Method and apparatus for performing communication in a wireless communication system

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure provides a method comprising receiving system information, the system information including configuration information related to PRACH resources corresponding to at least two first UL carriers; determining a first UL carrier in the at least two first UL carriers based on at least one of parameters; and performing a random access procedure based on the PRACH resource on the determined first UL carrier.

Description

METHOD AND APPARATUS FOR PERFORMING COMMUNICATION IN A WIRELESS COMMUNICATION SYSTEM

[0001] The present disclosure relates to the technical field of wireless communications, and in particular to a communication method, a user equipment (UE) and a base station.

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6GHz" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] In the existing communication systems, a cell includes one downlink (DL) carrier and at most two uplink (UL) carriers, wherein the two UL carriers are called a normal UL (NUL) carrier and a supplement UL (SUL) carrier respectively. If all UEs in the cell coverage access the network through these UL carriers, the UEs are highly possible to be congested in a random access procedure.

[0009] The present disclosure provides a method comprising receiving system information, the system information including configuration information related to PRACH resources corresponding to at least two first UL carriers; determining a first UL carrier in the at least two first UL carriers based on at least one of parameters; and performing a random access procedure based on the PRACH resource on the determined first UL carrier, wherein the parameters include an ID of the UE; a random number generated by the UE; a parameter value indicated by a higher layer or determined by a medium access control (MAC) layer, and a mapping between the parameter value and the first UL carrier; a UL carrier index indicated by a base station; and a downlink (DL) carrier where a monitored paging message is located, and a mapping between the DL carrier and the first UL carrier.

[0010] According to the present disclosure, the UE may use one of at least two first UL carriers configured with PRACH resources to access a network in a determination mode explained in the present disclosure, so that a flexibility of the communication system is significantly improved and a congestion phenomenon when the UE accesses the network is reduced.

[0011] In order to explain the technical solutions in the embodiments of the present disclosure more clearly, the drawings needed to be used in the description of the embodiments of the present disclosure will be briefly illustrated below.

[0012] FIG. 1 is a schematic diagram of an overall structure of a wireless network according to an embodiment of the present disclosure;

[0013] FIG. 2a is a schematic diagram of a transmit path according to an embodiment of the present disclosure;

[0014] FIG. 2b is a schematic diagram of a receive path according to an embodiment of the present disclosure;

[0015] FIG. 3a is a schematic structure diagram of a UE according to an embodiment of the present disclosure;

[0016] FIG. 3b is a schematic structure diagram of a base station according to an embodiment of the present disclosure;

[0017] FIG. 4 is a flowchart of a method executed by a UE according to an embodiment of the present disclosure; and

[0018] FIG. 5 is a schematic structure diagram of an electronic device according to an embodiment of the present disclosure.

[0019] An object of embodiments of the present disclosure is to solve the congestion problem of UEs when accessing a network.

[0020] In accordance with one aspect of the embodiments of the present disclosure, there is provided a method executed by a UE in a communication system, comprising: receiving system information, the system information including configuration information related to PRACH resources corresponding to at least two first UL carriers; determining a first UL carrier in the at least two first UL carriers based on at least one of parameters; and performing a random access procedure based on the PRACH resource on the determined first UL carrier, wherein the parameters includes: an ID of the UE; a random number generated by the UE; a parameter value indicated via a higher layer of the UE or determined by a medium access control (MAC) layer , and a mapping between the parameter value and the first UL carrier; a UL carrier index indicated by a base station; and a downlink (DL) carrier where a monitored paging message is located, and a mapping between the DL carrier and the first UL carrier.

[0021] In one optional implementation, the determining the first UL carrier in the at least two first UL carriers comprises: determining the first UL carrier in the at least two first UL carriers based on a measured reference signal received power (RSRP) value and preset RSRP thresholds.

[0022] In one optional implementation, in case that there are at least three first UL carriers and at least two preset RSRP thresholds, each first UL carrier in the at least three first UL carriers corresponds to an RSRP range determined based on the at least two preset RSRP thresholds respectively, and the determining the first UL carrier in the at least three first UL carriers based on the measured RSRP value and the at least two preset RSRP thresholds comprises: using a first UL carrier, among the at least three first UL carriers, corresponding to a RSRP range where the measured RSRP value is located as the determined first UL carrier.

[0023] In one optional implementation, the determining the first UL carrier in the at least two first UL carriers based on the ID of the UE comprises at least one of the following ways: performing a first modular operation on the ID of the UE and a number of first UL carriers, and determining the first UL carrier in the at least two first UL carriers based on the result of the first modular operation; or performing a second modular operation on the ID of the UE and a sum of weights of the at least two first UL carriers, and determining the first UL carrier in the at least two first UL carriers based on the result of the second modular operation.

[0024] In one optional implementation, the determining the first UL carrier in the at least two first UL carriers based on the ID of the UE comprises at least one of the following ways:

[0025] using the first UL carrier corresponding to the value of determined by a formula of as the determined first UL carrier; and

[0026] using the first UL carrier corresponding to the minimum value of satisfying a formula of as the determined first UL carrier;

[0027] where represents the ID of the UE, represents a number of first UL carriers, represents the modular operation, represents the carrier in the at least two first UL carriers, represents the carrier in the at least two first UL carriers, represents a weight corresponding to a UL carrier , represents a sum of weights of the at least two first UL carriers, and represents a sum of weights corresponding to first first UL carriers in the at least two first UL carriers.

[0028] In one optional implementation, the determining the first UL carrier in the at least two first UL carriers based on the random number generated by the UE comprises:

[0029] using a first UL carrier corresponding to a minimum value of satisfying a formula of as the determined first UL carrier;

[0030] where represents a number of first UL carriers, represents a weight corresponding to the UL carrier , represents a sum of weights of the at least two first UL carriers, represents a random number in a range of 0 to generated by the UE based on a uniform distribution, represents a carrier in the at least two first UL carriers, and represents a sum of weights corresponding to first first UL carriers in the at least two first UL carriers.

[0031] In one optional implementation, the determining the first UL carrier in the at least two first UL carriers based on the measured RSRP value, the preset RSRP thresholds, and the at least one of the parameters comprises at least one of the following:

[0032] in case that the at least two first UL carriers include at least two normal uplink (NUL) carriers and one supplement uplink (SUL) carrier, using the SUL carrier as the determined first UL carrier if the measured RSRP value is less than or equal to a preset first RSRP threshold, and determining the first UL carrier in the at least two NUL carriers based on the at least one of the parameters if the measured RSRP value is greater than the preset first RSRP threshold;

[0033] in case that the at least two first UL carriers include at least two NUL carriers and at least two SUL carriers, determining the first UL carrier in the at least two SUL carriers based on the at least one of the parameters if the measured RSRP value is less than or equal to a preset first RSRP threshold, and determining the first UL carrier in the at least two NUL carriers based on the at least one of the parameters if the measured RSRP value is greater than the preset first RSRP threshold; and

[0034] in case that the at least two first UL carriers include one NUL carrier and at least two SUL carriers, determining the first UL carrier in the at least two SUL carriers based on the at least one of the parameters if the measured RSRP value is less than or equal to a preset first RSRP threshold, and using the one NUL carrier as the determined first UL carrier if the measured RSRP value is greater than the preset first RSRP threshold.

[0035] In one optional implementation, the UL carrier index is indicated by the base station through at least one of the following:

[0036] a downlink control information (DCI) carried by a scheduling physical downlink control channel (PDCCH) of a physical downlink shared channel (PDSCH) used for transmitting a paging message;

[0037] a medium access control control element (MAC CE) carried by the PDSCH used for transmitting the paging message; and

[0038] the paging message.

[0039] In one optional implementation, the MAC CE indicates corresponding UL carrier indexes for different UE groups, respectively, and the determining the first UL carrier in the at least two first UL carriers based on the UL carrier index indicated by the base station and the ID of the UE comprises:

[0040] determining, based on the ID of the UE, a UE group where the UE is located, and using the carrier with the UL carrier index corresponding to the UE group where the UE is located as the determined first UL carrier.

[0041] In one optional implementation, in a case where the UE fails to initiate the random access procedure on the determined first UL carrier, the method further comprises:

[0042] switching to at least one of the following target UL carriers, and continuing to initiate the random access procedure on the target UL carrier:

[0043] a UL carrier corresponding to the DL carrier that transmits the system message;

[0044] a UL carrier with the smallest UL carrier index;

[0045] a UL carrier indicated by the base station, the UL carrier indicated by the base station being indicated through the system information or indicated through an MAC subheader included in a random access response medium access control protocol data unit (RAR MAC PDU);

[0046] a UL carrier having a lower frequency point than the first UL carrier used for PRACH transmission; and

[0047] an SUL carrier.

[0048] In one optional implementation, the random access procedure failure includes a predetermined number of continuous random access procedure failures.

[0049] In one optional implementation, if there are a plurality of UL carriers having lower frequency points than the first UL carrier used for PRACH transmission, the method further comprises:

[0050] selecting, from the plurality of UL carriers having lower frequency points than the first UL carrier used for PRACH transmission, one UL carrier as the target UL carrier based on at least one of the following methods:

[0051] randomly selecting a UL carrier;

[0052] selecting a UL carrier with the smallest UL carrier index;

[0053] selecting a UL carrier with the highest frequency point; and

[0054] selecting a UL carrier with the lowest frequency point.

[0055] In one optional implementation, the switching to the target UL carrier and continuing to initiate the random access procedure on the target UL carrier comprises at least one of the following situations:

[0056] when the random access procedure is still failed after the power of the PRACH ramps to the maximum transmission power, switching to the target UL carrier, and continuously initializing the random access procedure on the target UL carrier at the maximum transmission power or initial transmission power; and

[0057] switching to the target UL carrier, and when the random access procedure initiated on the target UL carrier is still failed, increasing the transmission power of the PRACH on the target UL carrier and initiating the random access procedure again.

[0058] In one optional implementation, the system information further includes configuration information related to physical uplink control channel (PUCCH) resources corresponding to at least two second UL carriers, and the method further comprises:

[0059] determining a second UL carrier in the at least two second UL carriers; and

[0060] transmitting a PUCCH based on a PUCCH resource on the determined second UL carrier.

[0061] In one optional implementation, the transmitting the PUCCH based on the PUCCH resource on the determined second UL carrier comprises:

[0062] before receiving UE-specific PUCCH configuration information, transmitting the PUCCH based on the PUCCH resource on the determined second UL carrier.

[0063] In one optional implementation, the determining the second UL carrier in the at least two second UL carriers comprises at least one of the following ways:

[0064] using the first UL carrier used for PRACH transmission as the determined second UL carrier;

[0065] determining the second UL carrier in the at least two second UL carriers based on the first UL carrier used for PRACH transmission and a mapping between the first UL carrier and the second UL carrier;

[0066] determining the second UL carrier in the at least two second UL carriers based on a mapping between the PRACH resource and the PUCCH resource;

[0067] using a second UL carrier, among the at least two second UL carriers, having a smallest UL carrier index as the determined second UL carrier;

[0068] determining the second UL carrier in the at least two second UL carriers based on an indication of a random access response included in a Message 2 in a four-step random access procedure, or based on an indication of scheduling downlink control information (DCI) of Message 4 in the four-step random access procedure, or based on an indication of a success random access response included in a Message B in a two-step random access procedure; and

[0069] determining the second UL carrier in the at least two second UL carriers based on the ID of the UE.

[0070] In one optional implementation, the determining the second UL carrier in the at least two second UL carriers based on the ID of the UE comprises at least one of the following ways:

[0071] performing a third modular operation on the ID of the UE and a number of second UL carriers, and determining the second UL carrier in the at least two second UL carriers based on the result of third modular operation; and

[0072] performing a fourth modular operation on the ID of the UE and a sum of weights of the at least two second UL carriers, and determining the second UL carrier in the at least two second UL carriers based on the result of fourth modular operation.

[0073] In one optional implementation, the determining the second UL carrier in the at least two second UL carriers based on the ID of the UE comprises at least one of the following ways:

[0074] using the second UL carrier corresponding to the value of determined by a formula of as the determined second UL carrier; and

[0075] using the second UL carrier corresponding to the minimum value of satisfying a formula of as the determined second UL carrier;

[0076] where represents the ID of the UE, represents the number of second UL carriers, represents the modular operation, represents the carrier in the at least two second UL carriers, represents the carrier in the at least two second UL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two second UL carriers, and represents the sum of weights corresponding to first second UL carriers in the at least two second UL carriers.

