Patent Publication Number: US-2023156739-A1

Title: Multiple dcis transmitted over pdsch

Description:
BACKGROUND 
     Technical Field 
     The present disclosure relates generally to communication systems, and more particularly, to transmission of multiple downlink control information (DCI) messages over a physical downlink shared channel. 
     INTRODUCTION 
     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. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra reliable low latency communications (URLLC). 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 obtains a downlink control information (DCI) message transmitted in a physical downlink control channel (PDCCH). The DCI message includes control information for obtaining a plurality of downlink control information (DCI) messages included in a physical downlink shared channel (PDSCH). The apparatus receives the PDSCH including the plurality of DCI messages. The apparatus obtains one or more of the plurality of DCI messages in the PDSCH based on the control information. 
     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. 
         FIGS.  2 A,  2 B,  2 C, and  2 D  are diagrams illustrating examples of a first 5G/NR frame, DL channels within a 5G/NR subframe, a second 5G/NR frame, and UL channels within a 5G/NR subframe, respectively. 
         FIG.  3    is a diagram illustrating an example of a base station and user equipment (UE) in an access network. 
         FIG.  4    is a signal flow diagram in accordance with various aspects of the present disclosure. 
         FIG.  5    is a diagram illustrating downlink control information (DCI) messages included in a physical downlink shared channel (PDSCH) in accordance with various aspects of the present disclosure. 
         FIG.  6    is a diagram illustrating the separate decoding of coded blocks to obtain the DCI messages included in the PDSCH in accordance with various aspects of the present disclosure. 
         FIG.  7    is a diagram illustrating the separate decoding of coded blocks to obtain the DCI messages included in the PDSCH in accordance with various aspects of the present disclosure. 
         FIG.  8    is a diagram illustrating single DCI messages piggybacked in PDSCH in accordance with various aspects of the present disclosure. 
         FIG.  9    is a flowchart of a method of wireless communication in accordance with various aspects of the present disclosure. 
         FIG.  10    is a flowchart of a method of wireless communication in accordance with various aspects of the present disclosure. 
         FIG.  11    is a conceptual data flow diagram illustrating the data flow between different means/components in an example 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 , an Evolved Packet Core (EPC)  160 , and another core network  190  (e.g., a 5G Core (5GC)). The base stations  102  may include macrocells (high power cellular base station) and/or small cells (low power cellular base station). The macrocells include base stations. The small cells include femtocells, picocells, and microcells. 
     The base stations  102  configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC  160  through backhaul links  132  (e.g., S1 interface). The base stations  102  configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network  190  through backhaul links  184 . 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 EPC  160  or core network  190 ) 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 macrocells 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, 400, etc. 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 fewer 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). 
     Certain UEs  104  may communicate with each other using device-to-device (D2D) communication link  158 . The D2D communication link  158  may use the DL/UL WWAN spectrum. 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), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR. 
     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. 
     A base station  102 , whether a small cell  102 ′ or a large cell (e.g., macro base station), may include an eNB, gNodeB (gNB), or another type of base station. Some base stations, such as gNB  180  may operate in a traditional sub 6 GHz spectrum, 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 (e.g., 3 GHz-300 GHz) has extremely high path loss and a short range. The mmW base station  180  may utilize beamforming  182  with the UE  104  to compensate for the extremely high path loss and short range. 
     The base station  180  may transmit a beamformed signal to the UE  104  in one or more transmit directions  182 ′. The UE  104  may receive the beamformed signal from the base station  180  in one or more receive directions  182 ″. The UE  104  may also transmit a beamformed signal to the base station  180  in one or more transmit directions. The base station  180  may receive the beamformed signal from the UE  104  in one or more receive directions. The base station  180 /UE  104  may perform beam training to determine the best receive and transmit directions for each of the base station  180 /UE  104 . The transmit and receive directions for the base station  180  may or may not be the same. The transmit and receive directions for the UE  104  may or may not be the same. 
     The EPC  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 EPC  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, 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 core network  190  may include a Access and Mobility Management Function (AMF)  192 , other AMFs  193 , a Session Management Function (SMF)  194 , and a User Plane Function (UPF)  195 . The AMF  192  may be in communication with a Unified Data Management (UDM)  196 . The AMF  192  is the control node that processes the signaling between the UEs  104  and the core network  190 . Generally, the AMF  192  provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF  195 . The UPF  195  provides UE IP address allocation as well as other functions. The UPF  195  is connected to the IP Services  197 . The IP Services  197  may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. 
     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), a transmit reception point (TRP), or some other suitable terminology. The base station  102  provides an access point to the EPC  160  or core network  190  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 large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, 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, heart monitor, 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. 
     Referring again to  FIG.  1   , in certain aspects, the UE  104  may be configured to obtain downlink control information (DCI) messages included in a physical downlink shared channel (PDSCH)  198 . 
       FIG.  2 A  is a diagram  200  illustrating an example of a first subframe within a 5G/NR frame structure.  FIG.  2 B  is a diagram  230  illustrating an example of DL channels within a 5G/NR subframe.  FIG.  2 C  is a diagram  250  illustrating an example of a second subframe within a 5G/NR frame structure.  FIG.  2 D  is a diagram  280  illustrating an example of UL channels within a 5G/NR subframe. The 5G/NR frame structure may be FDD in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL, or may be TDD in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by  FIGS.  2 A,  2 C , the 5G/NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL), where D is DL, U is UL, and X is flexible for use between DL/UL, and subframe 3 being configured with slot format 34 (with mostly UL). While subframes 3, 4 are shown with slot formats 34, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the description infra applies also to a 5G/NR frame structure that is TDD. 
     Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission). The number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies μ0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2 μ  slots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2 μ *15 kKz, where μ is the numerology 0 to 5. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=5 has a subcarrier spacing of 480 kHz. The symbol length/duration is inversely related to the subcarrier spacing.  FIGS.  2 A- 2 D  provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and symbol duration is approximately 66.7 μs. 
     A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. 
     As illustrated in  FIG.  2 A , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (indicated as R x  for one particular configuration, where 100× is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS). 
       FIG.  2 B  illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE  104  to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DM-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block. The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages. 
     As illustrated in  FIG.  2 C , some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. Although not shown, the UE may transmit sounding reference signals (SRS). The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL. 
       FIG.  2 D  illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a 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. 
       FIG.  3    is a block diagram of a base station  310  in communication with a UE  350  in an access network. In the DL, IP packets from the EPC  160  may be provided to a controller/processor  375 . The controller/processor  375  implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor  375  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  316  and the receive (RX) processor  370  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  316  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  374  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  350 . Each spatial stream may then be provided to a different antenna  320  via a separate transmitter  318 TX. Each transmitter  318 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     At the UE  350 , each receiver  354 RX receives a signal through its respective antenna  352 . Each receiver  354 RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor  356 . The TX processor  368  and the RX processor  356  implement layer 1 functionality associated with various signal processing functions. The RX processor  356  may perform spatial processing on the information to recover any spatial streams destined for the UE  350 . If multiple spatial streams are destined for the UE  350 , they may be combined by the RX processor  356  into a single OFDM symbol stream. The RX processor  356  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  310 . These soft decisions may be based on channel estimates computed by the channel estimator  358 . The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station  310  on the physical channel. The data and control signals are then provided to the controller/processor  359 , which implements layer 3 and layer 2 functionality. 
     The controller/processor  359  can be associated with a memory  360  that stores program codes and data. The memory  360  may be referred to as a computer-readable medium. In the UL, the controller/processor  359  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC  160 . The controller/processor  359  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  310 , the controller/processor  359  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  358  from a reference signal or feedback transmitted by the base station  310  may be used by the TX processor  368  to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor  368  may be provided to different antenna  352  via separate transmitters  354 TX. Each transmitter  354 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     The UL transmission is processed at the base station  310  in a manner similar to that described in connection with the receiver function at the UE  350 . Each receiver  318 RX receives a signal through its respective antenna  320 . Each receiver  318 RX recovers information modulated onto an RF carrier and provides the information to a RX processor  370 . 
     The controller/processor  375  can be associated with a memory  376  that stores program codes and data. The memory  376  may be referred to as a computer-readable medium. In the UL, the controller/processor  375  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE  350 . IP packets from the controller/processor  375  may be provided to the EPC  160 . The controller/processor  375  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     At least one of the TX processor  368 , the RX processor  356 , and the controller/processor  359  may be configured to perform aspects in connection with  198  of  FIG.  1   . 
     A UE may transmit an uplink control information (UCI) message in a physical uplink shared channel (PUSCH). This may be referred to as piggybacking the UCI message in the PUSCH. In some examples, and as previously described, the UCI message may include scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. 
     For the rate matching of the UCI message in the PUSCH, a code rate offset factor β offset  (e.g., β offset &gt;1) may be used to achieve a lower code rate than the code rate indicated by a modulation and coding scheme (MCS) for the PUSCH. The number of resource elements (REs) per layer for the UCI message may be determined using equation (1): 
     
