions and a processing circuit in communication with the memory. When the processing circuit executes the instructions, the processing circuit is configured to perform the above method.

[0009] In some other embodiments, the device for wireless communication may include a memory storing instructions and a processing circuit in communication with the memory. When the processing circuit executes the instructions, the processing circuit is configured to perform the above method.

[0010] In some other embodiments, a computer-readable medium includes instructions that, when executed by a computer, cause the computer to perform the above method.

[0011] The above-mentioned aspects and other aspects and embodiments thereof will be described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A An example of a wireless communication system including a radio network node and one or more user equipments is shown.

[0013] Figure 1B An exemplary configuration pattern of uplink (UL) subbands in the present disclosure is shown.

[0014] Figure 1C Another exemplary configuration pattern of the UL subband in the present disclosure is shown.

[0015] Figure 1D Another exemplary configuration pattern of the UL subband in the present disclosure is shown.

[0016] Figure 2 An example of a network node is shown.

[0017] Figure 3 An example of a user device is shown.

[0018] Figure 4A A flow chart of a method for wireless communication is shown.

[0019] Figure 4B A flow chart of another method for wireless communication is shown.

[0020] Figure 5 A schematic diagram of an exemplary embodiment for wireless communications is shown.

[0021] Figure 6 A schematic diagram of another exemplary embodiment for wireless communications is shown.

[0022] Figure 7 A schematic diagram of another exemplary embodiment for wireless communications is shown.

[0023] Fig. 8A A schematic diagram showing a configuration diagram of a physical random access channel (PRACH) opportunity in a UL subband in the present disclosure is shown.

[0024] Figure 8B A schematic diagram showing another configuration diagram of PRACH opportunities in a UL subband in the present disclosure.

[0025] Figure 8C A schematic diagram showing another configuration diagram of PRACH opportunities in a UL subband in the present disclosure. DETAILED DESCRIPTION

[0026] The present disclosure will now be described in detail below with reference to the accompanying drawings which form a part hereof and which show by way of illustration specific examples of embodiments. However, it is to be noted that the present disclosure may be embodied in a variety of different forms and therefore, the subject matter covered or claimed is intended to be construed as not being limited to any embodiment to be set forth below.

[0027] Throughout the specification and claims, terms may have subtle meanings that are suggested or implied in the context, beyond the explicitly stated meaning. Likewise, the phrases "in one embodiment" or "in some embodiments" as used herein do not necessarily refer to the same embodiment, and the phrases "in another embodiment" or "in other embodiments" as used herein do not necessarily refer to different embodiments. The phrases "in one embodiment" or "in some embodiments" as used herein do not necessarily refer to the same embodiment, and the phrases "in another embodiment" or "in other embodiments" as used herein do not necessarily refer to different embodiments. For example, it is intended that the claimed subject matter includes all or part of an exemplary embodiment or a combination of embodiments.

[0028] In general, terms can be understood at least in part from the usage in the context. For example, terms such as "and", "or" or "and / or" used in this article can include multiple meanings, which depend at least in part on the context in which these terms are used. Generally, "or" if used in an association list, such as A, B or C, means A, B and C, which are used here in an inclusive sense, and A, B or C, which are used here in an exclusive sense. In addition, the terms "one or more" or "at least one" used in this article depend at least in part on the context and can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or characteristics in a plural sense. Similarly, terms such as "one", "an" or "the" can also be understood to represent singular usage or plural usage, depending at least in part on the context. In addition, the term "based on..." or "determined by..." can be understood to not necessarily be intended to express a set of exclusive factors, and on the contrary, additional factors that are not necessarily explicitly described can be allowed to exist, depending at least in part on the context.

[0029] The present disclosure describes methods and apparatus for configuring and transmitting a Physical Random Access Channel (PRACH) transmission, particularly during a Random Access Channel Occasion (RO) of a UL subband.

[0030] Next-generation (NG) mobile communication systems are driving the world towards an increasingly connected and networked society. High-speed and low-latency wireless communications rely on efficient network resource management and allocation between user devices and wireless access network nodes (including but not limited to wireless base stations). NG networks are expected to provide high-speed, low-latency and ultra-reliable communication capabilities and meet the requirements of different industries and users.

[0031] In some existing wireless communication schemes, uplink (UL) symbols or time slots may be configured / scheduled for transmitting data or control information from a user equipment to a base station; and downlink (DL) symbols or time slots may be configured / scheduled for transmitting data or control information from a base station to a UE. In some existing schemes, UL symbols / time slots are fewer and / or discontinuous compared to DL symbols / time slots, resulting in relatively poor performance in terms of timeliness and / or edge coverage of UL transmissions, which may be due to the absence of more continuous UL symbols / time slots.

[0032] As a non-limiting example, for a time division duplex (TDD) carrier, DL symbols (or time slots) and UL symbols (or slots) are time-division configured. In addition, in some embodiments, DL symbols / time slots are configured to be more than UL symbols / time slots.

[0033] In the present disclosure, the description of various embodiments / implementations may focus on the time slot level (or the symbol level in some other various embodiments / implementations), which is not a limitation on one or more embodiments / implementations, and the described embodiments / implementations may be applied to both the time slot level and the symbol level.

[0034] As a non-limiting example, refer to Figure 1B , a typical symbol / slot structure is DDDSU (151, 152, 153, 154, and 155). Here, D represents DL symbol / slot, U represents UL symbol / slot, and S represents flexible symbol / slot including DL symbol and UL symbol. Obviously, UL slots are less and discontinuous, and these characteristics affect the performance of UL transmission. For example, due to the lack of more continuous or available UL slots, large data volume of UL may not be supported, and / or more importantly, the timeliness and edge coverage of UL transmission may be relatively poor.

[0035] In some embodiments, the UL subband-based full-duplex technology may be implemented as sub-band full-duplex (SBFD), where a configuration pattern of the UL subband may have various types.

[0036] Figure 1B One type of configuration pattern of UL subbands is shown, where UL subband 160 is configured only in DL symbols / slots. In some embodiments, UL subbands may be configured in some or all DL symbols / slots.

[0037] Figure 1C Another type of configuration pattern of UL subbands is shown, where UL subbands 170 are configured in DL symbols / slots and flexible symbols / slots. In some embodiments, UL subbands may be configured in some or all DL symbols / slots and some or all flexible symbols / slots.

[0038] Figure 1D Another type of configuration pattern of UL subbands is shown, where UL subbands 180 are configured in DL symbols / slots, flexible symbols / slots, and UL symbols / slots. In some embodiments, UL subbands may be configured in some or all DL symbols / slots, some or all flexible symbols / slots, and some or all UL symbols / slots.

[0039] In some embodiments, a UL subband may be configured to contain at least one DL symbol / slot.

[0040] In various embodiments, the UL subband may provide continuous UL symbols / time slots, which is beneficial for spreading UL resources, for example, reducing latency of UL transmissions by reducing the time to wait for UL opportunities, and / or improving uplink coverage. The present disclosure describes various embodiments for enhancing random access procedures based on UL subbands, thereby improving the performance of random access in terms of capacity, latency, and coverage.