[0077] In one optional implementation, the system information further includes configuration information related to initial uplink bandwidth parts (BWPs) corresponding to at least two third UL carriers, and the method further comprises:

[0078] determining a third UL carrier in the at least two third UL carriers; and

[0079] transmitting a PUSCH based on the initial uplink BWP on the determined third UL carrier.

[0080] In one optional implementation, the transmitting a PUSCH based on the initial uplink BWP on the determined third UL carrier comprises:

[0081] before establishment of a radio resource control (RRC) connected state, transmitting a PUSCH based on the initial uplink BWP on the determined third UL carrier.

[0082] In one optional implementation, the determining the third UL carrier in the at least two third UL carriers comprises at least one of the following ways:

[0083] if the configuration information related to the initial uplink BWP corresponding to the determined first UL carrier is received, using the determined first UL carrier as the determined third UL carrier;

[0084] if the configuration information related to the initial uplink BWP corresponding to the determined first UL carrier is not received, using a UL carrier corresponding to a DL carrier that transmits the system message as the determined third UL carrier, or determining the third UL carrier in the at least two third UL carriers;

[0085] determining the third UL carrier in the at least two third UL carriers based on a UL carrier index indicated in a random access response (RAR); and

[0086] determining the third UL carrier in the at least two third UL carriers based on the ID of the UE.

[0087] In one optional implementation, the determining the third UL carrier in the at least two third UL carriers based on the ID of the UE comprises at least one of the following ways:

[0088] performing a fifth modular operation on the ID of the UE and the number of third UL carriers, and determining one third UL carrier in the at least two third UL carriers based on the result of fifth modular operation; and

[0089] performing a sixth modular operation on the ID of the UE and the sum of weights of the at least two third UL carriers, and determining one third UL carrier in the at least two third UL carriers based on the result of sixth modular operation.

[0090] In one optional implementation, the determining the third UL carrier in the at least two third UL carriers based on the ID of the UE comprises at least one of the following ways:

[0091] using the third UL carrier corresponding to the value of determined by a formula of as the determined third UL carrier; and

[0092] using the third UL carrier corresponding to the minimum value of satisfying a formula of as the determined third UL carrier;

[0093] where represents the ID of the UE, represents the number of third UL carriers, represents the modular operation, represents the carrier in the at least two third UL carriers, represents the carrier in the at least two third UL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two third UL carriers, and represents the sum of weights corresponding to first third UL carriers in the at least two third UL carriers.

[0094] In one optional implementation, the system information further includes configuration information related to initial downlink BWPs corresponding to at least two first DL carriers, and the method further comprises:

[0095] determining a first DL carrier in the at least two first DL carriers; and

[0096] receiving a PDCCH and a PDSCH based on the initial downlink BWP on the determined first DL carrier.

[0097] In one optional implementation, the receiving a PDCCH and a PDSCH based on the initial downlink BWP on the determined first DL carrier comprises:

[0098] before establishment of an RRC connected state, receiving the PDCCH and the PDSCH based on the initial downlink BWP on the determined first DL carrier.

[0099] In one optional implementation, the determining the first DL carrier in the at least two first DL carriers comprises at least one of the following ways:

[0100] determining the first DL carrier in the at least two first DL carriers based on the determined first UL carrier and a mapping between the first UL carrier and the first DL carrier; and

[0101] determining the first DL carrier in the at least two first DL carriers based on the ID of the UE.

[0102] In one optional implementation, the determining the first DL carrier in the at least two first DL carriers based on the ID of the UE comprises at least one of the following ways:

[0103] performing a seventh modular operation on the ID of the UE and the number of first DL carriers, and determining the first DL carrier in the at least two first DL carriers based on the result of seventh modular operation; and

[0104] performing an eighth modular operation on the ID of the UE and the sum of weights of the at least two first DL carriers, and determining the first DL carrier in the at least two first DL carriers based on the result of eighth modular operation.

[0105] In one optional implementation, the determining the first DL carrier in the at least two first DL carriers based on the ID of the UE comprises at least one of the following ways:

[0106] using the first DL carrier corresponding to the value of determined by a formula of as the determined first DL carrier; and

[0107] using the first DL carrier corresponding to the minimum value of satisfying a formula of as the determined first DL carrier;

[0108] where represents the ID of the UE, represents the number of first DL carriers, represents the modular operation, represents the carrier in the at least two first DL carriers, represents the carrier in the at least two first DL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two first DL carriers, and represents the sum of weights corresponding to first first DL carriers in the at least two first DL carriers.

[0109] In one optional implementation, the system information further includes configuration information related to paging PDCCH search spaces for monitoring paging messages corresponding to at least two second DL carriers, and the method further comprises:

[0110] determining a second DL carrier in the at least two second DL carriers based on the ID of the UE; and

[0111] monitoring a scheduling PDCCH of a paging message based on the paging PDCCH search space on the determined second DL carrier.

[0112] In one optional implementation, the determining the second DL carrier in the at least two second DL carriers based on the ID of the UE comprises:

[0113] determining a paging occasion index based on the ID of the UE, performing a ninth modular operation on the paging occasion index and the number of second DL carriers, and determining the second DL carrier in the at least two second DL carriers based on the result of ninth modular operation; and

[0114] determining a paging occasion index based on the ID of the UE, performing a tenth modular operation on the paging occasion index and the sum of weights of the at least two second DL carriers, and determining the second DL carrier in the at least two second DL carriers based on the result of tenth modular operation.

[0115] In one optional implementation, the determining the second DL carrier in the at least two second DL carriers based on the ID of the UE comprises:

[0116] using the second DL carrier corresponding to the value of determined by a formula of as the determined second DL carrier; and

[0117] using the second DL carrier corresponding to the minimum value of satisfying a formula of as the determined second DL carrier;

[0118] where represents the ID of the UE, and are parameters used for determining the paging occasion index, represents a rounding-down operation, represents the determined paging occasion index, represents the number of second DL carriers, represents the modular operation, represents the carrier in the at least two second DL carriers, represents the carrier in the at least two second DL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two second DL carriers, and represents the sum of weights corresponding to first second DL carriers in the at least two second DL carriers.

[0119] In accordance with another aspect of the embodiments of the present disclosure, there is provided a user equipment, comprising:

[0120] a transceiver configured to transmit and receive signals; and

[0121] at least one processor coupled to the transceiver and configured to perform the method executed by a UE provided in the embodiments of the present disclosure.

[0122] In accordance with still another aspect of the embodiments of the present disclosure, there is provided a computer-readable storage medium having stored thereon a computer program, that when executed by a processor, implements the method executed by a UE provided in the embodiments of the present disclosure.

[0123] In accordance with yet another aspect of the embodiments of the present disclosure, there is provided a computer program product including a computer program, that when executed by a processor, implements the method executed by a UE provided in the embodiments of the present disclosure.

[0124] In the communication method and the user equipment provided in the embodiments of the present disclosure, system information is received, the system information including configuration information related to PRACH resources corresponding to at least two first UL carriers; and, a first UL carrier is determined in the at least two first UL carriers based on at least one of the following parameters, and a random access procedure is performed based on the PRACH resource on the determined first UL carrier: an ID of the UE; a random number generated by the UE; a parameter value indicated by a higher layer of the UE or determined by a medium access control (MAC) layer of the UE, and a mapping between the parameter value and the first UL carrier; a UL carrier index indicated by a base station; a downlink (DL) carrier where the monitored paging message is located, and a mapping between the DL carrier and the first UL carrier. That is, the UE may use one of at least two first UL carriers configured with PRACH resources to access a network in the above determination mode, so that the flexibility of the communication system is significantly improved and the congestion phenomenon when the UE accesses the network is reduced.

[0125] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein may be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

[0126] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0127] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0128] The term "include" or "may include" refers to the existence of a corresponding disclosed function, operation or component which may be used in various embodiments of the present disclosure and does not limit one or more additional functions, operations, or components. The terms such as "include" and / or "have" may be construed to denote a certain characteristic, number, step, operation, constituent element, component or a combination thereof, but may not be construed to exclude the existence of or a possibility of addition of one or more other characteristics, numbers, steps, operations, constituent elements, components or combinations thereof.

[0129] The term "or" used in various embodiments of the present disclosure includes any or all of combinations of listed words. For example, the expression "A or B" may include A, may include B, or may include both A and B.

[0130] Unless defined differently, all terms used herein, which include technical terminologies or scientific terminologies, have the same meaning as that understood by a person skilled in the art to which the present disclosure belongs. Such terms as those defined in a generally used dictionary are to be interpreted to have the meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present disclosure.

[0131] In order to meet the increasing demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also called "Beyond 4G networks" or "Post-LTE systems".

[0132] In order to achieve a higher data rate, 5G communication systems are implemented in higher frequency (millimeter, mmWave) bands, e.g., 60 GHz bands. In order to reduce propagation loss of radio waves and increase a transmission distance, technologies such as beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antenna, analog beamforming and large-scale antenna are discussed in 5G communication systems.

[0133] In addition, in 5G communication systems, developments of system network improvement are underway based on advanced small cell, cloud radio access network (RAN), ultra-dense network, device-to-device (D2D) communication, wireless backhaul, mobile network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation, etc.

[0134] In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as advanced coding modulation (ACM), and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0135] In the existing communication systems, a cell includes one downlink (DL) carrier and at most two uplink (UL) carriers, wherein the two UL carriers are called a normal UL (NUL) carrier and a supplement UL (SUL) carrier respectively. If all UEs in the cell coverage access the network through these UL carriers, the UEs are highly possible to be congested in a random access procedure.

[0136] FIG. 1 illustrates an example wireless network 100 according to various embodiments of the present disclosure. The embodiment of the wireless network 100 shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

[0137] The wireless network 100 includes a gNodeB (gNB) 101, a gNB 102, and a gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one Internet Protocol (IP) network 130, such as the Internet, a private IP network, or other data networks.

[0138] Depending on a type of the network, other well-known terms such as "base station" or "access point" may be used instead of "gNodeB" or "gNB". For convenience, the terms "gNodeB" and "gNB" are used in this patent document to refer to network infrastructure components that provide wireless access for remote terminals. And, depending on the type of the network, other well-known terms such as "mobile station", "user station", "remote terminal", "wireless terminal" or "user apparatus" may be used instead of "user equipment" or "UE". For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to remote wireless devices that wirelessly access the gNB, no matter whether the UE is a mobile device (such as a mobile phone or a smart phone) or a fixed device (such as a desktop computer or a vending machine).

[0139] gNB 102 provides wireless broadband access to the network 130 for a first plurality of User Equipments (UEs) within a coverage area 120 of gNB 102. The plurality of UEs include a UE 111, which may be located in a Small Business (SB); a UE 112, which may be located in an enterprise (E); a UE 113, which may be located in a WiFi Hotspot (HS); a UE 114, which may be located in a first residence (R); a UE 115, which may be located in a second residence (R); a UE 116, which may be a mobile device (M), such as a cellular phone, a wireless laptop computer, a wireless PDA, etc. GNB 103 provides wireless broadband access to network 130 for a plurality of UEs within a coverage area 125 of gNB 103. The plurality of UEs include a UE 115 and a UE 116. In some embodiments, one or more of gNBs 101-103 may communicate with each other and with UEs 111-116 using 5G, Long Term Evolution (LTE), LTE-A, WiMAX or other advanced wireless communication technologies.

[0140] The dashed lines show approximate ranges of the coverage areas 120 and 125, and the ranges are shown as approximate circles merely for illustration and explanation purposes. It should be clearly understood that the coverage areas associated with the gNBs, such as the coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on configurations of the gNBs and changes in the radio environment associated with natural obstacles and man-made obstacles.

[0141] As will be described in more detail below, one or more of gNB 101, gNB 102, and gNB 103 include a 2D antenna array as described in embodiments of the present disclosure. In some embodiments, one or more of gNB 101, gNB 102, and gNB 103 support codebook designs and structures for systems with 2D antenna arrays.

