WO2022260662A1

WO2022260662A1 - Apparatus and method of excluding preempted reference signals from a channel estimation

Info

Publication number: WO2022260662A1
Application number: PCT/US2021/036495
Authority: WO
Inventors: Charles Pandana; Chengzhi LI; Yuanye WANG
Original assignee: Zeku, Inc.
Priority date: 2021-06-08
Filing date: 2021-06-08
Publication date: 2022-12-15

Abstract

In one aspect of the disclosure, a baseband chip is disclosed. The baseband chip may include a determination circuit and a channel estimation control circuit. The determination unit may be configured to determine whether at least one downlink preemption condition is met. The determination unit may be further configured to activate a channel estimation control circuit when the at least one downlink preemption condition is met. The channel estimation control circuit may be configured to receive, from an interface unit, a transmission that includes a plurality of reference signals. The channel estimation control circuit may be further configured to perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption. The channel estimation control circuit may be configured to exclude the corrupted reference signals from a channel estimation.

Description

APPARATUS AND METHOD OF EXCLUDING PREEMPTED REFERENCE SIGNALS FROM A CHANNEL ESTIMATION

BACKGROUND

[0001] Embodiments of the present disclosure relate to apparatus and method for wireless communication.

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. In cellular communication, such as the 4th-generation (4G) Long Term Evolution (LTE) and the 5th- generation (5G) New Radio (NR), the 3rd Generation Partnership Project (3GPP) defines various new service categories such as, e.g., enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable and low latency communication (URLLC).

SUMMARY

[0003] Embodiments of apparatus and method for performing a channel estimation control procedure to exclude preempted reference signals from a channel estimation are disclosed herein. [0004] According to one aspect of the present disclosure, a baseband chip is disclosed. The baseband chip may include a determination circuit and a channel estimation control circuit. The determination unit may be configured to determine whether at least one downlink preemption condition is met. The determination unit may be further configured to activate a channel estimation control circuit when the at least one downlink preemption condition is met. The channel estimation control circuit may be configured to receive, from an interface unit, a transmission that includes a plurality of reference signals. The channel estimation control circuit may be further configured to perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption. The channel estimation control circuit may be configured to exclude the corrupted reference signals from a channel estimation.

[0005] According to one aspect of the present disclosure, an apparatus of a baseband chip is disclosed. The apparatus may include a memory and at least one processor coupled to the memory. The at least one processor may be configured to receive, from an interface unit, a transmission that includes a plurality of reference signals. The at least one processor may be configured to determine whether at least one downlink preemption condition is met. The at least one processor may be configured to perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption when it is determined that the downlink preemption condition is met. The at least one processor may be configured to exclude the corrupted reference signals from a channel estimation.

[0006] According to another aspect of the disclosure, a method of wireless communication is disclosed. The method may include determining, by a determination circuit, whether at least one downlink preemption condition is met. The method may also include activating, by the determination circuit, a channel estimation control circuit when the at least one downlink preemption condition is met. The method may also include receiving, at a channel estimation control circuit, a transmission that includes a plurality of reference signal. The method may also include performing, by the channel estimation control circuit, a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption. The method may also include excluding, by the channel estimation control circuit, the corrupted reference signals from a channel estimation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable a person skilled in the pertinent art to make and use the present disclosure.

[0008] FIG. 1 illustrates an exemplary wireless network, according to some embodiments of the present disclosure.

[0009] FIG. 2 illustrates a block diagram of an exemplary apparatus including a baseband chip, a radio frequency (RF) chip, and a host chip, according to some embodiments of the present disclosure.

[0010] FIG. 3 illustrates a call flow for a channel estimation control procedure used by an eMBB/mMTC UE to exclude preempted reference signals from a channel estimation prior to receiving a downlink preemption indication from the base station, according to some embodiments of the present disclosure. [0011] FIG. 4A illustrates a flow chart of a first exemplary method of wireless communication, according to some embodiments of the present disclosure.

[0012] FIG. 4B illustrates a flow chart of a second exemplary method of wireless communication, according to some embodiments of the present disclosure.

