Wireless communication method, apparatus and device

Abstract

The present application belongs to the field of communications. Disclosed are a wireless communication method, an apparatus and a device. The wireless communication method in the embodiments of the present application comprises: a terminal acquires first information, the first information comprising at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers and at least two downlink carriers; the terminal determines a target uplink carrier on the basis of the first information, and the terminal sends first uplink random access information on the basis of the target uplink carrier; and / or, the terminal determines a target downlink carrier on the basis of the first information, and the terminal receives first downlink random access information on the basis of the target downlink carrier.

Description

Wireless communication methods, apparatus and equipment

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411561166.0, filed on November 4, 2024, entitled "Wireless Communication Method, Apparatus and Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of communication technology, specifically relating to a wireless communication method, apparatus, and device. Background Technology

[0004] In related technologies, a multi-carrier-based random access procedure has been introduced. The multi-carrier-based random access procedure can be divided into scenarios with defined anchor carriers and scenarios without defined anchor carriers. The anchor carrier can also be referred to as the anchor cell.

[0005] In scenarios where an anchor carrier is defined, during multi-carrier-based random access, the terminal can initiate random access only from the anchor cell or only from a non-anchor cell. In scenarios where the terminal can only access from the anchor cell, a large number of users accessing the network can lead to high load on the anchor cell, impacting access performance. In scenarios where the terminal initiates random access from a non-anchor cell, the terminal receives system messages and related configurations from other non-anchor cells at the anchor cell, selects a non-anchor cell according to certain rules, and completes message transmission and reception during the random access process within the selected non-anchor cell. Supplementary uplinks (SULs) can also be supported for both anchor cells and non-anchor cells; uplink messages during the random access process can be sent via a normal uplink or a supplementary uplink. Overall, once the terminal selects a cell or carrier, the random access process is completed on the selected uplink and downlink carriers, which is relatively inflexible, as it does not support adjusting the carriers during the random access process due to changes in load, interference, etc.

[0006] In multi-carrier scenarios without a configured anchor carrier, it's equivalent to having multiple independent single-carrier-based random access methods. The terminal selects a carrier based on certain rules, and the random access process is the same as single-carrier-based random access. On one hand, compared to providing system messages for multiple carriers based on the anchor carrier, this method involves the network-side device sending synchronization signals and system messages on each downlink carrier supporting random access, increasing the carrier's active time and resulting in higher network power consumption. On the other hand, once the terminal selects a downlink carrier for random access, the random access process is completed on the selected uplink and downlink carriers. This method is relatively inflexible and does not support adjusting the carriers during the random access process due to changes in load, interference, etc.

[0007] Therefore, how to improve the performance of multi-carrier-based random access is a problem that needs to be solved. Summary of the Invention

[0008] This application provides a wireless communication method, apparatus, and device that can solve the problem of insufficient random access performance based on multi-carrier communication.

[0009] Firstly, a wireless communication method is provided, comprising:

[0010] The terminal acquires first information; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0011] The terminal determines a target uplink carrier based on the first information, and the terminal sends first uplink random access information based on the target uplink carrier; and / or,

[0012] The terminal determines the target downlink carrier based on the first information, and the terminal receives the first downlink random access information based on the target downlink carrier.

[0013] Secondly, a wireless communication method is provided, including:

[0014] The network-side device sends first information to the terminal; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0015] The network-side device receives first uplink random access information from the terminal, wherein the first uplink random access information is transmitted based on a target uplink carrier, and the target uplink carrier is determined based on the first information; and / or,

[0016] The network-side device sends first downlink random access information to the terminal, wherein the first downlink random access information is sent based on a target downlink carrier, and the target downlink carrier is determined based on the first information.

[0017] Thirdly, a wireless communication device is provided, comprising: a processing module, a transmitting module, and a receiving module;

[0018] The processing module is used to acquire first information; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0019] The processing module is further configured to determine a target uplink carrier based on the first information, and the transmitting module is configured to transmit first uplink random access information based on the target uplink carrier; and / or,

[0020] The processing module is further configured to determine a target downlink carrier based on the first information, and the receiving module is configured to receive first downlink random access information based on the target downlink carrier.

[0021] Fourthly, a wireless communication device is provided, comprising: a transmitting module and a receiving module;

[0022] The sending module is used to send first information to the terminal; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0023] The receiving module is used to receive first uplink random access information from the terminal, wherein the first uplink random access information is transmitted based on a target uplink carrier, and the target uplink carrier is determined based on the first information;

[0024] And / or,

[0025] The sending module is further configured to send first downlink random access information to the terminal, wherein the first downlink random access information is sent based on a target downlink carrier, and the target downlink carrier is determined based on the first information.

[0026] Fifthly, a wireless communication device is provided, the device being configured to perform the steps of the method described in the first aspect, or to implement the steps of the method described in the second aspect.

[0027] In a sixth aspect, a terminal is provided, the terminal including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the first aspect.

[0028] Seventhly, a terminal is provided, including a processor and a communication interface;

[0029] The processor is used to acquire first information; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0030] The processor is further configured to determine a target uplink carrier based on the first information, and the communication interface is configured to send first uplink random access information based on the target uplink carrier; and / or,

[0031] The processor is further configured to determine a target downlink carrier based on the first information, and the communication interface is configured to receive first downlink random access information based on the target downlink carrier.

[0032] Eighthly, a network-side device is provided, the network-side device including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the second aspect.

[0033] Ninthly, a network-side device is provided, including a processor and a communication interface;

[0034] The communication interface is used to send first information to the terminal; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0035] The communication interface is also used to receive first uplink random access information from the terminal, wherein the first uplink random access information is transmitted based on a target uplink carrier, and the target uplink carrier is determined based on the first information;

[0036] And / or,

[0037] The communication interface is also used to send first downlink random access information to the terminal, wherein the first downlink random access information is sent based on a target downlink carrier, and the target downlink carrier is determined based on the first information.

[0038] In a tenth aspect, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect, or implement the steps of the method described in the second aspect.

[0039] Eleventhly, a wireless communication system is provided, comprising: a terminal and a network-side device, wherein the terminal can be used to perform the steps of the method as described in the first aspect, and the network-side device can be used to perform the steps of the method as described in the second aspect.

[0040] In a twelfth aspect, a chip is provided, the chip including a processor and a communication interface coupled to the processor, the processor being configured to run programs or instructions to implement the method as described in the first aspect, or to implement the method as described in the second aspect.

[0041] In a thirteenth aspect, a computer program / program product is provided, which is stored in a storage medium and is executed by at least one processor to implement the steps of the wireless communication method as described in the first aspect, or to implement the steps of the wireless communication method as described in the second aspect.

[0042] In this embodiment, the terminal determines a target uplink carrier based on first information, and the terminal sends first uplink random access information based on the target uplink carrier; and / or, the terminal determines a target downlink carrier based on the first information, and the terminal receives first downlink random access information based on the target downlink carrier. Specifically, for the multi-carrier random access process, the target uplink carrier can be flexibly adjusted within an uplink carrier group or at least two uplink carriers, and / or the target downlink carrier can be flexibly adjusted within a downlink carrier group or at least two downlink carriers. While ensuring uplink and downlink transmission coverage, this helps to better achieve load balancing, reduce inter-carrier interference, and improve the performance of multi-carrier random access. Attached Figure Description

[0043] Figure 1 is a schematic diagram of a communication system architecture provided in an embodiment of this application.

[0044] Figure 2 is a schematic flowchart of a wireless communication method provided according to an embodiment of this application.

[0045] Figure 3 is a schematic diagram of an uplink carrier group and a downlink carrier group provided according to an embodiment of this application.

[0046] Figure 4 is a schematic diagram of a downlink carrier beam according to an embodiment of this application.

[0047] Figure 5 is a schematic diagram of a competition-based four-step random access process provided according to an embodiment of this application.

[0048] Figure 6 is a schematic diagram of a non-competitive four-step random access process provided according to an embodiment of this application.

[0049] Figure 7 is a schematic diagram of a competition-based two-step random access process provided according to an embodiment of this application.

[0050] Figure 8 is a schematic diagram of the beam association of a downlink carrier with RO and / or PO according to an embodiment of this application.

[0051] Figure 9 is a schematic diagram of a non-competitive two-step random access process provided according to an embodiment of this application.

[0052] Figure 10 is a schematic diagram of a two-step random access fallback to a four-step random access according to an embodiment of this application.

[0053] Figure 11 is a schematic block diagram of a wireless communication device according to an embodiment of this application.

[0054] Figure 12 is a schematic block diagram of another wireless communication device provided according to an embodiment of this application.

[0055] Figure 13 is a schematic block diagram of a communication device provided according to an embodiment of this application.

[0056] Figure 14 is a schematic diagram of the hardware structure of a terminal according to an embodiment of this application.

[0057] Figure 15 is a schematic block diagram of a network-side device provided according to an embodiment of this application. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0059] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, the first object can be one or more. Furthermore, "or" in this application indicates at least one of the connected objects. For example, the scope of protection for "A or B" covers at least three scenarios: Scenario 1: including A but not B; Scenario 2: including B but not A; Scenario 3: including both A and B. In addition, the terms "A and / or B," "at least one of A and B," and "at least one of A or B" also cover at least the above three scenarios. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0060] The term "instruction" in this application can be either a direct instruction (or explicit instruction) or an indirect instruction (or implicit instruction). A direct instruction can be understood as one in which the sender explicitly informs the receiver of specific information, the operation to be performed, or the requested result, etc., in the instruction sent. An indirect instruction can be understood as one in which the receiver determines the corresponding information based on the instruction sent by the sender, or makes a judgment and determines the operation to be performed or the requested result, etc., based on the judgment result.

[0061] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA), or other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and the term NR is used in most of the following description; however, these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) radio systems. th Generation 6G communication system.

[0062] Figure 1 shows a block diagram of a wireless communication system applicable to an embodiment of this application. Specifically, the wireless communication system includes a terminal 11 and a network-side device 12.

[0063] Terminal 11 can be a mobile phone, tablet computer, laptop computer, notebook computer, personal digital assistant (PDA), handheld computer, netbook, ultra-mobile personal computer (UMPC), mobile internet device (MID), augmented reality (AR), virtual reality (VR) device, robot, wearable device, flight vehicle, vehicle user equipment (VUE), shipborne equipment, pedestrian user equipment (PUE), smart home device (home device with wireless communication function, such as refrigerator, television, washing machine or furniture), game console, personal computer (PC), ATM or self-service machine, etc. Wearable devices include: smartwatches, smart bracelets, smart earphones, smart glasses, smart jewelry (smart bracelets, smart chains, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among these, in-vehicle devices can also be referred to as in-vehicle terminals, in-vehicle controllers, in-vehicle modules, in-vehicle components, in-vehicle chips, or in-vehicle units, etc. It should be noted that the specific type of terminal 11 is not limited in the embodiments of this application.

[0064] Among them, network-side equipment 12 may include access network equipment.

[0065] Alternatively, access network equipment may also be referred to as Radio Access Network (RAN) equipment, radio access network function, or radio access network unit. Access network equipment may include base stations, wireless local area network (WLAN) access points (APs), or wireless Fidelity (WiFi) nodes, etc. The term "base station" can be referred to as Node B (NB), Evolved Node B (eNB), Next Generation Node B (gNB), New Radio Node B (NR Node B), Access Point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), Radio Base Station, Radio Transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B, Transmit / Receive Point (TRP), or any other suitable term in the relevant field, as long as the same technical effect is achieved. The term "base station" is not limited to any specific technical terminology. It should be noted that this application embodiment only uses a base station in an NR system as an example for description and does not limit the specific type of base station.

[0066] To better understand the technical solution of this application, the random access process is explained below.

[0067] In NR systems, specifically 5G NR, during the initial access phase, the User Equipment (UE) needs to obtain the access carrier frequency by searching for a synchronization block (SS / PBCH Block, SSB) to achieve downlink synchronization. Due to the wide spectrum range of NR, to reduce search complexity, the UE performs SSB searches at certain frequency intervals specified in the protocol; this frequency interval is called the Synchronization Raster. The UE detects the Synchronization Signal Reference Signal Received Power (SS-RSRP) at the corresponding frequency point according to the Synchronization Raster and selects any SSB whose SS-RSRP is higher than a threshold (rsrp-ThresholdSSB). By demodulating the Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), and Physical Broadcast Channel (PBCH) signals in the selected SSB, the UE completes cell selection and synchronizes with the base station, after which random access is performed.

[0068] Random access procedures can be divided into contention-based random access procedures and contention-free random access procedures. Based on the process, random access procedures can also be divided into four-step random access procedures (also called Type-1 random access procedures) and two-step random access procedures (also called Type-2 random access procedures).

[0069] Competition-based four-step random access channel (RACH)

[0070] The UE first sends message 1 (Msg1) to the network device, such as a random access preamble. After detecting the preamble, the network device sends message 2 (Msg2) to the UE, such as a Random Access Response (RAR) message. This message contains the identifier of the preamble detected by the network device (also known as the preamble number), such as the RACH preamble ID (RAPID), the Physical Uplink Shared Channel (PUSCH) resource allocated to the UE for sending message 3 (Msg3) (indicated by the uplink grant information), the Temporary Cell Radio Network Temporary Identity (TC-RNTI), and the timing advance. Advance (TA) commands, etc.; after receiving Msg2, if the UE confirms that at least one of the preamble numbers carried in Msg2 matches the preamble number it sent, it sends Msg3 containing contention resolution information according to the uplink resources indicated in the RAR; if the network-side device does not receive Msg3 PUSCH, it can schedule the retransmission of Msg3 PUSCH in the TC-RNTI scrambled Physical Downlink Control Channel (PDCCH). After receiving Msg3, the network-side device will send message 4 (Msg4) containing contention resolution information; upon receiving Msg4, the UE confirms that the resolution information is consistent with the one it sent in Msg3, thus completing the four-step random access.

[0071] In a contention-based random access procedure, different UEs randomly select a preamble for transmission. This means different UEs might select the same preamble to send at the same random access time, a situation known as UE preamble conflict. In this case, different UEs will receive the same RAR (Registered Access Record), and each UE will transmit the Msg3 PUSCH according to the scheduling information in the RAR's UL grant. The network-side device can only resolve one UE's PUSCH (containing contention resolution information) on a single Msg3 PUSCH scheduling resource. The network-side device will then include the contention resolution information received in Msg3 in Msg4. If the contention resolution information received by the UE in Msg4 matches the contention resolution information sent in the Msg3 PUSCH, the UE considers the contention resolution successful. If they do not match, the contention resolution is considered unsuccessful. If the contention resolution is unsuccessful, the UE will reselect a RACH transmission resource and transmit via the Physical Random Access Channel (PRACH) for the next random access attempt.

[0072] Two-step random access procedure (RACH)

[0073] The first step is for the UE to send message A (MsgA) to the network-side device. After receiving MsgA, the network-side device sends message B (MsgB) to the UE. If the UE does not receive MsgB within a certain time, it will increment a counter counting the number of times MsgA has been sent and resend MsgA. If the counter count reaches a certain threshold, the UE will switch from a two-step random access procedure to a four-step random access procedure.

[0074] MsgA comprises a MsgA preamble and a MsgA PUSCH. The preamble is transmitted on the random access opportunity (RO) used for 2-step RACH, and the PUSCH is transmitted on the MsgA PUSCH resources associated with the transmitted MsgA preamble and RO. The MsgA PUSCH resources are a set of PUSCH resources configured relative to each PRACH slot, including time-frequency resources and demodulation reference signal (DMRS) resources.

[0075] In addition, there are random access procedures associated with multiple SSBs. In cell edge areas or areas with limited coverage, the uplink signal coverage performance of the terminal is inferior to the downlink signal coverage; that is, the coverage performance of Msg1 and Msg3 is inferior to that of Msg2 and Msg4. Furthermore, the difference in uplink and downlink coverage performance is even more pronounced in the high-frequency band FR2. To improve uplink signal coverage performance, a method of repeated uplink signal transmission is considered, and a repeated transmission mechanism for Msg3 is introduced to improve Msg3 coverage performance, but this is still limited to a single Msg3 signal.

[0076] To better understand the technical solution of this application, SUL is explained below.

[0077] To address the issue of poor uplink coverage in 5G due to higher frequency bands, NR introduced the Supplemental Uplink (SUL) feature. This feature decouples uplink and downlink, allowing the UE to utilize high-frequency resources for downlink while using SUL resources for uplink when coverage is weak. This ensures high downlink speeds while improving uplink coverage and speed. When using high-frequency resources, downlink base stations can use greater power and more antennas to enhance downlink coverage. However, uplink UEs have limited power and fewer antennas, resulting in significantly less uplink coverage than downlink coverage. Therefore, SUL is needed to enhance uplink coverage using uplink / downlink decoupling technology. Typically, a cell contains both uplink and downlink carriers within the same frequency band / band. However, in the 5G era, the band frequencies used are relatively high, such as millimeter waves. Higher frequencies result in greater signal transmission loss. Since the UE's transmit power is limited, this leads to limited uplink coverage. Therefore, SUL technology was proposed to provide a supplementary uplink (usually in a lower frequency band) to ensure uplink coverage for the UE. The normal uplink of a UE is called the uplink (UL), and the supplementary uplink is called the SUL.

[0078] In uplink and downlink decoupling, the UL carrier and the SUL carrier belong to the same cell. If the two uplink carriers correspond to the same downlink carrier, the UE can dynamically select the transmission link between UL and SUL. However, at any given time, the UE can only select one of them to transmit and cannot transmit uplink on both uplinks at the same time.

[0079] To better understand the technical solution of this application, the anchor carrier is explained below.

[0080] To reduce network power consumption, anchor cells and non-anchor cells were designed. Anchor cells can provide terminals with SSBs, system messages, and paging messages. Non-anchor cells are divided into two types: one is a non-anchor cell without system messages, from which terminals cannot receive system messages; the other is a non-anchor cell without both system messages and SSBs, from which terminals cannot receive either SSBs or system messages.

[0081] Depending on the design, the terminal may only be able to access the anchor cell, or it may be able to directly access the non-anchor cell. In the latter case, the anchor cell needs to provide the necessary information for access on the non-anchor cell.

[0082] Random access procedures can be divided into single-carrier-based random access and multi-carrier-based random access. Multi-carrier-based random access can be further divided into scenarios with defined anchor carriers and scenarios without defined anchor carriers. Anchor carriers can also be referred to as anchor cells.

[0083] In scenarios where an anchor carrier is defined, during multi-carrier-based random access, the terminal can initiate random access only from the anchor cell or only from a non-anchor cell. In scenarios where the terminal can only access from the anchor cell, a large number of users accessing the network can lead to high load on the anchor cell, impacting access performance. In scenarios where the terminal initiates random access from a non-anchor cell, the terminal receives system messages and related configurations from other non-anchor cells at the anchor cell, selects a non-anchor cell according to certain rules, and completes message transmission and reception during the random access process within the selected non-anchor cell. Supplementary uplinks (SULs) can also be supported for both anchor cells and non-anchor cells; uplink messages during the random access process can be sent via a normal uplink or a supplementary uplink. Overall, once the terminal selects a cell or carrier, the random access process is completed on the selected uplink and downlink carriers, which is relatively inflexible, as it does not support adjusting the carriers during the random access process due to changes in load, interference, etc.

[0084] In multi-carrier scenarios without a configured anchor carrier, this is equivalent to having multiple independent single-carrier-based random access methods. The terminal selects a carrier based on certain rules, and the random access process is the same as that of single-carrier-based random access. With this approach, on the one hand, compared to providing system messages for multiple carriers based on the anchor carrier, this method involves the network side sending synchronization signals and system messages on each downlink carrier supporting random access, increasing the carrier's active time and resulting in higher network power consumption. On the other hand, after the terminal selects a downlink carrier for random access, the random access process is completed on the selected uplink and downlink carriers. Again, this method is relatively inflexible and does not support adjusting the carriers during the random access process due to changes in load, interference, etc.

[0085] As mentioned earlier, for the above-mentioned multi-carrier-based random access process, whether it is based on an anchor carrier or not, the existing random access mechanism has certain problems. On the one hand, it is not flexible enough, and can only send and receive relevant messages in the random access process on the selected carrier, and does not support dynamic adjustment of the carrier due to changes in load and interference. On the other hand, for scenarios without configuring supplementary uplink SUL, if both uplink and downlink random access carriers are located at relatively high frequencies, uplink coverage problems will occur.

[0086] In multi-carrier scenarios, how to simultaneously balance flexibility, coverage performance, and transmission performance is an urgent problem to be solved.

[0087] Based on the above-mentioned technical problems, this application proposes a multi-carrier random access scheme. In the multi-carrier random access process, the transmission carriers are flexibly adjusted within the carrier group or at least two carriers. While ensuring uplink and downlink transmission coverage, this helps to achieve better load balancing, reduce inter-carrier interference, and improve performance.

[0088] The wireless communication method provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0089] Figure 2 is a schematic flowchart of a wireless communication method 200 according to an embodiment of this application. As shown in Figure 2, the wireless communication method 200 may include at least some of the following:

[0090] S210, the network-side device sends first information to the terminal; wherein, the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0091] S220, the terminal obtains first information; wherein, the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0092] S230, the terminal determines a target uplink carrier based on the first information, and the terminal sends first uplink random access information based on the target uplink carrier; and / or, the terminal determines a target downlink carrier based on the first information, and the terminal receives first downlink random access information based on the target downlink carrier;

[0093] S240, the network-side device receives the first uplink random access information; and / or, the network-side device sends the first downlink random access information to the terminal.

[0094] It should be understood that Figure 2 illustrates the steps or operations of the wireless communication method 200, but these steps or operations are merely examples, and other operations or variations of the various operations in Figure 2 may also be performed in this application.

[0095] In the embodiments of this application, for the random access process of multiple carriers, the target uplink carrier can be flexibly adjusted within the uplink carrier group or at least two uplink carriers, and / or the target downlink carrier can be flexibly adjusted within the downlink carrier group or at least two downlink carriers. While ensuring uplink and downlink transmission coverage, this helps to achieve better load balancing, reduce interference between carriers, and improve the random access performance of multiple carriers.

