Random access channel procedure in inter-band carrier aggregation with synchronization-free signal block carriers

Abstract

Certain aspects of the present disclosure provide a method of wireless communication by a user equipment (UE), generally including detecting a synchronization signal block (SSB) in a first carrier; determining whether the second carrier is configured to transmit an SSB; selecting one or more parameters for transmission or reception of one or more messages for a random access channel (RACH) procedure based on the determination; and performing the RACH procedure on the second carrier using the selected parameter.

Description

Background Art Technical Field

[0001] Aspects of the present disclosure relate to wireless communications, and more particularly to random access channel (RACH) procedures in a carrier lacking synchronization signal block (SSB) transmissions.

[0002] Related technical description

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts or other similar types of services. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available wireless communication system resources with those users.

[0004] Although wireless communication systems have made tremendous technical progress over the years, challenges still exist. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and wireless receivers. Therefore, there is a continuous desire to improve the technical performance of wireless communication systems, including, for example: improving the speed and data carrying capacity of communications, improving the efficiency of using shared communication media, reducing the power used by transmitters and receivers when performing communications, improving the reliability of wireless communications, avoiding redundant transmission and / or reception and related processing, improving the coverage area of ​​wireless communications, increasing the number and types of devices that can access wireless communication systems, increasing the ability of different types of devices to communicate with each other, increasing the number and types of wireless communication media available for use, etc. Therefore, there is a need to further improve wireless communication systems to overcome the above-mentioned technical challenges and other challenges. Summary of the invention

[0005] One aspect provides a method for wireless communication by a user equipment (UE). The method includes: detecting a synchronization signal block (SSB) in a first carrier; determining whether a second carrier is configured to transmit the SSB; selecting one or more parameters for transmission or reception of one or more messages of a random access channel (RACH) procedure based on the determination; and performing the RACH procedure on the second carrier using the selected parameters.

[0006] Another aspect provides a method for wireless communication by a network entity. The method includes: sending information indicating that a first carrier is configured for SSB transmission; determining one or more parameters for sending or receiving one or more messages for a RACH procedure based on whether a second carrier is configured to transmit SSB; and participating in a RACH procedure with a UE on the second carrier using the parameters.

[0007] Other aspects provide: an apparatus operable to, configured to, or otherwise adapted to perform any one or more of the foregoing methods and / or those described elsewhere herein; a non-transitory computer-readable medium comprising instructions that, when executed by a processor of the apparatus, cause the apparatus to perform the foregoing methods and those described elsewhere herein; a computer program product embodied on a computer-readable storage medium, the computer-readable storage medium comprising code for performing the foregoing methods and those described elsewhere herein; and / or an apparatus comprising components for performing the foregoing methods and those described elsewhere herein. By way of example, an apparatus may include a processing system, a device having a processing system, or a processing system in conjunction with one or more networks.

[0008] For purposes of illustration, the following description and drawings set forth certain features. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings depict certain features of the various aspects described herein and should not be considered to limit the scope of the disclosure.

[0010] Figure 1 An example wireless communication network is depicted.

[0011] Figure 2 An example disaggregated base station architecture is depicted.

[0012] Figure 3 Aspects of an example base station and example user equipment are depicted.

[0013] Figure 4A , Figure 4B , Figure 4C and Figure 4D Various example aspects of data structures for a wireless communication network are described.

[0014] Figure 5 A call flow diagram depicting the four-step Random Access Channel (RACH) procedure.

[0015] Figure 6 A call flow diagram depicting the two-step RACH procedure.

[0016] Figure 7 A table describing the potential overhead reduction that can be achieved by configuring a carrier without synchronization signal block (SSB) transmission is depicted.

[0017] Figure 8 Depicted are example changes resulting from configuration of a sleep bandwidth part (BWP).

[0018] Fig. 9Depicted is an example timeline of secondary cell (SCell) activation based on temporary reference signal (RS).

[0019] Fig.10 and Fig.11 Depicted are example timelines for different options for triggering a temporary RS for SCell activation.

[0020] Fig. 12A and Fig. 12B An example configuration without an SSB carrier is depicted.

[0021] Fig.13A and Fig. 13B Example configurations of a non-SSB carrier with and without a temporary reference signal (RS) are depicted.

[0022] Fig.14 A method for wireless communication is described.

[0023] Fig.15 A method for wireless communication is described.

[0024] Fig.16 Aspects of an example communications device are depicted.

[0025] Fig.17 Aspects of an example communications device are depicted. DETAILED DESCRIPTION

[0026] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for a random access channel (RACH) procedure in a carrier lacking synchronization signal block (SSB) transmission.

[0027] In the random access channel (RACH) procedure, the user equipment (UE) transmits a first message called a physical RACH (PRACH) preamble to a network entity (e.g., a base station) to synchronize the cell. The UE typically selects a cell to perform the RACH procedure based on SSB transmissions from different cells. Based on SSB detection, the UE can determine various parameters for the RACH procedure, such as time and frequency resources for RACH occasions (RO), spatial transmit filters, and uplink power control parameters.

[0028] Carrier aggregation (CA) may be deployed to achieve higher data rates and capacity by combining component carriers with various bandwidths. CA may allow data to be sent and received from two cell groups on multiple component carriers: a primary cell group (MCG) via a primary node and a secondary cell group (SCG) via a secondary node. In some CA deployments, SSBs may not be sent in a carrier. For example, in order to reduce power consumption in a radio access network (RAN) utilizing CA, one or more carriers may not send SBSs. Such carriers may be referred to herein as SSB-free carriers. This lack of SSBs may present challenges to the UE in determining parameters for the RACH process.

[0029] However, aspects of the present disclosure provide techniques for determining parameters for performing a RACH procedure in a non-SSB carrier. For example, a UE may detect an SSB in a first carrier and determine whether a second carrier is configured to transmit an SSB. The UE may then perform a RACH procedure on the second carrier using parameters selected based on the determination, regardless of whether the second carrier is configured to transmit an SSB.

[0030] Utilizing the techniques provided herein may provide significant advantages, especially for network power savings. For example, by supporting RACH procedures with SSB-free carriers, resource utilization may be improved through downlink overhead reduction. Additionally, such techniques may facilitate efficient secondary cell (SCell) activation and deactivation based on actual traffic, thereby reducing SCell latency. Furthermore, offloading physical RACH (PRACH) transmissions from the primary cell (PCell) to the SSB-free carrier may reduce PRACH conflicts and PRACH retransmissions, which provides benefits to the network and UE.

[0031] Introduction to wireless communication networks

[0032] The techniques and methods described herein can be used in various wireless communication networks. Although various aspects may be described herein using terms commonly associated with 3G, 4G and / or 5G wireless technologies, various aspects of the present disclosure may also be applicable to other communication systems and standards not explicitly mentioned herein.

[0033] Figure 1 An example of a wireless communication network 100 is depicted in which various aspects described herein may be implemented.

[0034] In general, the wireless communication network 100 includes various network entities (alternatively, network elements or network nodes). A network entity is typically a communication device and / or a communication function performed by a communication device (e.g., user equipment (UE), base station (BS), component of a BS, server, etc.). For example, various functions of a network and various devices associated with and interacting with the network may be considered network entities. In addition, the wireless communication network 100 includes ground aspects, such as ground-based network entities (e.g., BS 102), and non-ground aspects, such as satellites 140 and aircraft 145, which may include airborne network entities (e.g., one or more BSs) capable of communicating with other network elements (e.g., ground BSs) and user equipment.

[0035] In the depicted example, the wireless communication network 100 includes a BS 102, a UE 104, and one or more core networks (such as an evolved packet core (EPC) 160 and a 5G core (5GC) network 190) that interoperate to provide communication services over various communication links (including wired and wireless links).

[0036] Figure 1 Various example UEs 104 are depicted, which may more generally include: a cellular phone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player, a camera, a game console, a tablet computer, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, an Internet of Things (IoT) device, an Always-On (AON) device, an edge processing device, or other similar devices. UE 104 may also be more generally referred to as a mobile device, a wireless device, a wireless communication device, a station, a mobile station, a subscriber station, a mobile subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a remote device, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, and others.

[0037] BS 102 wirelessly communicates with (e.g., transmits signals to or receives signals from) UE 104 via communication link 120. Communication link 120 between BS 102 and UE 104 may include uplink (UL) (also referred to as a reverse link) transmissions from UE 104 to BS 102 and / or downlink (DL) (also referred to as a forward link) transmissions from BS 102 to UE 104. In various aspects, communication link 120 may employ multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity.