[0013] FIG. 5 illustrates a block diagram of an exemplary node, according to some embodiments of the present disclosure.

[0014] FIG. 6 illustrates a frame structure that includes an eMBB transmission preempted by a URLLC transmission.

[0015] FIG. 7A illustrates a first type of preemption indication of a slot group, according to some embodiments of the present disclosure.

[0016] FIG. 7B illustrates a second type of preemption indication of a slot group, according to some embodiments of the present disclosure.

[0017] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

DETAILED DESCRIPTION

[0018] Although specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the present disclosure. It will be apparent to a person skilled in the pertinent art that the present disclosure can also be employed in a variety of other applications.

[0019] It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” “some embodiments,” “certain embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of a person skilled in the pertinent art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0020] In general, terminology may be understood at least in part from usage in context.

For example, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a,” “an,” or “the,” again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

[0021] Various aspects of wireless communication systems will now be described 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, modules, units, components, circuits, steps, operations, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, firmware, computer software, or any combination thereof. Whether such elements are implemented as hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system.

[0022] The techniques described herein may be used for various wireless communication networks, such as code division multiple access (CDMA) system, time division multiple access (TDMA) system, frequency division multiple access (FDMA) system, orthogonal frequency division multiple access (OFDMA) system, single-carrier frequency division multiple access (SC- FDMA) system, wireless local area network (WLAN) system, and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio access technology (RAT), such as Universal Terrestrial Radio Access (UTRA), evolved UTRA (E-UTRA), CDMA 2000, etc. A TDMA network may implement a RAT, such as the Global System for Mobile Communications (GSM). An OFDMA network may implement a RAT, such as LTE or NR. A WLAN system may implement a RAT, such as Wi-Fi. The techniques described herein may be used for the wireless networks and RATs mentioned above, as well as other wireless networks and RATs.

[0023] In recent years, there has been an emergence of unprecedented services and applications such as autonomous vehicles, drone-based deliveries, smart cities and factories, remote medical diagnosis, robotic surgery, and artificial intelligence-based personalized assistants, just to name a few. Communication mechanisms associated with these new applications and services are different from traditional human-centric communications in terms of latency, energy efficiency, reliability, flexibility, and connection density. Therefore, 5GNR has been designed to support the coexistence of human-centric and machine-type services as well as hybrids of these types of services. To address diversified services and applications, 5G services have been classified into three categories, namely, eMBB, mMTC, and URLLC.

[0024] eMBB is a service category related to high bandwidth requirements, such as high- resolution video streaming, virtual reality, and augmented reality. Thus, smartphones and other human-centric wireless devices may fall into the category of eMBB devices. In order to achieve a 100-fold capacity increase over LTE, 5G NR supports new physical layer technologies that improve spectral efficiency and exploit different parts of the spectrum to increase throughput for eMBB devices as well as others.

[0025] mMTC is a service category that supports the access of a large number of machine- type devices to the 5G NR network. mMTC-based services, such as sensing, tagging, metering, and monitoring, utilize high connection density, while providing energy efficiency at the same time. mMTC devices provide low power consumption, low operation cost, and improved coverage.

[0026] URLLC is a service category that supports latency-sensitive services, e.g., such as surgical robotics, autonomous driving, and tactile Internet. Since the time for the human perception or reaction is in the order of tens of milliseconds, the transmission time for the mission-critical URLLC applications needs to be in the order of microseconds. To reduce the end-to-end latency, therefore, 5G NR includes fundamental changes in both wireless link and backbone network as compared to 4G. In the backbone link, software defined network (SDN) and virtual network slicing can be used to construct the private connection to the dedicated URLLC service. Indeed, by using the dedicated network, backbone link latency can be reduced significantly.