[0096] In the embodiments of this application, during the initial access procedure or random access procedure, the downlink carrier or uplink carrier to be transmitted is flexibly selected from at least two uplink available carriers or at least two downlink available carriers. The uplink available carriers and downlink available carriers can be flexibly paired without the need for a constrained correspondence.

[0097] In the embodiments of this application, "first uplink random access information" may also be referred to as or replaced by "first uplink random access message", and "first downlink random access information" may also be referred to as or replaced by "first downlink random access message". This application does not limit this.

[0098] Optionally, in S220, the terminal acquires the first information, including:

[0099] The terminal receives the first information from the network-side device; or,

[0100] The terminal obtains the first information based on the information agreed upon in the protocol; or,

[0101] The terminal obtains the first information based on pre-configured parameters.

[0102] The multiple carriers described in this application embodiment can correspond to different cells. For example, each carrier corresponds to one cell, and multiple carriers correspond to multiple cells; or multiple carriers can correspond to the same cell. In this scenario, the carrier can also be called a frequency domain unit, frequency resource, or other names. For example, a cell contains multiple frequency domain units (such as discontinuous frequency domain units), and the frequency domain units can correspond to the carriers described in this application embodiment.

[0103] The cell described in this application embodiment can be equivalent to a carrier, for example, a cell contains one carrier; or, it can be equivalent to a carrier group, for example, a cell contains a group of carriers, each carrier may have the same or different Physical Cell Identifier (PCI); or, it can be equivalent to multiple frequency domain units, for example, a cell contains multiple frequency domain units that are not contiguous in the frequency domain.

[0104] The SSB described in this application embodiment can also be referred to as any module that includes at least one of a synchronization signal, a broadcast signal, a broadcast channel (PBCH), other system message downlink broadcast channels, and their control channels. The SSB can also be other reference signals, such as Channel State Information Reference Signal (CSI-RS), Tracking Reference Signal (TRS), Positioning Reference Signal (PRS), Phase Tracking Reference Signal (PT-RS), Demodulation Reference Signal (DMRS), etc.

[0105] It should be noted that the SSB index described in the embodiments of this application may also be referred to as or replaced by SSB beam identifier, beam identifier, etc., and the embodiments of this application are not limited thereto.

[0106] The embodiments of this application can be applied to both contention-based random access (CBRA) and contention-free random access (CFRA).

[0107] The embodiments of this application can be applied to four-step random access (4-step RACH), such as contention-based four-step random access (CBRA with 4-step RACH) and non-contention-based four-step random access (CFRA with 4-step RACH).

[0108] The embodiments of this application can also be applied to two-step random access (2-step RACH), such as contention-based two-step random access (CBRA with 2-step RACH) and non-contention-based two-step random access (CFRA with 2-step RACH).

[0109] In some embodiments, a downlink carrier group is associated with one or more uplink carrier groups; and / or, an uplink carrier group is associated with one or more downlink carrier groups.

[0110] In this embodiment, a downlink carrier group is associated with one or more uplink carrier groups, so that the associated one or more uplink carrier groups can be determined based on a downlink carrier group.

[0111] In this embodiment, an uplink carrier group is associated with one or more downlink carrier groups, so that the associated one or more downlink carrier groups can be determined based on an uplink carrier group.

[0112] In some embodiments, the first information includes the association between uplink carrier groups and downlink carrier groups. Thus, the terminal can obtain the association between uplink carrier groups and downlink carrier groups from the network-side device, or the terminal can obtain the association between uplink carrier groups and downlink carrier groups from protocol-defined information.

[0113] In some embodiments, the association between the uplink carrier group and the downlink carrier group can also be agreed upon by the protocol.

[0114] In some embodiments, the association between uplink carrier groups and downlink carrier groups is determined based on at least one of the following: frequency band, frequency band combination, spectrum range, and bandwidth part (BWP).

[0115] In this embodiment, the terminal can determine the association between the uplink carrier group and the downlink carrier group based on at least one of the following: frequency band, frequency band combination, spectrum range, and BWP.

[0116] For example, when defining different bands, the protocol indirectly determines the association between the corresponding uplink carrier group and downlink carrier group.

[0117] In some embodiments, the first uplink random access information includes, but is not limited to, at least one of the following:

[0118] The uplink messages following Msg 1 in a contention-based four-step random access, Msg 3 in a contention-based four-step random access, Msg A in a contention-based two-step random access, and Msg4 in a four-step random access.

[0119] Optionally, the uplink message following Msg4 in the four-step random access can also be called Msg5. Specifically, after receiving Msg4 in the four-step random access, the terminal needs to send Msg5 in the four-step random access to complete the corresponding Radio Resource Control (RRC) connection establishment or recovery process. Msg5 in the four-step random access can be used to carry the RRC setup complete message, the RRC resume complete message, and the RRC reestablishment complete message.

[0120] Optionally, the carrier corresponding to Msg5 in random access includes at least one of the following: the scheduling carrier of Msg5 in random access, the transmission carrier of Msg5 in random access, and the retransmission carrier of Msg5 in random access.

[0121] In some embodiments, the first downlink random access information includes, but is not limited to, at least one of the following:

[0122] Msg 2 in contention-based four-step random access, Msg 4 in contention-based four-step random access, Hybrid Automatic Repeat reQuest (HARQ) feedback for Msg 4 in contention-based four-step random access, Msg B in contention-based two-step random access, HARQ feedback for Msg B in contention-based two-step random access, and 2-step RACH fallback indication.

[0123] In this embodiment, during random access or initial access, the network configures multiple available uplink / downlink carriers for sending / receiving different messages during random access. Considering hardware implementation, signal multiplexing, network load, transmission characteristics, etc., the determination of the uplink / downlink carrier can be divided into two steps:

[0124] Carrier group determination and indication;

[0125] Carrier determination and indication within a carrier group.

[0126] When all carriers belong to the same carrier group, the determination and indication of the carrier group can be an optional step.

[0127] It should be noted that initial access can be called initial access, and random access can be called random access (RA). For 4-step random access or 2-step random access, it can be called 4-step RA or 2-step RA, or 4-step RACH or 2-step RACH.

[0128] In some embodiments, the terminal determines the target uplink carrier based on the first information, including:

[0129] The terminal determines a target uplink carrier group from the at least one uplink carrier group, and the terminal determines the target uplink carrier from the target uplink carrier group; or,

[0130] The terminal determines the target uplink carrier from the at least two uplink carriers.

[0131] In this embodiment, the terminal determines a target uplink carrier group from at least one uplink carrier group, and determines a target uplink carrier from the target uplink carrier group, so that the terminal can send first uplink random access information based on the target uplink carrier. Alternatively, the terminal determines a target uplink carrier from at least two uplink carriers, so that the terminal can send first uplink random access information based on the target uplink carrier.

[0132] In some embodiments, the terminal determines the target downlink carrier based on the first information, including:

[0133] The terminal determines a target downlink carrier group from the at least one downlink carrier group, and the terminal determines the target downlink carrier from the target downlink carrier group; or,

[0134] The terminal determines the target downlink carrier from the at least two downlink carriers.

[0135] In this embodiment, the terminal determines a target downlink carrier group from at least one downlink carrier group, and the terminal determines a target downlink carrier from the target downlink carrier group, so that the terminal can transmit first downlink random access information based on the target downlink carrier. Alternatively, the terminal determines a target downlink carrier from at least two downlink carriers, so that the terminal can transmit first downlink random access information based on the target downlink carrier.

[0136] In the embodiments of this application, considering factors such as the purpose of the carrier, signal multiplexing, and signal differences between carriers, when configuring uplink and / or downlink carriers for random access, the network-side device can configure one or more uplink carrier groups and / or downlink carrier groups. Different carrier groups can have different purposes or characteristics, or carry different information.

[0137] Optionally, the network-side device provides random access configuration via system messages or RRC signaling, wherein the random access configuration includes one or more uplink carrier groups and / or one or more downlink carrier groups, wherein the uplink carrier group contains one or more uplink carriers and the downlink carrier group contains one or more downlink carriers; furthermore, the network side indicates the association between the uplink carrier group and the downlink carrier group.

[0138] In one possible implementation, the network-side device is configured with one or more uplink carrier groups for random access, and uplink information during the random access process is only transmitted on carriers within that carrier group.

[0139] In one possible implementation, the network-side device is configured with one or more downlink carrier groups for random access, and downlink information during the random access process will only be received on carriers within that carrier group.

[0140] In one possible implementation, the network-side device is configured with an uplink carrier group for PRACH transmission, which includes one or more carriers used for PRACH transmission.

[0141] In one possible implementation, the network-side device is configured with an uplink carrier group for non-PRACH, which contains one or more carriers. These carriers are used to transmit uplink signals other than PRACH during random access or before RRC establishment or RRC recovery, such as Msg 3, Msg 5 (uplink messages after Msg 4), RRC setup request messages, RRC resume request messages, RRC reestablishment request messages, RRC setup complete messages, RRC resume complete messages, and RRC reestablishment complete messages.

[0142] In one possible implementation, for one or more messages (such as msg1~msg5, MsgA, MsgB, etc.) during the random access process, the network-side device is configured with uplink carrier groups for transmission, each carrier group containing one or more uplink carriers; and downlink carrier groups for reception, each carrier group containing one or more downlink carriers; optionally, the carrier groups / carriers configured for different messages can be the same or different.

[0143] In one possible implementation, the network-side equipment is configured with one or more synchronization reference downlink carrier groups, each containing one or more carriers, and downlink synchronization between carriers can be multiplexed. For example, the carriers within the carrier group share a set of radio frequency devices on the base station side. Optionally, within the downlink carrier group, SSB can be transmitted on every carrier, or only on one or a few carriers, reducing SSB overhead.

[0144] In one possible implementation, the network-side device configures downlink carrier groups with associated SSBs. Each carrier group contains two or more carriers, and the SSBs within the carrier group are associated. For example, the number of SSBs and the SSB beam pointing can be the same across different carriers. Alternatively, the number of SSBs across different carriers can be different, but the SSB beams on different carriers can be associated. For instance, one SSB on a carrier with fewer SSBs can be associated with multiple SSBs on a carrier with more SSBs.

[0145] In one possible implementation, the downlink carrier group configured by the network-side device has the same SSB beam on different carriers. Optionally, in this case, the network-side device may transmit the SSB only on a certain carrier in the carrier group.

[0146] Figure 3 shows a carrier group configuration in a multi-carrier scenario. The network-side equipment is configured with downlink carrier group 1, downlink carrier group 2, uplink carrier group 1, and uplink carrier group 2, respectively. Downlink carrier group 1 is associated with uplink carrier group 1, and downlink carrier group 2 is associated with uplink carrier group 2. The uplink carriers within uplink carrier group 2 can be further divided, where uplink carrier 1, uplink carrier 4, and uplink carrier 6 are uplink carriers that can be used for PRACH transmission, and uplink carrier 2 and uplink carrier 5 are uplink carriers that can be used for non-PRACH transmission. Alternatively, in another implementation, uplink carrier 1, uplink carrier 4, and uplink carrier 6 are uplink carriers that can be used for PRACH transmission, and non-PRACH uplink channels / signals can be transmitted through uplink carrier 2 and uplink carrier 5, or non-PRACH uplink channels / signals can be transmitted through uplink carrier 1, uplink carrier 4, and uplink carrier 6. Optionally, as shown in Figure 3, the downlink carriers within downlink carrier group 1 may have the same SSB beam, or the SSBs between carriers may be associated, or the SSBs between carriers may be referenced (e.g., some downlink carriers do not transmit SSBs, but they can reuse other carriers). An example of SSB association between different carriers is shown in Figure 4, where downlink carrier 1 and downlink carrier 2 have the same transmit beam. Optionally, downlink carrier 2 does not transmit SSBs (SSB-less) and reuses the SSBs of downlink carrier 1; the number of SSB beams of downlink carrier 3 is less than the number of SSB beams of downlink carrier 1, and the SSB beams of downlink carrier 3 are associated with the SSB beams of downlink carrier 1, such as downlink carrier 3 beam 1 being associated with downlink carrier 1 beam 1 and beam 2; downlink carrier 3 beam 2 being associated with downlink carrier 1 beam 3 and beam 4.

[0147] In one possible implementation, a carrier can be configured in different carrier groups. For example, uplink carrier 1 can be configured in both the uplink carrier group used for PRACH transmission and the uplink carrier group used for non-PRACH transmission.

[0148] In one possible implementation, an uplink carrier can be associated with one or more downlink carrier groups. For example, as shown in Figure 3, in uplink carrier group 2, uplink carriers 4 and 6 are used for PRACH transmission, and they can be associated with downlink carrier group 2, or with downlink carrier group 1 and downlink carrier group 2.

[0149] In some embodiments, the target uplink carrier group is determined based on at least one of the following:

[0150] The first uplink random access information includes the available uplink carrier group, the terminal's identification information, the identification information of the terminal group to which the terminal belongs, the paging message sent by the network-side device, the uplink carrier group associated with the downlink carrier group selected by the terminal, the average signal quality of all downlink carriers in the downlink carrier group selected by the terminal, the highest signal quality of all downlink carriers in the downlink carrier group selected by the terminal, the amount of uplink data to be transmitted by the terminal, the amount of uplink buffered data by the terminal, the uplink quality of service (QoS) of the terminal, and the uplink transmission latency of the terminal.

[0151] In this embodiment, the terminal can flexibly determine the target uplink carrier group.

[0152] Optionally, the uplink carrier group available for the first uplink random access information can be one or more uplink carrier groups.

[0153] Optionally, the terminal's identification information includes the terminal's identifier or a portion of the terminal's identifier. For example, the terminal's identifier (UE ID) can be any one of the following: Cell-Radio Network Temporary Identifier (C-RNTI), Temporary Mobile Subscriber Identity (TMSI), or International Mobile Subscriber Identity (IMSI).

[0154] Optionally, the association between the terminal's identification information and the uplink carrier group can be agreed upon by the protocol, or the association can be configured by the network side. For example, the network side configures two uplink carrier groups, with terminals mod UE ID = 0 associated with the first uplink carrier group, and terminals mod UE ID = 1 associated with the second uplink carrier group, where mod represents the modulo operation.

[0155] Optionally, the association between the identification information of the terminal group to which the terminal belongs and the uplink carrier group can be agreed upon by the protocol, or the association between the identification information of the terminal group to which the terminal belongs and the uplink carrier group can be configured by the network side.

[0156] Optionally, the network-side device may also directly indicate the target uplink carrier group and / or the target uplink carrier via paging messages, and / or, the network-side device may also directly indicate the target downlink carrier group and / or the target downlink carrier via paging messages. Alternatively, the network-side device may also directly indicate the uplink carrier and / or the downlink carrier used for random access via paging messages, or the network-side device may also directly indicate the carrier used for random access via paging messages (without distinguishing between uplink and downlink carriers).

[0157] The signal quality described in the embodiments of this application can also be replaced or equivalent to the function or operation used to determine the signal quality.

[0158] The signal quality described in the embodiments of this application may include, but is not limited to, at least one of the following:

[0159] Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), and Signal to Interference plus Noise Ratio (SINR).

[0160] In some implementations, when the network-side equipment is configured with at least one uplink carrier group, the terminal can select the target uplink carrier group in one of the following ways:

[0161] The network-side equipment configures the association between uplink carrier groups and downlink carrier groups, and the terminal can determine the uplink carrier group based on the selected downlink carrier group.

[0162] When a downlink carrier group configured by the network-side device is associated with two or more uplink carrier groups, the uplink carrier group is determined based on the average RSRP of the downlink carrier group or the highest RSRP within the downlink carrier group. For example, if the RSRP is lower than the threshold configured by the network-side device, the first uplink carrier group is selected; if the RSRP is higher than the threshold configured by the network-side device, the second uplink carrier group is selected.

[0163] When the downlink carrier group configured by the network-side device is associated with two or more uplink carrier groups, the uplink carrier group is determined based on factors such as the amount of uplink data to be transmitted by the terminal, the amount of uplink buffered data by the terminal, uplink QoS, or uplink latency. For example, if the amount of uplink data to be transmitted by the terminal is lower than the threshold configured by the network-side device, the first uplink carrier group is selected; if the amount of uplink data to be transmitted by the terminal is higher than the first threshold, the second uplink carrier group is selected.

[0164] In some embodiments, the target downlink carrier group is determined based on at least one of the following:

[0165] The first downlink random access information includes the available downlink carrier group, the terminal identification information, the terminal group identification information to which the terminal belongs, the paging message sent by the network-side device, the downlink carrier group containing the downlink carrier with the highest measured signal quality in the at least one downlink carrier group, and the downlink carrier group with the highest average signal quality among all downlink carriers in the at least one downlink carrier group.

[0166] In this embodiment, the terminal can flexibly determine the target downlink carrier group.

[0167] Optionally, the downlink carrier group available for the first downlink random access information can be one or more downlink carrier groups.

[0168] For example, the target downlink carrier group can be the carrier group containing the carrier corresponding to the highest RSRP, or the target downlink carrier group can be the carrier group containing the carrier corresponding to the highest RSRQ, or the target downlink carrier group can be the carrier group containing the carrier corresponding to the highest SINR, or the target downlink carrier group can be the carrier group containing the carrier corresponding to the function or operation used to determine the highest RSRP, or the target downlink carrier group can be the carrier group containing the carrier corresponding to the function or operation used to determine the highest RSRQ, or the target downlink carrier group can be the carrier group containing the carrier corresponding to the function or operation used to determine the highest SINR.

[0169] For example, the target downlink carrier group can be the carrier group with the highest average RSRP of all downlink carriers, or the target downlink carrier group can be the carrier group with the highest average RSRQ of all downlink carriers, or the target downlink carrier group can be the carrier group with the highest average SINR of all downlink carriers, or the target downlink carrier group can be the carrier group containing the carrier corresponding to the function or operation used to determine the average RSRP, or the target downlink carrier group can be the carrier group containing the carrier corresponding to the function or operation used to determine the average RSRQ, or the target downlink carrier group can be the carrier group containing the carrier corresponding to the function or operation used to determine the average SINR.

[0170] In some implementations, when the network-side equipment is configured with at least one downlink carrier group, the terminal can select the target downlink carrier group in one of the following ways:

[0171] Based on the highest RSRP (or highest RSRQ, highest SINR) within a downlink carrier group, each downlink carrier group measures its SSBs, and the downlink carrier group containing the downlink carrier with the highest RSRP is selected. For example, RSRP (using RSRP as an example, it could also be RSRQ or SINR) measurement is based on one or more SSBs within a downlink carrier, and the highest RSRP corresponds to the RSRP of the SSB with the highest measurement result within the downlink carrier. Alternatively, RSRP measurement is based on one or more SSBs within a downlink carrier, and the highest RSRP corresponds to the RSRP of the average measurement result of the multiple SSBs within the downlink carrier.

[0172] Based on the average RSRP within the downlink carrier group, the SSB of each downlink carrier group is measured separately, and the downlink carrier group with the highest average RSRP is selected.

[0173] The network-side equipment is configured with a threshold. The SSB of each downlink carrier group is measured separately. For downlink carrier groups that are higher than the threshold, the downlink carrier group with the highest RSRP is selected, or the downlink carrier group with the highest average RSRP is selected.

[0174] Network-side equipment is configured with a threshold, and the SSB of each downlink carrier group is measured separately. Downlink carrier groups with values ​​above the threshold are randomly selected.

[0175] For example, in some scenarios, during the determination / measurement of the downlink carrier group, the terminal only measures one or some of the downlink carriers within the downlink carrier group. For instance, if the downlink carriers within the downlink carrier group belong to the same band (intra-band scenario), the terminal only measures one downlink carrier within the downlink carrier group and determines the RSRP based on the SSB measurement on that carrier.

[0176] It should be noted that determining the downlink carrier RSRP based on the RSRP corresponding to the highest SSB, or based on the average measurement results of multiple SSBs, is also applicable to the other methods described below, which will not be elaborated further.

[0177] In some embodiments, the downlink carriers within each downlink carrier group of the at least one downlink carrier group satisfy at least one of the following conditions:

[0178] Some or all downlink carriers correspond to the same SSB index;

[0179] There is a correlation between the SSB indices corresponding to some or all downlink carriers;

[0180] The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB.

[0181] An SSB index corresponding to a downlink carrier is associated with one or more ROs corresponding to uplink carriers.

[0182] An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices;

[0183] An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers;

[0184] A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers.

[0185] In this embodiment, in a downlink carrier group, some or all downlink carriers correspond to the same SSB index, so that the SSB indices of some or all downlink carriers in the downlink carrier group can be reused, thereby improving the performance of some or all downlink carriers in the downlink carrier group. For example, the SSB index corresponding to the downlink carrier that has not transmitted an SSB can reuse the SSB index corresponding to the downlink carrier that has transmitted an SSB.

[0186] In this embodiment, in a downlink carrier group, there is an association between some or all of the SSB indices corresponding to the downlink carriers, so that the SSB index corresponding to another downlink carrier can be determined based on the SSB index corresponding to one downlink carrier and the association between the SSB indices corresponding to the downlink carriers.

[0187] In this embodiment, in a downlink carrier group, the SSB index corresponding to a downlink carrier is associated with one or more ROs corresponding to uplink carriers, or the RO corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers, thereby improving coverage performance and random access performance.

[0188] In this embodiment, in a downlink carrier group, the SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers, or the random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers, thereby improving random access performance.

[0189] In some embodiments, the downlink carrier group in the at least one downlink carrier group satisfies at least one of the following conditions:

[0190] Some or all downlink carrier groups correspond to the same SSB index;

[0191] There is a correlation between the SSB indices corresponding to some or all downlink carrier groups;

[0192] An SSB index corresponding to a downlink carrier group is associated with one or more ROs corresponding to uplink carrier groups.

[0193] An RO corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups.

[0194] An SSB index corresponding to a downlink carrier group is associated with one or more random access preambles corresponding to uplink carrier groups.

[0195] A random access preamble corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups.

[0196] In this embodiment, in at least one downlink carrier group, some or all downlink carrier groups correspond to the same SSB index, so that the SSB indexes of some or all downlink carrier groups can be reused, thereby improving the performance of some or all downlink carrier groups. For example, the SSB index corresponding to the downlink carrier group that has not transmitted an SSB can reuse the SSB index corresponding to the downlink carrier group that has transmitted an SSB.