[0041] Figure 1A A wireless communication system 100 is shown that includes a radio network node 118 and one or more user equipment (UE) 110. The radio network node may include a network base station, which may be a Node B (NB, e.g., gNB) in a mobile telecommunication context. Each UE may wirelessly communicate with the radio network node via one or more radio channels 115 for downlink / uplink communications. For example, a first UE 110 may wirelessly communicate with the radio network node 118 via a channel including a plurality of radio channels during a specific time period. The network base station 118 may send high-layer signaling to the UE 110. The high-layer signaling may include configuration information for communication between the UE and the base station. In one embodiment, the high-layer signaling may include a radio resource control (RRC) message.

[0042] Figure 2 An example of an electronic device 200 for implementing a network base station is shown. The example electronic device 200 may include wireless transmit / receive (Tx / Rx) circuitry 208 for transmitting / receiving communications with UEs and / or other base stations. The electronic device 200 may also include network interface circuitry 209 for communicating the base station with other base stations and / or a core network (e.g., optical or wired interconnects, Ethernet, and / or other data transmission media / protocols). The electronic device 200 may optionally include an input / output (I / O) interface 206 for communicating with an operator or the like.

[0043] The electronic device 200 may also include a system circuit 204. The system circuit 204 may include one or more processors 221 and / or a memory 222. The memory 222 may include an operating system 224, instructions 226, and parameters 228. The instructions 226 may be configured for one or more processors 124 to perform the functions of a network node. The parameters 228 may include parameters that support the execution of the instructions 226. For example, the parameters may include network protocol settings, bandwidth parameters, radio frequency mapping allocations, and / or other parameters.

[0044] Figure 3An example of an electronic device for implementing a terminal device 300 (e.g., a user equipment (UE)) is shown. UE 300 may be a mobile device, such as a smart phone or a mobile communication module provided in a vehicle. UE 300 may include a communication interface 302, a system circuit 304, an input / output interface (I / O) 306, a display circuit 308, and a storage device 309. The display circuit may include a user interface 310. System circuit 304 may include any combination of hardware, software, firmware, or other logic / circuits. System circuit 304 may be implemented, for example, with one or more systems on a chip (SoC), application specific integrated circuits (ASICs), discrete analog and digital circuits, and other circuits. System circuit 304 may be part of an implementation of any desired function in UE 300. In this regard, the system circuit 304 may include, for example, logic to facilitate the decoding and playing of music and video, such as MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playback; running applications; accepting user input; saving and retrieving application data; establishing, maintaining, and terminating cellular phone calls or data connections, as an example, for Internet connections; establishing, maintaining, and terminating wireless network connections, Bluetooth connections, or other connections; and displaying relevant information on the user interface 310. The user interface 310 and the input / output (I / O) interface 306 may include a graphical user interface, a touch-sensitive display, tactile feedback or other tactile output, voice or facial recognition input, buttons, switches, speakers, and other user interface elements. Additional examples of the I / O interface 306 may include microphones, video and still image cameras, temperature sensors, vibration sensors, rotation and orientation sensors, headphone and microphone input / output jacks, universal serial bus (USB) connectors, memory card slots, radiation sensors (e.g., IR sensors), and other types of inputs.

[0045] refer to Figure 3, the communication interface 302 may include a radio frequency (RF) transmission (Tx) and reception (Rx) circuit 316, which processes the transmission and reception of signals through one or more antennas 314. The communication interface 302 may include one or more transceivers. The transceiver may be a wireless transceiver, which includes a modulation / demodulation circuit, a digital-to-analog converter (DAC), a shaping table, an analog-to-digital converter (ADC), a filter, a waveform shaper, a filter, a preamplifier, a power amplifier and / or other logic for transmitting and receiving through one or more antennas or (for some devices) through a physical (e.g., wired) medium. The transmitted and received signals may follow any of a variety of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM), frequency channels, bit rates, and encodings. As a specific example, the communication interface 302 may include a transceiver that supports transmission and reception under 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS), High Speed ​​Packet Access (HSPA) +, 4G / Long Term Evolution (LTE), 5G standards, and / or 6G standards. However, the techniques described below are applicable to other wireless communication technologies, whether derived from the 3rd Generation Partnership Project (3GPP), the GSM Association, 3GPP2, IEEE, or other partners or standards bodies.

[0046] refer to Figure 3 , the system circuit 304 may include one or more processors 321 and a memory 322. The memory 322 stores, for example, an operating system 324, instructions 326, and parameters 328. The processor 321 is configured to execute the instructions 326 to implement the desired functions of the UE 300. The parameters 328 may provide and specify configuration and operating options for the instructions 326. The memory 322 may also store any BT, WiFi, 3G, 4G, 5G, 6G, or other data that the UE 300 will send or has received through the communication interface 302. In various embodiments, the system power of the UE 300 may be supplied by a power storage device such as a battery or a transformer.

[0047] The present disclosure describes various embodiments for configuring and transmitting a physical random access channel (PRACH) transmission, particularly a random access channel opportunity (RO) in a UL subband, which may be partially or fully transmitted on the UL subband. Figures 2 to 3 The method is implemented on a network base station and / or user equipment described in the embodiment.

[0048] refer to Figure 4A, the present disclosure describes various embodiments of a method 400 for wireless communication, the method comprising performing, by a user equipment (UE), a physical random access channel (PRACH) transmission to a base station. The method may include some or all of the following steps: step 410, obtaining, by the UE, a random access channel timing (RO) configuration for a RO; step 420, determining, by the UE based on a set of predefined rules, whether the RO is valid for an uplink (UL) subband, wherein the UL subband includes at least one downlink (DL) symbol or at least one flexible symbol and occupies a portion of the frequency domain resources of the at least one DL symbol or the at least one flexible symbol; and / or step 430, in response to determining that the RO is valid, transmitting, by the UE, a PRACH transmission to the base station at the RO.

[0049] refer to Figure 4B , the present disclosure describes various embodiments of a method 450 for wireless communication, the method comprising receiving, by a base station, a physical random access channel (PRACH) transmission from a user equipment (UE). The method may include some or all of the following steps: step 460, configuring, by the base station, a random access channel opportunity (RO) configuration of the UE; step 470, determining, by the base station based on a set of predefined rules, whether the RO is valid for a UL subband, wherein the UL subband includes at least one downlink (DL) symbol or at least one flexible symbol and occupies a portion of a frequency domain resource of at least one DL symbol or at least one flexible symbol; and / or step 480, in response to determining that the RO is valid, receiving, by the base station, a PRACH transmission from the UE at the RO.

[0050] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more embodiments described, the set of predefined rules includes: configuring a UL subband for the UE, and the UE is provided with a specific information element (IE); and / or the set of predefined rule sets also includes at least one of the following: the RO is in the UL subband; the RO starts at least T symbols after the last pure downlink symbol, where T is an integer; the RO is before a specific symbol in the PRACH time slot, and the RO ends at least T symbols before the first specific symbol; the RO is after a specific symbol in the PRACH time slot, and the RO starts at least T symbols after the last specific symbol; or the RO starts at least T symbols after the last downlink symbol for downlink transmission for the UE.