[0038] BS 102 may generally include: Node B, enhanced Node B (eNB), next generation enhanced Node B (ng-eNB), next generation Node B (gNB or gNodeB), access point, base transceiver station, radio base station, radio transceiver, transceiver function, transmission and reception point, and / or other. Each of BS 102 may provide communication coverage for a corresponding geographic coverage area 110, which may sometimes be referred to as a cell, and may overlap in some cases (e.g., small cell 102' may have a coverage area 110' that overlaps with the coverage area 110 of a macro cell). For example, a BS may provide communication coverage for a macro cell (covering a relatively large geographic area), a pico cell (covering a relatively small geographic area, such as a stadium), a femto cell (relatively small geographic area (e.g., a home)), and / or other types of cells.

[0039] Although BS102 is depicted as a single communication device in various aspects, BS102 can be implemented in various configurations. For example, one or more components of the base station may be decomposed, including a central unit (CU), one or more distributed units (DU), one or more radio units (RU), a near real-time (near RT) RAN intelligent controller (RIC), or a non-real-time (non-RT) RIC, to name a few examples. In another example, various aspects of the base station may be virtualized. More generally, a base station (e.g., BS102) may include components located at a single physical location or components located at various physical locations. In an example in which the base station includes components located at various physical locations, the various components may each perform a function so that the various components together implement functionality similar to that of a base station located at a single physical location. In some aspects, a base station including components located at various physical locations may be referred to as a decomposed radio access network architecture (such as an open RAN (O-RAN) or virtualized RAN (VRAN) architecture). Figure 2 An example decomposed base station architecture is depicted and described.

[0040] Different BSs 102 within the wireless communication network 100 may also be configured to support different radio access technologies (such as 3G, 4G, and / or 5G). For example, a BS 102 configured for 4G LTE (collectively referred to as an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). A BS 102 configured for 5G (e.g., 5G NR or Next Generation RAN (NG-RAN)) may interface with the 5GC 190 via a second backhaul link 184. The BSs 102 may communicate with each other directly or indirectly (e.g., via the EPC 160 or the 5GC 190) over a third backhaul link 134 (e.g., an X2 interface), which may be wired or wireless.

[0041] The wireless communication network 100 may subdivide the electromagnetic spectrum into various categories, frequency bands, channels, or other characteristics. In some aspects, the subdivision is provided based on wavelength and frequency, where frequency may also be referred to as a carrier, subcarrier, channel, tone, or subband. For example, 3GPP currently defines frequency range 1 (FR1) as including 410 MHz-7125 MHz, which is often (interchangeably) referred to as "below 6 GHz". Similarly, 3GPP currently defines frequency range 2 (FR2) as including 24,250 MHz-52,600 MHz, which is sometimes (interchangeably) referred to as "millimeter wave" ("mmW" or "mmWave"). A base station (e.g., a mmWave base station such as BS180) configured to communicate using mmWave / near mmWave radio bands may utilize beamforming (e.g., 182) with a UE (e.g., 104) to improve path loss and range.

[0042] The communication link 120 between the BS 102 and, for example, the UE 104 may be through one or more carriers, which may have different bandwidths (e.g., 5 MHz, 10 MHz, 15 MHz, 20 MHz, 100 MHz, 400 MHz, and / or other MHz) and may be aggregated in various aspects. The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​compared to UL).

[0043] Communications using higher frequency bands may have higher path loss and shorter range than communications at lower frequencies. Figure 1 180) can utilize beamforming 182 with UE 104 to improve path loss and range. For example, BS 180 and UE 104 may each include multiple antennas, such as antenna elements, antenna panels and / or antenna arrays, to facilitate beamforming. In some cases, BS 180 may send beamformed signals to UE 104 in one or more transmit directions 182'. UE 104 may receive beamformed signals from BS 180 in one or more receive directions 182". UE 104 may also send beamformed signals to BS 180 in one or more transmit directions 182". BS 180 may also receive beamformed signals from UE 104 in one or more receive directions 182'. BS 180 and UE 104 may then perform beam training to determine the best receive direction and transmit direction for each of BS 180 and UE 104. It is worth noting that the transmit direction and receive direction of BS 180 may be the same or different. Similarly, the transmit direction and receive direction of UE 104 may be the same or different.

[0044] Wireless communication network 100 also includes Wi-Fi AP 150 that communicates with Wi-Fi stations (STAs) 152 via communication links 154 in, for example, the 2.4 GHz and / or 5 GHz unlicensed spectrum.

[0045] Certain UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), and / or a physical sidelink feedback channel (PSFCH).

[0046] The EPC 160 may include various functional components, including: a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and / or a packet data network (PDN) gateway 172, such as in the depicted example. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. In general, the MME 162 provides bearer and connection management.

[0047] Generally speaking, user Internet Protocol (IP) packets are delivered through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation and other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176, which may include, for example, the Internet, an Intranet, an IP Multimedia Subsystem (IMS), a Packet Switched (PS) streaming media service, and / or other IP services.

[0048] The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS delivery, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and / or may be used to schedule MBMS delivery. The MBMS Gateway 168 may be used to distribute MBMS services to BSs 102 belonging to a multicast broadcast single frequency network (MBSFN) area broadcasting a specific service, and / or may be responsible for session management (start / stop) and for collecting eMBMS related charging information.

[0049] 5GC 190 may include various functional components, including: access and mobility management function (AMF) 192, other AMFs 193, session management function (SMF) 194, and user plane function (UPF) 195. AMF 192 may communicate with unified data management (UDM) 196.

[0050] AMF 192 is a control node that handles signaling between UE 104 and 5GC 190. AMF 192 provides, for example, Quality of Service (QoS) flow and session management.

[0051] Internet Protocol (IP) packets are delivered through UPF 195, which is connected to IP Services 197 and provides IP address allocation for UEs and other functions for 5GC 190. IP Services 197 may include, for example, the Internet, Intranet, IMS, PS streaming services, and / or other IP services.

[0052] In various aspects, a network entity or network node may be implemented as a converged base station, a decomposed base station, a component of a base station, an integrated access and backhaul (IAB) node, a relay node, a sidelink node, to name a few examples.

[0053] Figure 2 An example disaggregated base station 200 architecture is depicted. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that may communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units, such as a near real-time (near-RT) RAN intelligent controller (RIC) 225 via an E2 link, or a non-real-time (non-RT) RIC 215 associated with a service management and orchestration (SMO) framework 205, or both. The CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an F1 interface. The DU 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RU 240 may communicate with respective UEs 104 via one or more radio frequency (RF) access links. In some implementations, a UE 104 may be served simultaneously by multiple RUs 240.

[0054] Each of the units (e.g., CU 210, DU 230, RU 240, and near-RT RIC 225, non-RT RIC 215, and SMO framework 205) may include or be coupled to one or more interfaces configured to receive or send signals, data, or information (collectively referred to as signals) via a wired transmission medium or a wireless transmission medium. Each of the units or an associated processor or controller that provides instructions to the communication interface of the unit may be configured to communicate with one or more of the other units via a transmission medium. For example, the units may include a wired interface configured to receive or send signals to one or more of the other units via a wired transmission medium. Additionally or alternatively, the unit may include a wireless interface that may include a receiver, a transmitter, or a transceiver (such as a radio frequency (RF) transceiver) configured to receive or send signals, or both, to one or more of the other units on a wireless transmission medium.

[0055] In some aspects, CU 210 may host one or more higher layer control functions. Such control functions may include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), etc. Each control function may be implemented using an interface configured to communicate signals with other control functions hosted by CU 210. CU210 may be configured to handle user plane functionality (e.g., central unit-user plane (CU-UP)), control plane functionality (e.g., central unit-control plane (CU-CP)), or a combination thereof. In some specific implementations, CU 210 may be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP unit may communicate bidirectionally with the CU-CP unit via an interface (such as an E1 interface). As needed, CU 210 may be implemented to communicate with DU 230 for network control and signaling.

[0056] DU 230 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RUs 240. In some aspects, DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) at least in part according to a functional split such as those defined by the 3rd Generation Partnership Project (3GPP). In some aspects, DU 230 may also host one or more low PHY layers. Each layer (or module) may be implemented using an interface that is configured to communicate signals with other layers (and modules) hosted by DU 230 or with control functions hosted by CU 210.

[0057] The lower layer functionality may be implemented by one or more RUs 240. In some deployments, a RU 240 controlled by a DU 230 may correspond to a logical node that hosts RF processing functions or low PHY layer functions (such as performing Fast Fourier Transform (FFT), Inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, etc.), or both, based at least in part on a functional split (such as a lower layer functional split). In such an architecture, the RU 240 may be implemented to handle over-the-air (OTA) communications with one or more UEs 104. In some implementations, real-time and non-real-time aspects of control plane and user plane communications with the RU 240 may be controlled by the corresponding DU 230. In some scenarios, this configuration may enable the implementation of the DU 230 and the CU 210 in a cloud-based RAN architecture (such as a vRAN architecture).