[0197] In this embodiment, in at least one downlink carrier group, there is an association between some or all of the SSB indices corresponding to the downlink carrier groups, so that the SSB index corresponding to another downlink carrier group can be determined based on the SSB index corresponding to one downlink carrier group and the association between the SSB indices corresponding to the downlink carrier groups.

[0198] In this embodiment, in at least one downlink carrier group, the SSB index corresponding to a downlink carrier group is associated with one or more ROs corresponding to uplink carrier groups, or the RO corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups, thereby improving coverage performance and random access performance.

[0199] In this embodiment, in at least one downlink carrier group, the SSB index corresponding to a downlink carrier group is associated with one or more random access preambles corresponding to uplink carrier groups, or the random access preamble corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups, thereby improving random access performance.

[0200] In some embodiments, the downlink carriers of the at least two downlink carriers satisfy at least one of the following conditions:

[0201] Some or all downlink carriers correspond to the same SSB index;

[0202] There is a correlation between the SSB indices corresponding to some or all downlink carriers;

[0203] The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB.

[0204] An SSB index corresponding to a downlink carrier is associated with one or more ROs corresponding to uplink carriers.

[0205] An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices;

[0206] An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers;

[0207] A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers.

[0208] In this embodiment, some or all of the downlink carriers in at least two downlink carriers correspond to the same SSB index, so that the SSB indexes of some or all of the downlink carriers in at least two downlink carriers can be reused, which improves the performance of some or all of the downlink carriers in the downlink carrier group. For example, the SSB index corresponding to the downlink carrier that has not transmitted an SSB can reuse the SSB index corresponding to the downlink carrier that has transmitted an SSB.

[0209] In this embodiment, among at least two downlink carriers, there is an association between some or all of the SSB indices corresponding to the downlink carriers, so that the SSB index corresponding to another downlink carrier can be determined based on the SSB index corresponding to one downlink carrier and the association between the SSB indices corresponding to the downlink carriers.

[0210] In this embodiment, among at least two downlink carriers, the SSB index corresponding to one downlink carrier is associated with one or more ROs corresponding to uplink carriers, or the RO corresponding to one uplink carrier is associated with one or more SSB indices corresponding to downlink carriers, thereby improving coverage performance and random access performance.

[0211] In this embodiment, among at least two downlink carriers, the SSB index corresponding to one downlink carrier is associated with one or more random access preambles corresponding to uplink carriers, or the random access preamble corresponding to one uplink carrier is associated with one or more SSB indices corresponding to downlink carriers, thereby improving random access performance.

[0212] In some embodiments, when an SSB index corresponding to a downlink carrier is associated with an RO corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier is associated with a random access preamble corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers for uplink repetitive transmission.

[0213] In this embodiment, when the SSB index corresponding to a downlink carrier is associated with the RO corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers used for uplink repetitive transmission; and / or, when the SSB index corresponding to a downlink carrier is associated with the random access preamble corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers used for uplink repetitive transmission, thereby improving the uplink repetitive transmission performance.

[0214] In some embodiments, when the SSB index corresponding to a downlink carrier group is associated with the RO corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups for uplink repetitive transmission; and / or, when the SSB index corresponding to a downlink carrier group is associated with the random access preamble corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups for uplink repetitive transmission.

[0215] In this embodiment, when the SSB index corresponding to a downlink carrier group is associated with the RO corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission; and / or, when the SSB index corresponding to a downlink carrier group is associated with the random access preamble corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission, thereby improving uplink repetitive transmission performance.

[0216] In some embodiments, the wireless communication method 200 further includes:

[0217] The terminal receives the second information;

[0218] The second information includes at least one of the following:

[0219] The conditions that the downlink carriers in each downlink carrier group of the at least one downlink carrier group satisfy;

[0220] The conditions that the downlink carrier groups in the at least one downlink carrier group satisfy;

[0221] The conditions that the downlink carriers of the at least two downlink carriers satisfy.

[0222] Accordingly, the network-side device sends the second information to the terminal.

[0223] In this embodiment, the terminal can obtain at least one of the following based on the second signal received from the network-side device: the conditions satisfied by the downlink carriers in each downlink carrier group in at least one downlink carrier group, the conditions satisfied by the downlink carrier group in at least one downlink carrier group, and the conditions satisfied by the downlink carriers in at least two downlink carriers.

[0224] Optionally, the second information can be carried by system messages or RRC signaling.

[0225] In some embodiments, repeated transmissions of the first uplink random access information correspond to the same uplink carrier or the same uplink carrier group, or repeated transmissions of the first uplink random access information correspond to different uplink carriers or different uplink carrier groups.

[0226] In this embodiment, repeated transmissions of the first uplink random access information correspond to the same uplink carrier or the same uplink carrier group, or repeated transmissions of the first uplink random access information correspond to different uplink carriers or different uplink carrier groups, thereby allowing for flexible design of the uplink carrier or uplink carrier group corresponding to the repeated transmissions of the first uplink random access information.

[0227] In some embodiments, repeated transmissions of the first downlink random access information correspond to the same downlink carrier or the same downlink carrier group, or repeated transmissions of the first downlink random access information correspond to different downlink carriers or different downlink carrier groups.

[0228] In this embodiment, repeated transmissions of the first downlink random access information correspond to the same downlink carrier or the same downlink carrier group, or repeated transmissions of the first downlink random access information correspond to different downlink carriers or different downlink carrier groups, thereby allowing for flexible design of the downlink carriers or downlink carrier groups corresponding to the repeated transmissions of the first downlink random access information.

[0229] In some embodiments, the first uplink random access information is PRACH in four-step random access;

[0230] The target uplink carrier is determined based on at least one of the following:

[0231] The identifier of the terminal;

[0232] Paging messages sent by network-side devices;

[0233] The uplink carrier available for PRACH in the four-step random access;

[0234] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0235] Downlink signal quality of the reference carrier;

[0236] DCI in the PDCCH used to trigger non-contentionable four-step random access;

[0237] The uplink carrier available for PRACH in the four-step random access associated with the downlink carrier that has the highest downlink signal quality (e.g., highest RSRP, highest RSRQ, or highest SINR).

[0238] It should be noted that PRACH in four-step random access can also be called or replaced by Msg1 or the random access preamble in four-step random access.

[0239] Optionally, the reference carrier may be agreed upon by a protocol, or the reference carrier may be configured by a network-side device.

[0240] Optionally, the reference carrier can be an anchor carrier or a default carrier.

[0241] In this multi-carrier scenario, for PRACH repetition, PRACH can be repeatedly transmitted on the same or different carriers. For example, repeated PRACH can be transmitted on different carriers within an uplink carrier group. In one possible implementation, when configuring SSB-RO or PRACH mapping relationships, the network-side device configures a first type of SSB-RO or PRACH mapping and a second type of SSB-RO or PRACH mapping. The first type of SSB-RO or PRACH mapping includes a mapping between an SSB of one downlink carrier and an RO / PRACH of one uplink carrier; the second type of SSB-RO or PRACH mapping includes a mapping between an SSB of one downlink carrier and an RO / PRACH of more than one uplink carrier. The multiple uplink carriers in the second type of SSB-RO or PRACH mapping can be uplink carriers used for PRACH repetition. For PRACH repetition scenarios, PRACH / RO repetitions on different carriers by the terminal are associated with the same SSB index or SSB beam (the same downlink beam of the same downlink carrier).

[0242] In some embodiments, the random access preamble in the PRACH of the four-step random access is used to indicate whether different random access messages following the PRACH in the four-step random access support transmission via different carriers; or, the random access preamble in the PRACH of the four-step random access is used to indicate whether different uplink random access messages following the PRACH in the four-step random access support transmission via different uplink carriers; or, the random access preamble in the PRACH of the four-step random access is used to indicate whether different downlink random access messages following the PRACH in the four-step random access support transmission via different downlink carriers.

[0243] For example, the terminal can also indicate whether it supports access based on multiple carriers or multiple carrier groups by sending a random access preamble. For instance, it can indicate whether different messages during the random access process are supported to be transmitted via different carriers, where the messages may include Msg2, Msg3, Msg4, and Msg5; or whether the terminal supports uplink transmission based on multiple carriers during the random access process, such as whether different messages during the random access process are supported to be transmitted via different carriers, where the messages may include Msg3 and Msg5; or whether the terminal supports downlink reception based on multiple carriers during the random access process, such as whether different messages during the random access process are supported to be received via different carriers, where the messages may include Msg2 and Msg4; or whether the terminal supports the transmission of a specific message based on multiple carriers during the random access process, where the message may include any one of Msg2, Msg3, Msg4, and Msg5. For example, the preamble sent by the terminal can be grouped, and different groups of preambles can implicitly indicate whether access based on multiple carrier groups is supported, or whether reception on other downlink carriers associated with the uplink carrier is supported. Based on this information, the network side can further determine the downlink carrier during the random access process.

[0244] Optionally, the association between the terminal's identifier and the uplink carrier can be agreed upon by a protocol, or the association can be configured by the network-side equipment. For example, the network-side equipment can configure or indicate the association between the terminal's identifier and the uplink carrier through paging messages.

[0245] In some embodiments, the first downlink random access information is the RAR in four-step random access;

[0246] The target downlink carrier is determined based on at least one of the following:

[0247] The identifier of the terminal;

[0248] Paging messages sent by network-side devices;

[0249] The downlink carriers available for RAR in the four-step random access;

[0250] The downlink carrier associated with the uplink carrier corresponding to the PRACH transmission in four-step random access;

[0251] The downlink carrier corresponding to the SSB used for synchronization;

[0252] Reference carrier;

[0253] Default downlink carrier;

[0254] The downlink carrier with the highest signal quality;

[0255] The downlink carrier with the highest average signal quality.

[0256] It should be noted that RAR in the four-step random access can also be called or replaced by Msg2 in the four-step random access, and this application does not limit it in this way.

[0257] Optionally, the reference carrier may be agreed upon by a protocol, or the reference carrier may be configured by a network-side device.

[0258] Optionally, the reference carrier can be an anchor carrier or a default carrier.

[0259] Optionally, the default downlink carrier can be agreed upon by a protocol, or the default downlink carrier can be configured by the network-side device. For example, the default downlink carrier is the anchor carrier.

[0260] In some embodiments, the network-side device can configure or indicate the association between the RAR DMRS and the SSB. As mentioned above, the RAR received carrier and the SSB received carrier can be the same or different. For example, the network-side device can configure the association between the first carrier SSB and the second carrier RAR DMRS; the association can be quasi-co-located (QCL), and the QCL relationship can be QCL Type-D, meaning the spatial parameters are the same, or that they have the same beam; it can also be other types of QCL relationships, such as QCL Type A (Doppler spread, Doppler offset, average delay, and average spread); QCL Type B (Doppler spread and Doppler offset); and QCL Type C (average delay and Doppler offset). The RAR DMRS includes DMRS for the RAR PDCCH and / or DMRS for the RAR PDSCH.

[0261] In some embodiments, the RAR in the four-step random access includes at least one of the following:

[0262] First indication information, the first indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the uplink random access information after RAR in the four-step random access, or, the first indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of the uplink random access information after RAR in the four-step random access.

[0263] The second indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the downlink random access information after RAR in the four-step random access, or the second indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the downlink random access information after RAR in the four-step random access.

[0264] The third indication information is used to indicate the PRACH transmission carrier and / or carrier group corresponding to the RAR in the four-step random access, wherein the range of the Random Access Radio Network Temporary Identity (RA-RNTI) corresponding to different PRACH transmission carriers and / or carrier groups is different, or the random access preamble identifier corresponding to different PRACH transmission carriers and / or carrier groups is different.

[0265] For example, due to the decoupling of uplink and downlink carriers, the carriers carrying uplink information and the carriers carrying downlink information do not have a predefined correspondence during the initial access process. Therefore, one RAR receive carrier may correspond to multiple PRACH transmit carriers. To solve the problem of overlapping RA-RNTI and preamble IDs corresponding to PRACH transmissions on different carriers and / or carrier groups, the RAR can explicitly or implicitly indicate the uplink carrier from which the corresponding PRACH originates. Several possible implementation methods are as follows:

[0266] The RAR indicates the carrier ID and / or carrier group ID, where the carrier ID and carrier group ID are the UL carrier and UL carrier group where the corresponding PRACH transmission is located; or...

[0267] The RA-RNTI ranges or preamble IDs corresponding to PRACH transmissions on different carriers and / or different carrier groups are different; or,

[0268] The unified numbering of ROs on different carriers and / or different carrier groups in the time domain or frequency domain ensures that the calculated RA-RNTI is not duplicated.

[0269] An exemplary RA-RNTI calculation is as follows:

[0270] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id + 14 × 80 × 8 × N × ul_carrier_group_id, where s_id indicates the index of the first Orthogonal Frequency-Division Multiplexing (OFDM) symbol of the PRACH, t_id indicates the index of the first slot of the PRACH in the system frame, f_id indicates the index of the PRACH in the frequency domain, ul_carrier_id represents the index of the uplink carrier within the uplink carrier group, ul_carrier_group_id represents the uplink carrier group index, and N represents the number of all uplink carriers within all uplink carrier groups whose numbers are less than that of the carrier group.

[0271] Another exemplary RA-RNTI calculation is as follows:

[0272] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id, where s_id indicates the index of the first OFDM symbol of the PRACH, t_id indicates the index of the first slot of the PRACH in the system frame, f_id indicates the index of the PRACH in the frequency domain, and ul_carrier_id represents the index of the uplink carrier within the uplink carrier group.

[0273] In some embodiments, both the PDCCH corresponding to the RAR in the four-step random access and the PDSCH corresponding to the RAR in the four-step random access are transmitted via the target downlink carrier; or...

[0274] The PDCCH corresponding to the RAR in the four-step random access is transmitted through the target downlink carrier, and the PDSCH corresponding to the RAR in the four-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to the RAR in the four-step random access.

[0275] For example, the PDCCH and PDSCH corresponding to the RAR are received using the same downlink carrier, for instance, the downlink carrier to be received is determined based on the above method.

[0276] For example, the PDCCH and PDSCH corresponding to the RAR can be received using different downlink carriers. The receiving carrier of the PDCCH corresponding to the RAR is determined in the manner described above, and the carrier of the PDSCH corresponding to the RAR is indicated by the RAR PDCCH.

[0277] In some embodiments, the first uplink random access information is Msg3 in the four-step random access method;

[0278] The target uplink carrier is determined based on at least one of the following:

[0279] The identifier of the terminal;

[0280] Paging messages sent by network-side devices;

[0281] Default uplink carrier;

[0282] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0283] The uplink carrier available for Msg3 in the four-step random access;

[0284] The uplink carrier indicated in the RAR during four-step random access;

[0285] The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

[0286] Specifically, after receiving the RAR message, the terminal will send Msg3 based on the uplink grant (UL grant) instruction in the RAR message. The transmission carrier of Msg3 can also be indicated by the RAR.

[0287] In one possible implementation, the RAR includes a Msg3 transmit carrier indication and a transmission indication within that carrier. For example, the UL grant includes a transmit carrier index or the transmit carrier's number within a carrier group.

[0288] In one possible implementation, the RAR message contains UL grants for multiple carriers, and the terminal selects one of the carriers to send, ignoring the UL grants on the other carriers.

[0289] For example, when there is no Msg3 transmission carrier indication in the RAR, the transmission carrier of Msg3 is the same as the PRACH transmission carrier, or the default carrier configured by the network.

[0290] In the multi-carrier scenario of this embodiment, for the Msg3 repetition scenario, Msg3 can be repeatedly transmitted on the same or different carriers. For example, Msg3 can be repeatedly transmitted on different carriers within the uplink carrier group, and the uplink carriers transmitting the repeated Msg3 can be indicated in the RAR.

[0291] In some embodiments, Msg3 in the four-step random access includes fourth indication information;

[0292] The fourth indication information is used to indicate whether the terminal supports cross-carrier scheduling of downlink random access information (such as Msg4) after Msg3 in the four-step random access.

[0293] Optionally, Msg4 can support cross-carrier scheduling, that is, in scenarios where the PDCCH listening carrier corresponding to Msg4 and the PDSCH receiving carrier corresponding to Msg4 are different. One possible indication method is that the terminal carries the ability to schedule Msg4 across carriers within the initial access carrier group through Msg3.

[0294] In some embodiments, the first downlink random access information is Msg4 in the four-step random access method;

[0295] The target downlink carrier is determined based on at least one of the following:

[0296] The identifier of the terminal;

[0297] Paging messages sent by network-side devices;

[0298] The downlink carrier available for Msg4 in the four-step random access;

[0299] The downlink carrier corresponding to the RAR transmission in the four-step random access;

[0300] In the four-step random access, the downlink carrier associated with the uplink carrier corresponding to the Msg3 transmission;

[0301] The downlink carrier corresponding to the SSB used for synchronization;

[0302] Reference carrier;

[0303] Default downlink carrier;

[0304] The downlink carrier with the highest signal quality;

[0305] The downlink carrier with the highest average signal quality.

[0306] In some embodiments, the PDCCH corresponding to Msg4 in the four-step random access and the PDSCH corresponding to Msg4 in the four-step random access correspond to the same downlink carrier or the same downlink carrier group; or, the PDCCH corresponding to Msg4 in the four-step random access and the PDSCH corresponding to Msg4 in the four-step random access correspond to different downlink carriers or different downlink carrier groups.

[0307] In some embodiments, if the time interval between the PDSCH corresponding to Msg4 in the four-step random access and the PDCCH corresponding to Msg4 in the four-step random access is less than or not greater than a first threshold, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is indicated by the RAR in the four-step random access; or, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is indicated by the network-side device or agreed by the protocol; or, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is the same as the downlink carrier corresponding to the PDCCH corresponding to Msg4 in the four-step random access.

[0308] And / or,

[0309] If the time interval between the PDSCH corresponding to Msg4 in the four-step random access and the PDCCH corresponding to Msg4 in the four-step random access is greater than or not less than a first threshold, the PDSCH corresponding to Msg4 in the four-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to Msg4 in the four-step random access.

[0310] In some embodiments, Msg4 in the four-step random access includes a fifth indication message;

[0311] The fifth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the uplink random access information after Msg4 in the four-step random access, or the fifth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of the uplink random access information after Msg4 in the four-step random access.

[0312] Specifically, Msg4 can be used to carry conflict resolution messages. Optionally, it can also carry RRC setup messages, RRC resume messages, or RRC reestablishment messages.

[0313] For example, in a multi-carrier scenario, the PDCCH reception corresponding to Msg4 and the PDSCH reception corresponding to Msg4 can be on the same carrier or on different carriers.

[0314] In one possible implementation, the RAR indicates the carrier that the PDCCH corresponding to Msg4 is listening to.

[0315] In one possible implementation, the protocol predefines that the PDCCH listening carrier corresponding to Msg4 is the same as the RAR receiving carrier, or is received based on a reference carrier, wherein the reference carrier can be an anchor carrier or a default carrier within a carrier group configured by the network.

[0316] In one possible implementation, the network-side device configures the PDCCH receive carrier corresponding to Msg4. For example, the network configures a certain carrier in the downlink carrier group as the PDCCH receive carrier corresponding to Msg4.

[0317] In one possible implementation, the PDCCH listening carrier corresponding to Msg4 is determined based on the transmit carrier of Msg3. For example, the downlink carrier corresponding to the transmit carrier of Msg3 is used to listen to the PDCCH corresponding to Msg4.

[0318] In one possible implementation, the RAR indicates the PDSCH receive carrier corresponding to Msg4.

[0319] In one possible implementation, the protocol is predefined, and the PDSCH listening carrier corresponding to Msg4 is the same as the RAR receiving carrier, or it is received based on the default carrier of the predefined / network configuration, or it is the same as the PDCCH listening carrier corresponding to Msg4.

[0320] In one possible implementation, the network-side device configures the PDSCH receive carrier corresponding to Msg4.

[0321] In one possible implementation, the method for determining the PDSCH carrier corresponding to Msg4 is related to the time-domain interval K0 between the PDCCH corresponding to Msg4 and the PDSCH corresponding to Msg4 configured in the network.

[0322] When K0 is less than 1, the PDSCH carrier corresponding to Msg4 is based on RAR indication, or the above-mentioned protocol predefined / network configuration, or the same PDCCH carrier as Msg4;

[0323] When K0 is greater than 1, the PDSCH corresponding to Msg4 is indicated by the DCI in the PDCCH corresponding to Msg4.

[0324] In one possible implementation, the PDCCH and PDSCH corresponding to Msg4 are always on the same carrier, either predefined by the protocol or indicated by the network-side device. For example, the carrier used for receiving Msg4 is indicated in the RAR (which applies to both the PDCCH and PDSCH corresponding to Msg4).

[0325] For example, the carrier wave that the terminal receives for Msg4 may be the same as or different from the carrier wave that the terminal receives for RAR.

[0326] Specifically, when the RAR does not specify the Msg4 listening / receiving carrier scenario, the Msg4 listening / receiving carrier is the same as the RAR receiving carrier, or the downlink carrier corresponding to the Msg3 transmission, or the network-configured Msg4 receiving carrier, or the protocol-predefined method (based on the reference carrier).

[0327] In the multi-carrier scenario of this embodiment, for the Msg4 repetition scenario, Msg4 (including the PDCCH and / or PDSCH corresponding to Msg4) can be repeatedly transmitted on the same or different carriers, and the multiple transmission carriers corresponding to the Msg4 repetition can be indicated by RAR or network configuration.

[0328] For example, the network-side device configures or indicates the association between RAR DMRS and SSB. The network-side device can configure or indicate the association between Msg4 DMRS and SSB. As mentioned earlier, the Msg4 received carrier and the SSB received carrier can be the same or different. For instance, the network-side device can configure or indicate the association between the first carrier SSB and the second carrier Msg4 DMRS. The association can be a QCL, which can be QCL Type-D, meaning the spatial parameters are the same, or that they have the same beam; or it can be other types of QCL relationships, such as QCL Type A (Doppler spread, Doppler offset, average delay, and average spread); QCL Type B (Doppler spread and Doppler offset); and QCL Type C (average delay and Doppler offset). Msg4 DMRS includes DMRS for the PDCCH corresponding to Msg4 and / or DMRS for the PDSCH corresponding to Msg4.