[0142] Although FIG. 1 illustrates an example of the wireless network 100, various changes may be made to FIG. 1. The wireless network 100 may include any number of gNBs and any number of UEs in any suitable arrangement, for example. Furthermore, gNB 101 may directly communicate with any number of UEs and provide wireless broadband access to the network 130 for those UEs. Similarly, each gNB 102-103 may directly communicate with the network 130 and provide direct wireless broadband access to the network 130 for the UEs. In addition, gNB 101, 102 and / or 103 may provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0143] FIGs. 2a and 2b illustrate example wireless transmission and reception paths according to the present disclosure. In the following description, the transmission path 200 may be described as being implemented in a gNB, such as gNB 102, and the reception path 250 may be described as being implemented in a UE, such as UE 116. However, it should be understood that the reception path 250 may be implemented in a gNB and the transmission path 200 may be implemented in a UE. In some embodiments, the reception path 250 is configured to support codebook designs and structures for systems with 2D antenna arrays as described in embodiments of the present disclosure.

[0144] The transmission path 200 includes a channel coding and modulation block 205, a Serial-to-Parallel (S-to-P) block 210, a size N Inverse Fast Fourier Transform (IFFT) block 215, a Parallel-to-Serial (P-to-S) block 220, a cyclic prefix addition block 225, and an up-converter (UC) 230. The reception path 250 includes a down-converter (DC) 255, a cyclic prefix removal block 260, a Serial-to-Parallel (S-to-P) block 265, a size N Fast Fourier Transform (FFT) block 270, a Parallel-to-Serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

[0145] In the transmission path 200, the channel coding and modulation block 205 receives a set of information bits, applies coding (such as Low Density Parity Check (LDPC) coding), and modulates the input bits (such as using Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM)) to generate a sequence of frequency-domain modulated symbols. The Serial-to-Parallel (S-to-P) block 210 converts (such as demultiplexes) serial modulated symbols into parallel data to generate N parallel symbol streams, where N is a size of the IFFT / FFT used in gNB 102 and UE 116. The size N IFFT block 215 performs IFFT operations on the N parallel symbol streams to generate a time-domain output signal. The Parallel-to-Serial block 220 converts (such as multiplexes) parallel time-domain output symbols from the Size N IFFT block 215 to generate a serial time-domain signal. The cyclic prefix addition block 225 inserts a cyclic prefix into the time-domain signal. The up-converter 230 modulates (such as up-converts) the output of the cyclic prefix addition block 225 to an RF frequency for transmission via a wireless channel. The signal may also be filtered at a baseband before switching to the RF frequency.

[0146] The RF signal transmitted from gNB 102 arrives at UE 116 after passing through the wireless channel, and operations in reverse to those at gNB 102 are performed at UE 116. The down-converter 255 down-converts the received signal to a baseband frequency, and the cyclic prefix removal block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. The Serial-to-Parallel block 265 converts the time-domain baseband signal into a parallel time-domain signal. The Size N FFT block 270 performs an FFT algorithm to generate N parallel frequency-domain signals. The Parallel-to-Serial block 275 converts the parallel frequency-domain signal into a sequence of modulated data symbols. The channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

[0147] Each of gNBs 101-103 may implement a transmission path 200 similar to that for transmitting to UEs 111-116 in the downlink, and may implement a reception path 250 similar to that for receiving from UEs 111-116 in the uplink. Similarly, each of UEs 111-116 may implement a transmission path 200 for transmitting to gNBs 101-103 in the uplink, and may implement a reception path 250 for receiving from gNBs 101-103 in the downlink.

[0148] Each of the components in FIGs. 2a and 2b may be implemented using only hardware, or using a combination of hardware and software / firmware. As a specific example, at least some of the components in FIGs. 2a and 2b may be implemented in software, while other components may be implemented in configurable hardware or a combination of software and configurable hardware. For example, the FFT block 270 and IFFT block 215 may be implemented as configurable software algorithms, in which the value of the size N may be modified according to the implementation.

[0149] Furthermore, although described as using FFT and IFFT, this is only illustrative and should not be interpreted as limiting the scope of the present disclosure. Other types of transforms may be used, such as Discrete Fourier transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions. It should be understood that for DFT and IDFT functions, the value of variable N may be any integer (such as 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of variable N may be any integer which is a power of 2 (such as 1, 2, 4, 8, 16, etc.).

[0150] Although FIGs. 2a and 2b illustrate examples of wireless transmission and reception paths, various changes may be made to FIGs. 2a and 2b. For example, various components in FIGs. 2a and 2b may be combined, further subdivided or omitted, and additional components may be added according to specific requirements. Furthermore, FIGs. 2a and 2b are intended to illustrate examples of types of transmission and reception paths that may be used in a wireless network. Any other suitable architecture may be used to support wireless communication in a wireless network.

[0151] FIG. 3a illustrates an example UE 116 according to the present disclosure. The embodiment of UE 116 shown in FIG. 3a is for illustration only, and UEs 111-115 of FIG. 1 may have the same or similar configuration. However, a UE has various configurations, and FIG. 3a does not limit the scope of the present disclosure to any specific implementation of the UE.

[0152] UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a transmission (TX) processing circuitry 315, a microphone 320, and a reception (RX) processing circuitry 325. UE 116 also includes a speaker 330, a processor / controller 340, an input / output (I / O) interface 345, an input device(s) 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0153] The RF transceiver 310 receives an incoming RF signal transmitted by a gNB of the wireless network 100 from the antenna 305. The RF transceiver 310 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is transmitted to the RX processing circuitry 325, where the RX processing circuitry 325 generates a processed baseband signal by filtering, decoding and / or digitizing the baseband or IF signal. The RX processing circuitry 325 transmits the processed baseband signal to speaker 330 (such as for voice data) or to processor / controller 340 for further processing (such as for web browsing data).

[0154] The TX processing circuitry 315 receives analog or digital voice data from microphone 320 or other outgoing baseband data (such as network data, email or interactive video game data) from processor / controller 340. The TX processing circuitry 315 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the outgoing processed baseband or IF signal from the TX processing circuitry 315 and up-converts the baseband or IF signal into an RF signal transmitted via the antenna 305.

[0155] The processor / controller 340 may include one or more processors or other processing devices and execute an OS 361 stored in the memory 360 in order to control the overall operation of UE 116. For example, the processor / controller 340 may control the reception of forward channel signals and the transmission of backward channel signals through the RF transceiver 310, the RX processing circuitry 325 and the TX processing circuitry 315 according to well-known principles. In some embodiments, the processor / controller 340 includes at least one microprocessor or microcontroller.

[0156] The processor / controller 340 is also capable of executing other processes and programs residing in the memory 360, such as operations for channel quality measurement and reporting for systems with 2D antenna arrays as described in embodiments of the present disclosure. The processor / controller 340 may move data into or out of the memory 360 as required by an execution process. In some embodiments, the processor / controller 340 is configured to execute the application 362 based on the OS 361 or in response to signals received from the gNB or the operator. The processor / controller 340 is also coupled to an I / O interface 345, where the I / O interface 345 provides UE 116 with the ability to connect to other devices such as laptop computers and handheld computers. I / O interface 345 is a communication path between these accessories and the processor / controller 340.

[0157] The processor / controller 340 is also coupled to the input device(s) 350 and the display 355. An operator of UE 116 may input data into UE 116 using the input device(s) 350. The display 355 may be a liquid crystal display or other display capable of presenting text and / or at least limited graphics (such as from a website). The memory 360 is coupled to the processor / controller 340. A part of the memory 360 may include a random access memory (RAM), while another part of the memory 360 may include a flash memory or other read-only memory (ROM).

[0158] Although FIG. 3a illustrates an example of UE 116, various changes may be made to FIG. 3a. For example, various components in FIG. 3a may be combined, further subdivided or omitted, and additional components may be added according to specific requirements. As a specific example, the processor / controller 340 may be divided into a plurality of processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, although FIG. 3a illustrates that the UE 116 is configured as a mobile phone or a smart phone, UEs may be configured to operate as other types of mobile or fixed devices.

[0159] FIG. 3b illustrates an example gNB 102 according to the present disclosure. The embodiment of gNB 102 shown in FIG. 3b is for illustration only, and other gNBs of FIG. 1 may have the same or similar configuration. However, a gNB has various configurations, and FIG. 3b does not limit the scope of the present disclosure to any specific implementation of a gNB. It should be noted that gNB 101 and gNB 103 may include the same or similar structures as gNB 102.

[0160] As shown in FIG. 3b, gNB 102 includes a plurality of antennas 370a-370n, a plurality of RF transceivers 372a-372n, a transmission (TX) processing circuit 374, and a reception (RX) processing circuit 376. In certain embodiments, one or more of the plurality of antennas 370a-370n include a 2D antenna array. gNB 102 also includes a controller / processor 378, a memory 380, and a backhaul or network interface 382.

[0161] RF transceivers 372a-372n receive an incoming RF signal from antennas 370a-370n, such as a signal transmitted by UEs or other gNBs. RF transceivers 372a-372n down-convert the incoming RF signal to generate an IF or baseband signal. The IF or baseband signal is transmitted to the RX processing circuit 376, where the RX processing circuit 376 generates a processed baseband signal by filtering, decoding and / or digitizing the baseband or IF signal. RX processing circuit 376 transmits the processed baseband signal to controller / processor 378 for further processing.

[0162] The TX processing circuit 374 receives analog or digital data (such as voice data, network data, email or interactive video game data) from the controller / processor 378. TX processing circuit 374 encodes, multiplexes and / or digitizes outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 372a-372n receive the outgoing processed baseband or IF signal from TX processing circuit 374 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 370a-370n.

[0163] The controller / processor 378 may include one or more processors or other processing devices that control the overall operation of gNB 102. For example, the controller / processor 378 may control the reception of forward channel signals and the transmission of backward channel signals through the RF transceivers 372a-372n, the RX processing circuit 376 and the TX processing circuit 374 according to well-known principles. The controller / processor 378 may also support additional functions, such as higher-level wireless communication functions. For example, the controller / processor 378 may perform a Blind Interference Sensing (BIS) process such as that performed through a BIS algorithm, and decode a received signal from which an interference signal is subtracted. A controller / processor 378 may support any of a variety of other functions in gNB 102. In some embodiments, the controller / processor 378 includes at least one microprocessor or microcontroller.

[0164] The controller / processor 378 is also capable of executing programs and other processes residing in the memory 380, such as a basic OS. The controller / processor 378 may also support channel quality measurement and reporting for systems with 2D antenna arrays as described in embodiments of the present disclosure. In some embodiments, the controller / processor 378 supports communication between entities such as web RTCs. The controller / processor 378 may move data into or out of the memory 380 as required by an execution process.

[0165] The controller / processor 378 is also coupled to the backhaul or network interface 382. The backhaul or network interface 382 allows gNB 102 to communicate with other devices or systems through a backhaul connection or through a network. The backhaul or network interface 382 may support communication over any suitable wired or wireless connection(s). For example, when gNB 102 is implemented as a part of a cellular communication system, such as a cellular communication system supporting 5G or new radio access technology or NR, LTE or LTE-A, the backhaul or network interface 382 may allow gNB 102 to communicate with other gNBs through wired or wireless backhaul connections. When gNB 102 is implemented as an access point, the backhaul or network interface 382 may allow gNB 102 to communicate with a larger network, such as the Internet, through a wired or wireless local area network or through a wired or wireless connection. The backhaul or network interface 382 includes any suitable structure that supports communication through a wired or wireless connection, such as an Ethernet or an RF transceiver.

[0166] The memory 380 is coupled to the controller / processor 378. A part of the memory 380 may include an RAM, while another part of the memory 380 may include a flash memory or other ROMs. In certain embodiments, a plurality of instructions, such as the BIS algorithm, are stored in the memory. The plurality of instructions are configured to cause the controller / processor 378 to execute the BIS process and decode the received signal after subtracting at least one interference signal determined by the BIS algorithm.

[0167] As will be described in more detail below, the transmission and reception paths of gNB 102 (implemented using RF transceivers 372a-372n, TX processing circuit 374 and / or RX processing circuit 376) support aggregated communication with FDD cells and TDD cells.

[0168] Although FIG. 3b illustrates an example of gNB 102, various changes may be made to FIG. 3b. For example, gNB 102 may include any number of each component shown in FIG. 3a. As a specific example, the access point may include many backhaul or network interfaces 382, and the controller / processor 378 may support routing functions to route data between different network addresses. As another specific example, although shown as including a single instance of the TX processing circuit 374 and a single instance of the RX processing circuit 376, gNB 102 may include multiple instances of each (such as one for each RF transceiver).