[0058] The SMO framework 205 may be configured to support RAN deployment and configuration of non-virtualized network elements and virtualized network elements. For non-virtualized network elements, the SMO framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operation and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-cloud) 290) to perform network element lifecycle management (such as instantiating virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements may include, but are not limited to, CU 210, DU 230, RU 240, and near-RT RIC 225. In some specific implementations, the SMO framework 205 may communicate with hardware aspects of the 4G RAN (such as an open eNB (O-eNB) 211) via the O1 interface. In addition, in some specific implementations, the SMO framework 205 may communicate directly with one or more RUs 240 via the O1 interface. The SMO framework 205 may also include a non-RT RIC 215 configured to support the functionality of the SMO framework 205 .

[0059] The non-RT RIC 215 may be configured to include logic functions that enable non-real-time control and optimization of RAN elements and resources, artificial intelligence / machine learning (AI / ML) workflows including model training and updating, or policy-based guidance of applications / features in the near-RT RIC 225. The non-RT RIC 215 may be coupled to or in communication with the near-RT RIC 225 (such as via an A1 interface). The near-RT RIC 225 may be configured to include logic functions that enable near-real-time control and optimization of RAN elements and resources via data collection and actions through an interface (such as via an E2 interface) that connects one or more CUs 210, one or more DUs 230, or both, and the O-eNB with the near-RT RIC 225.

[0060] In some implementations, in order to generate an AI / ML model to be deployed in the near-RT RIC 225, the non-RT RIC 215 may receive parameters or external enrichment information from an external server. Such information may be utilized by the near-RT RIC 225 and may be received from a non-network data source or from a network function at the SMO framework 205 or the non-RT RIC 215. In some examples, the non-RT RIC 215 or the near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 215 may monitor long-term trends and patterns of performance and employ AI / ML models to perform corrective actions through the SMO framework 205 (such as via reconfiguration of O1) or via creation of RAN management policies (such as A1 policies).

[0061] Figure 3 Aspects of an example BS 102 and UE 104 are depicted.

[0062] In general, BS 102 includes various processors (e.g., 320, 330, 338, and 340), antennas 334a-334t (collectively 334), transceivers 332a-332t (collectively 332) including modulators and demodulators, and other aspects that enable wireless transmission of data (e.g., data source 312) and wireless reception of data (e.g., data sink 339). For example, BS 102 can transmit and receive data between BS 102 and UE 104. BS 102 includes a controller / processor 340 that can be configured to implement various functions described herein related to wireless communication.

[0063] In general, the UE 104 includes various processors (e.g., 358, 364, 366, and 380), antennas 352a-352r (collectively 352), transceivers 354a-354r (collectively 354) including modulators and demodulators, and other aspects that enable wireless transmission of data (e.g., retrieved from a data source 362) and wireless reception of data (e.g., provided to a data sink 360). The UE 104 includes a controller / processor 380 that can be configured to implement various functions described herein related to wireless communications.

[0064] Regarding example downlink transmissions, BS 102 includes a transmit processor 320 that can receive data from a data source 312 and control information from a controller / processor 340. The control information can be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical HARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), and / or others. In some examples, the data can be for a physical downlink shared channel (PDSCH).

[0065] The transmit processor 320 may process (e.g., encode and symbol map) data and control information to obtain data symbols and control symbols, respectively. The transmit processor 320 may also generate reference symbols, such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a PBCH demodulation reference signal (DMRS), and a channel state information reference signal (CSI-RS).

[0066] The transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., pre-decoding) on ​​data symbols, control symbols, and / or reference symbols, where applicable, and may provide an output symbol stream to a modulator (MOD) in a transceiver 332a-332t. Each modulator in the transceiver 332a-332t may process a corresponding output symbol stream to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from the modulators in the transceivers 332a-332t may be transmitted via antennas 334a-334t, respectively.

[0067] To receive downlink transmissions, UE 104 includes antennas 352a-352r that can receive downlink signals from BS 102 and can provide received signals to demodulators (DEMODs) in transceivers 354a-354r, respectively. Each demodulator in transceivers 354a-354r can condition (e.g., filter, amplify, downconvert, and digitize) a corresponding received signal to obtain input samples. Each demodulator can further process the input samples to obtain received symbols.

[0068] A MIMO detector 356 may obtain received symbols from all demodulators in transceivers 354a-354r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 358 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 104 to a data sink 360, and provide decoded control information to a controller / processor 380.

[0069] With respect to example uplink transmissions, the UE 104 also includes a transmit processor 364 that may receive and process data from a data source 362 (e.g., for a PUSCH) and control information from a controller / processor 380 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 364 may also generate reference symbols for reference signals (e.g., a sounding reference signal (SRS)). The symbols from the transmit processor 364 may be pre-decoded by a TX MIMO processor 366, if applicable, further processed by a modulator in the transceivers 354a-354r (e.g., for SC-FDM), and transmitted to the BS 102.

[0070] At BS 102, uplink signals from UE 104 may be received by antennas 334 a-334 t, processed by demodulators in transceivers 332 a-332 t, detected by MIMO detector 336 if applicable, and further processed by receive processor 338 to obtain decoded data and control information transmitted by UE 104. Receive processor 338 may provide decoded data to data sink 339 and decoded control information to controller / processor 340.

[0071] Memories 342 and 382 may store data and program codes for BS 102 and UE 104, respectively.

[0072] Scheduler 344 may schedule UEs for data transmission on the downlink and / or uplink.

[0073] In various aspects, BS 102 may be described as sending and receiving various types of data associated with the methods described herein. In these contexts, "sending" may refer to various mechanisms for outputting data, such as outputting data from a data source 312, a scheduler 344, a memory 342, a transmit processor 320, a controller / processor 340, a TX MIMO processor 330, a transceiver 332a-332t, an antenna 334a-334t, and / or other aspects described herein. Similarly, "receiving" may refer to various mechanisms for obtaining data, such as obtaining data from an antenna 334a-334t, a transceiver 332a-332t, a RX MIMO detector 336, a controller / processor 340, a receive processor 338, a scheduler 344, a memory 342, and / or other aspects described herein.

[0074] In various aspects, the UE 104 may also be described as sending and receiving various types of data associated with the methods described herein. In these contexts, "sending" may refer to various mechanisms for outputting data, such as outputting data from a data source 362, a memory 382, ​​a transmit processor 364, a controller / processor 380, a TX MIMO processor 366, a transceiver 354a-354t, an antenna 352a-352t, and / or other aspects described herein. Similarly, "receiving" may refer to various mechanisms for obtaining data, such as obtaining data from an antenna 352a-352t, a transceiver 354a-354t, a RX MIMO detector 356, a controller / processor 380, a receive processor 358, a memory 382, ​​and / or other aspects described herein.

[0075] In some aspects, the processor may be configured to perform various operations (such as those associated with the methods described herein) and send (output) data to or receive (obtain) data from another interface configured to send or receive data, respectively.

[0076] Figure 4A , Figure 4B , Figure 4C and Figure 4D Describes a method for use in a wireless communication network such as Figure 1 Various aspects of the data structure of the wireless communication network 100).

[0077] Specifically, Figure 4A is a diagram 400 illustrating an example of a first subframe within a 5G (e.g., 5G NR) frame structure, Figure 4B is a diagram 430 illustrating an example of a DL channel within a 5G subframe, Figure 4C is a diagram 450 illustrating an example of a second subframe within a 5G frame structure, and Figure 4D FIG480 is a diagram illustrating an example of UL channels within a 5G subframe.

[0078] Wireless communication networks can utilize Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) on both the uplink and downlink. Such systems can also support half-duplex operation using Time Division Duplex (TDD). OFDM and Single Carrier Frequency Division Multiplexing (SC-FDM) can be used to maximize the system bandwidth (e.g., Figure 4B and Figure 4D The RF (depicted) is divided into multiple orthogonal subcarriers. Each subcarrier can be modulated with data. Modulation symbols can be transmitted in the frequency domain using OFDM and / or in the time domain using SC-FDM.

[0079] The wireless communication frame structure may be frequency division duplex (FDD), where for a particular set of subcarriers, subframes within the set of subcarriers are dedicated to either DL or UL. The wireless communication frame structure may also be time division duplex (TDD), where for a particular set of subcarriers, subframes within the set of subcarriers are dedicated to both DL and UL.

[0080] exist Figure 4A and Figure 4C In the wireless communication frame structure, TDD is used, where D is DL, U is UL, and X is used flexibly between DL / UL. The UE can be configured with a time slot format (dynamically configured by DL control information (DCI) or semi-statically / statically configured by radio resource control (RRC) signaling) through the received time slot format indicator (SFI). In the depicted example, the 10ms frame is divided into 10 equally sized 1ms subframes. Each subframe may include one or more time slots. In some examples, each time slot may include 7 or 14 symbols, depending on the time slot format. The subframe may also include a micro-time slot, which generally has fewer symbols than the entire time slot. Other wireless communication technologies may have different frame structures and / or different channels.