[0051] In some implementations, in addition to part, all, or any combination of one or more implementations / one or more examples described, the UE determines that the RO is valid in response to a set of predefined rules being satisfied.

[0052] In some implementations, in addition to part, all, or any combination of one or more implementations / examples described, the base station determines that the RO is valid in response to a set of predefined rules being satisfied.

[0053] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, the specific IE also includes an IE of tdd-UL-DL-ConfigurationCommon included in radio resource control (RRC) signaling.

[0054] In some embodiments, in addition to part, all or any combination of one or more embodiments / one or more examples described, the RO also includes at least one of the following in the UL subband: all time domain resources of the RO are within the time domain resources of the UL subband, and all random access resources in the frequency domain of the RO are within the frequency domain resources of the UL subband; all time domain resources of the RO are within the time domain resources of the UL subband, and a part of the random access resources in the frequency domain of the RO are within the frequency domain resources of the UL subband; a part of the time domain resources of the RO are within the time domain resources of the UL subband, and all random access resources in the frequency domain of the RO are within the frequency domain resources of the UL subband; or a part of the time domain resources of the RO are within the time domain resources of the UL subband, and a part of the random access resources in the frequency domain of the RO are within the frequency domain resources of the UL subband.

[0055] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, the specific symbol also includes an end or start synchronization signal (SS) / physical broadcast channel (PBCH) block symbol.

[0056] In some implementations, in addition to part, all, or any combination of one or more implementations / one or more embodiments described, a pure downlink symbol also includes a downlink symbol that is not configured with a UL subband.

[0057] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, the value of T is associated with the subcarrier spacing (SCS) corresponding to the RO; and / or the minimum value of T is 0.

[0058] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, a set of predefined rules includes that the UE is provided with a specific information element (IE) and the UE is instructed to perform PRACH transmission in the RO; and / or a set of predefined rules also includes at least one of the following: the RO includes one or more downlink symbols, or the interval between the RO and a specific symbol is less than a required interval threshold.

[0059] In some embodiments, in addition to part, all or any combination of one or more embodiments / one or more embodiments described, a set of predefined rules also includes at least one of the following: the RO spans the UL subband and uplink symbols in the time domain, the RO spans the UL subband and flexible symbols in the time domain, the flexible symbols are not dynamically indicated for downlink transmission, the timing advance (TA) of the uplink symbol is aligned with the TA of the UL subband, the timing advance (TA) of the flexible symbol is aligned with the TA of the UL subband, the timing advance offset between the UL subband symbol and the UL symbol is predefined to 0 or configured to 0 by the base station, the timing advance offset between the UL subband symbol and the flexible symbol is predefined to 0 or configured to 0 by the base station, the UL subband symbol and the UL symbol are continuous in the time domain, the UL subband symbol and the flexible symbol are continuous in the time domain, or the base station notifies the UE that the RO is valid.

[0060] In some implementations, in addition to part, all, or any combination of one or more implementations / examples described, a PRACH transmission is transmitted based on parameters corresponding to the RO.

[0061] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more embodiments described, the UE is configured with a UL subband; the RO is configured in the UL subband in at least one downlink symbol; and / or in response to a PRACH transmission by the UE in the RO within the UL subband: the base station determines the UE as a UE with UL subband capability, and at least one of the following: in response to the UE accessing the network, the uplink transmission is scheduled in the UL subband, the physical uplink shared channel (PUSCH) associated with the PRACH transmission is scheduled in the UL subband, the physical uplink control channel (PUCCH) associated with the PRACH transmission is scheduled in the UL subband, the hybrid automatic repeat request acknowledgment (HARQ-ACK) physical uplink control channel (PUCCH) associated with the PRACH transmission and corresponding to the reception of a physical downlink shared channel (PDSCH) with a UE contention resolution identifier is scheduled in the UL subband, or in response to a second PRACH transmission from a second RO being scheduled in the UL subband, the UE directly performs the second PRACH transmission without determining the validity of the second RO.

[0062] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more embodiments described, the UE is configured with a UL subband; the RO is configured in the UL subband in at least one downlink symbol; and in response to the base station receiving a PRACH transmission performed by the RO in the UL subband: the base station determines that the UE is a UE with UL subband capability, and at least one of the following: in response to receiving the UE's access to the network, the base station configures / schedules the uplink transmission in the UL subband, and the base station configures / schedules the physical uplink shared channel (PUSCH) associated with the PRACH transmission in the UL subband. In the UL subband, the base station configures / schedules a physical uplink control channel (PUCCH) associated with the PRACH transmission in the UL subband, the base station configures / schedules a hybrid automatic repeat request acknowledgment (HARQ-ACK) physical uplink control channel (PUCCH) associated with the PRACH transmission and corresponding to the physical downlink shared channel (PDSCH) with the UE contention resolution identifier in the UL subband, or the base station configures / schedules a second PRACH transmission for the UE from the second RO in the UL subband, so that the UE directly performs the second PRACH transmission without determining the validity of the second RO.

[0063] In some embodiments, except for part, all, or any combination of one or more embodiments / one or more examples described, the UE is not configured with a UL subband, and the base station is aware of the existence of the UL subband; and in response to the UE being scheduled to perform a second PRACH transmission from a second RO in a downlink symbol, the UE performs a second PRACH transmission from the second RO without determining the validity of the second RO, or in response to the UE being scheduled for an uplink transmission associated with the PRACH transmission from a downlink symbol, the UE performs the uplink transmission.

[0064] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more embodiments described, the base station knows that there is a UL subband that is not configured for the UE; and the base station schedules a second PRACH transmission from a second RO in a downlink symbol, so that the UE performs a second PRACH transmission from the second RO without determining the validity of the second RO, or the base station schedules an uplink transmission associated with the PRACH transmission from the downlink symbol, then the UE performs the uplink transmission.

[0065] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, the uplink transmission also includes at least one of the following: a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH).

[0066] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, the RO configuration also includes a first parameter and a second parameter in the frequency domain, wherein: the first parameter indicates the offset of the starting resource block (RB) of the RO relative to the starting RB of the UL subband, and / or the second parameter indicates the number of RBs in the RO.

[0067] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, the UL subband is configured to overlap with and exceed the initial UL bandwidth part (BWP) in the frequency domain; PRACH transmission is performed in frequency domain resources from the UL subband overlapping with the initial UL BWP; and / or PRACH transmission for purposes other than initial random access is performed in frequency domain resources from the UL subband exceeding the initial UL BWP.

[0068] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more embodiments described, the UL subband is configured to overlap with the initial UL BWP in the frequency domain and to be within the initial UL BWP; and / or PRACH transmission is performed in any frequency domain resource from the UL subband within the initial UL BWP.

[0069] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, in response to the frequency domain resources of the UL subband being not configured, the frequency domain resources of the UL subband are the same as the frequency domain resources of the initial UL BWP.