[0027] Among the above-described 5G NR service categories, the design of URLLC is perhaps the most challenging. This is because URLLC needs to meet two stringent requirements: low latency and ultra-high reliability. For example, when a URLLC service request is received by a base station (either during the scheduling period or in the middle of an mMTC transmission and/or eMBB transmission), the base station must send the URLLC transmission in a way that meets the low latency requirements for URLLC services. To meet the stringent latency requirement, some resource elements (REs) which were previously scheduled for eMBB and/or mMTC packets are punctured (also referred to herein as “preempted,” “interrupted,” and “corrupted”) with the URLLC transmission, as illustrated in FIG. 6. [0028] FIG. 6 illustrates a frame structure 600 used to carry mMTC transmission(s) 601, eMBB transmission(s) 604, and/or URLLC transmission(s) 606 from a base station. As seen in FIG. 6, when a transport block, which includes three codeblocks, is used for sending eMBB transmissions, each codeblock may be mapped sequentially to the scheduled time-frequency resources. Thus, when the URLLC service is initiated in the middle of the eMBB transport block, part of symbols in the third codeblock that were originally scheduled for an eMBB transmission 604 is replaced by the symbols of URLLC transmission 606. This preemption may be indicated to the eMBB UE after the eMBB transmission 604 is received and the decoding process has begun. The preemption is indicated via a preemption indication (also referred to as a “downlink preemption indication”), e.g., downlink control information format 2 1 (DCI2 1) transmission. The preemption indication informs the eMBB UE which of the symbols of its transmission were preempted by the URLLC transmission. In so doing, the eMBB UE may be able to recover from the URLLC preemption to reliably decode eMBB transmission 604. There are two types of preemption indications that can be provided to eMBB UE via timeFrequencySet information element configured by radio resource control (RRC) signaling; namely timeFrequencySet= ‘setO ’ and timeFrequencySet= ‘setl ’, additional details of which are provided below in connection with FIGs. 7 A and 7B.

[0029] FIG. 7A illustrates a preemption indication 700 for a first interrupted symbol set type ( timeFrequencySet= ‘setO ’), and FIG. 7B illustrates a preemption indication 701 for a second interrupted symbol set type ( timeFrequencySet= ‘setl ’). As shown in FIG. 7A, the preemption occurs within contiguous symbols of a slot group 702 within an interrupted bandwidth (BINT). On the other hand, as shown in FIG. 7B, the preemption occurs within contiguous symbols of the upper interrupted bandwidth part (BINTI) and in symbols in the lower interrupted bandwidth part (BINT2) that are shifted in the time domain.

[0030] In either interrupted symbol set type, a slot group 702 may include one or more slots, where each slot includes fourteen symbols. Thus, in FIGs. 7A and 7B, each symbol group may include one or more symbols. By way of example, if each symbol group (referred to hereinafter as a “symbol”) includes two symbols, then slot group 702 (referred to hereinafter as “slot 702”) includes two slots. The preemption indication (DCI2 1) includes an information element (NINT) indicating the number and position of an interrupted symbol (NINT) within the slot. In the example illustrated in FIG. 7A, NINT=14, 00011110000000. In FIG. 7B, NINT=14, 00001010010100 [0031] The preemption indication, DCI2 1, indicates the preempted time-frequency resources in the last symbols prior to the first symbol of the CORESET in

the slot, where ls the slot and symbol number, T_INT is the

time interval of the interruption, m and are both values indicated by the base station via RRC

signaling. Since the indication is for the last symbols the UE has received,

downlink chain processing most likely has begun processing the received data, and thus, it may be too late to change the downlink chain programming after detection of DCI2 1. Moreover, there is no guarantee that the preempted symbols exclude reference signals that are used by the eMBB UE for channel estimation. These reference signals may include, without limitation, demodulation reference signals (DMRS), channel state information reference signals (CSI-RS), and tracking reference signal (TRS), just to name a few. Each of these reference signals are important for accurate channel estimation, providing accurate channel state information (CSI) feedback, and accurate tracking/compensating of time/frequency error(s) in the received signal; therefore, affecting successful decoding of eMBB PDSCH transmissions. Thus, because the preemption indication is received after channel estimation of potentially preempted reference signals has begun, catastrophic errors in channel estimation may occur in such instances, thereby significantly degrading the accuracy of properly decoding physical downlink shared channel (PDSCH) packets by the eMBB.