[0329] In some embodiments, the first uplink random access information is the feedback of the Hybrid Automatic Repeat reQuest (HARQ) for Msg4 in the four-step random access process.

[0330] The target uplink carrier is determined based on at least one of the following:

[0331] The identifier of the terminal;

[0332] Paging messages sent by network-side devices;

[0333] Default uplink carrier;

[0334] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0335] The HARQ feedback of Msg4 in the four-step random access is available uplink carrier;

[0336] In the four-step random access process, Msg4 contains downlink control information (DCI) used to schedule the Physical Uplink Control Channel (PUCCH).

[0337] In the four-step random access process, Msg4 is used to schedule the DCI of the Media Access Control Element (MAC CE).

[0338] The uplink carrier corresponding to Msg3 transmission in the four-step random access;

[0339] The uplink carrier indicated in the RAR during four-step random access;

[0340] The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

[0341] Specifically, for Msg4 transmission, HARQ feedback is supported.

[0342] In one possible implementation, Msg4's HARQ feedback is based on PUCCH bearer. The network-side device configures one or more PUCCH carriers during the initial access phase, and the terminal transmits based on the configured default PUCCH carrier.

[0343] In one possible implementation, the HARQ feedback of Msg4 is based on the PUCCH bearer. The network-side device configures one or more PUCCH carriers during the initial access phase, and the terminal determines the feedback carrier based on the PUCCH feedback carrier indicated by the scheduling DCI of Msg4.

[0344] In one possible implementation, the HARQ feedback of Msg4 is based on the PUCCH bearer. The network-side device configures one or more PUCCH carriers during the initial access phase. The Msg4 HARQ feedback carrier is the same as the Msg3 transmission carrier or the PRACH transmission carrier.

[0345] In one possible implementation, the HARQ feedback of Msg4 is based on MAC CE feedback, and the carrier carrying the HARQ feedback can be based on the scheduling DCI indication of Msg4.

[0346] In one possible implementation, the HARQ feedback of Msg4 is based on MAC CE feedback, and the carrier carrying the HARQ feedback is based on the DCI indication that schedules the MAC CE (PUSCH).

[0347] In some embodiments, the first uplink random access information is the uplink message (such as Msg5) following Msg4 in the four-step random access process.

[0348] The target uplink carrier is determined based on at least one of the following:

[0349] The identifier of the terminal;

[0350] Paging messages sent by network-side devices;

[0351] Default uplink carrier;

[0352] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0353] The uplink carrier available for uplink messages after Msg4 in four-step random access;

[0354] The DCI used in Msg4 of the four-step random access process to schedule uplink messages after Msg4 in the four-step random access process.

[0355] The uplink carrier corresponding to Msg3 transmission in the four-step random access;

[0356] The uplink carrier indicated in the RAR during four-step random access;

[0357] The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

[0358] Specifically, after receiving Msg4, the terminal needs to send Msg5 to complete the corresponding RRC connection establishment or recovery process. Msg5 can be used to carry the RRC setup complete message, RRC resume complete message, and RRC reestablishment complete message.

[0359] For example, the transmission of Msg5 includes: a Msg5 scheduling carrier, a Msg5 transmission carrier, and optionally, a Msg5 retransmission carrier.

[0360] In one possible implementation, the Msg5 scheduling carrier is indicated by the Msg4 scheduling DCI; or the carrier is detected based on the default PDCCH of the network configuration; or based on the reference carrier (such as the anchor carrier) within the carrier group; or determined based on network / protocol preset rules, such as the Msg5 scheduling carrier being the same as the Msg4 scheduling carrier.

[0361] In one possible implementation, the transmission carrier of Msg5 is determined by its scheduling DCI indication or based on network / protocol preset rules, such as the same transmission carrier as Msg3.

[0362] In one possible implementation, similar to Msg3, for the scenario of repeated Msg5 transmission, Msg5 can be repeatedly transmitted on the same or different carriers. For example, repeated Msg5 can be transmitted on different carriers within the uplink carrier group. The uplink carriers for transmitting repeated Msg5 can be indicated by the scheduling DCI or configured by the network.

[0363] In some embodiments, the first uplink random access information is MsgA in two-step random access;

[0364] The target uplink carrier is determined based on at least one of the following:

[0365] The identifier of the terminal;

[0366] Paging messages sent by network-side devices;

[0367] The uplink carrier associated with the downlink carrier corresponding to the SSB transmission used for synchronization;

[0368] The uplink carrier available for MsgA in the two-step random access;

[0369] DCI in PDCCH used to trigger non-contention-based two-step random access;

[0370] Downlink signal quality of the reference carrier;

[0371] The uplink carrier available for MsgA in the two-step random access associated with the downlink carrier with the highest downlink signal quality.

[0372] For example, MsgA includes the MsgAPRACH part carrying the preamble and the MsgAPUSCH part carrying the payload. In a multi-carrier random access scenario, the PRACH corresponding to MsgA and the PUSCH corresponding to MsgA can be on the same carrier or different carriers.

[0373] In some embodiments, the PRACH corresponding to MsgA in the two-step random access and the PUSCH corresponding to MsgA in the two-step random access correspond to the same uplink carrier or the same uplink carrier group; or, the PRACH corresponding to MsgA in the two-step random access and the PUSCH corresponding to MsgA in the two-step random access correspond to different uplink carriers or different uplink carrier groups.

[0374] And / or,

[0375] In the two-step random access, different groups of PRACH corresponding to MsgA correspond to the same uplink carrier or the same uplink carrier group; or, different groups of PRACH corresponding to MsgA correspond to different uplink carriers or different uplink carrier groups; and / or, different groups of PUSCH corresponding to MsgA correspond to the same uplink carrier or the same uplink carrier group; or, different groups of PUSCH corresponding to MsgA correspond to different uplink carriers or different uplink carrier groups.

[0376] In some embodiments, the PUSCH corresponding to MsgA in the two-step random access includes at least one of the following:

[0377] The sixth indication information is used to indicate whether the terminal supports MsgB cross-carrier scheduling in two-step random access;

[0378] The seventh indication information is used to indicate the downlink carrier or downlink carrier group corresponding to MsgB in the two-step random access, or the seventh indication information is used to indicate the downlink carrier or downlink carrier group corresponding to MsgB in the two-step random access desired by the terminal.

[0379] In one possible implementation, the network-side device provides different types of MsgA configurations, including: MsgAPRACH and MsgAPUSCH on the same carrier, and MsgA PRACH and MsgAPUSCH on different carriers. The terminal selects the corresponding transmission resources based on its capabilities and other factors. For terminals that choose to transmit MsgA PRACH and MsgA PUSCH on different carriers, this implicitly indicates that the terminal supports multi-carrier transmission and reception capabilities during random access.

[0380] In one possible implementation, the network-side device provides configurations for MsgAPRACH and MsgAPUSCH on different carriers, as well as MsgAPUSCH carrier selection conditions. MsgAPRACH is transmitted via a first carrier, and MsgAPUSCH can be transmitted via either the first carrier or a second carrier (or other uplink carriers within the carrier group). In some embodiments, the MsgAPUSCH carrier selection condition can be based on data volume. For example, the network-side device configures data thresholds on different carriers, and the terminal selects the corresponding MsgAPUSCH carrier based on the load size. Different MsgAPUSCH carriers can be associated with different MsgAPRACH resources, preambles, or MsgAPUSCH carriers.

[0381] In one possible implementation, different groups of MsgAPRACH and / or MsgA PUSCH are configured to different carriers / carrier groups. For example, MsgAPUSCH has two groups, corresponding to MsgA with a large payload and MsgA with a small payload, respectively. This can be distinguished by the group in which the preamble is located. The network-side device can configure the preamble transmitted on the first uplink carrier to correspond to the MsgA PUSCH with a small payload, and the preamble transmitted on the second uplink carrier to correspond to the MsgA PUSCH with a large payload.

[0382] For example, different carriers / carrier groups are configured with independent MsgAPRACH resources or MsgAPUSCH resources.

[0383] Optionally, the PUSCH of MsgA may carry an indication of whether cross-carrier scheduling capability of MsgB is supported.

[0384] Optionally, the terminal carries a Msg B carrier indication via Msg A PUSCH to request the network to transmit Msg B via that carrier, or to notify the network-side device that it prefers to transmit the Msg B carrier.

[0385] In some embodiments, the first downlink random access information is MsgB in two-step random access;

[0386] The target downlink carrier is determined based on at least one of the following:

[0387] The identifier of the terminal;

[0388] Paging messages sent by network-side devices;

[0389] The downlink carrier corresponding to the SSB transmission used for synchronization;

[0390] The downlink carrier available for MsgB in the two-step random access;

[0391] The uplink carrier corresponding to the MsgA transmission in two-step random access;

[0392] The downlink carrier indicated in MsgA during two-step random access;

[0393] Reference carrier;

[0394] Default downlink carrier;

[0395] The downlink carrier with the highest signal quality;

[0396] The downlink carrier with the highest average signal quality.

[0397] In some embodiments, the PDCCH corresponding to MsgB in the two-step random access and the PDSCH corresponding to MsgB in the two-step random access correspond to the same downlink carrier or the same downlink carrier group; or, the PDCCH corresponding to MsgB in the two-step random access and the PDSCH corresponding to MsgB in the two-step random access correspond to different downlink carriers or different downlink carrier groups.

[0398] In some embodiments, if the time interval between the PDSCH corresponding to MsgB in the two-step random access and the PDCCH corresponding to MsgB in the two-step random access is less than or not greater than a first threshold, the downlink carrier corresponding to the PDSCH corresponding to MsgB in the two-step random access is indicated by the network-side device or agreed by the protocol, or the downlink carrier corresponding to the PDSCH corresponding to MsgB in the two-step random access is the same as the downlink carrier corresponding to the PDCCH corresponding to MsgB in the two-step random access.

[0399] And / or,

[0400] If the time interval between the PDSCH corresponding to MsgB in the two-step random access and the PDCCH corresponding to MsgB in the two-step random access is greater than or not less than a first threshold, the PDSCH corresponding to MsgB in the two-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to MsgB in the two-step random access.

[0401] In some embodiments, the first uplink random access information may be the HARQ feedback of MsgB in two-step random access.

[0402] The target uplink carrier is determined based on at least one of the following:

[0403] The identifier of the terminal;

[0404] Paging messages sent by network-side devices;

[0405] Default uplink carrier;

[0406] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0407] The uplink carrier available for the HARQ feedback of MsgB in the two-step random access;

[0408] The DCI used for scheduling PUCCH in MsgB during two-step random access;

[0409] DCI used to schedule MsgB transmissions in two-step random access;

[0410] The uplink carrier corresponding to the MsgA transmission in two-step random access;

[0411] The uplink carrier indicated in the Success RAR during two-step random access.

[0412] In some embodiments, the first downlink random access information is a fallback indication, which indicates a fallback from two-step random access to four-step random access;

[0413] The target downlink carrier is determined based on at least one of the following:

[0414] The identifier of the terminal;

[0415] Paging messages sent by network-side devices;

[0416] The downlink carrier corresponding to the SSB transmission used for synchronization;

[0417] The fallback indication is available downlink carriers;

[0418] The downlink carrier associated with the uplink carrier in the MsgA transmission during two-step random access;

[0419] The downlink carrier indicated in MsgA during two-step random access;

[0420] The downlink carrier corresponding to MsgB transmission in two-step random access;

[0421] Reference carrier;

[0422] Default downlink carrier;

[0423] The downlink carrier with the highest signal quality;

[0424] The downlink carrier with the highest average signal quality.

[0425] It should be noted that the fallback indication can also be replaced by or be equivalent to the fallback RAR.

[0426] In some embodiments, the rollback instruction includes at least one of the following:

[0427] The eighth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to Msg3 in the four-step random access, or the eighth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of Msg3 in the four-step random access.

[0428] The ninth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the PDCCH corresponding to Msg4 in the four-step random access, or the ninth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the PDCCH corresponding to Msg4 in the four-step random access.

[0429] The tenth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the PDSCH corresponding to Msg4 in the four-step random access, or the tenth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the PDSCH corresponding to Msg4 in the four-step random access.

[0430] In this embodiment, the transmission / reception of MsgA and MsgB is the same as in 2-step RACH. Compared with contention-based 2-step RACH, when 2-step RACH falls back to 4-step RACH, the fallback indication includes information such as the uplink grant of Msg3. For multi-carrier initial access scenarios, the fallback indication may also include at least one of the following information:

[0431] Msg3 transmits a carrier. Optionally, for scenarios that support Msg3 repetition, the backoff indication may include one or more carriers, such as supporting repetition on different carriers.

[0432] Msg4 corresponds to the PDCCH listening carrier;

[0433] Msg4 corresponds to the receive carrier of the PDSCH.

[0434] Optionally, the transmit carrier of the PDSCH corresponding to Msg4 can also be indicated by the DCI in the PDCCH corresponding to Msg4.

[0435] Optionally, the rollback instruction can be carried by a rollback RAR or other MAC CE.

[0436] In some embodiments, the wireless communication method 200 further includes:

[0437] The terminal sends third information;

[0438] The third information is used to indicate whether the terminal supports random access based on multiple carriers or multiple carrier groups, or the third information is used to indicate whether the terminal supports transmitting random access messages through different carriers, or the third information is used to indicate whether the terminal supports transmitting uplink random access messages through different carriers, or the third information is used to indicate whether the terminal supports transmitting downlink random access messages through different carriers.

[0439] Correspondingly, the network-side devices receive third-party information from the terminal.

[0440] In this embodiment, the terminal reports third information to the network-side device, thereby enabling the network-side device to determine whether the terminal supports random access based on multiple carriers or multiple carrier groups, or whether the terminal supports transmitting random access messages via different carriers, or whether the terminal supports transmitting uplink random access messages via different carriers, or whether the terminal supports transmitting downlink random access messages via different carriers.

[0441] Therefore, in this embodiment, the terminal determines the target uplink carrier based on the first information, and the terminal sends first uplink random access information based on the target uplink carrier; and / or, the terminal determines the target downlink carrier based on the first information, and the terminal receives first downlink random access information based on the target downlink carrier. Specifically, for the multi-carrier random access process, the target uplink carrier can be flexibly adjusted within an uplink carrier group or at least two uplink carriers, and / or the target downlink carrier can be flexibly adjusted within a downlink carrier group or at least two downlink carriers. While ensuring uplink and downlink transmission coverage, this helps to better achieve load balancing, reduce inter-carrier interference, and improve the performance of multi-carrier random access.

[0442] The technical solution of this application is described in detail below through specific embodiments.

[0443] Example 1 uses the contention-based four-step random access procedure (CBRA with 4-step RACH) as an example.

[0444] In Example 1, during the initial access process or random access process, the downlink carrier or uplink carrier to be transmitted is flexibly selected from multiple uplink available carriers or downlink available carriers. The uplink available carrier and the downlink available carrier can be flexibly paired without the need for a constrained correspondence.

[0445] For a contention-based four-step random access procedure, uplink and downlink information can be transmitted and received on different carriers within the carrier group at different stages. For example, as shown in Figure 5, the terminal completes synchronization and receives system messages on downlink carrier 1, sends a random access preamble on uplink carrier 1, receives a random access response on downlink carrier 2, transmits Msg3 on uplink carrier 3, and receives Msg4 on downlink carrier 3.

[0446] PRACH transmits carrier

[0447] The terminal can select an uplink carrier to transmit the PRACH based on the PRACH indicated by the network-side device (optionally, within the target uplink carrier group).

[0448] Optionally, the target uplink carrier group can be the uplink PRACH carrier group configured by the network-side device, or the target uplink carrier group can be the uplink random access carrier group configured by the network-side device (for example, the network-side device does not distinguish between PRACH carrier groups and non-PRACH carrier groups, but uniformly configures them as uplink random access carrier groups).

[0449] The PRACH carrier can be selected in one of the following ways:

[0450] The downlink RSRP is determined based on the reference carrier. If the network-side equipment is configured with a corresponding selection threshold, when the downlink RSRP of the reference carrier is higher than or not lower than the threshold, the PRACH transmission carrier is randomly selected from the target uplink carrier group. When the downlink RSRP of the reference carrier is lower than or not higher than the threshold, the uplink carrier with the lowest frequency point in the target uplink carrier group is selected as the PRACH transmission carrier. Optionally, the reference carrier can be configured by the network, or it can be an anchor carrier, or a carrier selected by the terminal through RSRP measurement.

[0451] The uplink carrier associated with the downlink carrier with the highest downlink RSRP in the target uplink carrier group is selected as the transmit carrier of PRACH; wherein, each uplink carrier in the target uplink carrier group has an associated downlink carrier, and each downlink carrier is associated with one PRACH carrier;

[0452] The uplink carrier in the target uplink carrier group is selected as the PRACH transmission carrier by one of at least two uplink carriers associated with the downlink carrier whose downlink RSRP is higher or lower than a threshold; wherein, each uplink carrier in the target uplink carrier group has an associated downlink carrier, and each downlink carrier is associated with at least two PRACH carriers; for example, the network-side equipment is configured with a corresponding selection threshold, and the threshold range is selected for the corresponding uplink carrier.

[0453] The terminal selects a transmission carrier based on at least two uplink carriers associated with the downlink carrier with the highest downlink RSRP in the target uplink carrier group, where one uplink carrier is the PRACH transmission carrier; the terminal may also select the carrier randomly.

[0454] Optionally, in multi-carrier scenarios, specifically for PRACH repetition, PRACH can be repeatedly transmitted on the same or different carriers. For example, repeated PRACH can be transmitted on different carriers within an uplink carrier group. In one possible implementation, when configuring SSB-RO or PRACH mapping relationships, the network-side device configures a first type of SSB-RO or PRACH mapping and a second type of SSB-RO or PRACH mapping. The first type of SSB-RO or PRACH mapping includes a mapping between an SSB on one downlink carrier and an RO / PRACH on one uplink carrier; the second type of SSB-RO or PRACH mapping includes a mapping between an SSB on one downlink carrier and an RO / PRACH on more than one uplink carrier. The multiple uplink carriers in the second type of SSB-RO or PRACH mapping can be uplink carriers used for PRACH repetition. In the PRACH repetition scenario, PRACH / RO repetitions on different carriers by the terminal are associated with the same SSB index or SSB beam (the same downlink beam on the same downlink carrier).

[0455] Optionally, the terminal can also indicate whether it supports access based on multiple carriers or multiple carrier groups by sending a preamble. For example, it can indicate whether different messages during random access are supported to be transmitted via different carriers, where the messages may include Msg2, Msg3, Msg4, and Msg5; or whether the terminal supports uplink transmission based on multiple carriers during random access, i.e., whether different messages during random access are supported to be transmitted via different carriers, where the messages include Msg3 and Msg5; or whether the terminal supports downlink reception based on multiple carriers during random access, such as whether different messages during random access are supported to be received via different carriers, where the messages include Msg2 and Msg4; or whether the terminal supports the transmission of a specific message during random access based on multiple carriers, where the message may include any one of Msg2, Msg3, Msg4, and Msg5. For instance, the preamble sent by the terminal can be grouped, and different groups of preambles can implicitly indicate whether access based on multiple carrier groups is supported, or whether reception on other downlink carriers associated with the uplink carrier is supported. Based on this information, the network-side equipment can further determine the downlink carrier during the random access process.

[0456] RAR receive carrier

[0457] After the terminal sends PRACH, it will detect / receive RAR messages on the corresponding carrier and within the corresponding time window, based on the protocol predefined or the network-side device configuration.

[0458] RAR receive carrier can be implemented in one of the following ways:

[0459] The network-side device configures a RAR receive carrier. For example, for each uplink carrier group associated with a downlink carrier group, the network-side device configures one of the carriers as a RAR receive carrier.

[0460] The downlink carrier associated with the PRACH transmission carrier. For example, if the PRACH is transmitted via the uplink carrier a, then the RAR receive carrier is the downlink carrier a corresponding to the uplink carrier a.

[0461] Based on a protocol-predefined method or a default carrier, for example, receiving based on a reference carrier, where the reference carrier can be an anchor carrier or a default carrier within a carrier group configured by the network-side device;

[0462] The carrier selected by the terminal when performing RSRP measurements, such as the carrier with the highest average SSB RSRP measurement result, or the carrier with the highest highest SSB RSRP measurement result.

[0463] In one possible implementation, the PDCCH corresponding to the RAR and the PDSCH corresponding to the RAR are received via the same carrier, which is determined in the manner described above.

[0464] In one possible implementation, the PDCCH and PDSCH corresponding to the RAR can be received using different carriers. The receiving carrier of the PDCCH corresponding to the RAR is determined in the manner described above, and the carrier of the PDSCH corresponding to the RAR is indicated by the PDCCH corresponding to the RAR.

[0465] Network-side equipment can configure or indicate the association between RAR DMRS and SSB. As mentioned earlier, the RAR received carrier and the SSB received carrier can be the same or different. For example, network-side equipment can configure the association between the first carrier SSB and the second carrier RAR DMRS; the association can be QCL, which can be QCL Type-D, meaning the spatial parameters are the same, or that they have the same beam; or it can be other types of QCL, such as QCL Type A (Doppler spread, Doppler offset, average delay, and average spread); QCL Type B (Doppler spread and Doppler offset); QCL Type C (average delay and Doppler offset).

[0466] RAR DMRS includes DMRS for RAR PDCCH and / or DMRS for RAR PDSCH.

[0467] Because uplink and downlink carriers are decoupled, the carriers carrying uplink information and downlink information do not have a predefined correspondence during the initial access process. Therefore, one RAR receive carrier may correspond to multiple PRACH transmit carriers. To solve the problem of overlapping RA-RNTI and preamble IDs corresponding to PRACH transmissions on different carriers and / or carrier groups, the RAR can explicitly or implicitly indicate the uplink carrier from which the corresponding PRACH originates. Several possible implementation methods are as follows:

[0468] The RAR indicates the carrier ID and / or carrier group ID, where the carrier ID and carrier group ID are the UL carrier and UL carrier group where the corresponding PRACH transmission is located.