[0169] In the existing communication systems, a cell is configured with at most two uplink carriers, i.e., NUL and SUL, wherein the SUL carrier is generally located in a lower frequency band to enhance the coverage of the uplink. If the operator has more spectrum resources, a plurality of carriers may also be deployed to increase the rate of the terminal. For example, by aggregating a plurality of carriers through carrier aggregation (CA), resources on the plurality of carriers may be allocated to the UE for use, so as to increase the data rate of the UE. Although the CA may aggregate many carriers, these carriers serve UEs through secondary cells. Since UEs may not use the carriers aggregated through CA before establishment of radio resource control (RRC) connections with the network, all UEs may only access the network through major cells, that is, all UEs access the network through at most two UL carriers, so that the UEs are highly possible to be congested in the random access procedure. Thus, the cell needs to configure more carriers to offload UEs, for example, configuring more UL carriers and / or more DL carriers.

[0170] In the embodiments of the present disclosure, on the basis of considering the necessity of adding a plurality of carriers in a cell, the technical details of determining, by a UE, one carrier in the plurality of carriers for use in the random access procedure are provided.

[0171] An embodiment of the present disclosure provides a method executed by a UE in a communication system. As shown in FIG. 4, the method includes the following steps.

[0172] In step S101, system information is received, the system information including configuration information related to physical random access channel (PRACH) resources on at least two first UL carriers.

[0173] In step S102, one first UL carrier is determined in the at least two first UL carriers based on at least one of the following parameters, and a random access procedure is performed based on the PRACH resource on the determined first UL carrier.

[0174] In the steps S101 and S102, the method of determining one first UL carrier in the at least two first UL carriers by the UE described in the embodiment of the present disclosure may be construed as a method of determining one PRACH configuration (resource pool) in at least two PRACH configurations (resource pools) by the UE. That is, the UE determines one PRACH configuration (resource pool) in the at least two PRACH configurations (resource pools), and transmits a PRACH based on the determined PRACH configuration (resource pool), wherein different PRACH configurations (resource pools) correspond to different UL carriers.

[0175] (1) Information for identifying the UE

[0176] The information for identifying the UE includes, but not limited to, an ID of the UE, a temporary mobile station identity (TMSI), an internal mobile subscriber identity (IMSI), and so on. For the convenience of description, the following embodiments will be described by taking the ID of the UE as an example.

[0177] That is, in the embodiment of the present disclosure, the UE determine one first UL carriers from a plurality of first UL carriers configured with PRACH resources based on its own ID (which may also be called UE ID or represented by UE_ID), and UE initiates a random access procedure on the determined first UL carrier to access the network, wherein UE_ID is the existing parameter used for determining a paging occasion, and UE_ID is determined by a 5G S-temporary mobile subscription identifier (5G-S-TMSI). If the UE is configured with extended discontinuous reception (eDRX), UE_ID = 5G-S-TMSI mod 4096; otherwise, UE_ID = 5G-S-TMSI mod 1024, where 5G-S-TMSI is a 48-bit serial number. If the UE has not registered with the network (that is, there is no 5G-S-TMSI), UE_ID = 0.

[0178] Optionally, if it is assumed that the total number of first UL carriers that are used for UE offloading and configured with PRACH resources is , the determining one first UL carrier in the at least two first UL carriers based on the ID of the UE may include at least one of the following methods.

[0179] Method 1: a first modular operation is performed on the ID of the UE and the number of first UL carriers, and one first UL carrier is determined in the at least two first UL carriers based on the result of first modular operation.

[0180] Specifically, the first UL carrier corresponding to the value of determined by a formula of may be used as the determined first UL carrier, where represents the ID of the UE, represents the number of first UL carriers, represents the modular operation, and represents the carrier in the at least two first UL carriers.

[0181] The first UL carriers are arranged in an order from smallest to largest UL carrier indexes, and refers to the carrier in the first UL carriers.

[0182] The method 1 may offload UEs accessing the network to different carriers, thus avoiding the random access congestion. In the above example, if it is assumed that each first UL carrier has the same weight for UE offloading, for example, if it is assumed that =4, the number of UEs that may be accepted by each first UL carrier is 1 / 4 (i.e., 25%) of the total number of UEs accessing the network. In practical applications, since the bandwidth of each first UL carrier may be different, the number of UEs that may be accepted on each first UL carrier may also be different. For example, the network may configure a weight for UE offloading for each carrier, that is, the first UL carriers with different weights may accept different numbers of UEs.

[0183] Method 2: a second modular operation is performed on the ID of the UE and the sum of weights of the at least two first UL carriers, and one first UL carrier is determined in the at least two first UL carriers based on the result of second modular operation (comparison with the sum of weights of the plurality of first UL carriers).

[0184] Specifically, if it is assumed that the number of first UL carriers that are used for UE offloading and configured with PRACH resource pools is , and each carrier is configured with the corresponding weight (where , and is a positive integer), the first UL carrier corresponding to the minimum value of satisfying a formula of may be used as the determined first UL carrier, where represents the ID of the UE, represents the number of first UL carriers, represents the modular operation, represents the carrier in the at least two first UL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two first UL carriers, and represents the sum of weights corresponding to first first UL carriers in the at least two first UL carriers.

[0185] In other words, if [ ]< , the UE selects the 1st first UL carrier in the first UL carriers; if [ ]< + , the UE selects the 2nd first UL carrier in the first UL carriers; and in the similar way, if [ ]< , the UE selects the first UL carrier in the first UL carriers.

[0186] (2) Random number generated by the UE

[0187] Optionally, the UE determines one first UL carrier in the at least two first UL carriers according to the comparison of the generated random number with the sum of weights of the plurality of first UL carriers. For example, if it is assumed that the number of first UL carriers that are used for UE offloading and configured with PRACH resource pools is , and each carrier is configured with the corresponding weight (where , and is a positive integer), when the random access procedure is triggered, based on a random number randomValue between 0 and generated based on a uniform distribution, the UE uses the first UL carrier corresponding to the minimum value of satisfying a formula of as the determined first UL carrier, where represents the number of first UL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two first UL carriers, represents the random number in a range of 0 to generated by the UE based on the uniform distribution, represents the carrier in the at least two first UL carriers, and represents the sum of weights corresponding to first first UL carriers in the at least two first UL carriers.

[0188] In other words, if , the UE selects the 1st first UL carrier in the first UL carriers; if , the UE selects the 2nd first UL carrier in the first UL carriers; and in the similar way, if , the UE selects the first UL carrier in the first UL carriers.

[0189] (3) A parameter value indicated by a higher layer of the UE or determined by a medium access control (MAC) layer of the UE, and a mapping between the parameter value and the first UL carrier;

[0190] Optionally, the UE determines one first UL carrier in the at least two first UL carriers according to the parameter value indicated by the higher layer or determined by the MAC layer and the mapping between the parameter value and the first UL carrier. Here, the parameter value indicated by the higher later may be related to a service type, a quality of service (QoS), a data priority, or a trigger scenario of the random access procedure. The trigger scenario of the random access procedure includes at least one of: initial access (including entering the RRC connected state from the RRC idle state), RRC connection reestablishment, cell handover, UL de-synchronization, UL data arrival in the RRC connected state, SR (scheduling request) failure, RRC synchronization reconfiguration request, entering the RRC connected state from the RRC inactive state, establishing time alignment when adding secondary cells (SCells), requesting other system information, and beam failure recovery. For example, each service type, QoS, data priority or trigger scenario of the random access procedure corresponds to one parameter value, and the value range of the parameter value is predefined. If the random access procedure is triggered by the RRC layer of the UE, the RRC layer of the UE will indicate the parameter value to the MAC layer; and, if the random access procedure is triggered by the MAC layer of the UE, the MAC layer of the UE may determine the parameter value, and each parameter value will be associated with one first UL carrier.

[0191] There may be two association modes between parameter values and UL carriers. The first association mode is predefined. For example, it is assumed that there are N1 parameter values and N2 UL carriers, which are associated sequentially according to the order of carrier indexes. That is, after the parameter values and the UL carriers are sorted according to the carrier indexes, the first parameter value is associated with the first UL carrier, the second parameter value is associated with the second UL carrier, the third parameter value is associated with the third UL carrier, and so on. If N1=N2, there is a one-to-one mapping between the parameter values and the UL carriers; if N1<N2, the spare UL carriers are sequentially associated again from the first parameter value, that is, there is a one-to-multiple mapping between the parameter values and the UL carriers; and, if N1>N2, the spare parameter values are sequentially associated again from the first UL carrier, that is, there is a multiple-to-one mapping between the parameter values and the UL carriers. The second association mode is preconfigured. For example, the network configures each parameter value with a UL carrier index associated therewith, or the network configures each UL carrier with a parameter value associated therewith. If one parameter value is associated to a plurality of UL carriers, the UE randomly selects one UL carriers from the plurality of UL carriers.

[0192] (4) UL carrier index indicated by the base station

[0193] That is, in the embodiment of the present disclosure, the UE determines, based on the UL carrier index indicated by the base station, one first UL carrier from a plurality of first UL carriers configured with PRACH resources, and initiates a random access procedure on the determined first UL carrier to access the network.

[0194] Optionally, the UE that is awakened to access the network by the network through a paging message may determine, based on the UL carrier index indicated by a physical downlink control channel (PDCCH) or physical downlink shared channel (PDSCH) where the paging message is located, one first UL carrier from a plurality of first UL carriers configured with PRACH resources. When the base station sends the paging message to awaken one UE to access the network, the base station also indicates the UL carrier index of the PRACH resource used to access the network by the UE.

[0195] Optionally, the UL carrier index used to access the network is indicated by the base station through at least one of the following:

[0196] 1. Downlink control information (DCI) carried by a scheduling PDCCH of a PDSCH used for transmitting the paging message

[0197] As an example, a field is included in the scheduling PDCCH for the paging message to indicate the UL carrier index, i.e., indicating one first UL carrier in a plurality of first UL carriers configured with PRACH resource pools. All UEs (in the RRC idle state) paged by the paging message corresponding to the PDCCH access the network based on the indicated carrier. The advantage is that the network can offload UEs awakened in different paging occasions to different first UL carriers to access the network, thus avoiding access congestion.

[0198] 2. Medium access control (MAC) control element (CE) carried by a PDSCH used for transmitting the paging message

[0199] As an example, an MAC CE is included in the PDSCH for the paging message, and the MAC CE indicates a UL carrier index, i.e., indicating one first UL carrier in a plurality of first UL carriers configured with PRACH resource pools. All UEs paged by the paging message included in the PDSCH access the network based on the indicated first UL carrier. The advantage is that the network can offload UEs awakened in different paging occasions to different first UL carriers to access the network, thus avoiding access congestion.

[0200] Alternatively, the MAC CE indicates one UL carrier index respectively for different UE groups. If a UE is awakened by the paging message included in the PDSCH where the MAC CE is located to access the network, the UE determines the index of the corresponding UE group according to the UE_ID, and then the UE accesses the network by using PRACH resources on the first UL carrier corresponding to the UE group to which the UE belongs. That is, the UE determines, based on the ID of the UE, a UE group where the UE is located, and uses the carrier with the UL carrier index corresponding to the UE group where the UE is located as the determined first UL carrier. The advantage is that the network can offload different UEs awakened in the same paging occasion to different first UL carriers to access the network, thus avoiding access congestion.

[0201] 3. Paging message

[0202] As an example, a UL carrier index is indicated in the paging message, that is, one first UL carrier in a plurality of first UL carriers configured with PRACH resource pools is indicated. All UEs paged by this paging message may access the network based on the indicated first UL carrier.

[0203] (5) Downlink (DL) carrier where the monitored paging message is located, and a mapping between the DL carrier and the first UL carrier

[0204] As an example, the UE that is awakened to access the network by the network through the paging message may determine, based on the DL carrier where the paging message is located, one first UL carriers from a plurality of first UL carriers configured with PRACH resources. A cell may be configured with a PDCCH search space for monitoring the paging message on a plurality of DL carriers, a UE may determine the corresponding DL carrier for monitoring the paging message according to the UE_ID, and each DL carrier configured with the PDCCH search space for the paging message is associated with one first UL carrier configured with PRACH resources. The mapping between the both may be predefined, or indicated through the system information. If a UE monitors a paging message on a DL carrier and needs to access the network, the UE accesses the network by using the first UL carrier configured with PRACH resources that is associated with the DL carrier.