[0081] In certain aspects, the number of slots within a subframe is based on the slot configuration and parameter set. For example, for slot configuration 0, different parameter sets (μ) 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different parameter sets 0 to 2 allow for 2, 4, and 8 slots per subframe, respectively. Thus, for slot configuration 0 and parameter set μ, there are 14 symbols / slot and 2μ slots / subframe. The subcarrier spacing and symbol length / duration are a function of the parameter set. The subcarrier spacing may be equal to 2 μ × 15kHz, where μ is parameter set 0 to 5. Thus, parameter set μ=0 has a subcarrier spacing of 15kHz, and parameter set μ=5 has a subcarrier spacing of 480kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figure 4A , Figure 4B , Figure 4C and Figure 4D An example is provided for slot configuration 0 with 14 symbols per slot and parameter set μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs.

[0082] like Figure 4A , Figure 4B , Figure 4C and Figure 4DAs depicted, a resource grid may be used to represent a frame structure. Each slot includes a resource block (RB) (also referred to as a physical RB (PRB)) extending, for example, over 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0083] like Figure 4A As illustrated, some REs carry data for UEs (e.g. Figure 1 and Figure 3 The RS may include a demodulation RS (DMRS) and / or a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and / or a phase tracking RS (PT-RS).

[0084] Figure 4B Examples of various DL channels within a subframe of a frame are illustrated.The Physical Downlink Control Channel (PDCCH) carries DCI within one or more Control Channel Elements (CCEs), each CCE comprising, for example, nine RE Groups (REGs), each REG comprising, for example, four consecutive REs in an OFDM symbol.

[0085] The primary synchronization signal (PSS) may be in symbol 2 of a particular subframe of a frame. The PSS is transmitted by a UE (e.g., Figure 1 and Figure 3 104) is used to determine subframe / symbol timing and physical layer identification.

[0086] A Secondary Synchronization Signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and radio frame timing.

[0087] Based on the physical layer identifier and the physical layer cell identifier group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the location of the aforementioned DMRS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides the system frame number (SFN) and the number of RBs in the system bandwidth. The physical downlink shared channel (PDSCH) carries user data, broadcast system information (such as system information blocks (SIBs)) that is not sent via the PBCH, and / or paging messages.

[0088] As in Figure 4CAs illustrated, some REs carry DMRS for channel estimation at the base station (indicated as R for a particular configuration, but other DMRS configurations are possible). The UE may send a DMRS for PUCCH and a DMRS for PUSCH. The PUSCH DMRS may be sent, for example, in the first one or two symbols of the PUSCH. The PUCCH DMRS may be sent in different configurations depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used. UE 104 may send a sounding reference signal (SRS). The SRS may be sent, for example, in the last symbol of a subframe. The SRS may have a comb structure, and the UE may send the SRS on one of the teeth of the comb. The SRS may be used by the base station for channel quality estimation to achieve frequency-dependent scheduling of the UL.

[0089] Figure 4D Examples of various UL channels within a subframe of a frame are illustrated. The PUCCH may be located at a position as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and HARQ ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0090] Example RACH Procedure

[0091] The random access channel (RACH) is so named because it refers to a wireless channel (medium) that can be shared by multiple UEs and used by these UEs to (randomly) access the network for communication. For example, RACH can be used for call establishment and access network for data transmission. In some cases, when the UE switches from radio resource control (RRC) connection idle mode to active mode, or when switching in RRC connection mode, RACH can be used for initial access to the network. In addition, when the UE is in RRC idle or RRC inactive mode, and when reestablishing the connection with the network, RACH can be used for downlink (DL) and / or uplink (UL) data arrival.

[0092] Figure 55 is a timing (or "call flow") diagram 500 illustrating an example four-step RACH procedure in accordance with certain aspects of the present disclosure. A first message (MSG1) may be transmitted from a UE to a network entity (e.g., a BS such as a gNB) on a physical random access channel (PRACH). In this case, MSG1 may include only a RACH preamble. The network entity may respond with a random access response (RAR) message (MSG2), which may include an identifier (ID) of the RACH preamble, a timing advance (TA), an uplink grant, a cell radio network temporary identifier (C-RNTI), and a fallback indicator. MSG2 may include a PDCCH communication including control information regarding subsequent communications on the PDSCH, as illustrated. In response to MSG2, MSG3 is sent from the UE to the network entity on the PUSCH. MSG3 may include one or more of an RRC connection request, a tracking area update request, a system information request, a location lock or positioning signal request, or a scheduling request. The network entity then responds with MSG 4 which may include a contention resolution message.

[0093] In some cases, in order to speed up access, a two-step RACH procedure may be supported. As the name implies, the two-step RACH procedure can effectively "collapse" the four messages of the four-step RACH procedure into two messages.

[0094] Figure 6 is a call flow diagram 600 illustrating an example two-step RACH procedure in accordance with certain aspects of the present disclosure. As illustrated, a UE may be configured with parameters for SSB monitoring and RACH procedures via system information (SI) and / or RRC signaling.

[0095] For a two-step RACH procedure, a first enhancement message (msgA) may be transmitted from the UE to the network entity. In some aspects, msgA includes some or all of the information of MSG1 and MSG3 from the four-step RACH procedure (effectively combining MSG1 and MSG3). For example, msgA may include MSG1 and MSG3 multiplexed together, such as using one of time division multiplexing or frequency division multiplexing. In some aspects, msgA includes a RACH preamble and a payload for random access. For example, the msgA payload may include a UE-ID and other signaling information (e.g., a buffer status report (BSR)) or a scheduling request (SR). BS102 may respond with a random access response (RAR) message (msgB), which may effectively combine the above-mentioned MSG2 and MSG4. For example, msgB may include an ID of the RACH preamble, a timing advance (TA), a backoff indicator, a contention resolution message, an UL / DL grant, and a transmit power control (TPC) command.

[0096] In the two-step RACH procedure, msgA may include a RACH preamble and a payload. In some cases, the RACH preamble and the payload may be transmitted in the msgA transmission opportunity.

[0097] The random access message (msgA) transmission opportunity generally includes the msgA preamble opportunity (used to send the preamble signal) and the msgA payload opportunity for sending the PUSCH. The msgA preamble transmission generally involves:

[0098] (1) Selection of preamble sequence; and

[0099] (2) Selection of preamble timing (for sending the selected preamble sequence) in the time / frequency domain.

[0100] The msgA payload sending generally involves:

[0101] (1) Construction of random access message payload (DMRS / PUSCH); and

[0102] (2) Selection of one or more PUSCH resource units (PRUs) in the time / frequency domain to send the message (payload).

[0103] In some cases, the UE monitors SSB transmissions transmitted (by the gNB using different beams) and associated with a limited set of time / frequency resources defining RACH occasions (ROs) and PRUs. Upon detecting an SSB, the UE may select the RO and one or more PRUs associated with the SSB for MSG1 / msgA transmissions.

[0104] There are several benefits to the two-step RACH procedure, such as speed of access and the ability to transmit relatively small amounts of data without the overhead of the entire four-step RACH procedure to establish a connection (as the four-step RACH message may be larger than the payload).

[0105] The two-step RACH procedure may operate in any RRC state and with any supported cell size.Networks using the two-step RACH procedure may typically support contention-based random access (CBRA) message (eg, msgA) transmissions within a limited range of payload sizes and with a limited number of MCS levels.

[0106] After the UE has selected an SSB (beam), for that SS block, there are predefined one or more ROs with specific time and frequency offsets and directions (eg, specific to the selected SSB).

[0107] This SSB to RO association is used by the gNB to know what beam the UE has acquired / is using (often referred to as beam establishment). One SSB can be associated with one or more ROs, or more than one SSB can be associated with one RO. The association is typically performed first in the frequency domain, then in the time domain within a RACH slot, and then in the time domain across RACH slots (e.g., starting from a lower SSB index). The association period is typically defined as the minimum number of RACH configuration periods such that all (configured) SSB beams are mapped into a RO.

[0108] Overview of Network Power Consumption

[0109] One of the significant costs for operating a cellular network is due to energy consumption (e.g., 23% of total cost). The majority of this cost comes from the radio access network (RAN) (e.g., about 50% in 5G). Therefore, network energy saving features are important to limit overall costs and promote the adoption and expansion of cellular networks. This may be particularly important in more complex systems that tend to require power, such as massive multiple-input multiple-output (MIMO) systems that utilize large antenna arrays.

[0110] In some cases, the framework may be adapted for power consumption modeling and assessment on the network (e.g., base station) side. This may include modeling and assessment of the relative energy consumption of DL and UL, for example, taking into account factors such as power amplifier (PA) efficacy, number of transmitter receiver units (TxRUs), base station loading, sleep states and associated transition times, and various benchmark parameters / configurations.