[0469] The RA-RNTI range or the preamble ID corresponding to PRACH transmissions on different carriers and / or different carrier groups are different.

[0470] Uniform numbering of ROs on different carriers and / or different carrier groups in terms of time or frequency resources ensures that the calculated RA-RNTI is not duplicated.

[0471] An exemplary RA-RNTI calculation is as follows:

[0472] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id + 14 × 80 × 8 × N × ul_carrier_group_id, where s_id indicates the index of the first OFDM symbol of the PRACH, t_id indicates the index of the first slot of the PRACH in the system frame, f_id indicates the index of the PRACH in the frequency domain, ul_carrier_id represents the index of the uplink carrier within the uplink carrier group, ul_carrier_group_id represents the uplink carrier group index, and N represents the number of all uplink carriers in all uplink carrier groups with numbers less than that of the carrier group.

[0473] Another exemplary RA-RNTI calculation is as follows:

[0474] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id, where s_id indicates the index of the first OFDM symbol of the PRACH, t_id indicates the index of the first slot of the PRACH in the system frame, f_id indicates the index of the PRACH in the frequency domain, and ul_carrier_id represents the index of the uplink carrier within the uplink carrier group.

[0475] Msg 3 transmits carrier

[0476] After receiving the RAR message, the terminal will send Msg3 based on the UL grant instruction in the RAR message. The transmission carrier of Msg3 can also be indicated by the RAR.

[0477] In one possible implementation, the RAR includes a Msg3 transmit carrier indication and a transmission indication within that carrier. For example, the UL grant includes a transmit carrier index or the transmit carrier's number within a carrier group.

[0478] In one possible implementation, the RAR message contains UL grants for multiple carriers, and the terminal selects one of the carriers to send, ignoring the UL grants on the other carriers.

[0479] In one possible implementation, when there is no Msg3 transmission carrier indication in the RAR, the transmission carrier of Msg3 is the same as the transmission carrier of PRACH, or the default carrier configured by the network-side device.

[0480] In the multi-carrier scenario of this embodiment, for the Msg3 repetition scenario, Msg3 can be repeatedly transmitted on the same or different carriers. For example, repeated Msg3 can be transmitted on different carriers within the uplink carrier group, and the uplink carriers transmitting repeated Msg3 can be indicated in the RAR.

[0481] Optionally, Msg4 can support cross-carrier scheduling, that is, in scenarios where the PDCCH listening carrier corresponding to Msg4 and the PDSCH receiving carrier corresponding to Msg4 are different. One possible indication method is that the terminal carries the ability to schedule Msg4 across carriers within the initial access carrier group through Msg3.

[0482] Msg 4 Receive Carrier

[0483] Msg 4 can be used to carry conflict resolution messages. Optionally, it can also carry RRC setup messages, RRC resume messages, RRC reestablishment messages, etc.

[0484] In a multi-carrier scenario, the PDCCH reception corresponding to Msg4 and the PDSCH reception corresponding to Msg4 can be on the same carrier or on different carriers.

[0485] In one possible implementation, the RAR indicates the carrier that the PDCCH corresponding to Msg4 is listening to.

[0486] In one possible implementation, the protocol predefines that the PDCCH listening carrier corresponding to Msg 4 is the same as the RAR receiving carrier, or is received based on a reference carrier, wherein the reference carrier can be an anchor carrier or a default carrier within a carrier group configured by the network.

[0487] In one possible implementation, the network-side device configures the PDCCH receive carrier corresponding to Msg4. For example, the network-side device configures a certain carrier in the downlink carrier group as the PDCCH receive carrier corresponding to Msg4.

[0488] In one possible implementation, the PDCCH listening carrier corresponding to Msg 4 is determined based on the transmit carrier of Msg 3. For example, the downlink carrier corresponding to the transmit carrier of Msg 3 is used to listen to the PDCCH corresponding to Msg 4.

[0489] In one possible implementation, the RAR indicates the PDSCH receive carrier corresponding to Msg 4.

[0490] In one possible implementation, the protocol predefines the PDSCH listening carrier corresponding to Msg4 to be the same as the RAR receiving carrier, or receives the carrier based on a predefined / network configured default carrier, or the PDSCH listening carrier corresponding to Msg4 to be the same as the PDCCH listening carrier corresponding to Msg4.

[0491] In one possible implementation, the network-side device configures the PDSCH receive carrier corresponding to Msg4.

[0492] In one possible implementation, the method for determining the PDSCH carrier corresponding to Msg4 is related to the time-domain interval K0 between the PDCCH corresponding to Msg4 and the PDSCH corresponding to Msg4 configured by the network-side device.

[0493] When K0 is less than 1, the PDSCH carrier corresponding to Msg4 is based on RAR indication, or the above-mentioned protocol predefined / network configuration, or the same PDCCH carrier as Msg4;

[0494] When K0 is greater than 1, the PDSCH corresponding to Msg4 is indicated by the DCI in the PDCCH corresponding to Msg4.

[0495] In one possible implementation, the PDCCH and PDSCH corresponding to Msg4 are always on the same carrier, either predefined by the protocol or indicated by the network. For example, the carrier used for receiving Msg4 is indicated in the RAR (which applies to both the PDCCH and PDSCH corresponding to Msg4).

[0496] The carrier wave that the terminal receives for Msg4 can be the same as or different from the carrier wave that it receives for RAR.

[0497] When the RAR does not specify the Msg4 listening / receiving carrier scenario, the Msg4 listening / receiving carrier is the same as the RAR receiving carrier, or the downlink carrier corresponding to the Msg3 transmission, or the network-side device is configured to receive the Msg4 carrier, or the method is predefined by the protocol (based on the reference carrier).

[0498] In a multi-carrier scenario, for the Msg4 repetition scenario, Msg4 (including the PDCCH and / or PDSCH corresponding to Msg4) can be retransmitted on the same or different carriers, through RAR indication or network configuration of multiple transmission carriers corresponding to Msg4 repetition.

[0499] Network-side equipment configures or indicates the association between RAR DMRS and SSB. Network-side equipment can configure or indicate the association between Msg4 DMRS and SSB. As mentioned earlier, the Msg4 received carrier and the SSB received carrier can be the same or different. For example, network-side equipment can configure or indicate the association between the first carrier SSB and the second carrier Msg4 DMRS. The association can be QCL, which can be QCL Type-D, meaning the spatial parameters are the same, or that they have the same beam; it can also be other types of QCL relationships, such as QCL Type A (Doppler spread, Doppler offset, average delay, and average spread); QCL Type B (Doppler spread and Doppler offset); QCL Type C (average delay and Doppler offset); Msg4 DMRS includes DMRS for the PDCCH corresponding to Msg4 and / or DMRS for the PDSCH corresponding to Msg4.

[0500] Msg 4HARQ feedback

[0501] For Msg 4 transmissions, HARQ feedback is supported.

[0502] In one possible implementation, the HARQ feedback of Msg 4 is based on the PUCCH bearer. The network-side device configures one or more PUCCH carriers during the initial access phase, and the terminal transmits based on the configured default PUCCH carrier.

[0503] In one possible implementation, the HARQ feedback of Msg 4 is based on the PUCCH bearer. The network-side device configures one or more PUCCH carriers during the initial access phase, and the terminal determines the feedback carrier based on the PUCCH feedback carrier indicated by the scheduling DCI of Msg 4.

[0504] In one possible implementation, the HARQ feedback of Msg 4 is based on the PUCCH bearer. The network-side device configures one or more PUCCH carriers during the initial access phase. The Msg4 HARQ feedback carrier is the same as the Msg3 transmission carrier or the PRACH transmission carrier.

[0505] In one possible implementation, the HARQ feedback of Msg4 is based on MAC CE feedback, and the carrier carrying the HARQ feedback can be based on the scheduling DCI indication of Msg4.

[0506] In one possible implementation, the HARQ feedback of Msg4 is based on MAC CE feedback, and the carrier carrying the HARQ feedback is based on the DCI indication that schedules the MAC CE (PUSCH).

[0507] Msg 5 scheduling, Msg 5 sending, or Msg 5 retransmission carrier.

[0508] After receiving Msg4, the terminal needs to send Msg5 to complete the corresponding RRC connection establishment or recovery process. Msg5 can be used to carry the RRC setup complete message, RRC resume complete message, and RRC reestablishment complete message.

[0509] The transmission of Msg5 includes: a Msg5 scheduling carrier, a Msg5 transmission carrier, and optionally, a Msg5 retransmission carrier. In one possible implementation, the Msg5 scheduling carrier is indicated by the Msg4 scheduling DCI; or it is detected based on the default PDCCH configured by the network; or it is based on a reference carrier within the carrier group (such as an anchor carrier); or it is determined based on network / protocol preset rules, such as the Msg5 scheduling carrier being the same as the Msg4 scheduling carrier.

[0510] In one possible implementation, the transmission carrier of Msg5 is determined by its scheduling DCI indication or based on network / protocol preset rules, such as the same transmission carrier as Msg3.

[0511] In one possible implementation, similar to Msg3, for the scenario of repeated Msg5 transmission, Msg5 can be repeatedly transmitted on the same or different carriers. For example, repeated Msg5 can be transmitted on different carriers within the uplink carrier group, and the uplink carriers for transmitting repeated Msg5 can be indicated by the scheduling DCI or configured by the network.

[0512] In Example 1, during the random access process, the transmission carrier and reception carrier of different messages can be different. Accordingly, the terminal needs to determine the reception beam and / or transmission beam on different carriers.

[0513] Beamforming and Indication

[0514] Network-side equipment configures carriers with beam association relationships into a downlink carrier group. Optionally, the network-side equipment indicates the SSB association relationship between different carriers within the carrier group, for example, indicating the association between SSBs on the first carrier and SSBs on the second carrier. This indication message can be carried through system messages or RRC signaling. For example, the number of SSBs on the first carrier within the downlink carrier group may be different from the number of SSBs on the second carrier, but the beams have an association relationship, such as an inclusion relationship.

[0515] In this embodiment, SSB transmission can be carried out on one or more carriers, or in one or more carrier groups, or on a specific carrier in each carrier group.

[0516] During random access, the downlink channel receive beam can be based on explicit indication.

[0517] In one possible implementation, the RAR indicates the SSB index associated with the PDCCH corresponding to Msg 4 and / or the SSB index associated with the PDSCH corresponding to Msg 4, and optionally, a carrier indication.

[0518] In one possible implementation, in the Msg4 cross-carrier scheduling scenario, the DCI of the PDCCH corresponding to Msg4 indicates the SSB index associated with the carrier where the PDSCH corresponding to Msg4 is located; at this time, the indication information can simultaneously include the carrier indication and the beam indication (SSB index) on that carrier.

[0519] During random access, the downlink channel receive beam is determined based on the inter-carrier correlation.

[0520] In one possible implementation, the reception of the downlink carrier is determined based on carrier association. For example, if the RAR receive carrier is on the second carrier, its reception beam can be determined based on the first carrier associated with the second carrier, for example, based on the beam corresponding to the SSB with the highest RSRP of the first carrier (corresponding scenario: the second carrier does not transmit SSB, and the network-side device is configured to reference / multiplex the SSB of the first carrier).

[0521] The downlink channel receive beam is determined based on explicit indication and inter-carrier correlation.

[0522] In one possible implementation, the downlink channel is received on the second carrier, and the downlink channel receive beam indication information includes the beam indication of the reference carrier configured by the network. In this case, the terminal determines the receive beam on the second carrier based on the beam association relationship between the second carrier and the reference carrier.

[0523] Optionally, the downlink channel includes at least one of the following: PDCCH corresponding to the scheduled RAR, PDSCH corresponding to the carried RAR, PDCCH corresponding to the scheduled Msg4, PDSCH corresponding to the carried Msg4, and PDCCH corresponding to the scheduled Msg5.

[0524] During random access, the uplink channel transmit beam can be determined using one of the following methods:

[0525] Same as PRACH transmit beam;

[0526] Based on the association between the transmit carrier and the reference carrier, the terminal determines the uplink transmission beam.

[0527] Optionally, the uplink channel includes at least one of the following: a PUSCH carrying Msg3, a PUCCH carrying HARQ feedback for Msg4, and a PUSCH carrying Msg5.

[0528] SSB and RO mapping

[0529] After determining the PRACH transmission carrier using the above method, the terminal also needs to determine the corresponding Random Access Occasion (RACH occasion, RO). The selected RO indicates the optimal downlink beam corresponding to the terminal in the network. The mapping between SSB and RO can take different forms.

[0530] In one possible implementation, each preamble transmit carrier includes a set of SSB-RO mappings, which can be intra-carrier mappings or cross-carrier mappings. For example, if the downlink carrier (DL carrier) corresponding to the uplink carrier (UL carrier) selected by the terminal does not contain an SSB, the terminal measures the SSBs on other DL carriers associated with that carrier and determines the PRACH resource based on the uplink / downlink carrier associations configured by the network-side equipment. That is, the network-side equipment configures the association of the downlink carrier SSB to the PRACH on the UL carrier (the corresponding downlink carrier does not contain an SSB) to determine the PRACH resource. Another example is that when the preamble transmit carrier (e.g., the first carrier) is different from the SSB receive carrier (e.g., the second carrier), the current carrier preamble transmit RO is determined based on the inter-carrier SSB mapping (e.g., the SSB mapping between the first and second carriers) and the SSB-RO configured for the preamble transmit carrier (configured for the first carrier).

[0531] In one possible implementation, each preamble transmits a carrier and contains multiple sets of SSB-RO mappings, each set corresponding to a different downlink carrier / carrier association (the downlink carrier corresponding to the uplink carrier).

[0532] Example 2 uses the non-contention-based four-step random access procedure (CFRA with 4-step RACH) as an example.

[0533] In Example 2, for a non-contention-based random access procedure, a downlink carrier or uplink carrier for transmission is flexibly selected from multiple available uplink carriers / available downlink carriers. The available uplink carriers and available downlink carriers can be flexibly paired without the need for a constrained correspondence.

[0534] For a non-contention-based four-step random access procedure, uplink and downlink information can be transmitted and received through different carriers within a carrier group, as shown in Figure 6.

[0535] For a non-contention-based random access procedure, the carrier in which the terminal receives the allocated random access preamble, the random access preamble transmit carrier, and the RAR receive carrier can be the same or different.

[0536] Similar to Embodiment 1 above, for a non-contention-based four-step random access procedure, the network-side device can also configure one or more uplink carrier groups and / or downlink carrier groups. The description of the carrier groups is the same as in Embodiment 1 above, and will not be repeated here.

[0537] For multi-carrier random access scenarios, the CFRA configuration configured by the higher layer includes random access configurations for different carrier groups and different carriers; optionally, it also includes selection conditions for different carrier groups and different carriers.

[0538] For a contention-free four-step random access procedure triggered by a PDCCH order, the DCI in the PDCCH order indicates the assigned random access preamble. Optionally, the DCI carries a carrier indication and / or a carrier group indication. When the DCI does not contain this indication, PRACH is transmitted based on the default carrier configured by the network-side equipment.

[0539] For RAR reception based on a non-contention-based four-step random access procedure, the RAR receive carrier can be determined in one of the following ways:

[0540] Network-side equipment is configured with carriers or carriers and carrier groups for RAR reception;

[0541] Determined based on the carrier or carrier and carrier group transmitted by the random access preamble, such as its corresponding downlink carrier / downlink carrier group;

[0542] Based on a predefined carrier, such as a reference carrier (e.g., an anchor carrier), or a default carrier configured by the network-side device.

[0543] Example 3 uses a contention-based two-step random access procedure (CBRA with 2-step RACH) as an example.

[0544] In Example 3, for the contention-based 2-step initial access procedure / random access procedure, the downlink carrier or uplink carrier to be transmitted is flexibly selected from multiple uplink available carriers / downlink available carriers, wherein the uplink available carrier and the downlink available carrier can be flexibly paired.

[0545] For multi-carrier-based random access, the 4-step RACH configuration in Embodiments 1 and 2 is mandatory, and optionally, a 2-step RACH configuration may also be included.

[0546] Similar to Example 1, for 2-step RACH, the network-side device can configure one or more uplink carrier groups and / or downlink carrier groups. The determination / indication of carrier groups is the same as in Example 1, and will not be listed here again.

[0547] Specifically, as shown in Figure 7, the contention-based 2-step RACH includes the transmission of Msg A and the reception of Msg B. Msg A includes the PRACH part corresponding to Msg A carrying the random access preamble and the PUSCH part corresponding to Msg A carrying the payload. For multi-carrier random access scenarios, based on the scheme in this embodiment, the PRACH corresponding to Msg A, the PUSCH corresponding to Msg A, the PDCCH corresponding to Msg B, and the PDSCH corresponding to Msg B can be on the same carrier or on different carriers.

[0548] Msg A sends a carrier wave

[0549] The PRACH corresponding to MsgA and the PUSCH corresponding to MsgA can be transmitted on the same or different carriers.

[0550] In one possible implementation, the network-side device configures the PRACH corresponding to MsgA and the PUSCH corresponding to MsgA to be transmitted on the same carrier. Based on the PRACH carrier corresponding to MsgA, the PUSCH carrier corresponding to MsgA, i.e., the resource, is also determined. The carrier determination method for the PRACH corresponding to MsgA is the same as in Embodiment 1, including:

[0551] The downlink RSRP is determined based on the reference carrier. If the network-side equipment is configured with a corresponding selection threshold, when the downlink RSRP of the reference carrier is higher than or not lower than the threshold, the PRACH transmission carrier is randomly selected from the target uplink carrier group. When the downlink RSRP of the reference carrier is lower than or not higher than the threshold, the uplink carrier with the lowest frequency point in the target uplink carrier group is selected as the PRACH transmission carrier. Optionally, the reference carrier can be configured by the network, or it can be an anchor carrier, or a carrier selected by the terminal through RSRP measurement.

[0552] The uplink carrier associated with the downlink carrier with the highest downlink RSRP in the target uplink carrier group is selected as the transmit carrier of PRACH; wherein, each uplink carrier in the target uplink carrier group has an associated downlink carrier, and each downlink carrier is associated with one PRACH carrier.

[0553] In one possible implementation, the network-side device provides different types of MsgA configurations, including: configurations where the MsgA-corresponding PRACH and PUSCH are transmitted on the same carrier, and configurations where the MsgA-corresponding PRACH and PUSCH are transmitted on different carriers. The terminal selects the corresponding transmission resources based on its capabilities and other factors. For terminals that choose to transmit the MsgA-corresponding PRACH and PUSCH on different carriers, this implicitly indicates that the terminal supports multi-carrier transmission and reception capabilities during random access.

[0554] In one possible implementation, the network-side device provides configurations for the PRACH and PUSCH corresponding to MsgA on different carriers, as well as carrier selection conditions for the PUSCH corresponding to MsgA. In this approach, the PRACH corresponding to MsgA is transmitted via a first carrier, and the PUSCH corresponding to MsgA can be transmitted via either the first carrier or a second carrier (or other uplink carriers within a carrier group). In some embodiments, the PUSCH carrier selection conditions can be based on data volume. For example, the network-side device configures data thresholds on different carriers, and the terminal selects the corresponding PUSCH carrier corresponding to MsgA based on the load size. Different PUSCH carriers corresponding to MsgA can be associated with different MsgA-corresponding PRACH resources, preambles, or MsgA carriers.

[0555] In one possible implementation, different groups of the PRACH and / or PUSCH corresponding to MsgA are configured to different carriers / carrier groups. For example, the PUSCH corresponding to MsgA has two groups, corresponding to Msg3 with a large payload and Msg3 with a small payload, respectively. This can be distinguished by the group in which the preamble is located. The network can be configured so that the preamble transmitted on the first carrier corresponds to Msg3 with a small payload, and the preamble transmitted on the second carrier corresponds to Msg3 with a large payload.

[0556] In one possible implementation, different carriers / carrier groups are configured with independent PRACH resources corresponding to MsgA and / or PUSCH resources corresponding to MsgA.

[0557] Optionally, the PUSCH corresponding to Msg A may carry an indication of whether cross-carrier scheduling capability of Msg B is supported.

[0558] Optionally, the UE carries a Msg B carrier indication in the PUSCH corresponding to Msg A, which is used to request the network to send Msg B through the carrier, or to notify the network that it prefers to send the carrier for Msg B.

[0559] SSB mapping to RO and / or MsgAPUSCH

[0560] The configuration message provided by the network-side device contains the mapping / association relationship between the SSB and the PRACH and / or PUSCH corresponding to MsgA. The PRACH carrier and PUSCH carrier corresponding to MsgA can be the same or different carriers. Similarly, the SSB transmission carrier configured by the network can be a corresponding carrier or a different carrier than the PRACH carrier corresponding to MsgA. For example, the configuration message of the network-side device includes the mapping relationship between the SSB on the first downlink carrier and the PRACH corresponding to Msg A on the first uplink carrier, and the PUSCH corresponding to the SSB on the first downlink carrier and the Msg A on the second uplink carrier. Based on the measurement results of the SSB on the first downlink carrier, the terminal determines the PRACH resource corresponding to Msg A on the first uplink carrier. For example, different SSB beams correspond to different PRACH resources corresponding to different Msg A in frequency division / time division. Based on the measurement results of the SSB on the first downlink carrier, the terminal determines the PUSCH resource corresponding to Msg A on the second uplink carrier. Different SSB beams correspond to different MsgAPUSCH resources in frequency division.

[0561] One schematic diagram is shown in Figure 8. Specifically, in Figure 8, RO stands for RACH occasion, used for PRACH transmission corresponding to MsgA; PO stands for PUSCH occasion, used for MsgAPUSCH transmission. In this example, the number of SSBs (also called SSB beams or SSB indices) in the first downlink carrier is 4. The SSBs in the first downlink carrier correspond one-to-one with the ROs on the first uplink carrier, and / or, the SSBs in the first downlink carrier correspond one-to-one with the POs on the second uplink carrier.

