Patent Publication Number: US-2022225403-A1

Title: Simultaneous uplink transmissions

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation of U.S. patent application Ser. No. 16/371,411, entitled “SIMULTANEOUS UPLINK TRANSMISSIONS” and filed on Apr. 1, 2019, which claims the benefits of U.S. Provisional Application Ser. No. 62/653,015, entitled “RACH DESIGN FOR NEW RADIO” and filed on Apr. 5, 2018; all of which are expressly incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     Field 
     The present disclosure relates generally to communication systems, and more particularly, to a random access procedure employed by a user equipment (UE). 
     Background 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems. 
     These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT)), and other requirements. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. 
     SUMMARY 
     The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. 
     In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The UE determines to transmit a preamble sequence to a base station at a random access occasion in a random access procedure when the UE is in a connected state. The UE determines that the random access occasion is in a same predetermined time period as an uplink channel or a sounding reference signal that is scheduled to be transmitted to the base station. The UE refrains from transmitting the preamble sequence or refraining from transmitting the uplink channel or the sounding reference signal. 
     To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a wireless communications system and an access network. 
         FIG. 2  is a diagram illustrating a base station in communication with a UE in an access network. 
         FIG. 3  illustrates an example logical architecture of a distributed access network. 
         FIG. 4  illustrates an example physical architecture of a distributed access network. 
         FIG. 5  is a diagram showing an example of a DL-centric subframe. 
         FIG. 6  is a diagram showing an example of an UL-centric subframe. 
         FIG. 7  is a diagram illustrating communications between a base station and UE. 
         FIG. 8  is a diagram illustrating a random access procedure of a UE in a connected state. 
         FIG. 9  is a diagram illustrating that a UE transmits a preamble sequence, a PUCCH, a PUSCH, and/or a sounding reference signal (SRS) in a time slot. 
         FIG. 10  is a flow chart of a method (process) for uplink transmission. 
         FIG. 11  is a conceptual data flow diagram illustrating the data flow between different components/means in an exemplary apparatus. 
         FIG. 12  is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. 
     Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. 
     By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. 
     Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. 
       FIG. 1  is a diagram illustrating an example of a wireless communications system and an access network  100 . The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations  102 , UEs  104 , and a core network  160 . The base stations  102  may include macro cells (high power cellular base station) and/or small cells (low power cellular base station). The macro cells include base stations. The small cells include femtocells, picocells, and microcells. 
     The base stations  102  (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) interface with the core network  160  through backhaul links  132  (e.g., S1 interface). In addition to other functions, the base stations  102  may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations  102  may communicate directly or indirectly (e.g., through the core network  160 ) with each other over backhaul links  134  (e.g., X2 interface). The backhaul links  134  may be wired or wireless. 
     The base stations  102  may wirelessly communicate with the UEs  104 . Each of the base stations  102  may provide communication coverage for a respective geographic coverage area  110 . There may be overlapping geographic coverage areas  110 . For example, the small cell  102 ′ may have a coverage area  110 ′ that overlaps the coverage area  110  of one or more macro base stations  102 . A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links  120  between the base stations  102  and the UEs  104  may include uplink (UL) (also referred to as reverse link) transmissions from a UE  104  to a base station  102  and/or downlink (DL) (also referred to as forward link) transmissions from a base station  102  to a UE  104 . The communication links  120  may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations  102 /UEs  104  may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100 MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). 
     The wireless communications system may further include a Wi-Fi access point (AP)  150  in communication with Wi-Fi stations (STAs)  152  via communication links  154  in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs  152 /AP  150  may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. 
     The small cell  102 ′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell  102 ′ may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP  150 . The small cell  102 ′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. 
     The gNodeB (gNB)  180  may operate in millimeter wave (mmW) frequencies and/or near mmW frequencies in communication with the UE  104 . When the gNB  180  operates in mmW or near mmW frequencies, the gNB  180  may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band has extremely high path loss and a short range. The mmW base station  180  may utilize beamforming  184  with the UE  104  to compensate for the extremely high path loss and short range. 