[0111] The evaluation method can be aimed at evaluating system-level network energy consumption and energy saving gains, as well as evaluating / balancing the impact on network and user performance. (For example, spectrum efficiency, capacity, latency, handover performance, call drop rate, initial access performance, SLA guarantee related key performance indicators (KPIs)), energy efficiency, and UE power consumption and complexity. The evaluation method can consider a variety of different KPIs, and existing KPIs can be reused, and new KPIs can be developed as appropriate.

[0112] In some cases, techniques may be identified at the gNB and UE side to improve network energy savings in terms of BS transmission and reception. Such techniques may include techniques designed to enable more efficient dynamic and / or semi-static operation and finer granularity transmission and / or reception adaptation in the time, frequency, space and power domains in one or more network energy saving techniques with potential support / feedback from the UE and potential UE assistance information, with possible information exchange / coordination through the network interface.

[0113] Power consumption under various network load conditions may be considered, such as idle / empty and low / medium load conditions, and different loads between carriers and neighboring cells may be allowed. The following example scenarios including single carrier and multi-carrier deployments may be considered: urban micro in FR1 (including TDD massive MIMO), FR2 beam-based scenarios, urban / rural macro in FR1 with / without DSS, and EN-DC / NR-DC macro with FDD PCell and TDD / massive MIMO at higher FR1 / FR2 frequencies. Energy saving techniques may be designed such that so-called legacy UEs are still able to continue to access the network implementing the network energy saving techniques (e.g., with the possible exception of techniques developed specifically for new deployments where the network did not previously exist (so-called greenfield deployments)).

[0114] Overview of Inter-Band CA with No SSB Carrier

[0115] As mentioned above, in some cases, inter-band carrier aggregation (CA) with non-synchronization signal block (SSB) carriers can be part of a network energy saving strategy. The potential energy savings can be understood when considering the percentage of active symbols in a radio frame that can be occupied by SSB transmissions. Figure 7 As illustrated in the table shown in , SSB transmissions may occupy from 6.5% (FR1) to 14.8% (for FR2) of the active symbols.

[0116] When utilizing a non-SSB carrier, the SSB in one carrier may provide timing and frequency (T / F) synchronization for the non-SSB carrier. In some cases, it may be assumed that no legacy UEs operate on the non-SSB carrier (e.g., greenfield deployment). In some examples, the non-SSB carrier may be associated with a FR1 segment band, where the bands are adjacent (e.g., at 700MHz / 800MHz / 900MHz, 1.8GHz / 2.1GHz, 1.9GHz / 2GHz / 2.3GHz).

[0117] Inter-band CA with SSB-free carriers can have several beneficial effects. For example, SSB-free carriers can help improve secondary cell (Scell) activation latency, facilitate efficient Scell ​​activation / deactivation based on actual traffic (which can lead to network power savings), and can improve resource utilization through downlink overhead reduction.

[0118] The RACH procedure in the non-SSB carrier may allow offloading of PRACH transmissions from the PCell to the non-SSB carrier. This may help reduce PRACH collisions, which benefits both the UE and the network by reducing PRACH retransmissions.

[0119] Overview of SCell Activation

[0120] A significant portion of the UE power consumption may also be used to monitor control channels, such as PDCCH. When SCell dormancy technology is implemented, the network may dynamically enable or disable PDCCH monitoring on the secondary cell (SCell). For example, when the SCell has little or no traffic, the SCell may transition to a dormant state, and when the SCell has a higher traffic load, the SCell may transition back to a non-dormant state.

[0121] Figure 8 It illustrates how the use of dormant BWP helps reduce the latency of SCell activation. As shown in the figure, the time to switch from dormant BWP to active BWP (via dormant DCI) can be significantly less than the latency when switching via MAC-CE based SCell activation.

[0122] In some cases, fast SCell activation can be enabled by triggering a "temporary RS" at an earlier timing than the SSB. Temporary RS (Temp RS) can be applied to both intra-band CA and inter-band CA. Temporary RS can be, for example, an aperiodic tracking reference signal (A-TRS) for AGC and T / F tracking. In some cases, the periodic TRS (P-TRS) in the Scell ​​to be activated can be a quasi-co-site (QCL) source for the temporary RS.

[0123] For SCell activation using Temp RS, please refer to Fig. 9 900 . As shown, after the UE receives an activation command (sent in the PCell) to activate the SCell, the SCell is not considered active until 3 ms after the UE transmits an acknowledgment (ACK). In addition, there is an additional delay to allow the UE to monitor reference signals, which the UE can use to adjust its time and frequency tracking before transmitting a channel state information (CSI) report. The sum of these delays is Fig. 9 is marked and is called T 激活时间 .

[0124] As mentioned above, if the UE relies on the SBS for initial CSI measurements in the SCell, the delay may be considerable due to the relatively long period between SBSs. The use of temporary RSs can substantially reduce the SCell activation time by allowing the UE to transmit valid CSI reports earlier than it would have to wait on subsequent SSBs.

[0125] According to certain aspects of the present disclosure, a UE may perform RRC configuration for a temporary RS using similar RRC signaling for aperiodic CSI-RS and a temporary RS, where the triggering states are defined using a "per carrier" structure. The temporary RS may be triggered by indicating one of the triggering states (and indicating the details of the temporary RS to the UE).

[0126] There are various options for triggering a temporary RS after SCell activation. Fig.10 As shown, the physical downlink shared channel (PDSCH) may carry a MAC CE that activates the Scell ​​and also triggers a temporary RS. In the illustrated example, the UE receives and acknowledges (via hybrid automatic repeat request acknowledgement HARQ-ACK) the MAC CE in the PCell. 3ms after the HARQ-ACK, the SCell may be considered activated and a temporary RS may be transmitted.

[0127] In this example, the MAC CE may indicate (e.g., via a bit field / code point) at least one trigger state in the per-carrier aperiodic state list for the SCell carrier. The UE may then monitor the temporary RS on the SCell based on the RS configuration associated with the at least one trigger state indicated in the MAC CE.

[0128] like Fig.11 As shown in , according to another option, MAC CE can trigger SCell activation, and DCI can trigger temporary RS. In this case, DCI can indicate (e.g., via a bit field / code point) at least one triggering state in the per-carrier aperiodic state list for the SCell carrier. The UE can then monitor the temporary RS on the SCell based on the RS configuration associated with the at least one triggering state indicated in the DCI.

[0129] As described herein, dormant BWPs can allow for fast SCell activation. In some cases, (NR Rel.17) Scell ​​activation with the assistance of a temporary RS can reduce Scell ​​activation latency (relative to Rel.15). In this case, the activation latency can be a function of the temporary RS availability time rather than the SSB availability time.

[0130] Various aspects related to a random access channel (RACH) in inter-band carrier aggregation (CA) with a synchronization signal block (SSB)-free carrier.

[0131] In some cases, inter-band CA with no SSB carrier can improve SCell activation by avoiding temporary RS for known SCells. The latency can be only the SCell activation MAC-CE process latency (3ms). Inter-band CA with no SSB carrier can also reduce the broadcast signaling overhead of known cells. Figure 7 As described, for Sub-6, 30kHz, 8SSB, TDD with slot configuration 7D:1S:2U and S slots (10D:2F:2U), 20ms SSB may have a time overhead of 6.5%. 160ms SSB may have a time overhead of 0.8%.

[0132] As described above, performing the RACH procedure in the non-SSB carrier may allow PRACH transmissions to be offloaded from the Pcell to the non-SSB carrier. This may help reduce PRACH collisions, which benefits both the UE and the network by reducing PRACH retransmissions.

[0133] If configured, the RACH procedure can be performed in the normal uplink NUL (Pcell) and the supplementary uplink (SUL) cell. When performing RACH on the SUL, Msg1 / Msg3 (four steps) or MsgA (two steps) can be sent on the SUL, while Msg2 / Msg4 (four steps) or MsgB (two steps) can be sent on the NUL. This can provide RACH coverage when using the SUL carrier.

[0134] As described above, the lack of SSB in a carrier may present a challenge to the UE for determining parameters for a RACH procedure. However, aspects of the present disclosure provide techniques for determining parameters for performing a RACH procedure in a carrier without SSB. For example, the UE may detect an SSB in a first carrier and determine whether a second carrier is configured to transmit an SSB. The UE may then select one or more parameters for transmission or reception of one or more messages for a random access channel (RACH) procedure based on the determination, and perform the RACH procedure on the second carrier using the selected parameters.

[0135] like Fig. 12A and Fig. 12B As shown, the first carrier may be an anchor carrier used for timing and frequency (T / F) synchronization, and the second carrier may be a non-anchor carrier. Fig. 12A The examples in assume a time division duplex (TDD) configuration where each non-anchor carrier is SSB-free and lacks a temporary RS. Fig. 12B The examples in assume a frequency division duplex (FDD) configuration such that one non-anchor carrier (Carrier 1) may be DL and another non-anchor carrier (Carrier 2) may be UL.