[0562] MsgB receives carrier

[0563] The reception of MsgB includes listening to the PDCCH corresponding to MsgB and receiving the PDSCH corresponding to MsgB. Furthermore, MsgB supports HARQ feedback. Similar to Embodiment 1 above, for multi-carrier random scenarios, it is also necessary to determine the MsgB feedback carrier. In multi-carrier scenarios, the PDCCH reception and PDSCH reception corresponding to MsgB can be on the same carrier or different carriers.

[0564] In one possible implementation, the PDCCH detection carrier corresponding to MsgB can be a protocol-predefined / network-configured reference carrier, wherein the reference carrier can be an anchor carrier or a default carrier within a network-configured carrier group.

[0565] In one possible implementation, the network-side device configures the PDCCH receive carrier corresponding to MsgB. For example, the network-side device configures a certain carrier in the downlink carrier group as the PDCCH receive carrier corresponding to MsgB.

[0566] In one possible implementation, the PDCCH listening carrier corresponding to MsgB is determined based on the transmit carrier of MsgA. For example, the downlink carrier corresponding to the PRACH transmit carrier corresponding to MsgA is used to listen to the PDCCH corresponding to MsgB, or the downlink carrier corresponding to the PUSCH transmit carrier corresponding to MsgA is used to listen to the PDCCH corresponding to MsgB.

[0567] In one possible implementation, the PDSCH receive carrier corresponding to MsgB is the same as the PDCCH detection carrier corresponding to MsgB by default.

[0568] In one possible implementation, the PDSCH detection carrier corresponding to MsgB can be a protocol-predefined / network-side device-configured reference carrier, wherein the reference carrier can be an anchor carrier or a default carrier within a carrier group configured by the network-side device.

[0569] In one possible implementation, the network-side device configures the PDSCH receive carrier corresponding to MsgB. For example, the network-side device configures a certain carrier in the downlink carrier group as the PDSCH receive carrier corresponding to MsgB.

[0570] In one possible implementation, the method for determining the PDSCH corresponding to MsgB is related to the time-domain interval K0 between the PDCCH corresponding to MsgB and the PDSCH corresponding to MsgB configured by the network-side device.

[0571] When K0 is less than 1, the PDSCH carrier corresponding to MsgB is based on RAR indication, or the above-mentioned protocol predefined / network configuration, or the same PDCCH carrier as MsgB.

[0572] When K0 is greater than 1, the PDSCH corresponding to MsgB is indicated by the DCI in the PDCCH corresponding to MsgB.

[0573] MsgB HARQ feedback carrier

[0574] In one possible implementation, the HARQ feedback carrier of Msg B can be indicated by RAR, such as the PUCCH carrier indicated in the success RAR.

[0575] In one possible implementation, the HARQ feedback carrier of Msg B is indicated by the scheduling DCI of Msg B.

[0576] Example 4 uses a non-contention-based two-step random access procedure (CFRA with 2-step RACH) as an example.

[0577] In Example 4, for the non-contention-based 2-step initial access procedure / random access procedure, the downlink carrier or uplink carrier to be transmitted is flexibly selected from multiple uplink available carriers / downlink available carriers, wherein the uplink available carrier and the downlink available carrier can be flexibly paired.

[0578] For multi-carrier-based random access, the 4-step RACH configuration in Embodiments 1 and 2 is mandatory, and optionally, a 2-step RACH configuration may also be included.

[0579] Similar to Example 1, for 2-step RACH, the network-side device can configure one or more uplink carrier groups and / or downlink carrier groups. The determination / indication of carrier groups is the same as in Example 1, and will not be listed here again.

[0580] Specifically, as shown in Figure 9, the non-contention-based 2-step RACH includes the transmission of Msg A and the reception of Msg B. Msg A includes the PRACH part corresponding to Msg A carrying the random access preamble and the PUSCH part corresponding to Msg A carrying the payload. For multi-carrier random access scenarios, based on the scheme in this embodiment, the PRACH corresponding to Msg A, the PUSCH corresponding to Msg A, the PDCCH corresponding to Msg B, and the PDSCH corresponding to Msg B can be on the same carrier or on different carriers.

[0581] Compared to contention-based two-step random access, contention-free two-step random access adds a random access preamble and a PUSCH allocation process, as shown in step 0 of Figure 9. The transmission of MsgA and the reception of MsgB are similar to those in contention-based two-step random access.

[0582] For a non-contention-based two-step random access procedure, the carrier in which the terminal receives the allocated random access preamble, the random access preamble transmit carrier, and the RAR receive carrier can be the same or different.

[0583] Similar to Embodiment 1, for non-contention-based two-step random access, the network-side device can also configure one or more uplink carrier groups and / or downlink carrier groups. The description of the carrier groups is the same as in Embodiment 1, and will not be repeated here.

[0584] For multi-carrier random access scenarios, the CFRA configuration configured by the higher layer includes 2-step random access configurations for different carrier groups and different carriers; optionally, it also includes selection conditions for different carrier groups and different carriers.

[0585] In one possible implementation, the PDCCH order triggers a non-contention-based random access, and the PDCCH DCI indicates the random access preamble of the allocated MsgA. Optionally, the DCI carries a PRACH carrier indication and / or carrier group indication corresponding to MsgA, as well as a PUSCH transmission carrier indication corresponding to MsgA.

[0586] In one possible implementation, the CFRA configuration configured by the higher layer includes the association between the PRACH corresponding to MsgA and the PUSCH corresponding to MsgA. PUSCHs corresponding to MsgA on different carriers can be associated with PRACHs corresponding to MsgA on the same carrier. The PUSCH carrier corresponding to MsgA is distinguished by the PRACH resource or premble. The PDCCH order triggers a non-contention-based random access mechanism. The allocated MsgA random access preamble is indicated in the PDCCH DCI. Optionally, the DCI carries a carrier indication and / or a carrier group indication. The PUSCH transmission carrier corresponding to MsgA is determined based on the allocated MsgA random access preamble.

[0587] When the DCI does not contain the carrier / carrier group indication, MsgA (including the PRACH and PUSCH corresponding to MsgA) is transmitted based on the default carrier configured by the network-side device.

[0588] For MsgB reception in a non-contention-based random access procedure, the methods described above for contention-based 2-step RACH are similar and will not be listed here again.

[0589] Example 5, taking the contention-based two-step random access procedure fallback (CBRA with 2-step RACH fallback) as an example, can be illustrated as shown in Figure 10.

[0590] In Example 5, the transmission / reception of MsgA and MsgB is the same as in 2-step RACH. Compared to contention-based 2-step RACH, when 2-step RACH falls back to 4-step RACH, the fallback indication includes information such as the uplink grant of Msg3. For multi-carrier initial access scenarios, the fallback indication may also include at least one of the following information:

[0591] Msg3 transmits a carrier; optionally, for scenarios that support Msg3 repetition, this indication may include one or more carriers, i.e., support repetition on different carriers;

[0592] Msg4 corresponds to the PDCCH listening carrier;

[0593] Msg 4 corresponds to the PDSCH receive carrier.

[0594] Optionally, the transmit carrier of the PDSCH corresponding to Msg4 can also be indicated by the DCI in the PDCCH corresponding to Msg4.

[0595] The fallback indication can be carried by a fallback RAR or other MAC CE.

[0596] Example 6: Taking the determination of the random access carrier based on the UE identifier as an example.

[0597] Unlike the previous embodiments, in Embodiment 6, the uplink / downlink carrier in the random access process can be dynamically adjusted as described in the previous embodiments; or the uplink and / or downlink carrier in the random access process can be fixed. For example, if the network-side device is configured with multiple random access carriers, after the random access carrier is determined based on the terminal identifier, all relevant messages in the random access process are transmitted through that carrier.

[0598] In Example 6, the determination of the carrier / carrier group used in the random access process is related to the terminal identifier, and the protocol defines or the network-side device configures the association between the carrier / carrier group and the terminal identifier.

[0599] In one possible implementation, the network-side device configures one or more carrier groups, with each carrier group associated with a group of UEs. The association between the carrier group and the UE identifier is predefined by the protocol or configured by the network-side device. For example, the network-side device configures two carrier groups. Terminals with mod UE ID = 0 are associated with the first carrier group, and terminals with mod UE ID = 1 are associated with the second carrier group, where mod represents the modulo operation. The terminal identifier can be any one of C-RNTI, TMSI, or IMSI. The terminal determines the carrier group based on the above method. Further, within the determined carrier group, it transmits and receives random access procedure messages through different carriers; or, within the determined carrier group, it selects the optimal carrier and / or beam for access, such as selecting the carrier and SSB with the highest RSRP, and uses this carrier and / or beam to complete the transmission and reception of messages during the random access procedure.

[0600] In one possible implementation, the network-side device configures multiple carriers for random access, with each carrier associated with a group of UEs. The association between carriers and UE identifiers is predefined by the protocol or configured by the network-side device. For example, the network-side device configures two carriers: terminals with mod UE ID = 0 are associated with the first carrier, and terminals with mod UE ID = 1 are associated with the second carrier, where mod represents the modulo operation. The terminal identifier can be any one of C-RNTI, TMSI, or IMSI. The terminal determines the random access carrier based on this method and performs the transmission and reception of random access procedure messages.

[0601] In one possible implementation, the network-side device configures multiple carriers for uplink transmission or downlink reception during random access (i.e., uplink and downlink are configured separately, or only uplink or downlink can be configured). Each carrier is associated with a group of UEs, and the association between the carrier and the UE identifier is predefined by the protocol or configured by the network-side device.

[0602] Example 7, taking paging indication random access carrier as an example.

[0603] Unlike the previous embodiments, in Embodiment 7, the uplink / downlink carrier in the random access process can be dynamically adjusted as described in the previous embodiments; or the uplink / downlink carrier in the random access process can be fixed, such as the network-side device configuring multiple uplink carriers, and configuring a corresponding downlink carrier for each uplink carrier. After the network indicates or the terminal selects the uplink carrier, the subsequent random access process uses the uplink carrier and its corresponding downlink carrier for transmission.

[0604] In Example 7, the carrier used in the random access process can be indicated by the network. In one possible implementation, the paging message carries an uplink carrier indication and / or a downlink carrier indication. For example, the paging message carries a random access transmission carrier indication, and the uplink messages in the random access process (including at least one of Msg1, MsgA, Msg3, and Msg5 mentioned above) are transmitted through the carrier indicated by the random access transmission carrier indication; the terminal determines its associated downlink carrier based on the random access transmission carrier indication, and the downlink messages in the random access process (including at least one of the PDCCHs corresponding to RAR, Msg4, and Msg5 mentioned above) are received through the determined associated downlink carrier.

[0605] The wireless communication method provided in this application can be executed by a wireless communication device. This application uses an example of a wireless communication device executing the wireless communication method to illustrate the wireless communication device provided in this application.

[0606] This application provides a wireless communication device. As an example, the wireless communication device may be a communication equipment or a component within a communication equipment, such as a chip. The communication equipment may be a terminal, a network-side device, or a server, etc. Exemplarily, the terminal may include, but is not limited to, the type of terminal 11 listed above, and the network-side device may include, but is not limited to, the type of network-side device 12 listed above. This application does not impose specific limitations.

[0607] The wireless communication device includes a receiving module, a transmitting module, and a processing module. These modules can be implemented in software or hardware. When implemented in hardware, the processing module can be implemented by a processor. For example, the processor can include general-purpose processors, special-purpose processors, such as a Central Processing Unit (CPU), microprocessor, Digital Signal Processor (DSP), Artificial Intelligence (AI) processor, Graphics Processing Unit (GPU), Application Specific Integrated Circuit (ASIC), Network Processor (NP), Field Programmable Gate Array (FPGA), or other programmable logic devices, gate circuits, transistors, discrete hardware components, etc. The receiving and transmitting modules can be implemented by a communication interface, which can include one or more of the following: transceiver, pins, circuits, bus, radio frequency unit, etc.

[0608] Referring to Figure 11, when the wireless communication device is a terminal or a component in a terminal, the wireless communication device 300 includes: a processing module 301, a transmitting module 302, and a receiving module 303;

[0609] The processing module 301 or the receiving module 303 is used to acquire first information; wherein, the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0610] The processing module 301 is further configured to determine a target uplink carrier based on the first information, and the transmitting module 302 is configured to transmit first uplink random access information based on the target uplink carrier; and / or,

[0611] The processing module 301 is further configured to determine a target downlink carrier based on the first information, and the receiving module 303 is configured to receive first downlink random access information based on the target downlink carrier.

[0612] In some embodiments, the processing module 301 is specifically used for:

[0613] Determine a target uplink carrier group from the at least one uplink carrier group, and determine the target uplink carrier from the target uplink carrier group; or,

[0614] The target uplink carrier is determined from the at least two uplink carriers;

[0615] And / or,

[0616] Determine a target downlink carrier group from the at least one downlink carrier group, and determine the target downlink carrier from the target downlink carrier group; or,

[0617] The target downlink carrier is determined from the at least two downlink carriers.

[0618] In some embodiments, the target uplink carrier group is determined based on at least one of the following:

[0619] The first uplink random access information includes the available uplink carrier group, the identification information of the wireless communication device 300, the identification information of the terminal group to which the wireless communication device 300 belongs, the paging message sent by the network-side device, the uplink carrier group associated with the downlink carrier group selected by the wireless communication device 300, the average signal quality of all downlink carriers in the downlink carrier group selected by the wireless communication device 300, the highest signal quality of all downlink carriers in the downlink carrier group selected by the wireless communication device 300, the amount of uplink data to be transmitted by the wireless communication device 300, the amount of uplink buffered data by the wireless communication device 300, the uplink quality of service (QoS) of the wireless communication device 300, and the uplink transmission delay of the wireless communication device 300.

[0620] And / or,

[0621] The target downlink carrier group is determined based on at least one of the following:

[0622] The first downlink random access information includes the available downlink carrier group, the identification information of the wireless communication device 300, the identification information of the terminal group to which the wireless communication device 300 belongs, the paging message sent by the network side device, the downlink carrier group containing the downlink carrier with the highest measured signal quality in the at least one downlink carrier group, and the downlink carrier group with the highest average signal quality among all downlink carriers in the at least one downlink carrier group.

[0623] In some embodiments, a downlink carrier group is associated with one or more uplink carrier groups; and / or,

[0624] An uplink carrier group is associated with one or more downlink carrier groups.

[0625] In some embodiments, the first information includes the association between the uplink carrier group and the downlink carrier group;

[0626] or,

[0627] The association between the uplink carrier group and the downlink carrier group is determined based on at least one of the following:

[0628] Frequency band, frequency band combination, spectrum range, bandwidth portion (BWP).

[0629] In some embodiments, the downlink carriers within each downlink carrier group of the at least one downlink carrier group satisfy at least one of the following conditions:

[0630] Some or all of the downlink carriers correspond to the same synchronization signal block (SSB) index;

[0631] There is a correlation between the SSB indices corresponding to some or all downlink carriers;

[0632] The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB.

[0633] A downlink carrier's SSB index is associated with one or more uplink carriers' random access opportunities (ROs).

[0634] An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices;

[0635] An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers;

[0636] A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers;

[0637] or,

[0638] The downlink carrier group in the at least one downlink carrier group satisfies at least one of the following conditions:

[0639] Some or all downlink carrier groups correspond to the same SSB index;

[0640] There is a correlation between the SSB indices corresponding to some or all downlink carrier groups;

[0641] An SSB index corresponding to a downlink carrier group is associated with one or more ROs corresponding to uplink carrier groups.

[0642] An RO corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups.

[0643] An SSB index corresponding to a downlink carrier group is associated with one or more random access preambles corresponding to uplink carrier groups.

[0644] A random access preamble corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups;

[0645] or,

[0646] The downlink carriers of the at least two downlink carriers satisfy at least one of the following conditions:

[0647] Some or all downlink carriers correspond to the same SSB index;

[0648] There is a correlation between the SSB indices corresponding to some or all downlink carriers;

[0649] The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB.

[0650] An SSB index corresponding to a downlink carrier is associated with one or more ROs corresponding to uplink carriers.

[0651] An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices;

[0652] An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers;

[0653] A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers.

[0654] In some embodiments, when an SSB index corresponding to a downlink carrier is associated with an RO corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier is associated with a random access preamble corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers for uplink repetitive transmission.

[0655] or,

[0656] When an SSB index corresponding to a downlink carrier group is associated with an RO corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier group is associated with a random access preamble corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission.

[0657] In some embodiments, the receiving module 303 is further configured to receive second information;

[0658] The second information includes at least one of the following:

[0659] The conditions that the downlink carriers in each downlink carrier group of the at least one downlink carrier group satisfy;

[0660] The conditions that the downlink carrier groups in the at least one downlink carrier group satisfy;

[0661] The conditions that the downlink carriers of the at least two downlink carriers satisfy.

[0662] In some embodiments, repeated transmissions of the first uplink random access information correspond to the same uplink carrier or the same uplink carrier group, or repeated transmissions of the first uplink random access information correspond to different uplink carriers or different uplink carrier groups.

[0663] And / or,

[0664] The repeated transmission of the first downlink random access information corresponds to the same downlink carrier or the same downlink carrier group, or the repeated transmission of the first downlink random access information corresponds to different downlink carriers or different downlink carrier groups.

[0665] In some embodiments, the first uplink random access information is the Physical Random Access Channel (PRACH) in the four-step random access process.

[0666] The target uplink carrier is determined based on at least one of the following:

[0667] The identifier of the wireless communication device 300;

[0668] Paging messages sent by network-side devices;

[0669] The uplink carrier available for PRACH in the four-step random access;

[0670] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0671] Downlink signal quality of the reference carrier;

[0672] DCI in the PDCCH used to trigger non-contentionable four-step random access;

[0673] The uplink carrier available for PRACH in the four-step random access associated with the downlink carrier with the highest downlink signal quality.

[0674] In some embodiments, the random access preamble in the PRACH of the four-step random access is used to indicate whether different random access messages following the PRACH in the four-step random access support transmission via different carriers; or, the random access preamble in the PRACH of the four-step random access is used to indicate whether different uplink random access messages following the PRACH in the four-step random access support transmission via different uplink carriers; or, the random access preamble in the PRACH of the four-step random access is used to indicate whether different downlink random access messages following the PRACH in the four-step random access support transmission via different downlink carriers.

[0675] In some embodiments, the first downlink random access information is the random access response (RAR) in a four-step random access process.

[0676] The target downlink carrier is determined based on at least one of the following:

[0677] The identifier of the wireless communication device 300;

[0678] Paging messages sent by network-side devices;

[0679] The downlink carriers available for RAR in the four-step random access;

[0680] The downlink carrier associated with the uplink carrier corresponding to the PRACH transmission in four-step random access;

[0681] The downlink carrier corresponding to the SSB used for synchronization;

[0682] Reference carrier;

[0683] Default downlink carrier;

[0684] The downlink carrier with the highest signal quality;

[0685] The downlink carrier with the highest average signal quality.

[0686] In some embodiments, the RAR in the four-step random access includes at least one of the following:

[0687] First indication information, the first indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the uplink random access information after RAR in the four-step random access, or, the first indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of the uplink random access information after RAR in the four-step random access.

[0688] The second indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the downlink random access information after RAR in the four-step random access, or the second indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the downlink random access information after RAR in the four-step random access.

[0689] The third indication information is used to indicate the PRACH transmission carrier and / or carrier group corresponding to RAR in the four-step random access, wherein the range of the random access radio network temporary identifier RA-RNTI corresponding to different PRACH transmission carriers and / or carrier groups is different, or the random access preamble identifier corresponding to different PRACH transmission carriers and / or carrier groups is different.

[0690] In some embodiments, the Physical Downlink Control Channel (PDCCH) corresponding to the RAR in the four-step random access and the Physical Downlink Shared Channel (PDSCH) corresponding to the RAR in the four-step random access are both transmitted through the target downlink carrier; or...

[0691] The PDCCH corresponding to the RAR in the four-step random access is transmitted through the target downlink carrier, and the PDSCH corresponding to the RAR in the four-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to the RAR in the four-step random access.

[0692] In some embodiments, the first uplink random access information is message 3Msg3 in the four-step random access process;

[0693] The target uplink carrier is determined based on at least one of the following:

[0694] The identifier of the wireless communication device 300;

[0695] Paging messages sent by network-side devices;

[0696] Default uplink carrier;

[0697] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0698] The uplink carrier available for Msg3 in the four-step random access;

[0699] The uplink carrier indicated in the RAR during four-step random access;

[0700] The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

[0701] In some embodiments, Msg3 in the four-step random access includes fourth indication information;

[0702] The fourth indication information is used to indicate whether the wireless communication device 300 supports cross-carrier scheduling of downlink random access information after Msg3 in the four-step random access.

[0703] In some embodiments, the first downlink random access information is message 4Msg4 in the four-step random access process;

[0704] The target downlink carrier is determined based on at least one of the following:

[0705] The identifier of the wireless communication device 300;

[0706] Paging messages sent by network-side devices;

[0707] The downlink carrier available for Msg4 in the four-step random access;

[0708] The downlink carrier corresponding to the RAR transmission in the four-step random access;

[0709] In the four-step random access, the downlink carrier associated with the uplink carrier corresponding to the Msg3 transmission;

[0710] The downlink carrier corresponding to the SSB used for synchronization;

[0711] Reference carrier;

[0712] Default downlink carrier;

[0713] The downlink carrier with the highest signal quality;

[0714] The downlink carrier with the highest average signal quality.

[0715] In some embodiments, the PDCCH corresponding to Msg4 in the four-step random access and the PDSCH corresponding to Msg4 in the four-step random access correspond to the same downlink carrier or the same downlink carrier group; or, the PDCCH corresponding to Msg4 in the four-step random access and the PDSCH corresponding to Msg4 in the four-step random access correspond to different downlink carriers or different downlink carrier groups.

[0716] In some embodiments, if the time interval between the PDSCH corresponding to Msg4 in the four-step random access and the PDCCH corresponding to Msg4 in the four-step random access is less than or not greater than a first threshold, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is indicated by the RAR in the four-step random access; or, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is indicated by the network-side device or agreed by the protocol; or, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is the same as the downlink carrier corresponding to the PDCCH corresponding to Msg4 in the four-step random access.