     The core network  160  may include 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 a Packet Data Network (PDN) Gateway  172 . The MME  162  may be in communication with a Home Subscriber Server (HSS)  174 . The MME  162  is the control node that processes the signaling between the UEs  104  and the core network  160 . Generally, the MME  162  provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway  166 , which itself is connected to the PDN Gateway  172 . The PDN Gateway  172  provides UE IP address allocation as well as other functions. The PDN Gateway  172  and the BM-SC  170  are connected to the IP Services  176 . The IP Services  176  may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service (PSS), and/or other IP services. The BM-SC  170  may provide functions for MBMS user service provisioning and delivery. The BM-SC  170  may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway  168  may be used to distribute MBMS traffic to the base stations  102  belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. 
     The base station may also be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The base station  102  provides an access point to the core network  160  for a UE  104 . Examples of UEs  104  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 (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a toaster, or any other similar functioning device. Some of the UEs  104  may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, etc.). The UE  104  may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. 
       FIG. 2  is a block diagram of a base station  210  in communication with a UE  250  in an access network. In the DL, IP packets from the core network  160  may be provided to a controller/processor  275 . The controller/processor  275  implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor  275  provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     The transmit (TX) processor  216  and the receive (RX) processor  270  implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor  216  handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator  274  may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE  250 . Each spatial stream may then be provided to a different antenna  220  via a separate transmitter  218 TX. Each transmitter  218 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     At the UE  250 , each receiver  254 RX receives a signal through its respective antenna  252 . Each receiver  254 RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor  256 . The TX processor  268  and the RX processor  256  implement layer 1 functionality associated with various signal processing functions. The RX processor  256  may perform spatial processing on the information to recover any spatial streams destined for the UE  250 . If multiple spatial streams are destined for the UE  250 , they may be combined by the RX processor  256  into a single OFDM symbol stream. The RX processor  256  then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station  210 . These soft decisions may be based on channel estimates computed by the channel estimator  258 . The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station  210  on the physical channel. The data and control signals are then provided to the controller/processor  259 , which implements layer 3 and layer 2 functionality. 
     The controller/processor  259  can be associated with a memory  260  that stores program codes and data. The memory  260  may be referred to as a computer-readable medium. In the UL, the controller/processor  259  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network  160 . The controller/processor  259  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     Similar to the functionality described in connection with the DL transmission by the base station  210 , the controller/processor  259  provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     Channel estimates derived by a channel estimator  258  from a reference signal or feedback transmitted by the base station  210  may be used by the TX processor  268  to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor  268  may be provided to different antenna  252  via separate transmitters  254 TX. Each transmitter  254 TX may modulate an RF carrier with a respective spatial stream for transmission. The UL transmission is processed at the base station  210  in a manner similar to that described in connection with the receiver function at the UE  250 . Each receiver  218 RX receives a signal through its respective antenna  220 . Each receiver  218 RX recovers information modulated onto an RF carrier and provides the information to a RX processor  270 . 
     The controller/processor  275  can be associated with a memory  276  that stores program codes and data. The memory  276  may be referred to as a computer-readable medium. In the UL, the controller/processor  275  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE  250 . IP packets from the controller/processor  275  may be provided to the core network  160 . 
     The controller/processor  275  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     New radio (NR) may refer to radios configured to operate according to a new air interface (e.g., other than Orthogonal Frequency Divisional Multiple Access (OFDMA)-based air interfaces) or fixed transport layer (e.g., other than Internet Protocol (IP)). NR may utilize OFDM with a cyclic prefix (CP) on the uplink and downlink and may include support for half-duplex operation using time division duplexing (TDD). NR may include Enhanced Mobile Broadband (eMBB) service targeting wide bandwidth (e.g. 80 MHz beyond), millimeter wave (mmW) targeting high carrier frequency (e.g. 60 GHz), massive MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low latency communications (URLLC) service. 