       
         
           
             
               
                 
                   
                     N 
                     
                       
                         R 
                         ⁢ 
                         E 
                       
                       , 
                       UCI 
                     
                   
                   = 
                   
                     
                       
                         
                           K 
                           UCI 
                         
                         · 
                         
                           β 
                           offset 
                         
                       
                       
                         K 
                         
                           UL 
                           - 
                           SCH 
                         
                       
                     
                     ⁢ 
                     
                       N 
                       
                         R 
                         ⁢ 
                         E 
                       
                     
                   
                 
               
               
                 
                   ( 
                   
                     equation 
                     ⁢ 
                         
                     1 
                   
                   ) 
                 
               
             
           
         
       
     
     where N RE,UCI  represents the number of resource elements (REs) per layer for the UCI message, K UCI  represents the payload size of the UCI message including cyclic redundancy check (CRC) (if any), β offset  represents a code rate offset factor, K UL-SCH  represents the uplink shared channel (UL-SCH) payload size including transport block (TB)/code block (CB) cyclic redundancy check (CRC) bits, and N RE  represents the total number of REs per layer of the PUSCH. It should be understood that equation (1) represents a simplified equation for the determination of N RE,UCI  for ease of understanding and that the determination of N RE,UCI  may be more complex in some cases. 
     In some examples, to prevent the UCI message from occupying more PUSCH resources than is necessary or desired, a portion factor α∈{0.5, 0.65, 0.8, 1.0} may be used to limit the maximum portion of PUSCH resources that the UCI message may occupy. In these examples, N RE,UCI  may be determined using equation (2): 
     
       
         
           
             
               
                 
                   
                     N 
                     
                       
                         R 
                         ⁢ 
                         E 
                       
                       , 
                       UCI 
                     
                   
                   = 
                   
                     
                       min 
                       ⁡ 
                       ( 
                       
                         
                           
                             
                               
                                 K 
                                 UCI 
                               
                               · 
                               
                                 β 
                                 offset 
                               
                             
                             
                               K 
                               
                                 UL 
                                 - 
                                 SCH 
                               
                             
                           
                           ⁢ 
                           
                             N 
                             
                               R 
                               ⁢ 
                               E 
                             
                           
                         
                         , 
                         
                           α 
                           · 
                           
                             N 
                             
                               R 
                               ⁢ 
                               E 
                             
                           
                         
                       
                       ) 
                     
                     . 
                   