[0717] And / or,

[0718] If the time interval between the PDSCH corresponding to Msg4 in the four-step random access and the PDCCH corresponding to Msg4 in the four-step random access is greater than or not less than a first threshold, the PDSCH corresponding to Msg4 in the four-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to Msg4 in the four-step random access.

[0719] In some embodiments, Msg4 in the four-step random access includes a fifth indication message;

[0720] The fifth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the uplink random access information after Msg4 in the four-step random access, or the fifth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of the uplink random access information after Msg4 in the four-step random access.

[0721] In some embodiments, the first uplink random access information is the Hybrid Automatic Repeat Request (HARQ) feedback for Msg4 in the four-step random access process.

[0722] The target uplink carrier is determined based on at least one of the following:

[0723] The identifier of the wireless communication device 300;

[0724] Paging messages sent by network-side devices;

[0725] Default uplink carrier;

[0726] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0727] The HARQ feedback of Msg4 in the four-step random access is available uplink carrier;

[0728] In the four-step random access process, Msg4 contains downlink control information (DCI) used to schedule the physical uplink control channel PUCCH.

[0729] In the four-step random access process, Msg4 is used to schedule the Media Access Control Layer Control Unit (MAC CE) DCI.

[0730] The uplink carrier corresponding to Msg3 transmission in the four-step random access;

[0731] The uplink carrier indicated in the RAR during four-step random access;

[0732] The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

[0733] In some embodiments, the first uplink random access information is the uplink message after Msg4 in the four-step random access process;

[0734] The target uplink carrier is determined based on at least one of the following:

[0735] The identifier of the wireless communication device 300;

[0736] Paging messages sent by network-side devices;

[0737] Default uplink carrier;

[0738] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0739] The uplink carrier available for uplink messages after Msg4 in four-step random access;

[0740] The DCI used in Msg4 of the four-step random access process to schedule uplink messages after Msg4 in the four-step random access process.

[0741] The uplink carrier corresponding to Msg3 transmission in the four-step random access;

[0742] The uplink carrier indicated in the RAR during four-step random access;

[0743] The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

[0744] In some embodiments, the first uplink random access information is message AMsgA in a two-step random access process;

[0745] The target uplink carrier is determined based on at least one of the following:

[0746] The identifier of the wireless communication device 300;

[0747] Paging messages sent by network-side devices;

[0748] The uplink carrier associated with the downlink carrier corresponding to the SSB transmission used for synchronization;

[0749] The uplink carrier available for MsgA in the two-step random access;

[0750] DCI in PDCCH used to trigger non-contention-based two-step random access;

[0751] Downlink signal quality of the reference carrier;

[0752] The uplink carrier available for MsgA in the two-step random access associated with the downlink carrier with the highest downlink signal quality.

[0753] In some embodiments, the PRACH corresponding to MsgA in the two-step random access and the PUSCH corresponding to MsgA in the two-step random access correspond to the same uplink carrier or the same uplink carrier group; or, the PRACH corresponding to MsgA in the two-step random access and the PUSCH corresponding to MsgA in the two-step random access correspond to different uplink carriers or different uplink carrier groups.

[0754] And / or,

[0755] In the two-step random access, different groups of PRACH corresponding to MsgA correspond to the same uplink carrier or the same uplink carrier group; or, different groups of PRACH corresponding to MsgA correspond to different uplink carriers or different uplink carrier groups; and / or, different groups of PUSCH corresponding to MsgA correspond to the same uplink carrier or the same uplink carrier group; or, different groups of PUSCH corresponding to MsgA correspond to different uplink carriers or different uplink carrier groups.

[0756] In some embodiments, the PUSCH corresponding to MsgA in the two-step random access includes at least one of the following:

[0757] The sixth indication information is used to indicate whether the wireless communication device 300 supports cross-carrier scheduling of message B MsgB in two-step random access.

[0758] The seventh indication information is used to indicate the downlink carrier or downlink carrier group corresponding to MsgB in the two-step random access, or the seventh indication information is used to indicate the downlink carrier or downlink carrier group corresponding to MsgB in the two-step random access desired by the wireless communication device 300.

[0759] In some embodiments, the first downlink random access information is MsgB in two-step random access;

[0760] The target downlink carrier is determined based on at least one of the following:

[0761] The identifier of the wireless communication device 300;

[0762] Paging messages sent by network-side devices;

[0763] The downlink carrier corresponding to the SSB transmission used for synchronization;

[0764] The downlink carrier available for MsgB in the two-step random access;

[0765] The uplink carrier corresponding to the MsgA transmission in two-step random access;

[0766] The downlink carrier indicated in MsgA during two-step random access;

[0767] Reference carrier;

[0768] Default downlink carrier;

[0769] The downlink carrier with the highest signal quality;

[0770] The downlink carrier with the highest average signal quality.

[0771] In some embodiments, the PDCCH corresponding to MsgB in the two-step random access and the PDSCH corresponding to MsgB in the two-step random access correspond to the same downlink carrier or the same downlink carrier group; or, the PDCCH corresponding to MsgB in the two-step random access and the PDSCH corresponding to MsgB in the two-step random access correspond to different downlink carriers or different downlink carrier groups.

[0772] In some embodiments, if the time interval between the PDSCH corresponding to MsgB in the two-step random access and the PDCCH corresponding to MsgB in the two-step random access is less than or not greater than a first threshold, the downlink carrier corresponding to the PDSCH corresponding to MsgB in the two-step random access is indicated by the network-side device or agreed by the protocol, or the downlink carrier corresponding to the PDSCH corresponding to MsgB in the two-step random access is the same as the downlink carrier corresponding to the PDCCH corresponding to MsgB in the two-step random access.

[0773] And / or,

[0774] If the time interval between the PDSCH corresponding to MsgB in the two-step random access and the PDCCH corresponding to MsgB in the two-step random access is greater than or not less than a first threshold, the PDSCH corresponding to MsgB in the two-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to MsgB in the two-step random access.

[0775] In some embodiments, the first uplink random access information is the HARQ feedback of MsgB in two-step random access;

[0776] The target uplink carrier is determined based on at least one of the following:

[0777] The identifier of the wireless communication device 300;

[0778] Paging messages sent by network-side devices;

[0779] Default uplink carrier;

[0780] The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization;

[0781] The uplink carrier available for the HARQ feedback of MsgB in the two-step random access;

[0782] The DCI used for scheduling PUCCH in MsgB during two-step random access;

[0783] DCI used to schedule MsgB transmissions in two-step random access;

[0784] The uplink carrier corresponding to the MsgA transmission in two-step random access;

[0785] The uplink carrier indicated in the successful RAR during two-step random access.

[0786] In some embodiments, the first downlink random access information is a fallback indication, which is used to indicate a fallback from two-step random access to four-step random access.

[0787] The target downlink carrier is determined based on at least one of the following:

[0788] The identifier of the wireless communication device 300;

[0789] Paging messages sent by network-side devices;

[0790] The downlink carrier corresponding to the SSB transmission used for synchronization;

[0791] The fallback indication is available downlink carriers;

[0792] The downlink carrier associated with the uplink carrier in the MsgA transmission during two-step random access;

[0793] The downlink carrier indicated in MsgA during two-step random access;

[0794] The downlink carrier corresponding to MsgB transmission in two-step random access;

[0795] Reference carrier;

[0796] Default downlink carrier;

[0797] The downlink carrier with the highest signal quality;

[0798] The downlink carrier with the highest average signal quality.

[0799] In some embodiments, the rollback instruction includes at least one of the following:

[0800] The eighth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to Msg3 in the four-step random access, or the eighth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of Msg3 in the four-step random access.

[0801] The ninth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the PDCCH corresponding to Msg4 in the four-step random access, or the ninth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the PDCCH corresponding to Msg4 in the four-step random access.

[0802] The tenth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the PDSCH corresponding to Msg4 in the four-step random access, or the tenth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the PDSCH corresponding to Msg4 in the four-step random access.

[0803] In some embodiments, the sending module 302 is further configured to send third information;

[0804] The third information is used to indicate whether the wireless communication device 300 supports random access based on multiple carriers or multiple carrier groups, or the third information is used to indicate whether the wireless communication device 300 supports transmitting random access messages through different carriers, or the third information is used to indicate whether the wireless communication device 300 supports transmitting uplink random access messages through different carriers, or the third information is used to indicate whether the wireless communication device 300 supports transmitting downlink random access messages through different carriers.

[0805] Referring to Figure 12, when the wireless communication device is a network-side device or a component in a network-side device, the wireless communication device 400 includes: a transmitting module 401 and a receiving module 402;

[0806] The sending module 401 is used to send first information to the terminal; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0807] The receiving module 402 is used to receive first uplink random access information, wherein the first uplink random access information is transmitted based on a target uplink carrier, and the target uplink carrier is determined based on the first information;

[0808] And / or,

[0809] The sending module 401 is used to send first downlink random access information to the terminal, wherein the first downlink random access information is sent based on a target downlink carrier, and the target downlink carrier is determined based on the first information.

[0810] In some embodiments, the target uplink carrier is determined from a target uplink carrier group in the at least one uplink carrier group, or the target uplink carrier is determined from the at least two uplink carriers;

[0811] And / or,

[0812] The target downlink carrier is determined from a target downlink carrier group in the at least one downlink carrier group, or the target downlink carrier is determined from the at least two downlink carriers.

[0813] In some embodiments, the target uplink carrier group is determined based on at least one of the following:

[0814] The first uplink random access information includes the available uplink carrier group, the terminal's identification information, the terminal group's identification information, the paging message sent by the network-side device, the uplink carrier group associated with the downlink carrier group selected by the terminal, the average signal quality of all downlink carriers in the downlink carrier group selected by the terminal, the highest signal quality of all downlink carriers in the downlink carrier group selected by the terminal, the amount of uplink data to be transmitted by the terminal, the amount of uplink buffered data by the terminal, the uplink quality of service (QoS) of the terminal, and the uplink transmission delay of the terminal.

[0815] And / or,

[0816] The target downlink carrier group is determined based on at least one of the following:

[0817] The first downlink random access information includes the available downlink carrier group, the terminal identification information, the terminal group identification information to which the terminal belongs, the paging message sent by the network-side device, the downlink carrier group containing the downlink carrier with the highest measured signal quality in the at least one downlink carrier group, and the downlink carrier group with the highest average signal quality among all downlink carriers in the at least one downlink carrier group.

[0818] In some embodiments, the first information includes the association between the uplink carrier group and the downlink carrier group;

[0819] In this context, a downlink carrier group is associated with one or more uplink carrier groups; and / or, an uplink carrier group is associated with one or more downlink carrier groups.

[0820] In some embodiments, the downlink carriers within each downlink carrier group of the at least one downlink carrier group satisfy at least one of the following conditions:

[0821] Some or all of the downlink carriers correspond to the same synchronization signal block (SSB) index;

[0822] There is a correlation between the SSB indices corresponding to some or all downlink carriers;

[0823] The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB.

[0824] A downlink carrier's SSB index is associated with one or more uplink carriers' random access opportunities (ROs).

[0825] An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices;

[0826] An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers;

[0827] A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers;

[0828] or,

[0829] The downlink carrier group in the at least one downlink carrier group satisfies at least one of the following conditions:

[0830] Some or all downlink carrier groups correspond to the same SSB index;

[0831] There is a correlation between the SSB indices corresponding to some or all downlink carrier groups;

[0832] An SSB index corresponding to a downlink carrier group is associated with one or more ROs corresponding to uplink carrier groups.

[0833] An RO corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups.

[0834] An SSB index corresponding to a downlink carrier group is associated with one or more random access preambles corresponding to uplink carrier groups.

[0835] A random access preamble corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups;

[0836] or,

[0837] The downlink carriers of the at least two downlink carriers satisfy at least one of the following conditions:

[0838] Some or all downlink carriers correspond to the same SSB index;

[0839] There is a correlation between the SSB indices corresponding to some or all downlink carriers;

[0840] The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB.

[0841] An SSB index corresponding to a downlink carrier is associated with one or more ROs corresponding to uplink carriers.

[0842] An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices;

[0843] An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers;

[0844] A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers.

[0845] In some embodiments, when an SSB index corresponding to a downlink carrier is associated with an RO corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier is associated with a random access preamble corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers for uplink repetitive transmission.

[0846] or,

[0847] When an SSB index corresponding to a downlink carrier group is associated with an RO corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier group is associated with a random access preamble corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission.

[0848] In some embodiments, the sending module 401 is further configured to send second information to the terminal;

[0849] The second information includes at least one of the following:

[0850] The conditions that the downlink carriers in each downlink carrier group of the at least one downlink carrier group satisfy;

[0851] The conditions that the downlink carrier groups in the at least one downlink carrier group satisfy;

[0852] The conditions that the downlink carriers of the at least two downlink carriers satisfy.

[0853] In some embodiments, repeated transmissions of the first uplink random access information correspond to the same uplink carrier or the same uplink carrier group, or repeated transmissions of the first uplink random access information correspond to different uplink carriers or different uplink carrier groups.

[0854] And / or,

[0855] The repeated transmission of the first downlink random access information corresponds to the same downlink carrier or the same downlink carrier group, or the repeated transmission of the first downlink random access information corresponds to different downlink carriers or different downlink carrier groups.

[0856] In some embodiments, the receiving module 402 is further configured to receive third information from the terminal;

[0857] The third information is used to indicate whether the terminal supports random access based on multiple carriers or multiple carrier groups, or the third information is used to indicate whether the terminal supports transmitting random access messages through different carriers, or the third information is used to indicate whether the terminal supports transmitting uplink random access messages through different carriers, or the third information is used to indicate whether the terminal supports transmitting downlink random access messages through different carriers.

[0858] Therefore, in this embodiment, the terminal determines the target uplink carrier based on the first information, and the terminal sends first uplink random access information based on the target uplink carrier; and / or, the terminal determines the target downlink carrier based on the first information, and the terminal receives first downlink random access information based on the target downlink carrier. Specifically, for the multi-carrier random access process, the target uplink carrier can be flexibly adjusted within an uplink carrier group or at least two uplink carriers, and / or the target downlink carrier can be flexibly adjusted within a downlink carrier group or at least two downlink carriers. While ensuring uplink and downlink transmission coverage, this helps to better achieve load balancing, reduce inter-carrier interference, and improve the performance of multi-carrier random access.

[0859] The wireless communication device provided in this application embodiment can implement the various processes implemented in the method embodiment of FIG2 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0860] As shown in Figure 13, this application embodiment also provides a communication device 500, including a processor 501 and a memory 502, wherein the memory 502 stores a program or instructions that can be run on the processor 501.

[0861] For example, when the communication device 500 is a terminal, the program or instructions executed by the processor 501 implement the various steps executed by the terminal in the above wireless communication method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0862] For example, when the communication device 500 is a network-side device, the program or instructions executed by the processor 501 implement the various steps executed by the network-side device in the above wireless communication method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0863] This application also provides a terminal, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps in the method embodiment shown in FIG2. The terminal embodiment corresponds to the above-described terminal-side method embodiment, and all implementation processes and methods of the above-described method embodiments can be applied to the terminal embodiment and achieve the same technical effect. The terminal may be the wireless communication device 300 shown in FIG11.

[0864] Specifically, Figure 14 is a schematic diagram of the hardware structure of a terminal implementing an embodiment of this application.

[0865] The terminal 600 includes, but is not limited to, at least some of the following components: radio frequency unit 601, network module 602, audio output unit 603, input unit 604, sensor 605, display unit 606, user input unit 607, interface unit 608, memory 609, and processor 610.

[0866] Those skilled in the art will understand that terminal 600 may also include a power supply (such as a battery) for powering various components. The power supply can be logically connected to processor 610 through a power management system, thereby enabling functions such as charging, discharging, and power consumption management through the power management system. The terminal structure shown in Figure 14 does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0867] It should be understood that, in this embodiment, the input unit 604 may include a graphics processor 6041 and a microphone 6042. The graphics processor 6041 processes image data of still images or videos obtained by an image capture device (such as a camera) in video capture mode or image capture mode. The display unit 606 may include a display panel 6061, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, or the like. The user input unit 607 includes at least one of a touch panel 6071 and other input devices 6072. The touch panel 6071 is also called a touch screen. The touch panel 6071 may include two parts: a touch detection device and a touch controller. Other input devices 6072 may include, but are not limited to, a physical keyboard, function keys (such as volume control buttons, power buttons, etc.), a trackball, a mouse, and a joystick, which will not be described in detail here.

[0868] In this embodiment, after receiving downlink data from the network-side device, the radio frequency unit 601 can transmit it to the processor 610 for processing; in addition, the radio frequency unit 601 can send uplink data to the network-side device. Typically, the radio frequency unit 601 includes, but is not limited to, antennas, amplifiers, transceivers, couplers, low-noise amplifiers, duplexers, etc.

[0869] The memory 609 can be used to store software programs or instructions, as well as various data. The memory 609 may primarily include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area may store the operating system, application programs or instructions required for at least one function (such as sound playback, image playback, etc.). Furthermore, the memory 609 may include volatile memory or non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DRRAM). The memory 609 in this embodiment includes, but is not limited to, these and any other suitable types of memory.

[0870] Processor 610 may include one or more processing units; optionally, processor 610 integrates an application processor and a modem processor, wherein the application processor mainly handles operations involving the operating system, user interface, and applications, and the modem processor mainly handles wireless communication signals, such as a baseband processor. It is understood that the aforementioned modem processor may also not be integrated into processor 610.

[0871] In some embodiments, the processor 610 or the radio frequency unit 601 is configured to acquire first information; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0872] The processor 610 is further configured to determine a target uplink carrier based on the first information, and the radio frequency unit 601 is further configured to transmit first uplink random access information based on the target uplink carrier; and / or,

[0873] The processor 610 is further configured to determine a target downlink carrier based on the first information, and the radio frequency unit 601 is further configured to receive first downlink random access information based on the target downlink carrier.

[0874] Therefore, in this embodiment, the terminal determines the target uplink carrier based on the first information, and the terminal sends first uplink random access information based on the target uplink carrier; and / or, the terminal determines the target downlink carrier based on the first information, and the terminal receives first downlink random access information based on the target downlink carrier. Specifically, for the multi-carrier random access process, the target uplink carrier can be flexibly adjusted within an uplink carrier group or at least two uplink carriers, and / or the target downlink carrier can be flexibly adjusted within a downlink carrier group or at least two downlink carriers. While ensuring uplink and downlink transmission coverage, this helps to better achieve load balancing, reduce inter-carrier interference, and improve the performance of multi-carrier random access.

[0875] It is understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description of the method embodiment and achieve the same or corresponding technical effect. To avoid repetition, it will not be described again here.

[0876] This application also provides a network-side device, including a processor and a communication interface. The communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method embodiment shown in FIG2. This network-side device embodiment corresponds to the method embodiment executed by the above-described network-side device. All implementation processes and methods of the above-described method embodiments can be applied to this network-side device embodiment and can achieve the same technical effect.

[0877] This application embodiment also provides a network-side device, which may be the wireless communication device 400 shown in FIG12.

[0878] Specifically, as shown in Figure 15, the network-side device 700 includes: an antenna 71, a radio frequency (RF) device 72, a baseband device 73, a processor 74, and a memory 75. The antenna 71 is connected to the RF device 72. In the uplink direction, the RF device 72 receives information through the antenna 71 and sends the received information to the baseband device 73 for processing. In the downlink direction, the baseband device 73 processes the information to be transmitted and sends it to the RF device 72. The RF device 72 processes the received information and then transmits it through the antenna 71.

[0879] The method executed by the network-side device in the above embodiments can be implemented in the baseband device 73, which includes a baseband processor.

[0880] The baseband device 73 may include at least one baseband board, on which multiple chips are disposed, as shown in FIG15. One of the chips is, for example, a baseband processor, which is connected to the memory 75 via a bus interface to call the program in the memory 75 to execute the operation of the network-side device shown in the above method embodiment.

[0881] The network-side device may also include a network interface 76, such as a Common Public Radio Interface (CPRI).

[0882] In some embodiments, the radio frequency device 72 is used to send first information to the terminal; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers;

[0883] The radio frequency device 72 is further configured to receive first uplink random access information and / or transmit first downlink random access information; wherein the first uplink random access information is transmitted based on a target uplink carrier, the target uplink carrier is determined based on the first information, the first downlink random access information is transmitted based on a target downlink carrier, and the target downlink carrier is determined based on the first information.

[0884] Specifically, the network-side device 700 in this application embodiment further includes: instructions or programs stored in memory 75 and executable on processor 74. Processor 74 calls the instructions or programs in memory 75 to execute the methods executed by each module shown in FIG12 and achieve the same technical effect. To avoid repetition, it will not be described in detail here.

[0885] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described wireless communication method embodiments and achieve the same technical effects. To avoid repetition, they will not be described again here.

[0886] The processor mentioned above is the processor in the terminal or network-side device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk. In some examples, the readable storage medium may be a non-transient readable storage medium.

[0887] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described wireless communication method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0888] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0889] This application also provides a computer program / program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described wireless communication method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0890] This application also provides a wireless communication system, including: a terminal and a network-side device. The terminal can be used to perform the steps performed by the terminal in the wireless communication method described above, and the network-side device can be used to perform the steps performed by the network-side device in the wireless communication method described above.

[0891] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0892] From the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of computer software products plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions to cause the terminal or network-side device to execute the methods described in the various embodiments of this application.

[0893] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other implementations under the guidance of this application without departing from the spirit and scope of the claims. All of these implementations are within the protection scope of this application.

Claims

1. A wireless communication method, wherein, include: The terminal acquires first information; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers; The terminal determines a target uplink carrier based on the first information, and the terminal sends first uplink random access information based on the target uplink carrier; and / or, The terminal determines the target downlink carrier based on the first information, and the terminal receives the first downlink random access information based on the target downlink carrier.

2. The method according to claim 1, wherein, The terminal determines the target uplink carrier based on the first information, including: The terminal determines a target uplink carrier group from the at least one uplink carrier group, and the terminal determines the target uplink carrier from the target uplink carrier group; or, The terminal determines the target uplink carrier from the at least two uplink carriers; And / or, The terminal determines the target downlink carrier based on the first information, including: The terminal determines a target downlink carrier group from the at least one downlink carrier group, and the terminal determines the target downlink carrier from the target downlink carrier group; or, The terminal determines the target downlink carrier from the at least two downlink carriers.