     A single component carrier bandwidth of 100 MHZ may be supported. In one example, NR resource blocks (RBs) may span  12  sub-carriers with a sub-carrier bandwidth of 60 kHz over a 0.125 ms duration or a bandwidth of 15 kHz over a 0.5 ms duration. Each radio frame may consist of 20 or 80 subframes (or NR slots) with a length of 10 ms. Each subframe may indicate a link direction (i.e., DL or UL) for data transmission and the link direction for each subframe may be dynamically switched. Each subframe may include DL/UL data as well as DL/UL control data. UL and DL subframes for NR may be as described in more detail below with respect to  FIGS. 5 and 6 . 
     The NR RAN may include a central unit (CU) and distributed units (DUs). A NR BS (e.g., gNB, 5G Node B, Node B, transmission reception point (TRP), access point (AP)) may correspond to one or multiple BSs. NR cells can be configured as access cells (ACells) or data only cells (DCells). For example, the RAN (e.g., a central unit or distributed unit) can configure the cells. DCells may be cells used for carrier aggregation or dual connectivity and may not be used for initial access, cell selection/reselection, or handover. In some cases DCells may not transmit synchronization signals (SS) in some cases DCells may transmit SS. NR BSs may transmit downlink signals to UEs indicating the cell type. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine NR BSs to consider for cell selection, access, handover, and/or measurement based on the indicated cell type. 
       FIG. 3  illustrates an example logical architecture  300  of a distributed RAN, according to aspects of the present disclosure. A 5G access node  306  may include an access node controller (ANC)  302 . The ANC may be a central unit (CU) of the distributed RAN  300 . The backhaul interface to the next generation core network (NG-CN)  304  may terminate at the ANC. The backhaul interface to neighboring next generation access nodes (NG-ANs) may terminate at the ANC. The ANC may include one or more TRPs  308  (which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs, or some other term). As described above, a TRP may be used interchangeably with “cell.” 
     The TRPs  308  may be a distributed unit (DU). The TRPs may be connected to one ANC (ANC  302 ) or more than one ANC (not illustrated). For example, for RAN sharing, radio as a service (RaaS), and service specific AND deployments, the TRP may be connected to more than one ANC. A TRP may include one or more antenna ports. The TRPs may be configured to individually (e.g., dynamic selection) or jointly (e.g., joint transmission) serve traffic to a UE. 
     The local architecture of the distributed RAN  300  may be used to illustrate fronthaul definition. The architecture may be defined that support fronthauling solutions across different deployment types. For example, the architecture may be based on transmit network capabilities (e.g., bandwidth, latency, and/or jitter). The architecture may share features and/or components with LTE. According to aspects, the next generation AN (NG-AN)  310  may support dual connectivity with NR. The NG-AN may share a common fronthaul for LTE and NR. 
     The architecture may enable cooperation between and among TRPs  308 . For example, cooperation may be preset within a TRP and/or across TRPs via the ANC  302 . According to aspects, no inter-TRP interface may be needed/present. 
     According to aspects, a dynamic configuration of split logical functions may be present within the architecture of the distributed RAN  300 . The PDCP, RLC, MAC protocol may be adaptably placed at the ANC or TRP. 
       FIG. 4  illustrates an example physical architecture of a distributed RAN  400 , according to aspects of the present disclosure. A centralized core network unit (C-CU)  402  may host core network functions. The C-CU may be centrally deployed. C-CU functionality may be offloaded (e.g., to advanced wireless services (AWS)), in an effort to handle peak capacity. A centralized RAN unit (C-RU)  404  may host one or more ANC functions. Optionally, the C-RU may host core network functions locally. The C-RU may have distributed deployment. The C-RU may be closer to the network edge. A distributed unit (DU)  406  may host one or more TRPs. The DU may be located at edges of the network with radio frequency (RF) functionality. 
       FIG. 5  is a diagram  500  showing an example of a DL-centric subframe. The DL-centric subframe may include a control portion  502 . The control portion  502  may exist in the initial or beginning portion of the DL-centric subframe. The control portion  502  may include various scheduling information and/or control information corresponding to various portions of the DL-centric subframe. In some configurations, the control portion  502  may be a physical DL control channel (PDCCH), as indicated in  FIG. 5 . The DL-centric subframe may also include a DL data portion  504 . The DL data portion  504  may sometimes be referred to as the payload of the DL-centric subframe. The DL data portion  504  may include the communication resources utilized to communicate DL data from the scheduling entity (e.g., UE or BS) to the subordinate entity (e.g., UE). In some configurations, the DL data portion  504  may be a physical DL shared channel (PDSCH). 