[0070] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, in response to the frequency domain resources of the UL subband being not configured and there being no activated UL BWP, the frequency domain resources of the UL subband are the same as the frequency domain resources of the initial UL BWP.

[0071] In some embodiments, in addition to part, all, or any combination of one or more embodiments / one or more examples described, in response to the frequency domain resources of the UL subband being not configured and there being an activated UL BWP, the frequency domain resources of the UL subband are the same as the frequency domain resources of the activated UL BWP.

[0072] The present disclosure describes some specific non-limiting embodiments for configuring and transmitting a Physical Random Access Channel (PRACH) transmission, particularly at a Random Access Channel Occasion (RO) of a UL subband.

[0073] Example 1

[0074] This disclosure describes how a UE (or base station) determines the validity of a RO.

[0075] In some embodiments, a PRACH opportunity (or RACH opportunity) (RO) is a resource for a UE to perform a PRACH transmission. Multiple ROs may be configured in the time domain. Within each RO in the time domain, one or more random access resources may be configured in the frequency domain. These random access resources may be continuous or discrete in the frequency domain. In some embodiments, if the RO is configured to include DL symbols, the base station and the UE may consider the RO to be invalid because the UE cannot perform UL transmission in the DL symbol. In addition, in a time slot configured with a RO, if the interval between the start of the RO and the DL symbol is not large enough, the RO may also be invalid considering that it takes a certain amount of time for the UE to switch between UL transmission and DL transmission.

[0076] The present disclosure describes various embodiments for supporting PRACH transmission in UL subbands, where a UE with UL subband capability may perform a random access procedure at the RO of the UL subband. In some embodiments, the UL subband contains at least one or more DL symbols.

[0077] The present disclosure describes various methods for determining the validity of a RO based on various rules. In some non-limiting exemplary methods, when the UL subband is configured for a TDD carrier, the base station and the UE may configure the RO based on existing RO configuration signaling by consensus, and / or determine the validity of the RO based on various rules.

[0078] In some implementations, an OFDM symbol may have only a single UL or DL ​​transmission direction, so the validity of the RO is determined based only on some time domain resource information.

[0079] In some embodiments, frequency domain resource information is further added to determine the validity of the RO because at least some UL subbands are configured in DL symbols. That is, a portion of the frequency domain resources of a DL symbol is used for UL transmission, wherein when the UL subband is configured in a DL symbol, the DL symbol may have a DL transmission direction and a UL transmission direction.

[0080] For one non-limiting rule (Rule 1), when the UL subband is configured (i.e., the UL subband exists for the UE or the UE has UL subband capability) and when the UE is provided with a specific information element (e.g., tdd-UL-DL-ConfigurationCommon), the PRACH opportunities in the PRACH slots in the UL subband are determined to be valid.

[0081] When the base station configures a UL subband (i.e., for the UE, there is a UL subband, or the UE has UL subband capability) and provides a timeslot configuration parameter (e.g., tdd-UL-DL-ConfigurationCommon) for the UE, and when the base station configures a RO in the UL subband, the base station determines that the RO is valid.

[0082] In some embodiments, the UL subband is configured in a DL symbol or a DL slot, where a DL slot may be a slot in which all symbols are DL symbols. In some embodiments, the RO includes one or more random access resources in the frequency domain.

[0083] In some embodiments, the RO in the UL subband may refer to any one or any combination of the following: the time domain resources of the RO are within the time domain resources of the UL subband, and the frequency domain resources of at least one random access resource in the RO are within the frequency domain of the UL subband; the time domain resources of the RO are within the time domain resources of the UL subband, and the frequency domain resources of all random access resources in the RO are within the frequency domain of the UL subband; a portion of the time domain resources of the RO are within the time domain resources of the UL subband, and the frequency domain resources of at least one random access resource in the RO are within the frequency domain of the UL subband; or a portion of the time domain resources of the RO are within the time domain resources of the UL subband, and the frequency domain resources of all random access resources in the RO are within the frequency domain of the UL subband.

[0084] For another non-limiting rule, when the UL subband is configured (i.e., for the UE, the UL subband exists, or the UE has UL subband capability), and when the UE is provided with a specific information element (e.g., tdd-UL-DL-ConfigurationCommon), a PRACH opportunity in a UL subband within a PRACH slot is valid when one or a combination of the following conditions is met.

[0085] One condition is that the PRACH opportunity does not precede the SS / PBCH block in the PRACH slot and starts at least T symbols after the last SS / PBCH block symbol, where the value of T is associated with the subcarrier spacing (SCS) corresponding to the RO resource. T can be a non-negative integer, and the minimum value of T can be 0. Figure 5 An example of such a condition is shown, where DL symbols (551), DL symbols (552), DL symbols (553), flexible symbols (554), and UL symbols (555) are configured. The UL subband (510) is configured for the UE in two DL symbols (552 and 553). The start of the RO (530) should meet the condition of at least T symbols after the end of the last SSB block symbol (520).

[0086] Another condition is that the PRACH opportunity does not precede the SS / PBCH block in the PRACH slot and starts at least T symbols after the last pure downlink symbol, where the value of T is associated with the SCS corresponding to the RO resource. T may be a non-negative integer, and the minimum value of T may be 0. Here, in the present disclosure, a pure DL symbol may be a DL symbol that is not configured with a UL subband.

[0087] Figure 6An example of such a condition is shown, where DL symbol (551), DL symbol (552), DL symbol (553), flexible symbol (554) and UL symbol (555) are configured. UL subband (610) is configured for the UE in two DL symbols (552 and 553). The start of RO (630) should meet the condition of at least T symbols after the end of the pure DL symbol (DL symbol (551) in this example).

[0088] Another condition is that the PRACH opportunity ends before the SS / PBCH block in the PRACH slot and at least T symbols before the first SS / PBCH block symbol, where the value of T is associated with the SCS corresponding to the RO resource. T can be a non-negative integer, and the minimum value of T can be 0.

[0089] Figure 7 An example of such a condition is shown, where DL symbols (551), DL symbols (552), DL symbols (553), flexible symbols (554), and UL symbols (555) are configured. A UL subband (710) is configured for the UE in two DL symbols (552 and 553). The end of the RO (730) should meet the condition of at least T symbols before the start of the first SSB block symbol (720).

[0090] Another condition is that the PRACH opportunity precedes the SS / PBCH block in the PRACH slot and starts at least T symbols after the last pure downlink symbol, where the value of T is associated with the SCS corresponding to the RO resource. T can be a non-negative integer, and the minimum value of T can be 0.

[0091] For another non-limiting rule (Rule 2), when the UL subband is configured (i.e., for the UE, there is a UL subband, or the UE has UL subband capability), and when the UE is provided with a specific information element (e.g., tdd-UL-DL-ConfigurationCommon), a PRACH opportunity in a DL symbol within a PRACH slot is valid when it is in a UL subband within a DL symbol.