[0032] Thus, there exists an unmet need for a technique that determines whether reference signals are corrupted/preempted in real-time at the start of a channel estimation procedure that begins prior to the receipt of a preemption indication from the base station. As used herein, “realtime” may be defined as the period between which a transmission including a preempted reference signal is received, and a preemption indication is received.

[0033] To overcome these and other challenges of URLLC preemption, the present disclosure provides a channel estimation control procedure that determines whether the transmission includes any preempted reference signals prior to performing channel estimation and before a preemption indication is detected. When preempted reference signals are included in the transmission, the UE (eMBB UE or mMTC UE) may exclude these reference signals from the channel estimation, thereby increasing the accuracy of computing the estimated channel and improving the reliability of decoded PDSCH packet. Additional details of the channel estimation control procedure of the present disclosure are provided below in connection with FIGs. 1-5. [0034] FIG. 1 illustrates an exemplary wireless network 100, in which some aspects of the present disclosure may be implemented, according to some embodiments of the present disclosure. As shown in FIG. 1, wireless network 100 may include a network of nodes, such as a user equipment 102 (e.g., eMBB UE, mMTC UE, URLLC UE, etc.), an access node 104, and a core network element 106. User equipment 102 may be any terminal device, such as a mobile phone, a desktop computer, a laptop computer, a tablet, a vehicle computer, a gaming console, a printer, a positioning device, a wearable electronic device, a smart sensor, or any other device capable of receiving, processing, and transmitting information, such as any member of a vehicle to everything (V2X) network, a cluster network, a smart grid node, or an Intemet-of-Things (IoT) node. It is understood that user equipment 102 is illustrated as a mobile phone simply by way of illustration and not by way of limitation.

[0035] Access node 104 may be a device that communicates with user equipment 102, such as a wireless access point, a base station (BS), a Node B, an enhanced Node B (eNodeB or eNB), a next-generation NodeB (gNodeB or gNB), a cluster master node, or the like. Access node 104 may have a wired connection to user equipment 102, a wireless connection to user equipment 102, or any combination thereof. Access node 104 may be connected to user equipment 102 by multiple connections, and user equipment 102 may be connected to other access nodes in addition to access node 104. Access node 104 may also be connected to other user equipments. When configured as a gNB, access node 104 may operate in millimeter wave (mmW) frequencies and/or near mmW frequencies in communication with the user equipment 102. When access node 104 operates in mmW or near mmW frequencies, the access node 104 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 or near mmW radio frequency band have extremely high path loss and a short range. The mmW base station may utilize beamforming with user equipment 102 to compensate for the extremely high path loss and short range. It is understood that access node 104 is illustrated by a radio tower by way of illustration and not by way of limitation.

[0036] Access nodes 104, which are collectively referred to as E-UTRAN in the evolved packet core network (EPC) and as NG-RAN in the 5G core network (5GC), interface with the EPC and 5GC, respectively, through dedicated backhaul links (e.g., SI interface). In addition to other functions, access node 104 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. Access nodes 104 may communicate directly or indirectly (e.g., through the 5GC) with each other over backhaul links (e.g., X2 interface). The backhaul links may be wired or wireless.

[0037] Core network element 106 may serve access node 104 and user equipment 102 to provide core network services. Examples of core network element 106 may include a home subscriber server (HSS), a mobility management entity (MME), a serving gateway (SGW), or a packet data network gateway (PGW). These are examples of core network elements of an evolved packet core (EPC) system, which is a core network for the LTE system. Other core network elements may be used in LTE and in other communication systems. In some embodiments, core network element 106 includes an access and mobility management function (AMF), a session management function (SMF), or a user plane function (UPF) of the 5GC for the NR system. The AMF may be in communication with a Unified Data Management (UDM). The AMF is the control node that processes the signaling between the user equipment 102 and the 5GC. Generally, the AMF provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF. The UPF provides UE IP address allocation as well as other functions. The UPF is connected to the IP Services. The IP Services may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. It is understood that core network element 106 is shown as a set of rack-mounted servers by way of illustration and not by way of limitation.