     The DL-centric subframe may also include a common UL portion  506 . The common UL portion  506  may sometimes be referred to as an UL burst, a common UL burst, and/or various other suitable terms. The common UL portion  506  may include feedback information corresponding to various other portions of the DL-centric subframe. For example, the common UL portion  506  may include feedback information corresponding to the control portion  502 . Non-limiting examples of feedback information may include an ACK signal, a NACK signal, a HARQ indicator, and/or various other suitable types of information. The common UL portion  506  may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests (SRs), and various other suitable types of information. 
     As illustrated in  FIG. 5 , the end of the DL data portion  504  may be separated in time from the beginning of the common UL portion  506 . This time separation may sometimes be referred to as a gap, a guard period, a guard interval, and/or various other suitable terms. This separation provides time for the switch-over from DL communication (e.g., reception operation by the subordinate entity (e.g., UE)) to UL communication (e.g., transmission by the subordinate entity (e.g., UE)). One of ordinary skill in the art will understand that the foregoing is merely one example of a DL-centric subframe and alternative structures having similar features may exist without necessarily deviating from the aspects described herein. 
       FIG. 6  is a diagram  600  showing an example of an UL-centric subframe. The UL-centric subframe may include a control portion  602 . The control portion  602  may exist in the initial or beginning portion of the UL-centric subframe. The control portion  602  in  FIG. 6  may be similar to the control portion  502  described above with reference to  FIG. 5 . The UL-centric subframe may also include an UL data portion  604 . The UL data portion  604  may sometimes be referred to as the pay load of the UL-centric subframe. The UL portion may refer to the communication resources utilized to communicate UL data from the subordinate entity (e.g., UE) to the scheduling entity (e.g., UE or BS). In some configurations, the control portion  602  may be a physical DL control channel (PDCCH). 
     As illustrated in  FIG. 6 , the end of the control portion  602  may be separated in time from the beginning of the UL data portion  604 . This time separation may sometimes be referred to as a gap, guard period, guard interval, and/or various other suitable terms. This separation provides time for the switch-over from DL communication (e.g., reception operation by the scheduling entity) to UL communication (e.g., transmission by the scheduling entity). The UL-centric subframe may also include a common UL portion  606 . The common UL portion  606  in  FIG. 6  may be similar to the common UL portion  606  described above with reference to  FIG. 6 . The common UL portion  606  may additionally or alternatively include information pertaining to channel quality indicator (CQI), sounding reference signals (SRSs), and various other suitable types of information. One of ordinary skill in the art will understand that the foregoing is merely one example of an UL-centric subframe and alternative structures having similar features may exist without necessarily deviating from the aspects described herein. 
     In some circumstances, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical mesh, and/or various other suitable applications. Generally, a sidelink signal may refer to a signal communicated from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying that communication through the scheduling entity (e.g., UE or BS), even though the scheduling entity may be utilized for scheduling and/or control purposes. In some examples, the sidelink signals may be communicated using a licensed spectrum (unlike wireless local area networks, which typically use an unlicensed spectrum). 
       FIG. 7  is a diagram  700  illustrating communications between a base station  702  and a UE  704 . The base station  702  may operates antenna ports  722 - 1  to  722 -N. The base station  702  provides transmitter side beams  726 - 1  to  726 -N at different directions. The UE  704  may use a random access procedure to gain access to a cell of the base station  702 . In this example, to facilitate a UE to perform the random access procedure, the base station  702  transmits a set of synchronization signal blocks (SSBs) including SSBs  732 - 1  to  732 -N, which are associated with the transmitter side beams  726 - 1  to  726 -N, respectively. More specifically, the Primary Synchronization Signal (PSS) and the Secondary Synchronization Signal (SSS), together with the Physical Broadcast Channel (PBCH), are jointly referred to as an SSB. Each of the SSBs  732 - 1  to  732 -N may include one or more Demodulation Reference Signals (DMRSs) for PBCH. The DMRSs are intended for channel estimation at a UE as part of coherent demodulation. 