[0092] For another non-limiting rule (Rule 3), when the UL subband is configured (i.e., for the UE, the UL subband exists, or the UE has UL subband capability), and when the UE is provided with a specific information element (e.g., tdd-UL-DL-ConfigurationCommon), the PRACH opportunity in the UL subband within the PRACH slot is valid when it does not precede the SS / PBCH block in the PRACH slot and starts at least T symbols after the last pure downlink symbol and at least T symbols after the last SS / PBCH block symbol. The value of T is associated with the SCS corresponding to the RO resource. T can be a non-negative integer, and the minimum value of T can be 0.

[0093] For another non-limiting rule (Rule 4), when the UL subband is configured (i.e., for the UE, the UL subband exists, or the UE has UL subband capability), and when the UE is provided with a specific information element (e.g., tdd-UL-DL-ConfigurationCommon), the PRACH opportunity in the UL subband within the PRACH slot is valid when it does not precede the SS / PBCH block in the PRACH slot and starts at least T symbols after the last DL symbol of the downlink transmission for the UE and at least T symbols after the last SS / PBCH block symbol. The value of T is associated with the SCS corresponding to the RO resource. T can be a non-negative integer, and the minimum value of T can be 0.

[0094] As a non-comprehensive and / or non-conclusive overview, in various embodiments, a UL subband is configured (i.e., for the UE, a UL subband exists, or the UE has UL subband capability), and if the UE is provided with a specific information element (e.g., tdd-UL-DL-ConfigurationCommon), then a PRACH opportunity in a DL symbol within a PRACH slot is valid if it satisfies one or more of the following conditions.

[0095] 1) RO is in the UL subband.

[0096] 2) The interval between the start symbol of the RO and the last pure DL symbol in the slot is at least T.

[0097] 3) The end symbol of RO is before the start symbol of SSB, and the interval between the end symbol of RO and the start symbol of SSB is at least T.

[0098] 4) The start symbol of RO is after the end symbol of SSB, and the interval between the start symbol of RO and the end symbol of SSB is at least T.

[0099] 5) For a UE, the interval between the start symbol of the RO and the last DL symbol for downlink transmission of the UE in the time slot is at least T.

[0100] In some implementations, the value of T is associated with the SCS corresponding to the RO resource. T may be a non-negative integer, and the minimum value of T may be 0.

[0101] In various embodiments / implementations of the present disclosure, the above rules are executed separately and / or respectively by the base station and the UE.

[0102] For the RO, when the above conditions described in various embodiments / implementations are not met, the UE considers the RO invalid; and / or the base station considers the RO invalid.

[0103] The present disclosure describes another method for determining the validity of a RO based on various rules. For a UE with UL subband capability, when the UE is not configured with a UL subband, but is provided with a specific information element (e.g., tdd-UL-DL-ConfigurationCommon), and when the UE is instructed to perform PRACH transmission at the RO, but the RO contains DL symbols (or the spacing between the RO and the SSB does not meet the spacing size required for a valid RO), the UE considers the RO to be valid and performs PRACH transmission at the RO.

[0104] In some embodiments, since the UE is not configured with a UL subband, the UE cannot identify the UL subband. The base station knows that the UL subband exists and there is a RO in the UL subband, so when the base station schedules or triggers a PRACH transmission in the RO, the UE considers the RO to be valid and performs a PRACH transmission in the RO. In some embodiments, this method can be used for PRACH transmission triggered by the base station. In some embodiments, the base station needs to ensure the validity of the RO for UEs with UL subband capabilities, and the UE does not need to determine the validity of the RO. The UE only needs to perform PRACH transmission according to the scheduling of the base station.

[0105] The present disclosure describes another method for determining the validity of a RO based on various rules, where the RO may span UL subbands and non-UL subbands in the time domain.

[0106] In some embodiments, reference Fig. 8A, DL symbol (801), DL symbol (802), DL symbol (803), flexible symbol (804) and UL symbol (805) are configured; and UL subband (810) includes one or more DL symbols (e.g., 801, 802 and 803). RO (815) can span UL subband (810) and one or more F symbols (04). In some embodiments, RO in F symbol can be a configured UL bandwidth part (BWP). SSB (880) can be configured.

[0107] In some embodiments, reference Figure 8B , a UL subband (820) may include one or more DL symbols (e.g., 801, 802, and 803) and one or more F symbols (804). A RO (825) may span a UL subband (820) and one or more UL symbols (e.g., 805). In some embodiments, a RO in a UL symbol is a configured UL BWP.

[0108] In some embodiments, reference Figure 8C , DL symbol (841), DL symbol (842), DL symbol (843), DL symbol (844) and UL symbol (845) are configured; and UL subband (830) can include one or more DL symbols (e.g., 841, 842, 843 and 844). RO (835) spans UL subband (830) and one or more UL symbols (e.g., 845). In some embodiments, the RO in the UL symbol is the configured UL BWP.

[0109] In such FIG. 8A to FIG. 8C In the above three non-limiting examples shown, a RO spans the UL subband and symbols not allocated to the UL subband in the time domain. In this case, for UEs with UL subband capabilities, the RO validity also needs to be determined. For this type of RO validity, the following conditions are used to determine. In some embodiments, the final validity of the RO may need to be determined in conjunction with any one or any combination of the above methods.

[0110] In some embodiments, the base station and the UE may separately or collaboratively determine that a RO is considered a valid RO when it spans a UL subband and a UL (or F) symbol in the time domain, wherein the UL subband is not configured in a UL (or F) symbol.

[0111] In some embodiments, the base station and the UE may separately or collaboratively determine that a RO is considered an invalid RO when it spans a UL subband and a UL (or F) symbol in the time domain, where the UL subband is not configured in the UL (or F) symbol.

[0112] In some embodiments, the base station and the UE may separately or collaboratively determine that when a RO spans a UL subband and an F symbol in the time domain, the RO is a valid RO when the F symbol is not dynamically indicated for DL ​​transmission, wherein the UL subband is not configured in the F symbol.

[0113] In some embodiments, the base station and the UE may separately or collaboratively determine that when a RO spans a UL subband and an F symbol in the time domain, the RO may be an invalid RO when the F symbol is dynamically indicated for DL ​​transmission, where the UL subband is not configured in the F symbol.

[0114] In some embodiments, the base station and the UE may separately or collaboratively determine that when the RO spans the UL subband and the UL (or F) symbol in the time domain, the RO is a valid RO when the timing advance (TA) of the UL (or F) symbol or the UL BWP (for example, the UL BWP is configured in the UL / F symbol) is aligned with the TA of the UL subband. Specifically, the TA alignment includes at least one of the following: the TA offset between the symbol of the UL subband and the UL (or F) symbol is predefined as 0 or configured to 0 by the base station; or the symbol of the UL subband and the UL (or F) symbol are continuous in the time domain.

[0115] In some embodiments, the base station and the UE may separately or collaboratively determine that when the RO spans the UL subband and the UL (or F) symbol in the time domain, when the timing advance (TA) of the UL (or F) symbol or the UL BWP (for example, the UL BWP is configured in the UL / F symbol) is not aligned with the TA of the UL subband, the RO may be an invalid RO. Specifically, the TA alignment includes at least one of the following: the TA offset between the symbol of the UL subband and the UL (or F) symbol is predefined as 0 or configured to 0 by the base station; or the symbol of the UL subband and the UL (or F) symbol are continuous in the time domain.