                 
               
               
                 
                   ( 
                   
                     equation 
                     ⁢ 
                         
                     2 
                   
                   ) 
                 
               
             
           
         
       
     
     Polar codes have been adopted as the channel coding technique for control channels (e.g., PDCCH) in 5G NR networks. In some examples, the maximum coded block size may be 512 bits for downlink transmissions and 1024 bits for uplink transmissions. The minimum coding rate may be 1/8. The maximum payload size without CRC may be 140 bits, and a 24-bit CRC may be appended to the payload. Rate-matching schemes may include shortening, puncturing and repetition. The decoding complexity may be expressed as O(N×log 2 (N)), where N is the number of coded bits. In other words, decoding complexity may not be a direct function of coding rate. There may be coding gain loss with more information bits. 
     Determination of a coded block size will now be described. In one example, K may represent a number of data bits (also referred to as information bits, payload, or payload size) to be encoded. K may be a positive integer value and the K number of data bits may be expressed as a sequence of bits c 0 , c 1 , c 2 , . . . , c K-1 . The K number of data bits may be encoded with a polar code to produce N=2 n  encoded bits, where N represents the code length of the polar code (also referred to as a mother code size N). For example, the N encoded bits may be expressed as a sequence of bits d 0 , d 1 , d 2 , . . . , d N-1 . In determining the code length N=2 n  of the polar code, the value of n may be determined using equation (3): 
         n =max{min{ n   1   ,n   2   ,n   max   },n   min }.  (equation 3)
 
     where n min  and n max  provide a lower and upper bound on the code length, respectively. In some examples, n min =5 and n max =9 for a downlink channel. The parameter 
     
       
         
           
             
               n 
               2 
             
             = 
             
               ⌈ 
               
                 
                   log 
                   2 
                 
                 ( 
                 
                   K 
                   
                     R 
                     min 
                   
                 
                 ) 
               
               ⌉ 
             
           
         
       
     
     sets an upper bound on the code rate based on the minimum code rate R min  admitted by the encoder (e.g., R min =1/8). The value of the parameter n 1  may be dependent on the rate matching scheme and is usually defined as n 1 =┌log 2  E┐, where E represents the code length (also referred to as the coded block size) after rate matching. However, if 
     
       
         
           
             
               E 
               ≤ 
               
                 
                   
                     ( 
                     
                       9 
                       8 
                     
                     ) 
                   
                   · 
                   
                     2 
                     
                       ( 
                       
                         
                           ⌈ 
                           
                             
                               log 
                               2 
                             
                             ⁢ 
                             E 
                           
                           ⌉ 
                         
                         - 
                         1 
                       
                       ) 
                     
                   
                 
                 ⁢ 
                     
                 and 
                 ⁢ 
                     
                 
                   K 
                   E 
                 
               
               &lt; 
               
                 9 
                 
                   1 
                   ⁢ 
                   6 
                 
               
             
             , 
           
         
       
     
     then n 1  may be defined as n 1 =┌log 2  E┐−1. 
     In the aspects described herein, multiple DCI messages may be transmitted in a PDSCH. As used herein, the terms “DCI” and “DCI message” are interchangeable. This may be referred to as piggybacking the DCI messages in the PDSCH. In some aspects of the disclosure, multiple DCI messages may be transmitted in the PDSCH in situations where the PDCCH may not have adequate resources to carry one or more of the multiple DCI messages. These situations may arise when the CORESET is reduced (e.g., when a base station is operating in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, etc.) and cannot accommodate the multiple DCI messages. For example, the DCI messages may be an aggregation of multiple DL/UL grants. In some cases, the delivery of these DL/UL grants in the PDSCH may be more efficient than transmitting them in a PDCCH, which would require a UE to perform blind decoding. 
     When the aggregated length of the multiple DCI messages to be transmitted to a UE is larger than the maximum of 164 bits supported in the PDCCH, segmentation of a transport block (TB) into multiple code blocks (CBs) may be performed. For example, one of several types of segmentation schemes may be used to perform the segmentation of the transport block (TB). These aggregation and segmentation schemes may improve coding gain and unitary protection. However, separately encoding each DCI message with a single code block may still provide acceptable performance. In this case, a UE may attempt to decode each of the separately encoded DCI messages and may use the successfully decoded DCI messages. 
     Determination of a total resource size of the multiple DCI messages included in the PDSCH and the allocation of resources for each DCI message encoded in a single code block will now be described. In some aspects of the disclosure, the base station may transmit multiple separately encoded DCI messages in an allocated PDSCH region, together with other data, to the same UE. The multiple separately encoded DCI messages may have the same size (e.g., same code length or payload size) and may be rate matched into the allocated PDSCH region. 
       FIG.  4    is a signal flow diagram in accordance with various aspects of the present disclosure. As shown in  FIG.  4   , a base station  404  may transmit a DCI message  406  to a UE  402  in a PDCCH. For example, with reference to  FIG.  5   , the DCI message  406  may include DCI bits  550  and CRC bits  552 . As further shown in  FIG.  4   , the UE  402  may obtain  408  the DCI message  406  in the PDCCH by performing blind decoding (also referred to as blind detection). For example, the UE  402  may perform blind decoding by checking all possible PDCCH locations, PDCCH formats, and DCI formats, and acting on the messages with correct CRCs. In some aspects of the disclosure, the DCI message  406  may include control information for the PDSCH, a number A representing the number of DCI messages included in a PDSCH, and a downlink (DL) code rate offset factor β offset   DL . For example, A may be an integer that is greater than or equal to two. For the rate matching of the DCI message in the PDSCH, the DL code rate offset factor β offset   DL  (e.g., β offset &gt;1) may be used to achieve a lower code rate than the code rate indicated by a modulation and coding scheme (MCS) for the PDSCH. 
     As shown in  FIG.  4   , the base station  404  may transmit A DCI messages  410  to the UE  402  in a PDSCH. For example, with reference to  FIG.  5   , in a scenario where two DCI messages (e.g., A=2) are transmitted to the UE  402  in the PDSCH, the DCI messages  410  may include a first DCI message  410 _ 1  and a second DCI message  410 _ 2  in a PDSCH  554 . The first DCI message  410 _ 1  may include DCI bits  556  (indicated as “DCI_ 1 ” in  FIG.  5   ) and CRC bits  558 , and the second DCI message  410 _ 2  may include DCI bits  560  (indicated as “DCI_ 2 ” in  FIG.  5   ) and CRC bits  562 . 
     As further shown in  FIG.  4   , the UE  402  may obtain  412  the A DCI messages  410  in PDSCH based on information in the DCI message  406  in the PDCCH. In some aspects of the disclosure, the UE  402  may determine the sizes of the A DCI messages included in a region of the PDSCH (also referred to as a DCI piggyback region). In some examples, the A DCI messages  410  may be zero padded to the same size. For example, the bit length of the first DCI message  410 _ 1  (e.g., the sum of the DCI bits  556  and the CRC bits  558 ) may be equal to the bit length of the second DCI message  410 _ 2  (e.g., the sum of the DCI bits  560  and the CRC bits  562 ). In some examples, each of the A DCI messages  410  may have the same size (e.g., the same bit length) as the DCI message  406 . The UE  402  may further determine the number of resource elements (RE) for each of the A DCI messages  410  and may decode the code blocks. 
     In scenarios where there codeword size is irregular, the UE may determine the total number of REs allocated for the A DCI messages  410  using equation (4): 
     