     Further, the base station  702  may transmit CSI-RS sets  734 - 1  to  734 -N that are specific to the UE  704  by using the transmitter side beams  726 - 1  to  726 -N, respectively. A CSI-RS is used by the UE to estimate the channel and report channel state information (CSI) to the base station. A CSI-RS is configured on a per-device basis. 
     In certain configurations, the UE  704  may select one of the transmitter side beams  726 - 1  to  726 -N randomly or based on a rule for deriving a corresponding preamble sequence used in the random access procedure. In certain configurations, the UE  704  may adjust the direction of a receiver side beam  728  to detect and measure the SSBs  732 - 1  to  732 -N or the CSI-RS sets  734 - 1  to  734 -N. Based on the detection and/or measurements (e.g., SNR measurements), the UE  704  may select a direction of the receiver side beam  728  and one of the transmitter side beams  726 - 1  to  726 -N for deriving a corresponding preamble sequence used in the random access procedure. 
     In one example, the UE  704  may select the transmitter side beam  726 - 2  for deriving an associated preamble sequence for use in the random access procedure. More specifically, the UE  704  is configured with one or more random access resources associated with each the SSBs  732 - 1  to  732 -N and/or one or more random access resources associated with each the CSI-RS sets  734 - 1  to  734 -N. 
     Accordingly, the UE  704  may select a random access resource associated with the down-link reference signal (e.g., SSB or CSI-RS) of the transmitter side beam  726 - 2  (i.e., the selected one of the transmitter side beams  726 - 1  to  726 -N). Subsequently, the UE  704  sends a preamble sequence  752  to the base station  702  through the receiver side beam  728  (by assuming a corresponding UE transmit beam can be derived from the receiver side beam  828 ) on the selected random access resource. Based on the location of the random access resource in time domain and frequency domain, the base station  702  can determine the transmitter side beam selected by the UE  704 . 
     Subsequently, the base station  702  and the UE  704  can further complete the random access procedure such that the base station  702  and the UE  704  can communicate through the transmitter side beam  726 - 2  and the receiver side beam  728 . As such, the UE  704  is in a connected state (e.g., RRC CONNECTED) with the base station  702 . The base station  702  may use the transmitter side beam  726 - 2  to transmit to the UE  704  a PDCCH  742 , a PDSCH  744 , and associated DMRSs  746 . 
       FIG. 8  is diagram  800  illustrating a random access procedure of a UE in a connected state. In certain circumstances, the UE  704 , although in a connected state, may need to conduct the random access procedure with the base station  702  or another base station. In this example, as described supra referring to  FIG. 7 , the UE  704  is connected to the base station  702 . The UE  704  may receive a request (e.g., a PDCCH order) from the base station  702  to initiate a random access procedure again. The UE  704  may detect an uplink data arrival without uplink synchronization and, thus, may conduct the random access procedure with the base station  702 . The UE  704  may detect a down-link data arrival without uplink synchronization and, thus, may conduct the random access procedure with the base station  702  and, thus, may conduct the random access procedure with the base station  702 . The UE  704  may decide to recover a beam and, thus, may conduct the random access procedure with the base station  702 . The UE  704  may be handed over from the base station  702  to another base station and, thus, may conduct the random access procedure with the other base station. 
     In this example, at procedure  802 , the base station  702  sends a PDCCH order to the UE  704 . In particular, the PDCCH order may be transmitted by using the transmitter side beam  726 - 2 . Accordingly, upon received the PDCCH order, at procedure  803 , the UE  704  initiates a random access procedure while in a connected state. In another example, the UE  704  may detect a beam failure and internally generates a beam failure recovery request. Accordingly, the UE  704  can also initiate a random access procedure while in a connected state. At procedure  804 , as described supra, the base station  702  sends the SSBs  732 - 1  to  732 -N and/or the CSI-RS sets  734 - 1  to  734 -N associated with the transmitter side beams  726 - 1  to  726 -N, respectively. The UE  704  may detect some or all of the SSBs  732 - 1  to  732 -N. Note that procedure  804  can also take place before procedure  802 . 