[0205] In the embodiment of the present disclosure, there may be two association modes between DL carriers and UL carriers. The first association mode is predefined. For example, it is assumed that there are N1 DL carriers and N2 UL carriers, which are associated sequentially according to the order of carrier indexes. That is, after the DL carriers and the UL carriers are sorted according to the carrier indexes, the first DL carrier is associated with the first UL carrier, the second DL carrier is associated with the second UL carrier, the third DL carrier is associated with the third UL carrier, and so on. If N1=N2, there is a one-to-one mapping between the DL carriers and the UL carriers; if N1<N2, the spare UL carriers are sequentially associated from the first DL carrier, that is, there is a one-to-multiple mapping between the DL carriers and the UL carriers; and, if N1>N2, the spare DL carriers are sequentially associated again from the first UL carrier, that is, there is a multiple-to-one mapping between the DL carriers and the UL carriers. The second association mode is preconfigured. For example, the network configures each DL carrier with a UL carrier index associated therewith, or the network configures each UL carrier with a DL carrier index associated therewith. If a DL carrier is associated to a plurality of UL carriers, the UE randomly selects one UL carrier from the plurality of UL carriers.

[0206] In the embodiment of the present disclosure, at least two first UL carriers each include at least one SUL carrier, for example, including at least one SUL carrier and at least two NUL carriers, or including at least two SUL carriers and at least one NUL carrier, and so on. Alternatively, at least two first UL carriers each include no SUL carrier, so that at least two NUL carriers may be included.

[0207] In the embodiment of the present disclosure, the UE may select (determine) one UL carrier from a plurality of UL carriers to transmit a PRACH based on the above method, thus achieving the purpose of UE offloading and reducing the probability of UE congestion in a random access procedure. In other words, the UE selects (determines) one PRACH resource pool from a plurality of PRACH resource pools, and then performs the random access procedure on the determined PRACH resource pool, wherein different PRACH resource pools are configured on different UL carriers.

[0208] In the embodiment of the present disclosure, a cell may include a plurality of DL carriers, wherein the DL carrier used for transmitting system information (which may also be called cell system message) may be described as an anchor DL carrier, while other DL carriers are described as non-anchor DL carriers. The base station transmits at least one of cell defining synchronization signal block (CD-SSB), system information block 1 (SIB1) and other system information on the anchor DL carrier, and the base station configures the information of other non-DL carriers and respective UL carriers (including an anchor UL carrier and non-anchor UL carriers) through the anchor DL carrier. When the anchor DL carrier is a TDD carrier, the anchor DL carrier and the anchor UL carrier are the same anchor carrier; and, when the anchor DL carrier is an FDD carrier, the anchor carriers include an anchor DL carrier and its paired anchor UL carrier. On the anchor DL carrier, an initial downlink bandwidth part (BWP) is configured; while on the anchor UL carrier, a PRACH resource (resource pool) used for accessing the network and an initial uplink BWP are configured. Based on these related configuration information, the UE may access the network through the anchor carriers.

[0209] In the embodiment of the present disclosure, a plurality of UL carriers (which may include the anchor UL carrier) may be configured with PRACH resources (resource pools), including PRACH resources used for a two-step random access procedure and / or MsgA resources used for a four-step random access procedure (including PRACH resources and physical uplink shared channel (PUSCH) resources), and the UE may access the network through one of the PRACH resource pools on the plurality of UL carriers.

[0210] That is, in the embodiment of the present disclosure, a plurality of carriers, such as at least two first UL carriers, belong to the same cell. The UE may use one of at least two first UL carriers configured with PRACH resources to access the network based on the above first UL carrier determination method, thereby significantly improving the flexibility of the communication system and reducing the congestion phenomenon when the UE accesses the network.

[0211] In the embodiment of the present disclosure, an optional implementation is further provided for the step S102. Specifically, the step S102 may include: determining one first UL carrier in the at least two first UL carriers based on a measured reference signal received power (RSRP) value and preset RSRP threshold.

[0212] Optionally, the RSRP value may be measured on the anchor DL carrier.

[0213] Optionally, there is one RSRP threshold or at least two RSRP thresholds, and the RSRP threshold(s) may be configured through the system information.

[0214] In the embodiment of the present disclosure, the UE may determine, according to the comparison of the RSRP value measured with respect to an SSB of the serving cell with at least two preset RSRP thresholds, one first UL carrier from a plurality of first UL carriers configured with PRACH resources. For example, each first UL carrier corresponds to one RSRP range or RSRP threshold. When the RSRP measured by the UE based on the SSB is within the preset RSRP range or less than the preset RSRP threshold, the corresponding first UL carrier is selected.

[0215] For example, optionally, there are at least three first UL carriers and at least two preset RSRP thresholds, each first UL carrier in the at least three first UL carriers corresponds to an RSRP range determined based on the at least two preset RSRP thresholds respectively, and the determining one first UL carrier in the at least three first UL carriers based on the measured RSRP value and the at least two preset RSRP thresholds may specifically comprise: based on the RSRP range where the measured RSRP value is located, using the first UL carrier corresponding to the located RSRP range as the determined first UL carrier. That is, in the embodiment of the present disclosure, different carriers may have different coverages, and the PRACH resources on each carrier may be used by UEs within a specific coverage to access the network.

[0216] As an example, by taking the number of first UL carriers configured with PRACH resources being 3 as an example, three RSRP ranges may be determined based on two RSRP thresholds. If the RSRP value measured by the UE based on the SSB is less than the first RSRP threshold (that is, the first RSRP range is less than the first RSRP threshold), the UE selects the 1stfirst UL carrier; if the RSRP value measured by the UE based on the SSB is greater than or equal to the first RSRP threshold and less than the second RSRP threshold (that is, the second RSRP range is greater than or equal to the first RSRP threshold and less than the second RSRP threshold), the UE selects the 2ndfirst UL carrier; and, if the RSRP value measured by the UE based on the SSB is greater than or equal to the second RSRP threshold (that is, the third RSRP range is greater than or equal to the second RSRP threshold), the UE selects the 3rdfirst UL carrier. Here, the second RSPR threshold is greater than the first RSRP threshold, and the first RSRP threshold and the second RSRP threshold may be configured through the system information of the cell.

[0217] It may be understood that the above ways of determining one first UL carrier in the at least two first UL carriers may be combined. As an example, one first UL carrier may be determined in the at least two first UL carriers based on the measured RSRP value, the preset RSRP thresholds, and the at least one of the parameters (i.e., at least one parameter used for determining one first UL carrier in the at least two first UL carriers in the step S102). Specifically, it may include, but not limited to, at least one of the following ways:

[0218] (1) When the at least two first UL carriers include two NUL carriers and one SUL carrier, the SUL carrier is used as the determined first UL carrier if the RSRP value is less than or equal to a preset first RSRP threshold, and one first UL carrier is determined in the at least two NUL carriers based on the at least one of the parameters if the RSRP value is greater than the first RSRP threshold.

[0219] By taking based on the measured RSRP value and preset RSRP thresholds and the UE ID as an example, in the embodiment of the present disclosure, a cell may be configured with a plurality of NUL carriers and at most one SUL carrier, and the method of offloading UEs based on the UE ID is used for the plurality of NUL carriers. Optionally, in the above methods 1 and 2, the number of first UL carriers used for UE offloading is the number of all UL carriers configured with PRACH resource pools except for the SUL carrier. For example, the UE may compare the RSRP value measured based on the SSB with the preset first RSRP threshold (e.g., the existing parameter rsrp-ThresholdSSB-SUL). If the measured RSRP value is less than the preset first RSRP threshold, the SUL carrier is selected to initiate a RACH procedure to access the network; and, if the measured RSRP value is greater than the preset first RSRP threshold, one NUL carrier is selected from the plurality of NUL carrier based on the UE ID by using the above method 1 or 2 to access the network. That is, the RACH procedure is initiated on the selected NUL carrier.

[0220] (2) When the at least two first UL carriers include at least two NUL carriers and at least two SUL carriers, one first UL carrier is determined in the at least two SUL carriers based on the at least one of the parameters if the RSRP value is less than or equal to the preset first RSRP threshold, and one first UL carrier is determined in the at least two NUL carriers based on the at least one of the parameters if the RSRP value is greater than the first RSRP threshold.

[0221] By taking based on the measured RSRP value and preset RSRP thresholds and the UE ID as an example, in the embodiment of the present disclosure, a cell may be configured with a plurality of SUL carriers and a plurality of NUL carriers. That is, in the above methods 1 and 2, the UL carriers used for UE offloading are divided into two groups, i.e., an NUL group and an SUL group. The number of first UL carriers used for UE offloading is the number of SUL carriers configured with PRACH resources and the number of NUL carriers configured with PRACH resources, respectively. For example, the RSRP value measured based on the SSB is compared with the preset first RSRP threshold (e.g., the existing parameter rsrp-ThresholdSSB-SUL). If the measured RSRP value is less than the preset second RSRP threshold, one SUL carrier is selected from the plurality of SUL carriers based on the UE ID by the above method 1 or 2 to access the network; and, if the measured RSRP value is greater than the preset first RSRP threshold, one NUL carrier is selected from the plurality of NUL carriers based on the UE ID by the above method 1 or 2 to access the network.

[0222] (3) When the at least two first UL carriers include at least one NUL carrier and at least two SUL carriers, one first UL carrier is determined in the at least two SUL carriers based on the at least one of the parameters if the RSRP value is less than or equal to the preset first RSRP threshold, and the NUL carrier is used as the determined first UL carrier if the RSRP value is greater than the first RSRP threshold.

[0223] By taking based on the measured RSRP value and preset RSRP thresholds and the UE ID as an example, in the embodiment of the present disclosure, a cell may be configured with a plurality of SUL carriers and at most one NUL carrier, and the method of offloading UEs based on the UE ID is used for the plurality of SUL carriers. Optionally, in the above methods 1 and 2, the number of first UL carriers used for UE offloading is the number of all UL carriers configured with PRACH resource pools except for the NUL carrier. For example, the UE may compare the RSRP value measured based on the SSB with the preset first RSRP threshold (e.g., the existing parameter rsrp-ThresholdSSB-SUL). If the measured RSRP value is less than the preset first RSRP threshold, one SUL carrier is selected from the plurality of SUL carriers based on the UE ID by the above method 1 or 2 to access the network, that is, a RACH procedure is initiated on the selected SUL carrier; and, if the measured RSRP value is greater than the preset first RSRP threshold, the NUL carrier is selected to initiate the RACH procedure to access the network.

[0224] In the embodiment of the present disclosure, in a case where the UE fails to initiate the random access procedure on the determined first UL carrier (including, but not limited to, a case where a predetermined number of continuous random access procedures are failed), the method may further comprise: switching to at least one of the following target UL carriers, and continuing to initiate the random access procedure on the target UL carrier:

[0225] (1) UL carrier corresponding to the DL carrier (i.e., anchor DL carrier) that transmits the system message

[0226] That is, it is possible to switch to the anchor UL carrier configured with PRACH resources, for example, switching to a carrier that transmits CD-SSBs and system information blocks (SIBs) (corresponding to the situation of TDD carrier), or switching to UL carrier paired with the DL carrier that transmits CD-SSBs and SIBs (corresponding to the situation of FDD carrier).

[0227] (2) UL carrier with the smallest UL carrier index

[0228] For example, it is possible to switch to the first UL carrier that has the smallest UL carrier index and is configured with PRACH resources.

[0229] (3) UL carrier indicated by the base station, the UL carrier indicated by the base station being indicated through the system information or indicated through an MAC subheader included in a random access response medium access control protocol data unit (RAR MAC PDU)

[0230] That is, it is possible to switch to a default UL carrier indicated by the base station, wherein the default UL carrier may be preconfigured by the base station through the SIB, or be a target UL carrier that is indicated through the MAC subheader carried by the RAR MAC PDU and switched when the RACH procedure is failed. For example, the UL carrier index of the target UL carrier is indicated through a newly defined MAC subheader. Alternatively, some indication bits of the existing Backoff Indicator (e.g., the last two bits of the existing Backoff Indicator field) are used to indicate the UL carrier index of the target UL carrier, or only the first two bits of the Backoff Indicator field are used to indicate four preset Backoff values. If the base station does not preconfigure the default UL carrier, it is switched to the anchor carrier.