       
         
           
             
               
                 
                   
                     N 
                     
                       RE 
                       , 
                       DCI 
                     
                   
                   = 
                   
                     
                       
                         A 
                         · 
                         
                           K 
                           DCI 
                         
                         · 
                         
                           β 
                           offset 
                           
                             D 
                             ⁢ 
                             L 
                           
                         
                       
                       
                         K 
                         
                           DL 
                           - 
                           SCH 
                         
                       
                     
                     ⁢ 
                     
                       N 
                       
                         R 
                         ⁢ 
                         E 
                       
                     
                   
                 
               
               
                 
                   ( 
                   
                     equation 
                     ⁢ 
                         
                     4 
                   
                   ) 
                 
               
             
           
         
       
     
     where N RE,DCI  is the total number of REs allocated for the A DCI messages  410 , K DCI  is the payload size for each of the A DCI messages  410  after zero padding, β offset   DL  is the DL code rate offset factor (e.g., β offset   DL &gt;1), K DL-SCH  is the payload size of the downlink shared channel (DL-SCH) including TB/CB CRC bits, and N RE  is the total number of REs per layer of the PDSCH. It should be understood that equation (4) represents a simplified equation for the determination of N RE,DCI  for ease of understanding and that the determination of N RE,DCI  may be more complex in some cases. 
     In some aspects of the disclosure, the UE  402  may be configured to separately decode each of the A DCI messages  410  from a single code block. For example, the UE  402  may first determine the coded bits belonging to each coded block. The UE  402  may then decode each coded block separately to obtain each DCI message. This approach is illustrated in  FIG.  6   . As shown in  FIG.  6   , the UE  402  may first determine the A coded blocks carrying the A DCI messages  410 . For example, the A coded blocks may include a first coded block  602  (labeled as “Coded block_ 1 ” in  FIG.  6   ) through an Ath coded block  604  (labeled as “Coded block_A” in  FIG.  6   ). The Ath coded block  604  may represent the last coded block. The UE  402  may decode the first coded block  602  to obtain a first DCI message  606 , where the DCI message  606  includes DCI bits  610  and CRC bits  612 . The UE  402  may finally decode the Ath coded block  604  to obtain an Ath DCI message  608 , where the DCI message  608  includes DCI bits  614  and CRC bits  616 . 
     To determine the coded bits belonging to each coded block, the UE  402  may first determine the total number of coded bits carrying the A DCI messages  410 . For example, the total number of coded bits may be M=N RE,DCI ·Q m , where Q m  is the number of data modulation bits over a single modulation symbol (e.g., Q m =2, 4, 6 for QPSK, QAM16, QAM64, respectively). The UE  402  may then determine the number of coded bits for each coded block carrying a DCI message. In some aspects of the present disclosure, the UE  402  may uniformly split the REs of different DCI messages. In these aspects, for example, the UE  402  may determine the number of coded bits for each coded block (e.g., for each DCI message) using the ratio M/A. The UE  402  may assign any residual coded bits  606  (e.g., M−└M/A┘·A bits) to the last code block. In some examples, the UE  402  may use K=K DCI  and E=└M/A┘ to determine the mother code size N (e.g., N=2 n ). After determining the coded bits belonging to each coded block, the UE  402  may then proceed to decode each coded block separately. Therefore, even if one or more of the coded blocks cannot be decoded, the UE  402  may still be able to successfully obtain the DCI messages from the remaining coded blocks. 
     In other aspects of the disclosure, instead of uniformly splitting the REs of different A DCI messages  410  as previously described, the UE  402  may split the coded bits to different DCI messages at the RE level. With this approach, for example, each of the A DCI messages  410  may include └N RE,DCI /A┘ REs, except for the final DCI message of the A DCI messages  410 , which will also include the residual bits. The UE  402  may split the total number of REs (e.g., N RE,DCI ) allocated for the A DCI messages  410  based on the number of REs (e.g., └N RE,DCI /A┘) carrying each of the A DCI messages  410  to obtain a number of coded blocks. The UE  402  may then decode each of the coded blocks separately to obtain each DCI message. 
     In scenarios where the codeword size is uniform, the UE  402  may determine the total number of REs allocated for the A DCI messages  410  (e.g., N RE,DCI ) using equation (5) or equation (6): 
     
       
         
           
             
               
                 
                   
                     N 
                     
                       RE 
                       , 
                       DCI 
                     
                   
                   = 
                   
                     A 
                     ⁢ 
                     
                       ⌊ 
                       
                         
                           