3. The method according to claim 2, wherein, The target uplink carrier group is determined based on at least one of the following: The first uplink random access information includes the available uplink carrier group, the terminal's identification information, the terminal group's identification information, the paging message sent by the network-side device, the uplink carrier group associated with the downlink carrier group selected by the terminal, the average signal quality of all downlink carriers in the downlink carrier group selected by the terminal, the highest signal quality of all downlink carriers in the downlink carrier group selected by the terminal, the amount of uplink data to be transmitted by the terminal, the amount of uplink buffered data by the terminal, the uplink quality of service (QoS) of the terminal, and the uplink transmission delay of the terminal. And / or, The target downlink carrier group is determined based on at least one of the following: The first downlink random access information includes the available downlink carrier group, the terminal identification information, the terminal group identification information to which the terminal belongs, the paging message sent by the network-side device, the downlink carrier group containing the downlink carrier with the highest measured signal quality in the at least one downlink carrier group, and the downlink carrier group with the highest average signal quality among all downlink carriers in the at least one downlink carrier group.

4. The method according to any one of claims 1 to 3, wherein, A downlink carrier group is associated with one or more uplink carrier groups; and / or, An uplink carrier group is associated with one or more downlink carrier groups.

5. The method according to claim 4, wherein, The first information includes the correlation between the uplink carrier group and the downlink carrier group; or, The association between the uplink carrier group and the downlink carrier group is determined based on at least one of the following: Frequency band, frequency band combination, spectrum range, bandwidth portion (BWP).

6. The method according to any one of claims 1 to 5, wherein, The downlink carriers within each of the at least one downlink carrier group satisfy at least one of the following conditions: Some or all of the downlink carriers correspond to the same synchronization signal block (SSB) index; There is a correlation between the SSB indices corresponding to some or all downlink carriers; The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB. A downlink carrier's SSB index is associated with one or more uplink carriers' random access opportunities (ROs). An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices; An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers; A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers; or, The downlink carrier group in the at least one downlink carrier group satisfies at least one of the following conditions: Some or all downlink carrier groups correspond to the same SSB index; There is a correlation between the SSB indices corresponding to some or all downlink carrier groups; An SSB index corresponding to a downlink carrier group is associated with one or more ROs corresponding to uplink carrier groups. An RO corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups. An SSB index corresponding to a downlink carrier group is associated with one or more random access preambles corresponding to uplink carrier groups. A random access preamble corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups; or, The downlink carriers of the at least two downlink carriers satisfy at least one of the following conditions: Some or all downlink carriers correspond to the same SSB index; There is a correlation between the SSB indices corresponding to some or all downlink carriers; The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB. An SSB index corresponding to a downlink carrier is associated with one or more ROs corresponding to uplink carriers. An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices; An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers; A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers.

7. The method according to claim 6, wherein, When an SSB index corresponding to a downlink carrier is associated with an RO corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers used for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier is associated with a random access preamble corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers used for uplink repetitive transmission. or, When an SSB index corresponding to a downlink carrier group is associated with an RO corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier group is associated with a random access preamble corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission.

8. The method according to claim 6 or 7, wherein, The method further includes: The terminal receives the second information; The second information includes at least one of the following: The conditions that the downlink carriers in each downlink carrier group of the at least one downlink carrier group satisfy; The conditions that the downlink carrier groups in the at least one downlink carrier group satisfy; The conditions that the downlink carriers of the at least two downlink carriers satisfy.

9. The method according to any one of claims 1 to 8, wherein, The repeated transmission of the first uplink random access information corresponds to the same uplink carrier or the same uplink carrier group, or the repeated transmission of the first uplink random access information corresponds to different uplink carriers or different uplink carrier groups. And / or, The repeated transmission of the first downlink random access information corresponds to the same downlink carrier or the same downlink carrier group, or the repeated transmission of the first downlink random access information corresponds to different downlink carriers or different downlink carrier groups.

10. The method according to any one of claims 1 to 9, wherein, The first uplink random access information is the Physical Random Access Channel (PRACH) in the four-step random access process; The target uplink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; The uplink carrier available for PRACH in the four-step random access; The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization; Downlink signal quality of the reference carrier; DCI in the PDCCH used to trigger non-contentionable four-step random access; The uplink carrier available for PRACH in the four-step random access associated with the downlink carrier with the highest downlink signal quality.

11. The method according to claim 10, wherein, The random access preamble in the PRACH of the four-step random access is used to indicate whether different random access messages following the PRACH in the four-step random access support transmission via different carriers; or, the random access preamble in the PRACH of the four-step random access is used to indicate whether different uplink random access messages following the PRACH in the four-step random access support transmission via different uplink carriers; or, the random access preamble in the PRACH of the four-step random access is used to indicate whether different downlink random access messages following the PRACH in the four-step random access support transmission via different downlink carriers.

12. The method according to any one of claims 1 to 9, wherein, The first downlink random access information is the Random Access Response (RAR) in the four-step random access process; The target downlink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; The downlink carriers available for RAR in the four-step random access; The downlink carrier associated with the uplink carrier corresponding to the PRACH transmission in four-step random access; The downlink carrier corresponding to the SSB used for synchronization; Reference carrier; Default downlink carrier; The downlink carrier with the highest signal quality; The downlink carrier with the highest average signal quality.

13. The method according to claim 12, wherein, The RAR in the four-step random access includes at least one of the following: First indication information, the first indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the uplink random access information after RAR in the four-step random access, or, the first indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of the uplink random access information after RAR in the four-step random access. The second indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the downlink random access information after RAR in the four-step random access, or the second indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the downlink random access information after RAR in the four-step random access. The third indication information is used to indicate the PRACH transmission carrier and / or carrier group corresponding to RAR in the four-step random access, wherein the range of the random access radio network temporary identifier RA-RNTI corresponding to different PRACH transmission carriers and / or carrier groups is different, or the random access preamble identifier corresponding to different PRACH transmission carriers and / or carrier groups is different.

14. The method according to claim 12 or 13, wherein, In the four-step random access method, both the Physical Downlink Control Channel (PDCCH) corresponding to the RAR and the Physical Downlink Shared Channel (PDSCH) corresponding to the RAR are transmitted through the target downlink carrier; or... The PDCCH corresponding to the RAR in the four-step random access is transmitted through the target downlink carrier, and the PDSCH corresponding to the RAR in the four-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to the RAR in the four-step random access.

15. The method according to any one of claims 1 to 9, wherein, The first uplink random access information is message 3Msg3 in the four-step random access process; The target uplink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; Default uplink carrier; The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization; The uplink carrier available for Msg3 in the four-step random access; The uplink carrier indicated in the RAR during four-step random access; The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

16. The method according to claim 15, wherein, Msg3 in the four-step random access includes fourth indication information; The fourth indication information is used to indicate whether the terminal supports cross-carrier scheduling of downlink random access information after Msg3 in the four-step random access process.

17. The method according to any one of claims 1 to 9, wherein, The first downlink random access information is message 4Msg4 in the four-step random access process; The target downlink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; The downlink carrier available for Msg4 in the four-step random access; The downlink carrier corresponding to the RAR transmission in the four-step random access; In the four-step random access, the downlink carrier associated with the uplink carrier corresponding to the Msg3 transmission; The downlink carrier corresponding to the SSB used for synchronization; Reference carrier; Default downlink carrier; The downlink carrier with the highest signal quality; The downlink carrier with the highest average signal quality.

18. The method according to claim 17, wherein, In the four-step random access, the PDCCH corresponding to Msg4 and the PDSCH corresponding to Msg4 in the four-step random access have the same downlink carrier or the same downlink carrier group; or, the PDCCH corresponding to Msg4 in the four-step random access and the PDSCH corresponding to Msg4 in the four-step random access have different downlink carriers or different downlink carrier groups.

19. The method according to claim 17 or 18, wherein, If the time interval between the PDSCH corresponding to Msg4 in the four-step random access and the PDCCH corresponding to Msg4 in the four-step random access is less than or not greater than a first threshold, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is indicated by the RAR in the four-step random access; or, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is indicated by the network-side device or agreed by the protocol; or, the downlink carrier corresponding to the PDSCH corresponding to Msg4 in the four-step random access is the same as the downlink carrier corresponding to the PDCCH corresponding to Msg4 in the four-step random access. And / or, If the time interval between the PDSCH corresponding to Msg4 in the four-step random access and the PDCCH corresponding to Msg4 in the four-step random access is greater than or not less than a first threshold, the PDSCH corresponding to Msg4 in the four-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to Msg4 in the four-step random access.

20. The method according to any one of claims 17 to 19, wherein, Msg4 in the four-step random access includes the fifth indication information; The fifth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the uplink random access information after Msg4 in the four-step random access, or the fifth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of the uplink random access information after Msg4 in the four-step random access.

21. The method according to any one of claims 1 to 9, wherein, The first uplink random access information is the Hybrid Automatic Repeat Request (HARQ) feedback for Msg4 in the four-step random access process. The target uplink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; Default uplink carrier; The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization; The HARQ feedback of Msg4 in the four-step random access is available uplink carrier; In the four-step random access process, Msg4 contains downlink control information (DCI) used to schedule the physical uplink control channel PUCCH. In the four-step random access process, Msg4 is used to schedule the Media Access Control Layer Control Unit (MAC CE) DCI. The uplink carrier corresponding to Msg3 transmission in the four-step random access; The uplink carrier indicated in the RAR during four-step random access; The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

22. The method according to any one of claims 1 to 9, wherein, The first uplink random access information is the uplink message after Msg4 in the four-step random access process; The target uplink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; Default uplink carrier; The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization; The uplink carrier available for uplink messages after Msg4 in four-step random access; The DCI used in Msg4 of the four-step random access process to schedule uplink messages after Msg4 in the four-step random access process. The uplink carrier corresponding to Msg3 transmission in the four-step random access; The uplink carrier indicated in the RAR during four-step random access; The uplink carrier corresponding to the PRACH transmission in the four-step random access process.

23. The method according to any one of claims 1 to 9, wherein, The first uplink random access information is message A MsgA from the two-step random access process; The target uplink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; The uplink carrier associated with the downlink carrier corresponding to the SSB transmission used for synchronization; The uplink carrier available for MsgA in the two-step random access; DCI in PDCCH used to trigger non-contention-based two-step random access; Downlink signal quality of the reference carrier; The uplink carrier available for MsgA in the two-step random access associated with the downlink carrier with the highest downlink signal quality.

24. The method according to claim 23, wherein, In the two-step random access, the PRACH corresponding to MsgA and the PUSCH corresponding to MsgA have the same uplink carrier or the same uplink carrier group, or the PRACH corresponding to MsgA and the PUSCH corresponding to MsgA have different uplink carriers or different uplink carrier groups. And / or, In the two-step random access, different groups of PRACH corresponding to MsgA correspond to the same uplink carrier or the same uplink carrier group; or, different groups of PRACH corresponding to MsgA correspond to different uplink carriers or different uplink carrier groups; and / or, different groups of PUSCH corresponding to MsgA correspond to the same uplink carrier or the same uplink carrier group; or, different groups of PUSCH corresponding to MsgA correspond to different uplink carriers or different uplink carrier groups.

25. The method according to claim 23 or 24, wherein, The PUSCH corresponding to MsgA in the two-step random access includes at least one of the following: The sixth indication information is used to indicate whether the terminal supports cross-carrier scheduling of message B MsgB in two-step random access; The seventh indication information is used to indicate the downlink carrier or downlink carrier group corresponding to MsgB in the two-step random access, or the seventh indication information is used to indicate the downlink carrier or downlink carrier group corresponding to MsgB in the two-step random access desired by the terminal.

26. The method according to any one of claims 1 to 9, wherein, The first downlink random access information is MsgB in the two-step random access procedure; The target downlink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; The downlink carrier corresponding to the SSB transmission used for synchronization; The downlink carrier available for MsgB in the two-step random access; The uplink carrier corresponding to the MsgA transmission in two-step random access; The downlink carrier indicated in MsgA during two-step random access; Reference carrier; Default downlink carrier; The downlink carrier with the highest signal quality; The downlink carrier with the highest average signal quality.

27. The method according to claim 26, wherein, In the two-step random access, the PDCCH corresponding to MsgB and the PDSCH corresponding to MsgB in the two-step random access have the same downlink carrier or the same downlink carrier group; or, the PDCCH corresponding to MsgB in the two-step random access and the PDSCH corresponding to MsgB in the two-step random access have different downlink carriers or different downlink carrier groups.

28. The method according to claim 26 or 27, wherein, If the time interval between the PDSCH corresponding to MsgB in the two-step random access and the PDCCH corresponding to MsgB in the two-step random access is less than or not greater than a first threshold, the downlink carrier corresponding to the PDSCH corresponding to MsgB in the two-step random access is indicated by the network-side device or agreed by the protocol, or the downlink carrier corresponding to the PDSCH corresponding to MsgB in the two-step random access is the same as the downlink carrier corresponding to the PDCCH corresponding to MsgB in the two-step random access. And / or, If the time interval between the PDSCH corresponding to MsgB in the two-step random access and the PDCCH corresponding to MsgB in the two-step random access is greater than or not less than a first threshold, the PDSCH corresponding to MsgB in the two-step random access is transmitted through the downlink carrier indicated by the PDCCH corresponding to MsgB in the two-step random access.

29. The method according to any one of claims 1 to 9, wherein, The first uplink random access information is the HARQ feedback of MsgB in the two-step random access; The target uplink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; Default uplink carrier; The uplink carrier associated with the downlink carrier corresponding to the SSB used for synchronization; The uplink carrier available for the HARQ feedback of MsgB in the two-step random access; The DCI used for scheduling PUCCH in MsgB during two-step random access; DCI used to schedule MsgB transmissions in two-step random access; The uplink carrier corresponding to the MsgA transmission in two-step random access; The uplink carrier indicated in the successful RAR during two-step random access.

30. The method according to any one of claims 1 to 9, wherein, The first downlink random access information is a fallback indication, which is used to indicate a fallback from two-step random access to four-step random access; The target downlink carrier is determined based on at least one of the following: The identifier of the terminal; Paging messages sent by network-side devices; The downlink carrier corresponding to the SSB transmission used for synchronization; The fallback indication is available downlink carriers; The downlink carrier associated with the uplink carrier in the MsgA transmission during two-step random access; The downlink carrier indicated in MsgA during two-step random access; The downlink carrier corresponding to MsgB transmission in two-step random access; Reference carrier; Default downlink carrier; The downlink carrier with the highest signal quality; The downlink carrier with the highest average signal quality.

31. The method according to claim 30, wherein, The rollback instruction includes at least one of the following: The eighth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to Msg3 in the four-step random access, or the eighth indication information is used to indicate the uplink carrier or uplink carrier group corresponding to the initial transmission and / or retransmission of Msg3 in the four-step random access. The ninth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the PDCCH corresponding to Msg4 in the four-step random access, or the ninth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the PDCCH corresponding to Msg4 in the four-step random access. The tenth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the PDSCH corresponding to Msg4 in the four-step random access, or the tenth indication information is used to indicate the downlink carrier or downlink carrier group corresponding to the initial transmission and / or retransmission of the PDSCH corresponding to Msg4 in the four-step random access.

32. The method according to any one of claims 1 to 31, wherein, The method further includes: The terminal sends third information; The third information is used to indicate whether the terminal supports random access based on multiple carriers or multiple carrier groups, or the third information is used to indicate whether the terminal supports transmitting random access messages through different carriers, or the third information is used to indicate whether the terminal supports transmitting uplink random access messages through different carriers, or the third information is used to indicate whether the terminal supports transmitting downlink random access messages through different carriers.

33. A wireless communication method, wherein, include: The network-side device sends first information to the terminal; wherein the first information includes at least one of the following: at least one uplink carrier group, at least one downlink carrier group, at least two uplink carriers, and at least two downlink carriers; The network-side device receives first uplink random access information, wherein the first uplink random access information is transmitted based on a target uplink carrier, and the target uplink carrier is determined based on the first information; and / or, The network-side device sends first downlink random access information to the terminal, wherein the first downlink random access information is sent based on a target downlink carrier, and the target downlink carrier is determined based on the first information.

34. The method according to claim 33, wherein, The target uplink carrier is determined from the target uplink carrier group in the at least one uplink carrier group, or the target uplink carrier is determined from the at least two uplink carriers; And / or, The target downlink carrier is determined from a target downlink carrier group in the at least one downlink carrier group, or the target downlink carrier is determined from the at least two downlink carriers.

35. The method according to claim 34, wherein, The target uplink carrier group is determined based on at least one of the following: The first uplink random access information includes the available uplink carrier group, the terminal's identification information, the identification information of the terminal group to which the terminal belongs, the paging message sent by the network-side device, the uplink carrier group associated with the downlink carrier group selected by the terminal, the average signal quality of all downlink carriers in the downlink carrier group selected by the terminal, the highest signal quality of all downlink carriers in the downlink carrier group selected by the terminal, the amount of uplink data to be transmitted by the terminal, the amount of uplink buffered data by the terminal, the uplink quality of service (QoS) of the terminal, and the uplink transmission delay of the terminal. And / or, The target downlink carrier group is determined based on at least one of the following: The first downlink random access information includes the available downlink carrier group, the terminal identification information, the terminal group identification information to which the terminal belongs, the paging message sent by the network-side device, the downlink carrier group containing the downlink carrier with the highest measured signal quality in the at least one downlink carrier group, and the downlink carrier group with the highest average signal quality among all downlink carriers in the at least one downlink carrier group.

36. The method according to any one of claims 33 to 35, wherein, The first information includes the correlation between the uplink carrier group and the downlink carrier group; In this context, a downlink carrier group is associated with one or more uplink carrier groups; and / or, an uplink carrier group is associated with one or more downlink carrier groups.

37. The method according to any one of claims 33 to 36, wherein, The downlink carriers within each of the at least one downlink carrier group satisfy at least one of the following conditions: Some or all of the downlink carriers correspond to the same synchronization signal block (SSB) index; There is a correlation between the SSB indices corresponding to some or all downlink carriers; The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB. A downlink carrier's SSB index is associated with one or more uplink carriers' random access opportunities (ROs). An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices; An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers; A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers; or, The downlink carrier group in the at least one downlink carrier group satisfies at least one of the following conditions: Some or all downlink carrier groups correspond to the same SSB index; There is a correlation between the SSB indices corresponding to some or all downlink carrier groups; An SSB index corresponding to a downlink carrier group is associated with one or more ROs corresponding to uplink carrier groups. An RO corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups. An SSB index corresponding to a downlink carrier group is associated with one or more random access preambles corresponding to uplink carrier groups. A random access preamble corresponding to an uplink carrier group is associated with one or more SSB indices corresponding to downlink carrier groups; or, The downlink carriers of the at least two downlink carriers satisfy at least one of the following conditions: Some or all downlink carriers correspond to the same SSB index; There is a correlation between the SSB indices corresponding to some or all downlink carriers; The SSB index corresponding to the downlink carrier that has not transmitted SSB is multiplexed with the SSB index corresponding to the downlink carrier that has transmitted SSB. An SSB index corresponding to a downlink carrier is associated with one or more ROs corresponding to uplink carriers. An uplink carrier's corresponding RO is associated with one or more downlink carriers' corresponding SSB indices; An SSB index corresponding to a downlink carrier is associated with one or more random access preambles corresponding to uplink carriers; A random access preamble corresponding to an uplink carrier is associated with one or more SSB indices corresponding to downlink carriers.

38. The method according to claim 37, wherein, When an SSB index corresponding to a downlink carrier is associated with an RO corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers used for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier is associated with a random access preamble corresponding to multiple uplink carriers, the multiple uplink carriers are uplink carriers used for uplink repetitive transmission. or, When an SSB index corresponding to a downlink carrier group is associated with an RO corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission; and / or, when an SSB index corresponding to a downlink carrier group is associated with a random access preamble corresponding to multiple uplink carrier groups, the multiple uplink carrier groups are uplink carrier groups used for uplink repetitive transmission.

39. The method according to claim 37 or 38, wherein, The method further includes: The network-side device sends the second information to the terminal; The second information includes at least one of the following: The conditions that the downlink carriers in each downlink carrier group of the at least one downlink carrier group satisfy; The conditions that the downlink carrier groups in the at least one downlink carrier group satisfy; The conditions that the downlink carriers of the at least two downlink carriers satisfy.

40. The method according to any one of claims 33 to 39, wherein, The repeated transmission of the first uplink random access information corresponds to the same uplink carrier or the same uplink carrier group, or the repeated transmission of the first uplink random access information corresponds to different uplink carriers or different uplink carrier groups. And / or, The repeated transmission of the first downlink random access information corresponds to the same downlink carrier or the same downlink carrier group, or the repeated transmission of the first downlink random access information corresponds to different downlink carriers or different downlink carrier groups.

41. The method according to any one of claims 33 to 40, wherein, The method further includes: The network-side device receives third information from the terminal; The third information is used to indicate whether the terminal supports random access based on multiple carriers or multiple carrier groups, or the third information is used to indicate whether the terminal supports transmitting random access messages through different carriers, or the third information is used to indicate whether the terminal supports transmitting uplink random access messages through different carriers, or the third information is used to indicate whether the terminal supports transmitting downlink random access messages through different carriers.

42. A wireless communication device, wherein, The wireless communication device is configured to perform the wireless communication method as described in any one of claims 1 to 32, or to implement the wireless communication method as described in any one of claims 33 to 41.

43. A terminal, wherein, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the wireless communication method as described in any one of claims 1 to 32.

44. A network-side device, wherein, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the wireless communication method as described in any one of claims 33 to 41.

45. A readable storage medium, wherein, The readable storage medium stores a program or instructions that, when executed by a processor, implement the wireless communication method as described in any one of claims 1 to 32, or implement the steps of the wireless communication method as described in any one of claims 33 to 41.

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