[0231] (4) UL carrier having a lower frequency point than the first UL carrier used for PRACH transmission (i.e., UL carrier having a lower frequency point than the previously determined first UL carrier)

[0232] For example, it is possible to switch to the first UL carrier that has a lower frequency point than the previous first UL carrier which initiates the RACH and is configured with PRACH resources. Optionally, there is a plurality of UL carriers that have lower frequency points than the previous first UL carrier and are configured with PRACH resources, one carrier may be selected from the plurality of UL carriers.

[0233] Optionally, one UL carrier is selected, as the target UL carrier, from a plurality of UL carriers having lower frequency points than the first UL carrier used for PRACH transmission based on at least one of the following methods: randomly selecting one UL carrier; selecting the UL carrier with the smallest UL carrier index; selecting the UL carrier with the highest frequency point; and, selecting the UL carrier with the lowest frequency point.

[0234] (5) SUL carrier

[0235] That is, it is switched to an SUL carrier configured with PRACH resources. If a cell is configured with a plurality of SUL carriers and each SUL carrier is configured with PRACH resources, it is possible to randomly select one SUL carrier from the plurality of SUL carriers, or select the SUL carrier with the lowest frequency point from the plurality of SUL carriers.

[0236] In the embodiment of the present disclosure, in an example, if the UE fails to initiate one or more continuous random access procedures on the selected first UL carrier and the selected carrier is an NUL carrier, the UE may switch to other carriers determined in the above way to continue to initiate the RACH procedure to access the network.

[0237] In the embodiment of the present disclosure, the step of switching to the target UL carrier and continuing to initiate the random access procedure on the target UL carrier comprises at least one of the following situations:

[0238] (1) When the random access procedure is still failed after the power of the PRACH ramps to the maximum transmission power, it is switched to the target UL carrier, and the random access procedure is continuously initiated on the target UL carrier at the maximum transmission power or initial transmission power.

[0239] That is, carrier switching after a RACH procedure failure should be performed after ramping of the power of the PRACH. That is, if the RACH procedure initiated on the selected first UL carrier by the UE is failed, the RACH procedure is initiated again by increasing the transmission power of the PRACH. Only when the RACH procedure is still failed after the PRACH ramps to the maximum transmission power, it is switched to the target UL carrier to initiate the RACH procedure, and a PRACH is transmitted on the target UL carrier at the maximum transmission power or a PRACH is transmitted on the target UL carrier at the initial transmission power.

[0240] (2) It is switched to the target UL carrier, and in case that the random access procedure initiated on the target UL carrier is still failed, the transmission power of the PRACH on the target UL carrier is increased and the random access procedure is initiated again.

[0241] That is, carrier switching after a RACH procedure failure may be performed after ramping of the power of the PRACH. That is, if the RACH procedure initiated on the selected first UL carrier by the UE is failed, it is switched to other UL carriers. If the RACH procedure initiated on the other UL carriers is failed, the RACH procedure is initiated again by increasing the transmission power of the PRACH on the other UL carriers.

[0242] In the method executed by a UE in a wireless communication system according to the embodiment of the present disclosure, the UE may use one of at least two first UL carriers configured with PRACH resources to access the network based on any one of the above determination methods, thus significantly improving the flexibly of the communication system and reducing the congestion phenomenon when the UE accesses the network.

[0243] In the embodiment of the present disclosure, the system information received in the step S101 further includes configuration information related to physical uplink control channel (PUCCH) resources on at least two second UL carriers, and the method executed by a UE in the communication system may further comprise the following steps.

[0244] In step S201, one second UL carrier is determined in the at least two second UL carriers.

[0245] In step S202, a PUCCH is transmitted based on a PUCCH resource on the determined second UL carrier.

[0246] In the steps S201 and S202, the method of determining one second UL carrier in the at least two second UL carriers by the UE in the embodiment of the present disclosure may be construed as a method of determining one PUCCH configuration (resources) in at least two PUCCH configurations (resources) by the UE. That is, the UE determines one PUCCH configuration (resource) in the at least two PUCCH configurations (resources), and transmits a PUCCH based on the determined PUCCH configuration (resource), wherein different PUCCH configurations (resources) correspond to different UL carriers.

[0247] Optionally, before UE-specific PUCCH configuration information is received, the PUCCH is transmitted based on the PUCCH resource on the determined second UL carrier.

[0248] In the embodiment of the present disclosure, a plurality of UL carriers are configured on a cell, and each UL carrier is configured with a common PUCCH resource, wherein the plurality of UL carriers belong to the same cell. The UE may select one of the PUCCH resources on the plurality of UL carriers for PUCCH transmission before receiving UE-specific PUCCH configuration information (which may be called PUCCH resource configuration information, which is used for PUCCH resource configuration), including a PUCCH corresponding to the acknowledge (ACK) of Msg4 (Message 4 in the four-step random access procedure), a PUCCH corresponding to the ACK of a success random access response (RAR) included in MsgB (Message B in the two-step random access procedure), and a PUCCH corresponding to the ACK / NACK (negative acknowledgement) of other PDSCHs.

[0249] In the embodiment of the present disclosure, the at least two second UL carriers may be completely or partially the same as the at least two first UL carriers (for example, at least one UL carrier belongs to both the first UL carriers and the second UL carriers), or may be completely different from the at least two first UL carriers (for example, a cell includes at least four UL carriers).

[0250] In the embodiment of the present disclosure, some optional implementations are provided for the step S201. Specifically, the step S201 may include at least one of the following ways.

[0251] Way (1): The first UL carrier used for PRACH transmission is used as the determined second UL carrier.

[0252] In the embodiment of the present disclosure, the UE transmits a PRACH on one carrier (first UL carrier) to access the network. If the carrier is also configured with a common PUCCH resource (that is, the first UL carrier is also a second UL carrier), the UE transmits, based on the PUCCH resources on the carrier, a PUCCH before receiving the UE-specific PUCCH resource configuration. If the first UL carrier is not configured with a common PUCCH resource (that is, the first UL carrier is not a second UL carrier), the UE transmits, based on PUCCH resources on other carriers (the determined second UL carrier), a PUCCH before receiving the UE-specific PUCCH resource configuration.

[0253] Way (2): One second UL carrier is determined in the at least two second UL carriers based on the first UL carrier used for PRACH transmission and a mapping between the first UL carrier and the second UL carrier.

[0254] In the embodiment of the present disclosure, the determined second UL carrier may be a carrier associated with the carrier (the determined first UL carrier) of the PRACH resource used by the UE, that is, each first UL carrier configured with the PRACH resource is associated with one second UL carrier configured with the PUCCH resource. The mapping between the both may be predefined, or indicated by the network. The way (2) may be combined with the above way (1). For example, the way (2) is used to determine other carriers in the above way (1). The way (1) is preferred. However, if no PUCCH resource is configured on the first UL carrier where the random access procedure is initiated, the way (2) is used to determine the second UL carrier.

[0255] Way (3): One second UL carrier is determined in the at least two second UL carriers based on a mapping between the PRACH resource and the PUCCH resource.

[0256] In the embodiment of the present disclosure, the determined second UL carrier may be a carrier corresponding to the PUCCH resource associated with the PRACH resource used by the UE, that is, each configured PRACH resource is associated with one configured PUCCH resource. The mapping between the both may be predefined, or indicated by the network. The way (3) may be combined with the above way (1). For example, the way (3) is used to determine other carriers in the above way (1). The way (1) is preferred. However, if no PUCCH resource is configured on the first UL carrier where the random access procedure is initiated, the way (3) is used to determine the second UL carrier.

[0257] Way (4): The second UL carrier having the smallest UL carrier index is used as the determined second UL carrier.

[0258] In the embodiment of the present disclosure, the way (4) may also be combined with the above way (1). For example, the other carries in the above way (1) may be second UL carriers that have the smallest UL carrier index and are configured with common PUCCH resources. The way (1) is preferred. However, if no PUCCH resource is configured on the first UL carrier where the random access procedure is initiated, the way (4) is used to determine the second UL carrier.

[0259] Way (5): One second UL carrier is determined in the at least two second UL carriers based on an indication of a random access response (RAR) of Msg2 (Message 2 in the four-step random access procedure), or an indication of a scheduling DCI of Msg4 or an indication of a success RAR included in MsgB.

[0260] In the embodiment of the present disclosure, for the four-step random access procedure, the second UL carrier where the PUCCH transmission before receiving the UE-specific PUCCH resource configuration is located may be indicated by the RAR of Msg2, and the RAR of Msg2 includes a field for indicating the UL carrier index of the PUCCH resource; or, the second UL carrier where the PUCCH transmission before receiving the UE-specific PUCCH resource configuration is located may also be indicated by the scheduling DCI of Msg4, and the scheduling DCI of Msg4 includes a field for indicating the UL carrier index of the PUCCH resource. That is, the UE determines one second UL carrier from a plurality of second UL carriers configured with common PUCCH resources according to the indication of the RAR of Msg2 or the scheduling DCI of Msg4, and uses the PUCCH resources on the determined second UL carrier to transmit a PUCCH, until the UE receives the UE-specific PUCCH resource configuration.

[0261] For the two-step random access procedure, the second UL carrier where the PUCCH transmission before receiving the UE-specific PUCCH resource configuration is located may be indicated by the success RAR included in MsgB, and the success RAR included in MsgB includes a field for indicating the UL carrier index of the PUCCH resource. That is, the UE determines one second UL carrier from a plurality of second UL carriers configured with common PUCCH resources according to the indication of the success RAR included in MsgB, and uses the PUCCH resources on the determined second UL carrier to transmit a PUCCH, until the UE receives the UE-specific PUCCH resource configuration.

[0262] Way (6): One second UL carrier is determined in the at least two second UL carriers based on an ID of the UE.

[0263] The description of the ID of the UE may refer to the above and will not be repeated here.

[0264] Optionally, if it is assumed that the total number of second UL carriers configured with common PUCCH resources is , the determining one second UL carrier in the at least two second UL carriers based on the ID of the UE may comprise at least one of the following methods.

[0265] Method 1: A third modular operation is performed on the ID of the UE and the number of second UL carriers, and one second UL carrier is determined in the at least two second UL carriers based on the result of third modular operation.

[0266] Specifically, the second UL carrier corresponding to the value of determined by a formula of may be used as the determined second UL carrier, where represents the ID of the UE, represents the number of second UL carriers, represents the modular operation, and represents the carrier in the at least two second UL carriers.

[0267] Method 2: A fourth modular operation is performed on the ID of the UE and the sum of weights of the at least two second UL carriers, and one second UL carrier is determined in the at least two second UL carriers based on the result of fourth modular operation.

[0268] Specifically, the second UL carrier corresponding to the minimum value of satisfying a formula of is used as the determined second UL carrier, where represents the ID of the UE, represents the number of second UL carriers, represents the modular operation, represents the carrier in the at least two second UL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two second UL carriers, and represents the sum of weights corresponding to first second UL carriers in the at least two second UL carriers.

[0269] The details may refer to the above description of the method of determining one first UL carrier from a plurality of first UL carriers configured with PRACH resources based on the UE ID and will not be repeated here.

[0270] In the embodiment of the present disclosure, the system information received in the step S101 further includes configuration information related to initial uplink BWPs on at least two third UL carriers, and the method executed by a UE in a communication system may further comprise the following steps.

[0271] In step S301, one third UL carrier is determined in the at least two third UL carriers.

[0272] In step S302, a PUSCH is transmitted based on the initial uplink BWP on the determined third UL carrier.

[0273] In the steps S301 and S302, the method of determining one third UL carrier in the at least two third UL carriers by the UE in the embodiment of the present disclosure may be construed as a method of determining one initial uplink BWP in at least two initial uplink BWPs by the UE. That is, the UE determines one initial uplink BWP in the at least two initial uplink BWPs, and transmits a PUSCH based on the determined initial uplink BWP, wherein different initial uplink BWPs correspond to different UL carriers.

[0274] Optionally, before establishment of an RRC connected state, a PUSCH is transmitted based on the initial uplink BWP on the determined third UL carrier.

[0275] In the embodiment of the present disclosure, a plurality of UL carriers are configured on a cell, and each UL carrier is configured with an initial uplink BWP, wherein the plurality of UL carriers belong to the same cell. The UE may select one initial uplink BWP from the initial uplink BWPs on the plurality of UL carriers to transmit Msg3 (Message 3 in the four-step random access procedure) and a PUSCH before receiving a first active uplink BWP configuration (firstActiveUplinkBWP-Id) in the RRC connected state.