[0038] Core network element 106 may connect with a large network, such as the Internet

108, or another Internet Protocol (IP) network, to communicate packet data over any distance. In this way, data from user equipment 102 may be communicated to other user equipments connected to other access points, including, for example, a computer 110 connected to Internet 108, for example, using a wired connection or a wireless connection, or to a tablet 112 wirelessly connected to Internet 108 via a router 114. Thus, computer 110 and tablet 112 provide additional examples of possible user equipments, and router 114 provides an example of another possible access node. [0039] A generic example of a rack-mounted server is provided as an illustration of core network element 106. However, there may be multiple elements in the core network including database servers, such as a database 116, and security and authentication servers, such as an authentication server 118. Database 116 may, for example, manage data related to user subscription to network services. A home location register (HLR) is an example of a standardized database of subscriber information for a cellular network. Likewise, authentication server 118 may handle authentication of users, sessions, and so on. In the NR system, an authentication server function (AUSF) device may be the specific entity to perform user equipment authentication. In some embodiments, a single server rack may handle multiple such functions, such that the connections between core network element 106, authentication server 118, and database 116, may be local connections within a single rack.

[0040] In order to allow inter-RAT (IRAT) handover between the EPC and 5GC, 4G/5G interworking may be supported by a common subscription data access function (HSS/UDM), combined functions such as PGW-C/SMF, PDN Gateway User Plane (PGW-U) / UPF, and the N26 interface between the MME and the AMF. This enables service continuity and mobility outside of 5G coverage areas, and also enables a smooth migration to a fully realized 5G network during the nascent stages of its deployment. In certain implementations, access node 104 and core network elements 106 within the 5G network may access the 5GC using control signaling independent of the EPC (and vice versa) and achieve interoperability between 4G and 5G networks through their core networks. 4G/5G interworking mainly includes cell (re)selection in RRC IDLE state, redirection, and handover in RRC CONNECTED state. User equipment 102 may camp on the 5G cell and initiate services (such as IMS voice sessions) from the NR serving cell that may be fulfilled by either the 5G system (5GS), or, in instances when those services are not available at the 5G network (IMS voice, for example), the evolved packet system (EPS). Thus, EPS fallback is required to guarantee voice service (by moving user equipment 102 from 5GS to EPS) before IMS-based voice services are connected to 5GC (namely, before VoNR is available on all NR cells) or for one of the various other reasons mentioned above.

[0041] Each element in FIG. 1 may be considered a node of wireless network 100. More detail regarding the possible implementation of a node is provided by way of example in the description of a node 500 in FIG. 5. Node 500 may be configured as user equipment 102, access node 104, or core network element 106 in FIG. 1. Similarly, node 500 may also be configured as computer 110, router 114, tablet 112, database 116, or authentication server 118 in FIG. 1. As shown in FIG. 5, node 500 may include a processor 502, a memory 504, and a transceiver 506. These components are shown as connected to one another by a bus, but other connection types are also permitted. When node 500 is user equipment 102, additional components may also be included, such as a user interface (UI), sensors, and the like. Similarly, node 500 may be implemented as a blade in a server system when node 500 is configured as core network element 106. Other implementations are also possible.

[0042] Transceiver 506 may include any suitable device for sending and/or receiving data.

Node 500 may include one or more transceivers, although only one transceiver 506 is shown for simplicity of illustration. An antenna 508 is shown as a possible communication mechanism for node 500. Multiple antennas and/or arrays of antennas may be utilized for receiving multiple spatially multiplex data streams. Additionally, examples of node 500 may communicate using wired techniques rather than (or in addition to) wireless techniques. For example, access node 104 may communicate wirelessly to user equipment 102 and may communicate by a wired connection (for example, by optical or coaxial cable) to core network element 106. Other communication hardware, such as a network interface card (NIC), may be included as well.