                             
                               K 
                               DCI 
                             
                             · 
                             
                               β 
                               offset 
                               
                                 D 
                                 ⁢ 
                                 L 
                               
                             
                           
                           
                             K 
                             
                               
                                 D 
                                 ⁢ 
                                 L 
                               
                               - 
                               
                                 S 
                                 ⁢ 
                                 C 
                                 ⁢ 
                                 H 
                               
                             
                           
                         
                         ⁢ 
                         
                           N 
                           
                             R 
                             ⁢ 
                             E 
                           
                         
                       
                       ⌋ 
                     
                   
                 
               
               
                 
                   ( 
                   
                     equation 
                     ⁢ 
                         
                     5 
                   
                   ) 
                 
               
             
           
         
       
       
         
           
             
               
                 
                   
                     N 
                     
                       RE 
                       , 
                       DCI 
                     
                   
                   = 
                   
                     A 
                     ⁢ 
                     
                       ⌈ 
                       
                         
                           
                             
                               K 
                               DCI 
                             
                             · 
                             
                               β 
                               offset 
                               
                                 D 
                                 ⁢ 
                                 L 
                               
                             
                           
                           
                             K 
                             
                               
                                 D 
                                 ⁢ 
                                 L 
                               
                               - 
                               
                                 S 
                                 ⁢ 
                                 C 
                                 ⁢ 
                                 H 
                               
                             
                           
                         
                         ⁢ 
                         
                           N 
                           
                             R 
                             ⁢ 
                             E 
                           
                         
                       
                       ⌉ 
                     
                   
                 
               
               
                 
                   ( 
                   
                     equation 
                     ⁢ 
                         
                     6 
                   
                   ) 
                 
               
             
           
         
       
     