[0136] The UE may perform a RACH procedure on a non-anchor carrier. As shown, the UE may treat the anchor carrier (w / SSB and SI transmission) and one or more non-anchor carriers (without SSB) as a single cell. The (anchor and non-anchor) carriers may be in the same frequency band or in different frequency bands.

[0137] Aspects of the present disclosure allow a UE to perform RACH procedures on a non-anchor carrier, which may help reduce collisions of Physical Random Access Channel (PRACH) transmissions. In some cases, potentially all RACH messages may be transmitted on a non-anchor carrier.

[0138] Using the techniques presented herein, a UE may determine one or more parameters for a RACH procedure. These parameters may allow for carrier selection, time and frequency resources for RACH timing (RO) determination, spatial transmit filters, quasi co-located (QCL) sources, and UL power control.

[0139] The techniques provided herein may be used for a UE that is configured to transmit a physical random access channel (PRACH) / physical uplink shared channel (PUSCH) on a non-anchor carrier that supports time division duplex (TDD) operation and the non-anchor carrier does not transmit a synchronization signal block (SSB) (i.e., a non-SSB carrier), such as in Fig.13A and Fig. 13B As shown in the example.

[0140] For example, the UE may use SSB in the (anchor) carrier that provides T / F synchronization for the non-anchor carrier in order to determine the parameters for PRACH / PUSCH transmission. For example, from the SSB, the UE may determine the RO resources (e.g., for PRACH only), spatial transmit filters, and power control (e.g., path loss measurement). If the non-anchor carrier transmits a temporary RS, such as in Fig. 13B In the example shown in , the UE may determine the spatial transmit filter and / or power control parameters based on the temporary RS. In this context, the PUSCH transmission may be a Msg3 PUSCH (for four-step RACH) or a MsgA PUSCH (for two-step RACH).

[0141] In some cases, when the UE is configured to transmit PRACH / PUSCH on a non-anchor carrier supporting TDD operation and the non-anchor carrier transmits SSBs, the UE may determine parameters for PRACH / PUSCH transmissions (in the non-anchor carrier) using one of various options.

[0142] According to the first option, the UE may use the SSB in the anchor carrier to determine the parameters for PRACH / PUSCH transmission. According to the second option, the UE may use the SSB in the non-anchor carrier to determine the parameters for PRACH / PUSCH transmission. In some cases, the NW may configure which option the UE uses, for example via system information (SI).

[0143] In some cases, the UE may be configured to receive PDCCH / PDSCH on a non-anchor carrier, and the non-anchor carrier does not transmit SSB (i.e., is an SSB-free carrier). In this case, the UE may use the SSB in the carrier that provides T / F synchronization for the non-anchor carrier as the QCL source for PDCCH / PDSCH reception.

[0144] In some cases, the UE may be configured to receive PDCCH / PDSCH on a non-anchor carrier and the non-anchor carrier may transmit SSBs. In some cases, the UE may use SSBs in the anchor carrier as a QCL source for PDCCH / PDSCH reception. In other cases, the UE may use SSBs in the non-anchor carrier as a QCL source for PDCCH / PDSCH reception. In some cases, the NW may configure which option the UE uses, for example, via SI or via DCI for PDSCH reception.

[0145] Example Operation of User Equipment

[0146] Fig.14 Shown by UE (such as Figure 1 and Figure 3 An example of a method 1400 for performing wireless communications with a UE 104).

[0147] Method 1400 begins at step 1405, where an SSB in a first carrier is detected. In some cases, the operation of this step refers to or can be performed as described in reference to Fig.16 The described circuits for detection and / or codes for detection are implemented.

[0148] Then, method 1400 proceeds to step 1410, where it is determined whether the second carrier is configured to transmit SSB. In some cases, the operation of this step refers to or can be performed by reference to Fig.16 The described circuits for determining and / or codes for determining are performed.

[0149] Method 1400 then proceeds to step 1415, where one or more parameters for transmission or reception of one or more messages for a RACH procedure are selected based on the determination. In some cases, the operation of this step refers to or may be performed by reference to Fig.16The described circuits for selecting and / or codes for selecting are implemented.

[0150] Then, method 1400 proceeds to step 1420, where a RACH procedure is performed on the second carrier using the selected parameters. In some cases, the operation of this step refers to or can be referred to as Fig.16 The described circuits for execution and / or codes for execution are executed.

[0151] In some aspects, the one or more parameters include RO resources, spatial transmit filters, and power control parameters.

[0152] In some aspects, the second carrier supports TDD.

[0153] In some aspects, the one or more messages include at least one of a PRACH preamble or a PUSCH.

[0154] In some aspects, the second carrier is not configured to transmit SSBs; and selecting includes selecting one or more parameters based on the SSBs transmitted in the first carrier.

[0155] In some aspects, the one or more parameters include RO resources; and the second carrier is configured to send a temporary RS.

[0156] In some aspects, the method 1400 also includes determining at least one of a spatial transmit filter or a power control parameter based on the temporary RS. In some cases, the operation of this step refers to or can be performed by reference to Fig.16 The described circuits for determining and / or codes for determining are performed.

[0157] In some aspects, the second carrier is configured to transmit the SSB; and selecting includes selecting one or more parameters based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier.

[0158] In some aspects, the method 1400 also includes receiving signaling indicating whether the UE selects one or more parameters based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier. In some cases, the operation of this step refers to or can be performed by, for example, referring to Fig.16 The described circuits for receiving and / or codes for receiving are performed.

[0159] In some aspects, the one or more messages include at least one of a PDCCH or a PDSCH; and the one or more parameters include a QCL source for receiving the PDCCH or the PDSCH.

[0160] In some aspects, the second carrier is not configured to transmit SSBs; and selecting includes selecting the SSBs transmitted in the first carrier as a QCL source for receiving the PDCCH or the PDSCH.

[0161] In some aspects, the second carrier is configured to transmit an SSB; and selecting includes selecting the SSB transmitted in the first carrier or the SSB transmitted in the second carrier as a QCL source for receiving the PDCCH or the PDSCH.

[0162] In some aspects, the method 1400 also includes receiving signaling indicating whether the UE selects the SSB transmitted in the first carrier or the SSB transmitted in the second carrier as the QCL source for receiving the PDCCH or PDSCH. In some cases, the operation of this step refers to or can be performed by reference to Fig.16 The described circuits for receiving and / or codes for receiving are performed.

[0163] In one aspect, method 1400 or any aspect related thereto may be performed by an apparatus such as Fig.16 The method 1400 is performed by a communication device 1600 that includes various components operable to, configured to, or adapted to perform the method 1400. The communication device 1600 is described in more detail below.

[0164] Please note that Fig.14 This is merely one example of a method, and other methods including fewer, additional, or alternative steps may also be consistent with the present disclosure.

[0165] Example Operations of Network Entities

[0166] Fig.15 shows a method for use by network entities such as Figure 1 and Figure 3 BS102 or as relative to Figure 2 An example of a method 1500 of performing wireless communications with a decomposed base station is discussed.

[0167] Method 1500 begins at step 1505, where information indicating that the first carrier is configured for SSB transmission is sent. In some cases, the operation of this step refers to or can be performed by reference to Fig.17 The described circuits for sending and / or codes for sending are performed.

[0168] Method 1500 then proceeds to step 1510, where one or more parameters for transmission or reception of one or more messages of a RACH procedure are determined based on whether the second carrier is configured to transmit SSB. In some cases, the operation of this step refers to or may be performed by reference to Fig.17 The described circuits for determining and / or codes for determining are performed.

[0169] Then, method 1500 proceeds to step 1515, where the parameters are used to participate in a RACH procedure with the UE on the second carrier. In some cases, the operation of this step refers to or can be referred to as Fig.17 The described circuits for participating and / or codes for participating are performed.

[0170] In some aspects, the one or more parameters include RO resources, spatial transmit filters, and power control parameters.

[0171] In some aspects, the second carrier supports TDD.

[0172] In some aspects, the one or more messages include at least one of a PRACH preamble or a PUSCH.

[0173] In some aspects, the second carrier is not configured to transmit the SSB; and the one or more parameters are determined based on the SSB transmitted in the first carrier.

[0174] In some aspects, the second carrier is configured to transmit the SSB; and the one or more parameters are determined based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier.

[0175] In some aspects, the method 1500 also includes sending signaling indicating whether the UE is to select one or more parameters for the RACH procedure based on the SSB sent in the second carrier or the SSB sent in the first carrier. In some cases, the operation of this step refers to or can be performed by, for example, referring to Fig.17 The described circuits for sending and / or codes for sending are performed.