     At procedure  806 , as described supra, in certain configurations, the UE  704  may select one of the transmitter side beams  726 - 1  to  726 -N randomly or based on the measurement result. As an example, the base station  702  may select the transmitter side beam  726 - 1  for deriving an associated preamble sequence  752  for use in the random access procedure. 
     Accordingly, the base station  702  may use a correspondent beam of the transmitter side beam  726 - 2  to receive the preamble sequence  752 , which is transmitted on a random access resource associated with the down-link reference signals of the transmitter side beam  726 - 1 . The UE  704  determines a timing advance (TA) for the UE  704  based on the preamble sequence  752  received through the transmitter side beam  726 - 2 . 
     As such, the base station  702  may receive the preamble sequence  752  on the transmitter side beam  726 - 2 . The network of the base station  702  can also determine that the preamble sequence  752  was transmitted at a random access resource associated with the SSB  732 - 2  and/or the CSI-RS set  734 - 2  of the transmitter side beam  726 - 2 . As such, the network learns that the UE  704  selected the transmitter side beam  726 - 2 . 
     At procedure  810 , the base station  702  (under the control of the network) generates a random-access response (RAR). The RAR may include information about the preamble sequence  752  the network detected and for which the response is valid, a TA calculated by the network based on the preamble sequence receive timing, a scheduling grant indicating resources the UE  704  will use for the transmission of the subsequent message, and/or a temporary identity, the TC-RNTI, used for further communication between the device and the network. 
     At procedure  812 , the base station  702  transmits a PDCCH scheduling command for scheduling transmission of the RAR by using the transmitter side beam  726 - 2 . Accordingly, DMRS of the PDCCH scheduling command and DMRS of the PDCCH order at procedure  802  are quasi-colocated. Further, the PDCCH scheduling command may be scrambled by a cell radio network temporary identifier (C-RNTI) of the UE  704 , which is known to the network. Further, as described supra, the UE  704  is in a connected state. The serving beam from the base station  702  to the UE  704  may be the transmitter side beam  726 - 1 . At or about the same time the base station  702  sends the PDCCH scheduling command for scheduling transmission of the RAR on the transmitter side beam  726 - 2 , the base station  702  may also send a PDCCH on the transmitter side beam  726 - 1  for scheduling a PDSCH carrying user data. 
     At procedure  814 , the base station  702  transmits the RAR to the UE  704  on the transmitter side beam  726 - 2 . The RAR may be transmitted in a conventional downlink PDSCH. As such, the random access procedure completes for the UE  704 , which is in a connected state. 
       FIG. 9  is a diagram  900  illustrating that a UE transmits a preamble sequence, a PUCCH, a PUSCH, and/or a sounding reference signal (SRS) in a time slot. More specifically, the UE  704  may decide to transmit the preamble sequence  752  (as described supra referring to  FIG. 7 ) to the base station  702  in a slot  912 . Further, in this example, as the UE  704  is in a connected state, the UE  704  may also be configured to transmit a PUCCH  962 , a PUSCH  964 , and/or an SRS  966  in the slot  912 . (In another example, rather than a single time slot, within a predetermined time period such as half a time slot, two time slots, a subframe, a mini-slot, several consecutive symbol periods, or an OFDM symbol period, the UE  704  may decide to transmit the preamble sequence  752  and be configured to transmit one or more of the PUCCH  962 , the PUSCH  964 , and the SRS  966 .) 
     In this example, when the UE  704  transmits the preamble sequence  752 , the UE  704  is configured to use a default timing advance value. Accordingly, the UE  704  applies the default timing advance value to calculate a time point at which the transmission of the preamble sequence  752  is to be started. 
     On the other hand, as the UE  704  is in a connected state, the base station  702  has assigned a timing advance value to the UE  704  for uplink transmission. Accordingly, the UE  704  applies the assigned timing advance value to calculate a time point at which the transmission of the PUCCH  962 , the PUSCH  964 , or the SRS  966  is to be started. 