[0276] In the embodiment of the present disclosure, the at least two third UL carriers may be completely or partially the same as the at least two first UL carriers (for example, at least one UL carrier belongs to both the first UL carriers and the third UL carriers), or may be completely different from the at least two first UL carriers.

[0277] In the embodiment of the present disclosure, some optional implementations are provided for the step S301. Specifically, the step S301 may include at least one of the following ways.

[0278] (1) If the configuration information related to the initial uplink BWP corresponding to the determined first UL carrier is received, the determined first UL carrier is used as the determined third UL carrier.

[0279] In the embodiment of the present disclosure, if the first UL carrier where the PRACH resource used to access the network by the UE is located is configured with an initial uplink BWP (that is, this first UL carrier is also a third UL carrier), the UE transmits Msg3 based on the carrier where the PRACH resource is located.

[0280] (2) If the configuration information related to the initial uplink BWP corresponding to the determined first UL carrier is not received, a UL carrier (i.e., an anchor UL carrier) corresponding to a DL carrier that transmits the system message is used as the determined third UL carrier, or one third UL carrier is determined in the at least two third UL carriers.

[0281] In the embodiment of the present disclosure, if the first UL carrier where the PRACH resource used to access the network by the UE is not configured with an initial uplink BWP (that is, this first UL carrier is not a third UL carrier), the UE transmits Msg3 based on the initial uplink BWP on the anchor carrier, or the UE determines an initial uplink BWP on a third UL carrier to transmit Msg3 based on the network configuration.

[0282] (3) One third UL carrier is determined in the at least two third UL carriers based on a UL carrier index indicated in a random access response (RAR).

[0283] In the embodiment of the present disclosure, the UL carrier index of the third UL carrier used for transmitting Msg3 is indicated in the RAR, and the UE determines one third UL carrier to transmit Msg3 based on the indication of the RAR. This way may be combined with the above solutions. For example, if the first UL carrier where the PRACH resource used to access the network by the UE is not configured with an initial uplink BWP, the UE determines one third UL carrier to transmit Msg3 according to the indication of the RAR.

[0284] (4) One third UL carrier is determined in the at least two third UL carriers based on the ID of the UE.

[0285] The description of the ID of the UE may refer to the above and will not be repeated here.

[0286] Optionally, if it is assumed that the total number of third UL carriers configured with initial uplink BWPs is , the determining one third UL carrier in the at least two third UL carriers based on the ID of the UE may include at least one of the following methods.

[0287] Method 1: A fifth modular operation is performed on the ID of the UE and the number of third UL carriers, and one third UL carrier is determined in the at least two third UL carriers based on the result of fifth modular operation.

[0288] Specifically, the third UL carrier corresponding to the value of determined by a formula of = may be used as the determined third UL carrier, where represents the ID of the UE, represents the number of third UL carriers, represents the modular operation, and represents the carrier in the at least two third UL carriers.

[0289] Method 2: A sixth modular operation is performed on the ID of the UE and the sum of weights of the at least two third UL carriers, and one third UL carrier is determined in the at least two third UL carriers based on the result of sixth modular operation.

[0290] Specifically, the third UL carrier corresponding to the minimum value of satisfying a formula of is used as the determined third UL carrier, where represents the ID of the UE, represents the number of third UL carriers, represents the modular operation, represents the carrier in the at least two third UL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two third UL carriers, and represents the sum of weights corresponding to first third UL carriers in the at least two third UL carriers.

[0291] The details may refer to the above description of the method of determining one first UL carrier from a plurality of first UL carriers configured with PRACH resources based on the UE ID and will not be repeated here.

[0292] In the embodiment of the present disclosure, the system information received in the step S101 further includes configuration information related to initial downlink BWPs on at least two first DL carriers, and the method executed by a UE in a communication system may further comprise the following steps.

[0293] In step S401, one first DL carrier is determined in the at least two first DL carriers.

[0294] In step S402, a PDCCH and a PDSCH are received based on the initial downlink BWP on the determined first DL carrier.

[0295] In the steps S401 and S402, the method of determining one first DL carrier in the at least two first DL carriers by the UE in the embodiment of the present disclosure may be construed as a method of determining one initial downlink BWP in at least two initial downlink BWPs by the UE. That is, the UE determines one initial downlink BWP in the at least two initial downlink BWPs, and receives the PDCCH and the PDSCH based on the determined initial downlink BWP, wherein different initial downlink BWPs correspond to different DL carriers.

[0296] Optionally, before establishment of an RRC connected state, the PDCCH and the PDSCH are received based on the initial downlink BWP on the determined first DL carrier.

[0297] In the embodiment of the present disclosure, a plurality of DL carriers are configured on a cell, the plurality of DL carriers are configured with initial downlink BWPs, and the respective initial downlink BWPs are configured with PDCCH search spaces for monitoring the RAR, wherein the plurality of DL carriers belongs to the same cell. The UE may select one initial downlink BWP from the initial downlink BWPs on the plurality of DL carriers to receive the PDCCH and the PDSCH, for example, monitoring a scheduling PDCCH of Msg2, Msg4 or MsgB on the determined initial downlink BWP, and a PDCCH before establishment of the RRC connected state, i.e., a PDCCH before receiving the first active uplink BWP configuration (firstActiveUplinkBWP-Id).

[0298] In the embodiment of the present disclosure, the first DL carriers may or may not include an anchor DL carrier.

[0299] In the embodiment of the present disclosure, some optional implementations are provided for the step S401. Specifically, the step S401 may include at least one of the following ways.

[0300] (1) One first DL carrier is determined in the at least two first DL carriers based on the determined first UL carrier and a mapping between the first UL carrier and the first DL carrier.

[0301] In the embodiment of the present disclosure, each first UL carrier configured with the PRACH resource is associated with one first DL carrier configured with a PDCCH search space for RAR, and the mapping between the both is predefined, or indicated by the network. If a UE transmits a PRACH on one first UL carrier to access the network, the UE monitors Msg2, Msg4 or MsgB on the initial downlink BWP of the first DL carrier associated with the first UL carrier.

[0302] (2) One first DL carrier is determined in the at least two first DL carriers based on the ID of the UE.

[0303] The description of the ID of the UE may refer to the above and will not be repeated here.

[0304] Optionally, if it is assumed that the total number of first DL carriers configured with PDCCH search spaces for RAR is , the determining one first DL carrier in the at least two first DL carriers based on the ID of the UE may include at least one of the following methods.

[0305] Method 1: A seventh modular operation is performed on the ID of the UE and the number of first DL carriers, and one first DL carrier is determined in the at least two first DL carriers based on the result of seventh modular operation.

[0306] Specifically, the first DL carrier corresponding to the value of determined by a formula of may be used as the determined first DL carrier, where represents the ID of the UE, represents the number of first DL carriers, represents the modular operation, and represents the carrier in the at least two first DL carriers.

[0307] Method 2: An eighth modular operation is performed on the ID of the UE and the sum of weights of the at least two first DL carriers, and one first DL carrier is determined in the at least two first DL carriers based on the result of eighth modular operation.

[0308] Specifically, the first DL carrier corresponding to the minimum value of satisfying a formula of is used as the determined first DL carrier, where represents the ID of the UE, represents the number of first DL carriers, represents the modular operation, represents the carrier in the at least two first DL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two first DL carriers, and represents the sum of weights corresponding to first first DL carriers in the at least two first DL carriers.

[0309] The details may refer to the above description of the method of determining one first UL carrier from a plurality of first UL carriers configured with PRACH resources based on the UE ID and will not be repeated here.

[0310] In the embodiment of the present disclosure, the system information received in the step S101 further includes configuration information related to paging PDCCH search spaces for monitoring paging messages on at least two second DL carriers, and the method executed by a UE in a communication system may further comprise the following steps.

[0311] In step S501, one second DL carrier is determined in the at least two second DL carriers based on the ID of the UE.

[0312] In step S502, a scheduling PDCCH of a paging message is monitored based on the paging PDCCH search space on the determined second DL carrier.

[0313] In the steps S501 and S502, the method of determining one second DL carrier in the at least two second DL carriers by the UE in the embodiment of the present disclosure may also be construed as a method of determining one paging PDCCH search space in at least two paging PDCCH search spaces by the UE. That is, the UE determines one paging PDCCH search space in at least two paging PDCCH search spaces and monitors the scheduling PDCCH of the paging message based on the determined paging PDCCH search space, wherein different paging PDCCH search spaces correspond to different DL carriers.

[0314] In the embodiment of the present disclosure, a plurality of DL carriers are configured on a cell, and each DL carrier is configured with a PDCCH search space (paging PDCCH search space) for monitoring the paging message, wherein the plurality of DL carriers belong to the same cell. The UE may select one PDCCH search space from the PDCCH search spaces of corresponding paging messages on the plurality of DL carriers to monitor a PDCCH of the paging message.

[0315] In the embodiment of the present disclosure, the second DL carriers may or may not include an anchor DL carrier.

[0316] In the embodiment of the present disclosure, the UE determines one second DL carrier from a plurality of second DL carriers configured with paging PDCCH search spaces based on the UE ID, and the UE monitors a PDCCH of Paging on the determined second DL carrier, wherein the UE_ID is determined through 5G-S-TMSI. If the UE is configured with eDRX, UE_ID = 5G-S-TMSI mod 4096; otherwise, UE_ID = 5G-S-TMSI mod 1024.

[0317] Specifically, if it is assumed that the number of carriers configured with paging PDCCH search spaces is , the determining one second DL carrier in the at least two second DL carriers based on the ID of the UE may include at least one of the following methods.

[0318] Method 3: A paging occasion index is determined based on the ID of the UE, a ninth modular operation is performed on the paging occasion index and the number of second DL carriers, and one second DL carrier is determined in the at least two second DL carriers based on the result of ninth modular operation.

[0319] Specifically, the second DL carrier corresponding to the value of determined by a formula of is used as the determined second DL carrier, wherein represents the ID of the UE, and are parameters used for determining the paging occasion index, represents a rounding-down operation, represents the determined paging occasion index, represents the number of second DL carriers, represents the modular operation, and represents the carrier in the at least two second DL carriers.

[0320] The second DL carriers are arranged in an order from smallest to largest DL carrier indexes, , and all are the existing parameters used for determining the paging occasion index, is the total number of paging frames within a period of time T, is the number of paging occasions in one paging frame, and the values of and are configured by the network through the system information.

[0321] This method may offload UEs that monitor the same paging occasion (PO) to different second DL carriers, thus avoiding paging congestion. In the above example, if it is assumed that each second DL carrier has the same weight for UE offloading, for example, if it is assumed that =4, each second DL carrier may offload 1 / 4 (i.e., 25%) of UEs that monitor the same PO. In practical applications, since the bandwidth of each second DL carrier is different in size, the number of UEs that may be offloaded by each second DL carrier may also be different. For example, the network may configure a weight for each carrier that may offload the UE, that is, the carriers with different weights may offload different numbers of UEs.

[0322] Method 4: If it is assumed that there are second DL carriers configured with paging PDCCH search spaces and each second DL carrier is configured with the corresponding weight (where , and is a positive integer), the UE may determine a paging occasion index based on the ID of the UE, perform a tenth modular operation on the paging occasion index and the sum of weights of the at least two second DL carriers, and determine one second DL carrier in the at least two second DL carriers based on the result of tenth modular operation.

[0323] Specifically, the second DL carrier corresponding to the minimum value of satisfying a formula of is used as the determined second DL carrier, where represents the ID of the UE, and are parameters used for determining the paging occasion index, represents a rounding-down operation, represents the determined paging occasion index, represents the number of second DL carriers, represents the modular operation, represents the carrier in the at least two second DL carriers, represents the weight corresponding to the UL carrier , represents the sum of weights of the at least two carriers, and represents the sum of weights corresponding to first second DL carriers in the at least two second DL carriers.

[0324] In other words, if , the UE selects the 1st second DL carrier in the second DL carriers; if , the UE selects the 2ndsecond DL carrier in the second DL carriers; and in the similar way, if , the UE selects the second DL carrier in the second DL carriers.