[0116] In some implementations, as a flexible method, when the RO spans across a UL subband and a UL (or F) symbol in the time domain, the base station notifies via signaling that the RO is valid.

[0117] In some implementations, as a flexible method, when the RO spans over a UL subband and a UL (or F) symbol in the time domain, the base station notifies the RO invalidity via signaling.

[0118] In the above-mentioned embodiments / implementations, the conditions for determining the validity of RO resources may also be applied to PUSCH and PUCCH in the UL subband. For example, the above-mentioned methods / rules / conditions are applicable to PUSCH or PUCCH. When the UE is scheduled by the base station for PUSCH transmission or PUCCH transmission in the UL subband, the UE may not expect the PUSCH or PUCCH not to satisfy the above-mentioned conditions related to the interval; in other words, the UE expects the PUSCH or PUCCH to satisfy the above-mentioned interval conditions. As a non-limiting example, for the UE, the interval between the PUSCH or PUCCH and the SSB (or the last pure downlink symbol in the time slot, or the last DL symbol in the time slot scheduled for downlink data for the UE) may satisfy the interval T within a time slot. Therefore, by replacing RO with PUSCH or PUCCH, the above-mentioned various embodiments / implementations are generally applicable.

[0119] In some embodiments, for a valid RO determined in the various embodiments / implementations described above, when random access is allowed to be performed in the RO, PRACH transmission is based on parameters related to the RO configuration, for example, the SCS and PRACH structure parameters of the RO configuration, which may not be based on the parameters configured for the UL subband.

[0120] In some implementations, for the effective RO determined in the various embodiments / implementations described above, the SCS of the RO may remain the same as the SCS of the UL subband. The purpose is that since the RO is located in some DL symbols, the UL subband may have more interference when the SCS of the RO is different from the SCS of the DL transmission in these DL symbols.

[0121] Example 2

[0122] This disclosure describes how a UE and / or a base station schedules UL transmissions in a UL subband. In some embodiments, a RO within a UL subband is used to identify UEs with UL subband capabilities. The UL subband is configured in a DL symbol.

[0123] As a non-limiting example, the UE is configured with a UL subband and the RO is configured in the UL subband in a DL symbol.

[0124] Regarding base station side operation, when a PRACH transmission is received by a RO in a UL subband, the base station considers the UE corresponding to the PRACH transmission to be a UE with UL subband capabilities. When the UE accesses the network, the base station can schedule the UE to perform UL transmission (PUSCH or PUCCH) in the UL subband.

[0125] Regarding UE side operation, when PRACH transmission is transmitted by UE in RO within UL subband, the base station considers the UE corresponding to the PRACH transmission to be a UE with UL subband capability. When the UE accesses the network, the base station can schedule the UE to perform UL transmission (PUSCH or PUCCH) in the UL subband.

[0126] In some implementations, PRACH transmission may be actively initiated by the UE, or may be scheduled / triggered by a base station, such as triggered by a PDCCH command.

[0127] Regarding base station side operation, when a PRACH transmission is received by a RO of the base station within a UL subband, a PUSCH (e.g., msg3) associated with the PRACH transmission (or scheduled by a UL grant scrambled by a RA-RNTI (or RAR UL grant)) may be scheduled in that UL subband and / or UL symbol.

[0128] In some implementations, the UL symbol may be replaced by a UL BWP, since UL transmission is performed in a UL BWP within the UL symbol. The same process is supported below.

[0129] In some implementations, the UL symbols may be replaced by flexible (F) symbols. The same process is supported below.

[0130] Regarding UE side operation, when PRACH transmission is transmitted by the UE in the RO within the UL subband, the PUSCH (e.g., msg3) associated with the PRACH transmission (or scheduled by the RA-RNTI scrambled UL grant (or RAR UL grant)) can be scheduled in the UL subband and / or UL symbol.

[0131] In some implementations, PRACH transmission may be actively initiated by the UE, or may be scheduled / triggered by a base station, such as triggered by a PDCCH command.

[0132] Regarding base station side operation, when a PRACH transmission is received by the base station from a RO in a UL subband, a HARQ-ACK PUCCH associated with the PRACH transmission and corresponding to a PDSCH reception with a UE contention resolution indicator may be scheduled in the UL subband and / or UL symbol.

[0133] Regarding UE side operation, when PRACH transmission is transmitted by the UE from the RO in the UL subband, a HARQ-ACK PUCCH associated with the PRACH transmission and corresponding to the PDSCH reception with the UE contention resolution indicator can be scheduled in the UL subband and / or UL symbol.

[0134] In some implementations, PRACH transmission may be actively initiated by the UE, or may be scheduled / triggered by a base station, such as triggered by a PDCCH command.

[0135] Regarding base station side operation, a UE with UL subband capability accessing the network reports the capability to the base station. After the base station obtains that the UE has UL subband capability, the base station can schedule or trigger the UE to perform PRACH transmission from the RO in the UL subband in the DL symbol. When the base station receives a PRACH transmission scheduled or triggered by the base station from the RO in the UL symbol (including a PRACH transmission triggered by a PDCCH command), the PUSCH or PUCCH associated with the PRACH transmission can be scheduled in the UL subband and / or UL symbol.

[0136] Regarding UE side operation, for UEs with UL subband capability accessing the network, the UE reports the capability to the base station. The UE may be scheduled or triggered to perform PRACH transmission from the RO in the UL subband of the DL symbol. When the UE transmits a PRACH transmission scheduled or triggered by the base station (including a PRACH transmission triggered by a PDCCH command) from the RO in the UL symbol, the PUSCH or PUCCH associated with the PRACH transmission may be scheduled in the UL subband and / or UL symbol.

[0137] Regarding base station side operation, when the base station schedules / triggers a RO for PRACH transmission in a UL subband (even if the RO does not meet the above interval condition, ie, the RO is an invalid RO), the base station expects the UE to perform PRACH transmission in the RO.

[0138] Regarding UE side operation, when the UE is scheduled / triggered to perform PRACH transmission on the RO in the UL subband (but the RO does not meet the above-mentioned interval condition, that is, the RO is an invalid RO), the UE directly performs PRACH transmission on the RO. That is, if the base station schedules / triggers the UE to perform PRACH transmission from the RO in the UL subband, the UE directly performs PRACH transmission from the RO without judging the validity of the RO.

[0139] As another non-limiting example, the UL subband is not configured for the UE, but the base station knows that the UL subband exists. The UE will not actively initiate PRACH transmission in the RO in the UL subband, but the base station can schedule / trigger the UE to perform PRACH transmission in the RO in the UL subband when the UE reports that it has UL subband capability.

[0140] Regarding base station side operation, the base station may schedule or trigger a UE with UL subband capability to perform PRACH transmission from RO in DL symbols. The base station allows PUSCH or HARQ-ACK PUCCH (corresponding to PDSCH reception with UE contention resolution identifier) ​​associated with PRACH transmission (or scheduled by RA-RNTI scrambled UL grant (or RAR UL grant)) to be scheduled as transmission from DL symbols and / or in UL symbols.