     where N RE,DCI , A, K DCI , β offset   DL , K DL-SCH , and N RE  are each described herein with reference to equation (4). It should be noted that equation (5) includes a floor function while equation (6) includes a ceiling function. Therefore, either equation (5) or equation (6) may ensure that the value of N RE,DCI  (e.g., the total number of REs allocated for the A DCI messages  410 ) is a multiple of A. 
     In some aspects of the disclosure, the UE  402  may be configured to separately decode each of the A DCI messages  410  from a single code block. For example, the UE  402  may first determine the coded bits belonging to each coded block. The UE  402  may then decode each coded block separately to obtain each DCI message. This approach is illustrated in  FIG.  7   . As shown in  FIG.  7   , the UE  402  may first determine the A coded blocks carrying the A DCI messages  410 . For example, the A coded blocks may include a first coded block  702  (labeled as “Coded block_ 1 ” in  FIG.  7   ) through an Ath coded block  704  (labeled as “Coded block_A” in  FIG.  7   ). The Ath coded block  704  may represent the last coded block. The UE  402  may decode the first coded block  702  to obtain a first DCI message  706 , where the DCI message  706  includes DCI bits  710  and CRC bits  712 . The UE  402  may finally decode the Ath coded block  704  to obtain an Ath DCI message  708 , where the DCI message  708  includes DCI bits  714  and CRC bits  716 . 
     To determine the coded bits belonging to each coded block, the UE  402  may first determine the total number of coded bits carrying the A DCI messages  410 . For example, the total number of coded bits may be M=N RE,DCI ·Q m , where Q m  is the number of data modulation bits over a single modulation symbol (e.g., Q m =2, 4, 6 for QPSK, QAM16, QAM64, respectively). The UE  402  may then determine the number of coded bits for each coded block carrying a DCI message. In some aspects of the present disclosure, the UE  402  may uniformly split the REs of different DCI messages. In these aspects, for example, the UE  402  may determine the number of coded bits for each coded block (e.g., for each DCI message) using the ratio M/A. In some examples, the UE  402  may use K=K DCI  and E=└M/A┘ to determine the mother code size N (e.g., N=2 n ). After determining the coded bits belonging to each coded block, the UE  402  may then proceed to decode each coded block separately. Therefore, even if one or more of the coded blocks cannot be decoded, the UE  402  may still be able to successfully obtain the DCI messages from the remaining coded blocks. 
     Blind Decoding of DCI Message Having Different Sizes 
     In some aspects of the disclosure, the A DCI messages  410  in the PDSCH may have different sizes (e.g., different bit lengths). For example, in one scenario, the PDSCH may include a first DCI message with DCI format 0_1 and a second DCI message with DCI format 1_1, where the first and second DCI messages have different sizes. For example, in another scenario, the PDSCH may include a first DCI message with DCI format 0_1, a second DCI message with DCI format 1_1, a third DCI message with DCI format 0_2, and a fourth DCI message with DCI format 1_2. In this scenario, the first and second DCI messages may have the same size, but the third and/or fourth DCI messages may have a different size relative to the first and second DCI messages. 
     When the A DCI messages  410  in the PDSCH have different sizes, the UE  402  may apply different assumptions regarding the payload size of each DCI message and may perform multiple decoding operations to obtain the A DCI messages  410 . However, it may be difficult for the UE  402  to apply the different assumptions to determine the total payload size of the A DCI messages  410 , which is needed for the determination of the number of REs (e.g., N RE,DCI ). 
     In some aspects of the disclosure, if the A DCI messages  410  may include DCI messages having different sizes, the UE  402  may use a nominal DCI payload size when determining the total payload size of the A DCI messages  410  and the number of REs for each DCI message. The REs may still be uniformly split between the A DCI messages  410 . As a result, the coding gain for smaller DCI messages may be higher. For example, whereas the previously described payload size K DCI  may vary for DCI messages with different DCI formats, the UE  402  may instead use a nominal payload size K DCI ′ (e.g., a common value used for different DCI message sizes) for determination of the K and E values. 
     It should be noted that when decoding the PDCCH, the UE  402  may attempt different K DCI  values, which may significantly increase decoding complexity. Therefore, the previously described aspects of the present disclosure including the use of the nominal payload size K DCI ′ may achieve a suitable compromise between decoding complexity (e.g., the number of decoding operations that need to be performed by the UE  402 ) and coding gaps (e.g., avoiding zero padding). 
     Decoding Multiple DCI Messages Having Different Sizes without Blind Decoding 
     In some aspects of the disclosure, to avoid blind decoding (reduce complexity), the UE  402  may receive information that indicates the sizes of the multiple DCI messages included in the PDSCH. For example, the UE  402  may receive the information via RRC configuration and/or a DCI message in the PDCCH. 
     In some aspects of the disclosure, if all of the DCI messages in the PDSCH have the same size, the UE  402  may receive control information indicating the size of the DCI messages. For example, the UE  402  may receive the control information via a DCI message in the PDCCH. In some aspects of the present disclosure, all of the DCI messages in the PDSCH may be configured have a same size that is selected from a set of candidate DCI message sizes. For example, the set of candidate DCI message sizes may include a first size and a second size, where the first size is different from the second size. In this example, the control information may indicate the first size or the second size. The control information may be a single bit, where the single bit is set to a first value (e.g., the single bit is set to ‘0’) to indicate the first size and set to a second value (e.g., the single bit is set to ‘1’) to indicate the second size. The set of candidate DCI message sizes (e.g., the first and second sizes) may be configured via RRC configuration. In other examples, the previously described set of candidate DCI message sizes may include more than two candidate DCI message sizes. 
     In some aspects of the disclosure, two sets of control information may be included in the DCI message in the PDCCH. The first set of control information may indicate to the UE  402  the number of DCI messages having a first size and a first code rate offset factor for the DCI messages having the first size, and the second set of control information may indicate to the UE  402  the number of DCI messages having a second size and a second code rate offset factor for the DCI messages having the second size. The first size may be different from the second size. In some examples, the first and second code rate offset factors may be the same for the DCI messages having the first and second sizes. 
     In some implementations, the order (e.g., with respect to DCI message size) in which the DCI messages of different sizes appear in the DCI piggyback region of the PDSCH may be predetermined and known by the UE  402 . For example, DCI messages having the first size may appear in the PDSCH before DCI messages having the second size, where the first size is smaller than the second size. Alternatively, the DCI messages having the second size may appear in the PDSCH before DCI messages having the first size. The two candidate DCI message sizes (e.g., the first and second DCI message sizes) may be configured via an RRC configuration. In this case, for example, the UE  402  may accurately determine the total payload size of the A DCI messages  410  by summing the payload sizes of the different DCI messages having different sizes. The number of REs may be allocated differently/proportionally between the DCI messages having different sizes. In other examples, more than two candidate DCI message sizes may be configured. 
     In some aspects of the present disclosure, the PDSCH may include (e.g., in a DCI message piggyback region of the PDSCH) different combinations of DCI message formats and DCI message sizes in a PDSCH transmission. In one aspect, the DCI messages included in the PDSCH may be configured to have one size. For example, the DCI messages may have the same size and may be based on the DCI format 0_1 and the DCI format 1_1. As another example, the DCI messages may have the same size and may be based on the DCI format 0_2 and the DCI format 1_2. 