[0325] An embodiment of the present disclosure provides an electronic device, comprising: a transceiver configured to transmit and receive signals; and a processor coupled to the transceiver and configured to implement the steps in the embodiments of the above methods. Optionally, if the electronic device may refer to a UE, the processor is configured to implement the steps in the embodiments of the methods executed by the UE. The detailed functional descriptions and the achieved beneficial effects may refer to the above description of the embodiments of the methods executed by the UE and will not be repeated here. In practical applications, the UE or base station may be construed as different network nodes.

[0326] An embodiment of the present disclosure further provides an electronic device, comprising a processor, and may optionally include a transceiver and / or memory coupled to the processor. The processor is configured to execute the steps of the method provided in any one of the optional embodiments of the present disclosure.

[0327] FIG. 5 shows a schematic structure diagram of an electronic device to which the embodiment of the present disclosure is applied. As shown in FIG. 5, the electronic device 4000 shown in FIG. 5 may include a processor 4001 and a memory 4003. The processor 4001 is connected to the memory 4003, for example, through a bus 4002. Optionally, the electronic device 4000 may further include a transceiver 4004 that may be used for data exchange, for example, transmission and reception of data, between the electronic device and other electronic device. It should be noted that, in practical applications, the number of transceiver 4004 is not limited to one, and the structure of the electronic device 4000 does not constitute any limitations to the embodiments of the present disclosure. Optionally, the electronic device may be a first network node, a second network node or a third network node.

[0328] The processor 4001 may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute various exemplary logical blocks, modules and circuits described in connection with the present disclosure. The processor 4001 may also be a combination for realizing computing functions, for example, a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0329] The bus 4002 may include a path to transfer information between the components described above. The bus 4002 may be a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus, etc. The bus 4002 may be an address bus, a data bus, a control bus, etc. For ease of presentation, the bus is represented by only one thick line in FIG. 5. However, it does not mean that there is only one bus or one type of buses.

[0330] The memory 4003 may be, but not limited to, read only memories (ROMs) or other types of static storage devices that may store static information and instructions, random access memories (RAMs) or other types of dynamic storage devices that may store information and instructions, may be electrically erasable programmable read only memories (EEPROMs), compact disc read only memories (CD-ROMs) or other optical disk storages, optical disc storages (including compact discs, laser discs, discs, digital versatile discs, blue-ray discs, etc.), magnetic storage media or other magnetic storage devices, or any other media that may carry or store desired program codes in the form of instructions or data structures and that may be accessed by computers.

[0331] The memory 4003 is used to store computer program for executing the solutions of the present disclosure, and is controlled by the processor 4001. The processor 4001 is used to execute the computer program stored in the memory 4003 to implement the solution provided in any method embodiment described above.

[0332] Embodiments of the present disclosure provide a computer-readable storage medium having a computer program stored on the computer-readable storage medium, the computer program, when executed by a processor, implements the steps and corresponding contents of the foregoing method embodiments.

[0333] Embodiments of the disclosure may be combined to be implemented, when required. For example, portions of the methods provided by the disclosure may be combined with each other to enable the BS or the UE to operate.

[0334] Embodiments of the present disclosure also provide a computer program product including a computer program, the computer program when executed by a processor realizing the steps and corresponding contents of the preceding method embodiments.

[0335] The terms "first", "second", "third", "fourth", "1", "2", etc. (if present) in the specification and claims of this application and the accompanying drawings above are used to distinguish similar objects and need not be used to describe a particular order or sequence. It should be understood that the data so used is interchangeable where appropriate so that embodiments of the present disclosure described herein may be implemented in an order other than that illustrated or described in the text.

[0336] It should be understood that while the flow diagrams of embodiments of the present disclosure indicate the individual operational steps by arrows, the order in which these steps are performed is not limited to the order indicated by the arrows. Unless explicitly stated herein, in some implementation scenarios of embodiments of the present disclosure, the implementation steps in the respective flowcharts may be performed in other orders as desired. In addition, some, or all of the steps in each flowchart may include multiple sub-steps or multiple phases based on the actual implementation scenario. Some or all of these sub-steps or stages may be executed at the same moment, and each of these sub-steps or stages may also be executed at different moments separately. The order of execution of these sub-steps or stages may be flexibly configured according to requirements in different scenarios of execution time, and the embodiments of the present disclosure are not limited thereto.

[0337] The above-mentioned description and the drawings are provided merely as examples to help readers to understand the present disclosure, and they should not be interpreted or aim to limit the scope of the present disclosure in any way. Although some embodiments are provided, it is apparent for those skilled in the art to adopt other similar implementation means based on the technical idea of the present disclosure without departing from the technical concept of the solution of the present disclosure.

Claims

1.A method performed by a user equipment (UE) in a communication system, comprising:receiving system information, the system information including configuration information related to physical random access channel (PRACH) resources corresponding to at least two first uplink (UL) carriers;determining a first UL carrier in the at least two first UL carriers based on at least one of parameters; andperforming a random access procedure based on a PRACH resource on the determined first UL carrier,wherein the parameters include:an ID of the UE;a random number generated by the UE;a parameter value indicated via a higher layer or determined by a medium access control (MAC) layer, and a mapping between the parameter value and the first UL carrier;a UL carrier index indicated by a base station; anda downlink (DL) carrier where a monitored paging message is located, and a mapping between the DL carrier and the first UL carrier.2.The method of claim 1, wherein the determining the first UL carrier in the at least two first UL carriers comprises:determining the first UL carrier in the at least two first UL carriers based on a measured reference signal received power (RSRP) value and preset RSRP thresholds.3.The method of claim 2, wherein in case that there are at least three first UL carriers and at least two preset RSRP thresholds:each first UL carrier in the at least three first UL carriers corresponds to an RSRP range determined based on the at least two preset RSRP thresholds respectively, and the determining the first UL carrier in the at least three first UL carriers based on the measured RSRP value and the at least two preset RSRP thresholds comprises:using a first UL carrier, among the at least three first UL carriers, corresponding to a RSRP range where the measured RSRP value is located as the determined first UL carrier.4.The method of claim 2, wherein the determining the first UL carrier in the at least two first UL carriers based on the ID of the UE comprises at least one of the following ways:performing a first modular operation on the ID of the UE and a number of first UL carriers, and determining the first UL carrier in the at least two first UL carriers based on the result of the first modular operation; orperforming a second modular operation on the ID of the UE and a sum of weights of the at least two first UL carriers, and determining the first UL carrier in the at least two first UL carriers based on the result of the second modular operation.5.The method of claim 1, wherein the determining the first UL carrier in the at least two first UL carriers based on the random number generated by the UE comprises:using a first UL carrier corresponding to a minimum value ofsatisfying a formula ofas the determined first UL carrier;whererepresents a number of first UL carriers,represents a weight corresponding to the UL carrier,represents a sum of weights of the at least two first UL carriers,represents a random number in a range of 0 togenerated by the UE based on a uniform distribution,represents acarrier in the at least two first UL carriers, andrepresents a sum of weights corresponding to firstfirst UL carriers in the at least two first UL carriers.6.The method of claim 2, wherein the determining the first UL carrier in the at least two first UL carriers based on the measured RSRP value, the preset RSRP thresholds, and the at least one of the parameters, comprises at least one of the following:in case that the at least two first UL carriers include at least two normal uplink (NUL) carriers and one supplement uplink (SUL) carrier:using the SUL carrier as the determined first UL carrier if the measured RSRP value is less than or equal to a preset first RSRP threshold, anddetermining the first UL carrier in the at least two NUL carriers based on the at least one of the parameters if the measured RSRP value is greater than the preset first RSRP threshold;in case that the at least two first UL carriers include at least two NUL carriers and at least two SUL carriers:determining the first UL carrier in the at least two SUL carriers based on the at least one of the parameters if the measured RSRP value is less than or equal to a preset first RSRP threshold, anddetermining the first UL carrier in the at least two NUL carriers based on the at least one of the parameters if the measured RSRP value is greater than the preset first RSRP threshold; andin case that the at least two first UL carriers include one NUL carrier and at least two SUL carriers:determining the first UL carrier in the at least two SUL carriers based on the at least one of the parameters if the measured RSRP value is less than or equal to a preset first RSRP threshold, andusing the one NUL carrier as the determined first UL carrier if the measured RSRP value is greater than the preset first RSRP threshold.7.The method of claim 1, wherein the UL carrier index is indicated by the base station through at least one of the following:a downlink control information (DCI) carried by a scheduling physical downlink control channel (PDCCH) of a physical downlink shared channel (PDSCH) used for transmitting a paging message;a medium access control control element (MAC CE) carried by the PDSCH used for transmitting the paging message; andthe paging message.8.The method of claim 1, wherein the system information further comprises configuration information related to physical uplink control channel (PUCCH) resources corresponding to at least two second UL carriers, the method further comprises:determining a second UL carrier in the at least two second UL carriers; andtransmitting a PUCCH based on a PUCCH resource on the determined second UL carrier.9.The method of claim 8, wherein the determining the second UL carrier in the at least two second UL carriers comprises at least one of the following ways:using the first UL carrier used for PRACH transmission as the determined second UL carrier;determining the second UL carrier in the at least two second UL carriers based on the first UL carrier used for PRACH transmission and a mapping between the first UL carrier and the second UL carrier;determining the second UL carrier in the at least two second UL carriers based on a mapping between the PRACH resource and the PUCCH resource;using a second UL carrier, among the at least two second UL carriers, having a smallest UL carrier index as the determined second UL carrier;determining the second UL carrier in the at least two second UL carriers based on an indication of a random access response included in a Message 2 in a four-step random access procedure, or based on an indication of scheduling downlink control information (DCI) of Message 4 in the four-step random access procedure, or based on an indication of a success random access response included in a Message B in a two-step random access procedure; anddetermining the second UL carrier in the at least two second UL carriers based on the ID of the UE.10.The method of claim 1, wherein the system information further comprises configuration information related to at least one initial uplink bandwidth part (BWP) corresponding to at least two third UL carriers, the method further comprises:determining a third UL carrier in the at least two third UL carriers; andtransmitting a physical uplink shared channel (PUSCH) based on an initial uplink BWP on the determined third UL carrier.11.The method of claim 10, wherein the determining the third UL carrier in the at least two third UL carriers comprises at least one of the following ways:if configuration information related to an initial uplink BWP corresponding to the determined first UL carrier is received, using the determined first UL carrier as the determined third UL carrier;if the configuration information related to the initial uplink BWP corresponding to the determined first UL carrier is not received, using a UL carrier corresponding to a DL carrier that transmits the system information as the determined third UL carrier, or determining the third UL carrier in the at least two third UL carriers;determining the third UL carrier in the at least two third UL carriers based on a UL carrier index indicated in a random access response (RAR); anddetermining the third UL carrier in the at least two third UL carriers based on the ID of the UE.12.The method of claim 1, wherein the system information further comprises configuration information related to at least one initial downlink BWP corresponding to at least two first DL carriers, the method further comprises:determining a first DL carrier in the at least two first DL carriers; andreceiving a PDCCH and a PDSCH based on an initial downlink BWP on the determined first DL carrier.13.The method of claim 12, wherein the receiving the PDCCH and the PDSCH based on the initial downlink BWP on the determined first DL carrier comprises:before establishment of an radio resource control (RRC) connected state, receiving the PDCCH and the PDSCH based on the initial downlink BWP on the determined first DL carrier.14.The method of claim 12, wherein the determining the first DL carrier in the at least two first DL carriers comprises at least one of the following ways:determining the first DL carrier in the at least two first DL carriers based on the determined first UL carrier and a mapping between the first UL carrier and the first DL carrier; anddetermining the first DL carrier in the at least two first DL carriers based on the ID of the UE.15.A user equipment (UE) in a communication system, comprising:a transceiver; andat least one processor coupled with the transceiver and configured to:receive system information, the system information including configuration information related to physical random access channel (PRACH) resources corresponding to at least two first uplink (UL) carriers,determine one first UL carrier in the at least two first UL carriers based on at least one of parameters, andperform a random access procedure based on a PRACH resource on the determined first UL carrier,wherein the parameters include:an ID of the UE;a random number generated by the UE;a parameter value indicated via a higher layer or identified by a medium access control (MAC) layer, and a mapping between the parameter value and the first UL carrier;a UL carrier index indicated by a base station; anda downlink (DL) carrier where a monitored paging message is located, and a mapping between the DL carrier and the first UL carrier.

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