[0176] In some aspects, the one or more messages include at least one of a PDCCH or a PDSCH; and the one or more parameters include a QCL source for receiving the PDCCH or the PDSCH.

[0177] In some aspects, the method 1500 also includes receiving signaling indicating whether the UE selects the SSB transmitted in the first carrier or the SSB transmitted in the second carrier as the QCL source for receiving the PDCCH or PDSCH. In some cases, the operation of this step refers to or can be performed by reference to Fig.17 The described circuits for receiving and / or codes for receiving are performed.

[0178] In one aspect, method 1500 or any aspect related thereto may be performed by an apparatus such as Fig.17 The method 1500 is performed by a communication device 1700 that includes various components that are operable, configured, or adapted to perform the method 1500. The communication device 1700 is described in more detail below.

[0179] Please note that Fig.15 This is merely one example of a method, and other methods including fewer, additional, or alternative steps may also be consistent with the present disclosure.

[0180] Example Communication Device

[0181] Fig.16 Depicted are aspects of an example communications device 1600. In some examples, communications device 1600 is user equipment, such as described above with respect to Figure 1 and Figure 3 UE 104 is described.

[0182] The communication device 1600 includes a processing system 1605 coupled to a transceiver 1675 (e.g., a transmitter and / or a receiver). The transceiver 1675 is configured to transmit and receive signals for the communication device 1600, such as various signals as described herein, via an antenna 1680. The processing system 1605 may be configured to perform processing functions for the communication device 1600, including processing signals received and / or to be transmitted by the communication device 1600.

[0183] The processing system 1605 includes one or more processors 1610. In various aspects, such as with respect to Figure 3 As depicted, the one or more processors 1610 may represent one or more of the receive processor 358, the transmit processor 364, the TX MIMO processor 366, and / or the controller / processor 380. The one or more processors 1610 are coupled to the computer-readable medium / memory 1640 via the bus 1670. In certain aspects, the computer-readable medium / memory 1640 is configured to store instructions (e.g., computer-executable code) that, when executed by the one or more processors 1610, cause the one or more processors 1610 to perform operations with respect to the computer-readable medium / memory 1640. Fig.14 The described method 1400 or any aspect related thereto. Note that references to a processor performing a function of the communication device 1600 may include one or more processors 1610 performing that function of the communication device 1600 .

[0184] In the depicted example, computer-readable medium / memory 1640 stores code (e.g., executable instructions) such as code for detecting 1645, code for determining 1650, code for selecting 1655, code for executing 1660, and code for receiving 1665. Processing of code for detecting 1645, code for determining 1650, code for selecting 1655, code for executing 1660, and code for receiving 1665 may cause communication device 1600 to perform operations related to Fig.14The described method 1400 or any aspect related thereto.

[0185] The one or more processors 1610 include circuits configured to implement (e.g., execute) code stored in the computer-readable medium / memory 1640, including circuits such as circuits for detecting 1615, circuits for determining 1620, circuits for selecting 1625, circuits for executing 1630, and circuits for receiving 1635. Processing with the circuits for detecting 1615, circuits for determining 1620, circuits for selecting 1625, circuits for executing 1630, and circuits for receiving 1635 may cause the communication device 1600 to perform operations related to the communication device 1600. Fig.14 The described method 1400 or any aspect related thereto.

[0186] The various components of the communication device 1600 may be provided for performing Fig.14 The described means of method 1400 or any aspect thereof. For example, means for sending, transmitting, or outputting for sending may include Figure 3 The illustrated transceiver 354 and / or antenna 352 of the UE 104, and / or Fig.16 The transceiver 1675 and antenna 1680 of the communication device 1600 in FIG. 1 may include Figure 3 The illustrated transceiver 354 and / or antenna 352 of the UE 104, and / or Fig.16 The transceiver 1675 and antenna 1680 of the communication device 1600 in FIG.

[0187] Fig.17 Aspects of an example communications device 1700 are depicted. In some aspects, communications device 1700 is a network entity such as Figure 1 and Figure 3 BS102 or as relative to Figure 2 The decomposed base station in question.

[0188] The communication device 1700 includes a processing system 1705 coupled to a transceiver 1765 (e.g., a transmitter and / or a receiver) and / or a network interface 1775. The transceiver 1765 is configured to transmit and receive signals for the communication device 1700 via an antenna 1770, such as various signals as described herein. The network interface 1775 is configured to transmit and receive signals for the communication device 1700 via a communication link (such as, for example, as described herein with respect to Figure 2 The processing system 1705 may be configured to perform the processing functions of the communication device 1700, including processing signals received and / or to be transmitted by the communication device 1700.

[0189] The processing system 1705 includes one or more processors 1710. In various aspects, such as with respect to Figure 3 As described, the one or more processors 1710 may represent one or more of the receive processor 338, the transmit processor 320, the TX MIMO processor 330, and / or the controller / processor 340. The one or more processors 1710 are coupled to the computer-readable medium / memory 1735 via the bus 1760. In some aspects, the computer-readable medium / memory 1735 is configured to store instructions (e.g., computer-executable code) that, when executed by the one or more processors 1710, cause the one or more processors 1710 to perform operations with respect to the computer-readable medium / memory 1735. Fig.15 The described method 1500 or any aspect related thereto. Note that references to a processor of the communication device 1700 that performs a function may include one or more processors 1710 of the communication device 1700 that perform that function.

[0190] In the depicted example, computer readable medium / memory 1735 stores code (e.g., executable instructions), such as code 1740 for sending, code 1745 for determining, code 1750 for participating, and code 1755 for receiving. Processing of code 1740 for sending, code 1745 for determining, code 1750 for participating, and code 1755 for receiving may cause communication device 1700 to perform operations relative to Fig.15 The described method 1500 or any aspect related thereto.

[0191] The one or more processors 1710 include circuits configured to implement (e.g., execute) code stored in the computer-readable medium / memory 1735, including circuits for transmitting 1715, circuits for determining 1720, circuits for participating 1725, and circuits for receiving 1730. Processing using the circuits for transmitting 1715, circuits for determining 1720, circuits for participating 1725, and circuits for receiving 1730 may cause the communication device 1700 to perform operations with respect to Fig.15 The described method 1500 or any aspect related thereto.

[0192] The various components of the communication device 1700 may be provided for performing Fig.15 Means for sending, transmitting, or outputting for sending may include: Figure 3 The illustrated transceiver 332 and / or antenna 334 of the BS 102, and / or Fig.17 The transceiver 1765 and antenna 1770 of the communication device 1700 in FIG. 1 may include Figure 3The illustrated transceiver 332 and / or antenna 334 of the BS 102, and / or Fig.17 The transceiver 1765 and antenna 1770 of the communication device 1700.

[0193] Sample Clauses

[0194] Specific implementation examples are described in the following numbered clauses:

[0195] Clause 1: A method of wireless communications by a UE, comprising: detecting a SSB in a first carrier; determining whether a second carrier is configured to transmit the SSB; selecting one or more parameters for transmission or reception of one or more messages of a RACH procedure based on the determination; and performing the RACH procedure on the second carrier using the selected parameters.

[0196] Clause 2: The method of clause 1, wherein the one or more parameters include RO resources, spatial transmit filters, and power control parameters.

[0197] Clause 3: A method as described in any of clauses 1 and 2, wherein the second carrier supports TDD.

[0198] Clause 4: A method as described in any of clauses 1 to 3, wherein the one or more messages comprise at least one of a PRACH preamble or a PUSCH.

[0199] Clause 5: The method of clause 4, wherein: the second carrier is not configured to transmit SSBs; and the selecting comprises selecting the one or more parameters based on SSBs transmitted in the first carrier.

[0200] Clause 6: A method according to clause 5, wherein: the one or more parameters include RO resources; the second carrier is configured to send a temporary RS; and the method further includes determining at least one of a spatial transmit filter or a power control parameter based on the temporary RS.

[0201] Clause 7: A method as described in clause 4, wherein: the second carrier is configured to transmit SSB; and selecting includes selecting one or more parameters based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier.

[0202] Clause 8: The method of clause 7, further comprising receiving signaling indicating whether the UE selected the one or more parameters based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier.

[0203] Clause 9: A method as described in any of clauses 1 to 8, wherein: the one or more messages include at least one of a PDCCH or a PDSCH; and the one or more parameters include a QCL source for receiving the PDCCH or PDSCH.

[0204] Clause 10: A method as described in clause 9, wherein: the second carrier is not configured to transmit SSB; and the selecting includes selecting SSB transmitted in the first carrier as the QCL source for receiving the PDCCH or PDSCH.

[0205] Clause 11: A method according to clause 9, wherein: the second carrier is configured to transmit SSB; and the selecting includes selecting the SSB transmitted in the first carrier or the SSB transmitted in the second carrier as the QCL source for receiving the PDCCH or PDSCH.