     In another aspect, the DCI messages included in the PDSCH may be configured to have two sizes. For example, the DCI messages may have one size for the DCI format 0_1 and another size for the DCI format 1_1. As another example, two DCI message size configurations may be selected from a set of DCI message size configurations. The set of DCI message size configurations may include a first configuration where the DCI messages may have the same size and may be based on the DCI format 0_1 and the DCI format 1_1, a second configuration where the DCI messages may have the same size and may be based on the DCI format 0_2 and the DCI format 1_2, and a third configuration where the DCI messages may have the same size and may be based on the DCI format 0_0 and the DCI format 1_0. 
     In another aspect, the DCI messages included in the PDSCH may be configured to have three different DCI message sizes. For example, DCI messages based on the DCI format 0_1 and the DCI format 1_1 may both have a first size, DCI messages based on the DCI format 0_2 and the DCI format 1_2 may both have a second size, and DCI messages based on the DCI format 0_0 and the DCI format 1_0 may both have a third size. The previously discussed first, second, and third sizes may be different from one another. It should be understood that the previously described combinations of DCI message formats and DCI message sizes are not intended to be exhaustive and that additional and/or different combinations relative to those described herein may be used. 
     In some aspects of the present disclosure, the number of DCI messages included in the PUSCH or the PDSCH may be based on a capability of a UE (e.g., UE  104 ). For example, since low performance UEs may not be able to support decoding of multiple DCI messages piggybacked in the PDSCH, such low performance UEs may still be able to decode a single DCI message piggybacked in the PDSCH. Therefore, in some aspects of the disclosure, only a single DCI message may be allowed in the PUSCH or the PDSCH. With respect to the uplink (UL), for example, the UE may use a multi-PUSCH grant to grant multiple slots. With respect to the downlink (DL), for example, a DCI message in one slot of the PDSCH (e.g., in a piggyback region of the PDSCH) may include control information (e.g., a DL grant) for a next slot of the PDSCH. The next slot of the PDSCH may include another DCI message (e.g., in a piggyback region of the next slot of the PDSCH). An example implementation of this aspect is illustrated in  FIG.  8   . 
       FIG.  8    shows a DCI message  802  included in the PDCCH, where the DCI message  802  includes DCI bits  804  and CRC bits  806 . The UE may use blind decoding to obtain the DCI message  802  from the PDCCH. The DCI message  802  may indicate the control information for first PDSCH resources  808 . As shown in  FIG.  8   , the first PDSCH resources  808  may include a DCI message  810 , where the DCI message  810  includes DCI bits  812  and CRC bits  814 . As indicated with the arrow  816  in  FIG.  8   , the DCI message  810  may indicate the control information for second PDSCH resources  818 . The second PDSCH resources  818  may include a DCI message  820 , where the DCI message  820  includes DCI bits  822  and CRC bits  824 . As indicated with the arrow  826  in  FIG.  8   , the DCI message  820  may indicate the control information for third PDSCH resources  828 . The third PDSCH resources  828  may include a DCI message  830 , where the DCI message  830  includes DCI bits  832  and CRC bits  834 . 
     In the aspects described with reference to  FIG.  8   , transmission of the piggybacked DCI messages  810 ,  820 ,  830  to the UE may not require a control region (e.g., a CORESET) and may not require rate matching. Furthermore, the piggybacked DCI messages  810 ,  820 ,  830  may be decoded based on the aspects described herein and, therefore, the UE may not need to perform blind decoding to obtain the DCI messages  810 ,  820 ,  830 . Accordingly, the UE may avoid additional processing and may reduce power consumption. 
       FIG.  9    is a flowchart  900  of a method of wireless communication. The method may be performed by a UE (e.g., the UE  104 ,  402 ; the apparatus  1102 / 1102 ′; the processing system  1214 , which may include the memory  360  and which may be the entire UE  104 ,  402  or a component of the UE  104 ,  402 , such as the TX processor  368 , the RX processor  356 , and/or the controller/processor  359 ). 
     At  902 , the UE obtains a downlink control information (DCI) message transmitted in a physical downlink control channel (PDCCH). The DCI message includes control information for obtaining a plurality of downlink control information (DCI) messages included in a physical downlink shared channel (PDSCH). 
     In some aspects of the disclosure, the control information indicates at least a total number of the plurality of DCI messages and a code rate offset factor. For example, the total number of the plurality of DCI messages may be represented by the parameter A and the code rate offset factor may be the DL code rate offset factor β offset   DL , where β offset   DL &gt;1. 
     In some aspects of the disclosure, each of the plurality of DCI messages in the PDSCH have a same payload size. In these aspects, the control information indicates at least a total number of the plurality of DCI messages and the payload size. In some aspects, the payload size is one of a set of preconfigured payload sizes. 
     In some aspects of the disclosure, a first number of the plurality of DCI messages in the PDSCH have a first payload size and a second number of the plurality of DCI messages in the PDSCH have a second payload size. The first number of the plurality of DCI messages may be configured to appear before the second number of the plurality of DCI messages in the PDSCH. In these aspects, the control information indicates the first number of the plurality of DCI messages and the second number of the plurality of DCI messages. In some aspects, control information further indicates a first code rate offset factor for the first number of the plurality of DCI messages and a second code rate offset factor for the second number of the plurality of DCI messages. 
     At  904 , the UE receives the PDSCH including the plurality of DCI messages. 
     Finally, at  906 , the UE obtains one or more of the plurality of DCI messages in the PDSCH based on the control information. 
     In some aspects of the disclosure, the plurality of DCI messages in the PDSCH have a same size (e.g., same payload size K=K DCI ). In these aspects, the UE obtains the one or more of the plurality of DCI messages in the PDSCH by determining a total number of resource elements (REs) allocated for the plurality of DCI messages in the PDSCH. For example, the total number of resource elements (REs) allocated for the plurality of DCI messages in the PDSCH may be N RE,DCI  in equation (4). The UE may then determine a total number of coded bits for the plurality of DCI messages in the PDSCH based on the total number of REs. For example, the total number of coded bits for the plurality of DCI messages in the PDSCH may be M=N RE,DCI ·Q m . The UE determines a number of coded bits for each of the plurality of DCI messages in the PDSCH. For example, the number of coded bits for each of the plurality of DCI messages in the PDSCH may be E=└M/A┘. The UE may split the total number of coded bits based on the number of coded bits to obtain a plurality of coded blocks (e.g., coded blocks  602 ,  604 ). In some scenarios, one or more residual coded bits may remain after splitting the total number of coded bits. In these scenarios, the UE assigns the one or more residual coded bits to a last coded block of the plurality of coded blocks. The UE then separately decodes each of the plurality of coded blocks to determine the plurality of DCI messages  606 ,  608  in the PDSCH. 
     In some aspects of the disclosure, the plurality of DCI messages in the PDSCH have a same size (e.g., same payload size K=K DCI ). In these aspects, the UE obtains the one or more of the plurality of DCI messages in the PDSCH by determining a total number of resource elements (REs) allocated for the plurality of DCI messages in the PDSCH. For example, the total number of resource elements (REs) allocated for the plurality of DCI messages in the PDSCH may be N RE,DCI  in equation (4). The UE may then determine a number of REs used for each of the plurality of DCI messages in the PDSCH. For example, the number of REs used for each of the plurality of DCI messages may be └N RE,DCI /A┘. The UE may split the total number of REs based on the number of REs used for each of the plurality of DCI messages to obtain a plurality of coded blocks (e.g., coded blocks  602 ,  604 ). In some scenarios, one or more residual REs may remain after splitting the total number of REs. In these scenarios, the UE assigns the one or more residual REs to a last coded block of the plurality of coded blocks. The UE then separately decodes each of the plurality of coded blocks to determine the plurality of DCI messages  606 ,  608  in the PDSCH. 