     The default timing advance value and the assigned timing advance value may not be the same. In certain configurations, the UE  704  does not have the capability to apply different timing advance values in a single time slot (e.g., the slot  912 ) or in the predetermined time period described supra. In these scenarios, when the UE  704  transmits the preamble sequence  752  in the slot  912 , the UE  704  does not transmit the PUCCH  962 , the PUSCH  964 , and/or the SRS  966  in the slot  912  (or the predetermined time period). That is, the UE  704  refrains from transmitting the PUCCH  962 , the PUSCH  964 , and/or the SRS  966  in the slot  912  (or the predetermined time period). 
     In certain configurations, the UE  704  has the capability to apply different timing advance values in a single time slot (e.g., the slot  912 ) or in the predetermined time period described supra. In these scenarios, the UE  704  may send an indication to the base station  702  to report the capability of the UE  704 . Further, when the UE  704  transmits the preamble sequence  752  in the slot  912  with the default timing advance value, the UE  704  may also transmit the PUCCH  962 , the PUSCH  964 , and/or the SRS  966  in the slot  912  (or the predetermined time period) with the assigned timing advance value. 
     In the above example, the preamble sequence  752  as well as the PUCCH  962 , the PUSCH  964 , and the SRS  966  are all transmitted on a same cell  982 . Further, in one configuration, the preamble sequence  752  as well as the PUCCH  962 , the PUSCH  964 , and the SRS  966  are all transmitted on a same uplink carrier. In another configuration, the preamble sequence  752  is transmitted on a first uplink carrier on the cell  982 , while the PUCCH  962 , the PUSCH  964 , and the SRS  966  are transmitted on a second, different uplink carrier. 
     In another example, the preamble sequence  752 ′ is transmitted on a cell  984  that is different from the cell  982 , while the PUCCH  962 , the PUSCH  964 , and the SRS  966  are transmitted on the cell  982 . Further, in one configuration, the cell  982  and the cell  984  are operated as intra-band carrier aggregation. In another configuration, the cell  982  and the cell  984  are operated as inter-band carrier aggregation. 
       FIG. 10  is a flow chart  1000  of a method (process) for uplink transmission. The method may be performed by a UE (e.g., the UE  704 , the apparatus  1102 , and the apparatus  1102 ′). At operation  1002 , the UE determines to transmit a preamble sequence to a base station at a random access occasion in a random access procedure when the UE is in a connected state. 
     At operation  1004 , the UE determines that the random access occasion is in a same predetermined time period as an uplink channel or a sounding reference signal that is scheduled to be transmitted to the base station. 
     At operation  1006 , the UE determines whether the UE has capability to transmit a preamble sequence and an uplink channel or a sounding reference signal in the same predetermined time period. When the UE has the ability, at operation  1008 , the UE transmits an indicator to the base station to indicate that the UE has the capability. 
     When the UE does not have the ability, at operation  1010 , the UE refrains from transmitting the preamble sequence or refraining from transmitting the uplink channel or the sounding reference signal. 
     In certain configurations, the uplink channel is a PUCCH or a PUSCH. In certain configurations, the uplink channel or the sounding reference signal is refrained from transmitting. In certain configurations, the preamble sequence is refrained from transmitting. In certain configurations, the predetermined time period is a slot, a number of symbol periods, or a plurality of slots. In certain configurations, the random access occasion for the preamble sequence transmission is on a first cell, the uplink channel or the sounding reference signal is on a second cell, and the first cell is different from the second cell. 
     In certain configurations, the first cell and the second cell are operated as intra-band carrier aggregation. In certain configurations, the first cell and the second cell are operated as inter-band carrier aggregation. In certain configurations, the random access occasion is allocated on a first uplink carrier of a cell and the uplink channel or the sounding reference signal is scheduled on a second uplink carrier of the cell. 
       FIG. 11  is a conceptual data flow diagram  1100  illustrating the data flow between different components/means in an exemplary apparatus  1102 . The apparatus  1102  may be a UE. The apparatus  1102  includes a reception component  1104 , a capability component  1108 , a RA component  1112 , and a transmission component  1110 . 