[0141] Regarding UE operation, when the UE is scheduled or triggered to perform PRACH transmission from a RO in a DL symbol, the UE performs PRACH transmission from the RO (without judging the validity of the RO). In addition, when a PUSCH or PUCCH associated with a PRACH transmission is scheduled to be transmitted from a DL symbol, the UE performs PUSCH or PUCCH transmission according to the scheduling information.

[0142] Example 3

[0143] This disclosure describes how a UE and / or a base station configures a RO in a UL subband. In some embodiments, the RO is independently configured as a UL subband by the UE and the base station.

[0144] In various embodiments of the present disclosure, the RO may include time domain resources and frequency domain resources, and the frequency domain resource configuration of the RO may use one or more parameters, including at least one of the following parameters.

[0145] A parameter (parameter 1) can be introduced to describe the offset of the starting RB of the PRACH opportunity relative to the starting RB of the UL subband, thereby determining the starting RB of the first random access resource in the frequency domain within the RO. Here, the PRACH opportunity indicates that the first random access resource in the RO is in the frequency domain.

[0146] Another parameter (parameter 2) can be introduced to describe the number of random access resources in the RO in the frequency domain. The size of the random access resources in the frequency domain can be determined based on the random access sequence length and SCS of the RO. Multiple random access resources in the RO can be continuous in the frequency domain.

[0147] Example 4

[0148] The present disclosure describes how UE and / or base station configures frequency domain resources of RO in UL subband, especially the relationship between UL subband and initial UL BWP. UL subband may include at least one of the following types: DL symbol, UL symbol and / or F symbol.

[0149] In some embodiments, in the frequency domain, the size and position of the UL subband may be configured to exceed the size and position of the initial UL BWP. When the UE wants to perform PRACH transmission, PUSCH transmission, or PUCCH transmission from the UL subband, within the UL subband, the same frequency domain resources as the initial UL BWP may be used (or the entire frequency domain resources of the UL subband may be used). The base station and the UE may agree or determine that in the frequency domain resources outside the initial UL BWP, the UE is not allowed to perform PRACH transmission for initial random access, but may perform PRACH transmission for other purposes.

[0150] In some embodiments, in the frequency domain, the size and position of the UL subband may be configured not to exceed the size and position of the initial ULBWP. When the UE wants to perform PRACH transmission, PUSCH transmission, or PUCCH transmission from the UL subband, the entire frequency domain resources of the UL subband may be used for PRACH transmission, PUSCH transmission, or PUCCH transmission.

[0151] In some embodiments, the base station and the UE may agree or determine separately or collaboratively that, in the frequency domain, when the frequency domain resources of the UL subband are not configured, the frequency domain resources of the UL subband may be the same as the frequency domain resources of the initial UL BWP.

[0152] In some embodiments, the base station and the UE may determine by consensus or separately or collaboratively that, in the frequency domain, when the frequency domain resources of the UL subband are not configured and there is no activated UL BWP, the frequency domain resources of the UL subband may be the same as the frequency domain resources of the initial UL BWP.

[0153] In some embodiments, the base station and the UE may determine by consensus or separately or collaboratively that, in the frequency domain, when the frequency domain resources of the UL subband are not configured and there is an activated UL BWP, the frequency domain resources in the UL subband may be the same as the frequency domain resources of the activated UL BWP.

[0154] Various embodiments / implementations described in the present disclosure may implement the related configuration of the initial UL BWP and the UL subband, making the system more robust.

[0155] The present disclosure describes methods, apparatus, and computer-readable media for wireless communications. The present disclosure addresses the problem of configuring and transmitting physical random access channel (PRACH) transmissions, particularly at random access channel opportunities (ROs) in UL subbands. The methods, devices, and computer-readable media described in the present disclosure can improve the performance of wireless communications by configuring and transmitting ROs in UL subbands, thereby improving efficiency and overall performance. The methods, devices, and computer-readable media described in the present disclosure can improve the overall efficiency of wireless communication systems.

[0156] References to features, advantages, or similar language in this specification do not imply that all features and advantages that can be implemented by the present solution should or are included in any single embodiment thereof. Rather, language referring to features and advantages is understood to mean that a specific feature, advantage, or characteristic described in conjunction with an embodiment is included in at least one embodiment of the present solution. Thus, discussion of features and advantages and similar language throughout the specification may, but does not necessarily, refer to the same embodiment.

[0157] Furthermore, in one or more embodiments, the features, advantages, and characteristics of the present solution may be combined in any suitable manner. Based on the description herein, one of ordinary skill in the relevant art will recognize that the present solution may be practiced without one or more specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be identified in a particular embodiment that may not be present in all embodiments of the present solution.

Claims

1. A method for wireless communication, the method comprising: Physical Random Access Channel (PRACH) transmissions are performed by the user equipment (UE) to the base station in the following manner: The UE obtains a random access channel opportunity (RO) configuration of the RO; determining, by the UE based on a set of predefined rules, whether the RO is valid for an uplink (UL) subband, wherein the UL subband includes at least one downlink (DL) symbol or at least one flexible symbol, and the UL subband occupies a portion of frequency domain resources of the at least one DL symbol or the at least one flexible symbol; and In response to determining that the RO is valid, transmitting, by the UE, a PRACH transmission at the RO to the base station.

2. A method for wireless communication, the method comprising: A physical random access channel (PRACH) transmission is received by a base station from a user equipment (UE) in the following manner: The base station configures a random access channel opportunity (RO) configuration for the UE; Determining, by the base station based on a set of predefined rules, whether the RO is valid for a UL subband, wherein the UL subband includes at least one downlink (DL) symbol or at least one flexible symbol, and the UL subband occupies a portion of frequency domain resources of the at least one DL symbol or the at least one flexible symbol; as well as In response to determining that the RO is valid, receiving, by the base station, a PRACH transmission from the UE at the RO.

3. The method according to any one of claims 1 to 2, wherein: The set of predefined rules includes that the UL subband is configured for the UE and the UE is provided with a specific information element (IE); and The set of predefined rules also includes at least one of the following: The RO is in the UL subband; The RO starts at least T symbols after the last pure downlink symbol, where T is an integer; The RO is before a specific symbol in the PRACH time slot, and the RO ends at least T symbols before the first specific symbol; The RO is after a specific symbol in a PRACH time slot, and the RO starts at least T symbols after the last specific symbol; or The RO starts at least T symbols after a last downlink symbol of a downlink transmission for the UE.

4. The method according to claim 3, wherein: In response to the set of predefined rules being satisfied, the UE determines that the RO is valid.

5. The method according to claim 3, wherein: In response to the set of predefined rules being satisfied, the base station determines that the RO is valid.

6. The method according to claim 3, wherein: The specific IE includes an IE of tdd-UL-DL-ConfigurationCommon included in radio resource control (RRC) signaling.