     In some aspects of the disclosure, the plurality of DCI messages in the PDSCH have a same size (e.g., same payload size K=K DCI ). In these aspects, the UE obtains the one or more of the plurality of DCI messages in the PDSCH by determining a total number of resource elements (REs) allocated for the plurality of DCI messages in the PDSCH. For example, the total number of resource elements (REs) allocated for the plurality of DCI messages in the PDSCH may be N RE,DCI  in equation (4). In some aspects of the disclosure, the total number of REs is a multiple of a total number of the plurality of DCI messages. The UE may then determine a total number of coded bits for the plurality of DCI messages in the PDSCH based on the total number of REs. For example, the total number of coded bits for the plurality of DCI messages in the PDSCH may be M=N RE,DCI ·Q m . The UE determines a number of coded bits for each of the plurality of DCI messages in the PDSCH. For example, the number of coded bits for each of the plurality of DCI messages in the PDSCH may be E=└M/A┘. The UE may split the total number of coded bits based on the number of coded bits to obtain a plurality of coded blocks (e.g., coded blocks  702 ,  704 ). The UE then separately decodes each of the plurality of coded blocks to determine the plurality of DCI messages  706 ,  708  in the PDSCH. 
     In some aspects of the disclosure, at least two of the plurality of DCI messages in the PDSCH have different sizes (e.g., different payload size K). In these aspects, the UE obtains the one or more of the plurality of DCI messages in the PDSCH by determining a total number of resource elements (REs) allocated for the plurality of DCI messages in the PDSCH based on a nominal payload size for each of the plurality of DCI messages in the PDSCH. The UE determines a total number of coded bits for the plurality of DCI messages in the PDSCH based on the total number of REs. The UE determines a number of coded bits for each of the plurality of DCI messages in the PDSCH. The UE splits the total number of coded bits based on the number of coded bits to obtain a plurality of coded blocks. The UE separately decoding each of the plurality of coded blocks to determine the plurality of DCI messages in the PDSCH. 
       FIG.  10    is a flowchart  1000  of a method of wireless communication. The method may be performed by a UE (e.g., the UE  104 ,  402 ; the apparatus  1102 / 1102 ′; the processing system  1214 , which may include the memory  360  and which may be the entire UE  104 ,  402  or a component of the UE  104 ,  402 , such as the TX processor  368 , the RX processor  356 , and/or the controller/processor  359 ). 
     At  1002 , the UE obtains a first downlink control information (DCI) message transmitted in a physical downlink control channel (PDCCH). The first DCI message includes first control information for a physical downlink shared channel (PDSCH) including a second DCI message. 
     At  1004 , the UE receives the PDSCH including the second DCI message. 
     Finally, at  1006 , the UE obtains the second DCI message in the PDSCH based on the first control information. The second DCI message includes second control information for a next slot of the PDSCH. 
       FIG.  11    is a conceptual data flow diagram  1100  illustrating the data flow between different means/components in an example apparatus  1102 . The apparatus may be a UE. The apparatus includes a reception component  1104  that receives a physical downlink control channel (PDCCH)  1112  and a physical downlink shared channel (PDSCH)  1114  from a base station  1150 . The base station  1150  may be a 5G NR base station in some implementations. The PDSCH  1114  may include a number A of DCI messages (e.g., in resources of the PDSCH  1114  referred to as a piggyback region for carrying the A DCI messages). 
     The apparatus further includes a downlink control information (DCI) in PDCCH obtaining component  1106  that obtains control information  1120  from the PDCCH  1112 . The downlink control information (DCI) in PDCCH obtaining component  1106  may provide PDSCH configuration information  1118  to the reception component  1104  to enable receiving of the PDSCH  1114 . In some examples, the control information  1120  indicates at least a total number (e.g., A) of the plurality of DCI messages included in the PDSCH  1114  and a code rate offset factor. 
     The apparatus further includes a downlink control information (DCI) in PDSCH obtaining component  1108  that obtains one or more of the plurality of DCI messages in the PDSCH  1114  based on the control information  1120 . In some examples, the DCIs in PDSCH include a DL grant  1124  and/or a UL grant  1126 . 
     The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of  FIGS.  9  and  10   . As such, each block in the aforementioned flowcharts of  FIGS.  9  and  10    may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. 
       FIG.  12    is a diagram  1200  illustrating an example of a hardware implementation for an apparatus  1102 ′ employing a processing system  1214 . The processing system  1214  may be implemented with a bus architecture, represented generally by the 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 the processor  1204 , the components  1104 ,  1106 ,  1108 ,  1110  and the 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, which are well known in the art, and therefore, will not be described any further. 
     The processing system  1214  may be coupled to a transceiver  1210 . The transceiver  1210  is coupled to one or more antennas  1220 . 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 a processor  1204  coupled to a computer-readable medium/memory  1206 . The processor  1204  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory  1206 . The software, when executed by the processor  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 processor  1204  when executing software. The processing system  1214  further includes at least one of the components  1104 ,  1106 ,  1108 ,  1110 . The components may be software components running in the processor  1204 , resident/stored in the computer readable medium/memory  1206 , one or more hardware components coupled to the processor  1204 , or some combination thereof. The processing system  1214  may be a component of the UE  350  and may include the memory  360  and/or at least one of the TX processor  368 , the RX processor  356 , and the controller/processor  359 . Alternatively, the processing system  1214  may be the entire UE (e.g., see  350  of  FIG.  3   ). 
     In one configuration, the apparatus  1102 / 1102 ′ for wireless communication includes means for obtaining a downlink control information (DCI) message transmitted in a physical downlink control channel (PDCCH), wherein the DCI message includes control information for obtaining a plurality of downlink control information (DCI) messages included in a physical downlink shared channel (PDSCH), means for receiving the PDSCH including the plurality of DCI messages, means for obtaining one or more of the plurality of DCI messages in the PDSCH based on the control information, means for obtaining a first downlink control information (DCI) message transmitted in a physical downlink control channel (PDCCH), wherein the first DCI message includes first control information for a physical downlink shared channel (PDSCH) including a second DCI message, means for receiving the PDSCH including the second DCI message, and means for obtaining the second DCI message in the PDSCH based on the first control information, the second DCI message including second control information for a next slot of the PDSCH. 
     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  368 , the RX Processor  356 , and the controller/processor  359 . As such, in one configuration, the aforementioned means may be the TX Processor  368 , the RX Processor  356 , and the controller/processor  359  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 example 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. As used herein, the term “obtaining” may include one or more actions including, but not limited to, determining, decoding, calculating, or any combination thereof. 
     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.”