[0206] Clause 12: A method according to clause 11, the method further comprising: receiving signaling indicating whether the UE selects the SSB transmitted in the first carrier or the SSB transmitted in the second carrier as the QCL source for receiving the PDCCH or PDSCH.

[0207] Clause 13: A method of wireless communications by a network entity, comprising: sending information indicating that a first carrier is configured for SSB transmission; determining one or more parameters for transmission or reception of one or more messages for a RACH procedure based on whether a second carrier is configured to transmit SSB; and participating in the RACH procedure with a UE on the second carrier using the parameters.

[0208] Clause 14: The method of clause 13, wherein the one or more parameters include RO resources, spatial transmit filters, and power control parameters.

[0209] Clause 15: A method as described in any of clauses 13 and 14, wherein the second carrier supports TDD.

[0210] Clause 16: A method as described in any of clauses 13 to 15, wherein the one or more messages comprise at least one of a PRACH preamble or a PUSCH.

[0211] Clause 17: A method as described in clause 16, wherein: the second carrier is not configured to transmit SSB; and the one or more parameters are determined based on SSB transmitted in the first carrier.

[0212] Clause 18: A method as described in clause 16, wherein: the second carrier is configured to transmit SSB; and the one or more parameters are determined based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier.

[0213] Clause 19: A method as described in clause 18, the method further comprising: sending signaling indicating whether the UE selects one or more parameters for the RACH procedure based on the SSB sent in the second carrier or the SSB sent in the first carrier.

[0214] Clause 20: A method as described in any of clauses 13 to 19, wherein: the one or more messages include at least one of a PDCCH or a PDSCH; and the one or more parameters include a QCL source for receiving the PDCCH or PDSCH.

[0215] Clause 21: A method according to clause 20, the method further comprising: receiving signaling indicating whether the UE selects SSB transmitted in the first carrier or SSB transmitted in the second carrier as the QCL source for receiving the PDCCH or PDSCH.

[0216] Clause 22: An apparatus comprising: a memory including executable instructions; and a processor configured to execute the executable instructions and cause the apparatus to perform the method according to any one of clauses 1 to 21.

[0217] Clause 23: An apparatus comprising means for performing the method according to any one of clauses 1 to 21.

[0218] Clause 24: A non-transitory computer readable medium comprising executable instructions which, when executed by a processor of an apparatus, cause the apparatus to perform the method of any one of clauses 1 to 21.

[0219] Clause 25: A computer program product embodied on a computer readable storage medium, the computer program product comprising code for performing the method according to any one of clauses 1 to 21.

[0220] Additional considerations

[0221] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein are not limited to the scope, applicability or aspects set forth in the claims. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For example, without departing from the scope of the present disclosure, the functions and arrangements of the elements discussed may be changed. Each example may ignore, replace or add each process or component as appropriate. For example, the described method may be performed in an order different from the described order, and various actions may be added, omitted or combined. In addition, the features described for some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such devices or methods practiced using other structures, functions, or structures and functionality that are supplemented or substituted for the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the present claim.

[0222] The various illustrative logic blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or executed using a general purpose processor, a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, a system on a chip (SoC), or any other such configuration.

[0223] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items (including single members). For example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0224] As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, a database, or another data structure), ascertaining, and the like. Moreover, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. In addition, "determining" may include resolving, selecting, choosing, establishing, and the like.

[0225] The method disclosed herein includes one or more actions for implementing the method. The method actions can be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and / or use of specific actions can be modified without departing from the scope of the claims. In addition, the various operations of the method described above can be performed by any appropriate component that can perform the corresponding function. The component may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs) or processors.

[0226] The following claims are not intended to be limited to the various aspects shown herein, but should be granted the full scope consistent with the language of the claims. Within the claims, unless otherwise specified, references to elements in the singular form are not intended to mean "one and only one", but "one or more". Unless otherwise specified, the term "some" refers to one or more. Any claim element is not interpreted according to the provisions of 35 U.S.C. § 112 (f) unless the element is explicitly stated using the phrase "member for...". All structural and functional equivalents of the elements of the various aspects described throughout the present disclosure that are known or will be known later to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims.

Claims

1. A method for wireless communication by a user equipment (UE), the method comprising: detecting a synchronization signal block (SSB) in a first carrier; determining whether the second carrier is configured to transmit SSB; selecting one or more parameters for transmission or reception of one or more messages for a random access channel (RACH) procedure based on the determination; and The RACH procedure is performed on the second carrier using the selected parameters.

2. The method of claim 1, wherein the one or more parameters include RACH opportunity (RO) resources, spatial transmit filters, and power control parameters. The method of claim 1 , wherein the second carrier supports time division duplex (TDD).

4. The method of claim 1, wherein the one or more messages comprise at least one of a physical RACH (PRACH) preamble or a physical uplink shared channel (PUSCH).

5. The method according to claim 4, wherein: The second carrier is not configured to transmit SSB; and The selecting includes selecting the one or more parameters based on the SSB transmitted in the first carrier.

6. The method according to claim 5, wherein: The one or more parameters include a RACH opportunity (RO) resource; The second carrier is configured to transmit a temporary reference signal (RS); and The method also includes determining at least one of a spatial transmit filter or a power control parameter based on the temporary RS.

7. The method according to claim 4, wherein: The second carrier is configured to transmit SSB; and The selecting includes selecting the one or more parameters based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier.

8. The method according to claim 7, further comprising: Signaling is received indicating whether the UE selects the one or more parameters based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier.

9. The method according to claim 1, wherein: The one or more messages include at least one of a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH); and The one or more parameters include a quasi co-located (QCL) source for receiving the PDCCH or PDSCH.

10. The method according to claim 9, wherein: The second carrier is not configured to transmit SSB; and The selecting includes selecting the SSB transmitted in the first carrier as the QCL source for receiving the PDCCH or PDSCH.

11. The method according to claim 9, wherein: The second carrier is configured to transmit SSB; and The selecting includes selecting the SSB transmitted in the first carrier or the SSB transmitted in the second carrier as the QCL source for receiving the PDCCH or the PDSCH.

12. The method according to claim 11, further comprising: Signaling indicating whether the UE selects the SSB transmitted in the first carrier or the SSB transmitted in the second carrier as the QCL source for receiving the PDCCH or PDSCH is received.

13. A method for wireless communication by a network entity, the method comprising: transmitting information indicating that the first carrier is configured for synchronization signal block (SSB) transmission; determining one or more parameters for transmission or reception of one or more messages for a random access channel (RACH) procedure based on whether the second carrier is configured to transmit the SSB; as well as The RACH procedure is engaged with a user equipment (UE) on the second carrier using the parameters.

14. The method of claim 13, wherein the one or more parameters include RACH opportunity (RO) resources, spatial transmit filters, and power control parameters.

15. The method of claim 13, wherein the second carrier supports time division duplex (TDD).

16. The method of claim 13, wherein the one or more messages include at least one of a physical RACH (PRACH) preamble or a physical uplink shared channel (PUSCH).

17. The method of claim 16, wherein: The second carrier is not configured to transmit SSB; and The one or more parameters are determined based on the SSB transmitted in the first carrier.

18. The method of claim 16, wherein: The second carrier is configured to transmit SSB; and The one or more parameters are determined based on the SSB transmitted in the second carrier or the SSB transmitted in the first carrier.

19. The method according to claim 18, further comprising: Signaling is sent indicating whether the UE selects one or more parameters for the RACH procedure based on the SSB sent in the second carrier or the SSB sent in the first carrier.

20. The method of claim 13, wherein: The one or more messages include at least one of a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH); and The one or more parameters include a quasi co-located (QCL) source for receiving the PDCCH or PDSCH.

21. The method according to claim 20, further comprising: Signaling indicating whether the UE selects the SSB transmitted in the first carrier or the SSB transmitted in the second carrier as the QCL source for receiving the PDCCH or PDSCH is received.

22. An apparatus for wireless communication by a user equipment (UE), the apparatus comprising: a memory including executable instructions; and One or more processors configured to execute the executable instructions and cause the reader device to: detecting a synchronization signal block (SSB) in a first carrier; determining whether the second carrier is configured to transmit SSB; selecting one or more parameters for transmission or reception of one or more messages for a random access channel (RACH) procedure based on the determination; as well as The RACH procedure is performed on the second carrier using the selected parameters.

23. An apparatus for wireless communication by a network entity, the apparatus comprising: a memory including executable instructions; and One or more processors configured to execute the executable instructions and cause the reader device to: transmitting information indicating that the first carrier is configured for synchronization signal block (SSB) transmission; determining one or more parameters for transmission or reception of one or more messages for a random access channel (RACH) procedure based on whether the second carrier is configured to transmit the SSB; as well as The RACH procedure is engaged with a user equipment (UE) on the second carrier using the parameters.

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