     The RA component  1112  determines to transmit a preamble sequence to a base station at a random access occasion in a random access procedure when the UE is in a connected state. The RA component  1112  determines that the random access occasion is in a same predetermined time period as an uplink channel or a sounding reference signal that is scheduled to be transmitted to the base station. 
     The capability component  1108  determines whether the UE has capability to transmit a preamble sequence and an uplink channel or a sounding reference signal in the same predetermined time period. When the UE has the ability, the capability component  1108  transmits an indicator to the base station to indicate that the UE has the capability. 
     When the UE does not have the ability, the RA component  1112  refrains from transmitting the preamble sequence or refraining from transmitting the uplink channel or the sounding reference signal. 
     In certain configurations, the uplink channel is a PUCCH or a PUSCH. In certain configurations, the uplink channel or the sounding reference signal is refrained from transmitting. In certain configurations, the preamble sequence is refrained from transmitting. In certain configurations, the predetermined time period is a slot, a number of symbol periods, or a plurality of slots. In certain configurations, the random access occasion for the preamble sequence transmission is on a first cell, the uplink channel or the sounding reference signal is on a second cell, and the first cell is different from the second cell. 
     In certain configurations, the first cell and the second cell are operated as intra-band carrier aggregation. In certain configurations, the first cell and the second cell are operated as inter-band carrier aggregation. In certain configurations, the random access occasion is allocated on a first uplink carrier of a cell and the uplink channel or the sounding reference signal is scheduled on a second uplink carrier of the cell. 
       FIG. 12  is a diagram  1200  illustrating an example of a hardware implementation for an apparatus  1102 ′ employing a processing system  1214 . The apparatus  1102 ′ may be a UE. The processing system  1214  may be implemented with a bus architecture, represented generally by a bus  1224 . The bus  1224  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  1214  and the overall design constraints. The bus  1224  links together various circuits including one or more processors and/or hardware components, represented by one or more processors  1204 , the reception component  1104 , the capability component  1108 , the transmission component  1110 , the RA component  1112 , and a computer-readable medium/memory  1206 . The bus  1224  may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, etc. 
     The processing system  1214  may be coupled to a transceiver  1210 , which may be one or more of the transceivers  254 . The transceiver  1210  is coupled to one or more antennas  1220 , which may be the communication antennas  252 . 
     The transceiver  1210  provides a means for communicating with various other apparatus over a transmission medium. The transceiver  1210  receives a signal from the one or more antennas  1220 , extracts information from the received signal, and provides the extracted information to the processing system  1214 , specifically the reception component  1104 . In addition, the transceiver  1210  receives information from the processing system  1214 , specifically the transmission component  1110 , and based on the received information, generates a signal to be applied to the one or more antennas  1220 . 
     The processing system  1214  includes one or more processors  1204  coupled to a computer-readable medium/memory  1206 . The one or more processors  1204  are responsible for general processing, including the execution of software stored on the computer-readable medium/memory  1206 . The software, when executed by the one or more processors  1204 , causes the processing system  1214  to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory  1206  may also be used for storing data that is manipulated by the one or more processors  1204  when executing software. The processing system  1214  further includes at least one of the reception component  1104 , the capability component  1108 , the transmission component  1110 , and the RA component  1112 . The components may be software components running in the one or more processors  1204 , resident/stored in the computer readable medium/memory  1206 , one or more hardware components coupled to the one or more processors  1204 , or some combination thereof. The processing system  1214  may be a component of the UE  250  and may include the memory  260  and/or at least one of the TX processor  268 , the RX processor  256 , and the communication processor  259 . 
     In one configuration, the apparatus  1102 /apparatus  1102 ′ for wireless communication includes means for performing each of the operations of  FIG. 10 . The aforementioned means may be one or more of the aforementioned components of the apparatus  1102  and/or the processing system  1214  of the apparatus  1102 ′ configured to perform the functions recited by the aforementioned means. 
     As described supra, the processing system  1214  may include the TX Processor  268 , the RX Processor  256 , and the communication processor  259 . As such, in one configuration, the aforementioned means may be the TX Processor  268 , the RX Processor  256 , and the communication processor  259  configured to perform the functions recited by the aforementioned means. 
     It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.”