7. The method according to claim 3, wherein: The RO includes at least one of the following in the UL subband: All time domain resources of the RO are within the time domain resources of the UL sub-band, and all random access resources in the frequency domain of the RO are within the frequency domain resources of the UL sub-band; All time domain resources of the RO are within the time domain resources of the UL sub-band, and a portion of random access resources in the frequency domain of the RO are within the frequency domain resources of the UL sub-band; A portion of the time domain resources of the RO is within the time domain resources of the UL sub-band, and all random access resources in the frequency domain of the RO are within the frequency domain resources of the UL sub-band; or A portion of the time domain resources of the RO is within the time domain resources of the UL sub-band, and a portion of the random access resources in the frequency domain of the RO is within the frequency domain resources of the UL sub-band.

8. The method according to claim 3, wherein: The specific symbol includes an end or start synchronization signal (SS) / physical broadcast channel (PBCH) block symbol.

9. The method according to claim 3, wherein: The pure downlink symbol includes a downlink symbol not configured with the UL subband.

10. The method according to claim 3, wherein: The value of T is associated with a subcarrier spacing (SCS) corresponding to the RO; and The minimum value of T is 0.

11. The method according to any one of claims 1 to 2, wherein: The set of predefined rules includes the UE being provided with a specific information element (IE), and the UE being instructed to perform the PRACH transmission at the RO; and The set of predefined rules also includes at least one of the following: The RO includes one or more downlink symbols, or The interval between the RO and the specific symbol is smaller than the required interval threshold.

12. The method according to any one of claims 3 to 11, wherein: The set of predefined rules also includes at least one of the following: The RO spans the UL subband and uplink symbols in the time domain, The RO spans the UL subband and flexible symbols in the time domain, The flexible symbols are not dynamically indicated for downlink transmission, The timing advance (TA) of the uplink symbol is aligned with the TA of the UL subband, A timing advance (TA) of the flexible symbol is aligned with a TA of the UL subband, The timing advance offset between the symbol of the UL subband and the UL symbol is predefined as 0 or configured by the base station to be 0, The timing advance offset between the symbol of the UL subband and the flexible symbol is predefined as 0 or configured by the base station to be 0, The symbol of the UL subband is continuous with the UL symbol in the time domain, The symbols of the UL subband and the flexible symbols are continuous in the time domain, or The base station notifies the UE that the RO is valid.

13. The method according to any one of claims 1 to 2, wherein: The PRACH transmission is transmitted based on parameters corresponding to the RO.

14. The method of claim 1, wherein: The UE is configured with a UL subband; The RO is configured in the UL subband in at least one downlink symbol; and In response to the RO transmission of the PRACH transmission by the UE in the UL subband: The UE is determined by the base station as a UE with UL subband capability, and at least one of the following: In response to the UE accessing the network, uplink transmission is scheduled in the UL subband, A physical uplink shared channel (PUSCH) associated with the PRACH transmission is scheduled in the UL subband, A physical uplink control channel (PUCCH) associated with the PRACH transmission is scheduled in the UL subband, A hybrid automatic repeat request acknowledgement (HARQ-ACK) physical uplink control channel (PUCCH) associated with the PRACH transmission and corresponding to a physical downlink shared channel (PDSCH) reception with a UE contention resolution indicator is scheduled in the UL subband, or In response to a second PRACH transmission from a second RO being scheduled in the UL subband, the UE directly performs the second PRACH transmission without determining validity of the second RO.

15. The method of claim 2, wherein: The UE is configured with a UL subband; The RO is configured in the UL subband in at least one downlink symbol; and In response to receiving, by the base station, the PRACH transmission at the RO within the UL subband: The base station determines the UE as a UE with UL subband capability, and at least one of the following: In response to receiving access of the UE to the network, the base station configures uplink transmission in the UL subband, The base station configures a physical uplink shared channel (PUSCH) associated with the PRACH transmission in the UL subband, The base station configures a physical uplink control channel (PUCCH) associated with the PRACH transmission in the UL subband, The base station configures a hybrid automatic repeat request acknowledgement (HARQ-ACK) physical uplink control channel (PUCCH) associated with the PRACH transmission and corresponding to a physical downlink shared channel (PDSCH) reception with a UE contention resolution indicator in the UL subband, or The base station configures a second PRACH transmission by the UE from the second RO in the UL subband, so that the UE directly performs the second PRACH transmission without determining the validity of the second RO.

16. The method of claim 1, wherein: The UE is not configured with the UL subband, and the base station is aware of the existence of the UL subband; and In response to the UE being scheduled to perform a second PRACH transmission from a second RO in a downlink symbol, the UE performs the second PRACH transmission from the second RO without determining the validity of the second RO, or In response to the UE being scheduled with an uplink transmission associated with the PRACH transmission from the downlink symbol, the UE performs the uplink transmission.

17. The method of claim 2, wherein: The base station is aware of the existence of the UL subband that is not configured for the UE; and The base station schedules a second PRACH transmission from a second RO in a downlink symbol so that the UE performs the second PRACH transmission from the second RO without determining the validity of the second RO, or The base station schedules uplink transmission associated with the PRACH transmission from the downlink symbol so that the UE performs the uplink transmission.

18. A method according to any one of claims 14 to 17, wherein: The uplink transmission includes at least one of: a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH).

19. The method according to any one of claims 1 to 2, wherein: The RO configuration includes a first parameter and a second parameter in the frequency domain, wherein: The first parameter indicates an offset of a starting resource block (RB) of the RO relative to a starting RB of a UL subband, and The second parameter indicates the number of RBs in the RO.

20. The method according to any one of claims 1 to 2, wherein: The UL subband is configured to overlap with and exceed an initial UL bandwidth part (BWP) in the frequency domain; The PRACH transmission is performed in frequency domain resources from the UL subband overlapping with the initial UL BWP; and The PRACH transmission for purposes other than initial random access is performed in frequency domain resources from the UL subband exceeding the initial UL BWP.

21. The method according to any one of claims 1 to 2, wherein: The UL subband is configured to overlap with an initial UL BWP in the frequency domain and to be within the initial UL BWP; and The PRACH transmission is performed in any frequency domain resource from the UL subband within the initial UL BWP.

22. The method according to any one of claims 1 to 2, wherein: In response to the frequency domain resources of the UL subband being not configured, the frequency domain resources of the UL subband are the same as the frequency domain resources of the initial UL BWP.

23. The method according to any one of claims 1 to 2, wherein: In response to the frequency domain resources of the UL subband not being configured and there being no activated UL BWP, the frequency domain resources of the UL subband are the same as the frequency domain resources of the initial UL BWP.

24. The method according to any one of claims 1 to 2, wherein: In response to the frequency domain resources of the UL subband being not configured and there being an activated UL BWP, the frequency domain resources of the UL subband are the same as the frequency domain resources of the activated UL BWP.

25. A wireless communication device comprising a processor and a memory, wherein: The processor is configured to read code from the memory and implement the method according to any one of claims 1 to 24.

26. A computer program product comprising computer readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement the method according to any one of claims 1 to 24.

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