[0043] As shown in FIG. 5, node 500 may include processor 502. Although only one processor is shown, it is understood that multiple processors can be included. Processor 502 may include microprocessors, microcontroller units (MCUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), 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 functions described throughout the present disclosure. Processor 502 may be a hardware device having one or more processing cores. Processor 502 may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, 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. Software can include computer instructions written in an interpreted language, a compiled language, or machine code. Other techniques for instructing hardware are also permitted under the broad category of software. [0044] As shown in FIG. 5, node 500 may also include memory 504. Although only one memory is shown, it is understood that multiple memories can be included. Memory 504 can broadly include both memory and storage. For example, memory 504 may include random-access memory (RAM), read-only memory (ROM), static RAM (SRAM), dynamic RAM (DRAM), ferroelectric RAM (FRAM), electrically erasable programmable ROM (EEPROM), compact disc readonly memory (CD-ROM) or other optical disk storage, hard disk drive (HDD), such as magnetic disk storage or other magnetic storage devices, Flash drive, solid-state drive (SSD), or any other medium that can be used to carry or store desired program code in the form of instructions that can be accessed and executed by processor 502. Broadly, memory 504 may be embodied by any computer-readable medium, such as a non-transitory computer-readable medium.

[0045] Processor 502, memory 504, and transceiver 506 may be implemented in various forms in node 500 for performing wireless communication functions. In some embodiments, processor 502, memory 504, and transceiver 506 of node 500 are implemented (e.g., integrated) on one or more system-on-chips (SoCs). In one example, processor 502 and memory 504 may be integrated on an application processor (AP) SoC (sometimes known as a “host,” referred to herein as a “host chip”) that handles application processing in an operating system (OS) environment, including generating raw data to be transmitted. In another example, processor 502 and memory 504 may be integrated on a baseband processor (BP) SoC (sometimes known as a “modem,” referred to herein as a “baseband chip”) that converts the raw data, e.g., from the host chip, to signals that can be used to modulate the carrier frequency for transmission, and vice versa, which can run a real-time operating system (RTOS). In still another example, processor 502 and transceiver 506 (and memory 504 in some cases) may be integrated on an RF SoC (sometimes known as a “transceiver,” referred to herein as an “RF chip”) that transmits and receives RF signals with antenna 508. It is understood that in some examples, some or all of the host chip, baseband chip, and RF chip may be integrated as a single SoC. For example, a baseband chip and an RF chip may be integrated into a single SoC that manages all the radio functions for cellular communication.

[0046] Referring back to FIG. 1, in some embodiments, user equipment 102 may include an eMBB UE and/or mMTC UE. User equipment 102 may receive a transmission from access node 104. The transmission may include one or more reference signals that are preempted by a URLLC transmission. To achieve a reliable channel estimation, user equipment 102 may perform a real-time channel estimation control procedure to determine whether any of the reference signals are preempted. In so doing, user equipment 102 may exclude such preempted reference signals from a channel estimation procedure, thereby improving the reliability of the channel estimation and subsequent PDSCH packet decoding. [0047] FIG. 2 illustrates a block diagram of an apparatus 200 including a baseband chip

202, an RF chip 204, and a host chip 206, according to some embodiments of the present disclosure. Apparatus 200 may be implemented as user equipment 102 of wireless network 100 in FIG. 1. As shown in FIG. 2, apparatus 200 may include baseband chip 202, RF chip 204, host chip 206, and one or more antennas 210. In some embodiments, baseband chip 202 is implemented by processor 502 and memory 504, and RF chip 204 is implemented by processor 502, memory 504, and transceiver 506, as described above with respect to FIG. 5. Besides the on-chip memory 218 (also known as “internal memory,” e.g., registers, buffers, or caches) on each chip 202, 204, or 206, apparatus 200 may further include an external memory 208 (e.g., the system memory or main memory) that can be shared by each chip 202, 204, or 206 through the system/main bus. Although baseband chip 202 is illustrated as a standalone SoC in FIG. 2, it is understood that in one example, baseband chip 202 and RF chip 204 may be integrated as one SoC; in another example, baseband chip 202 and host chip 206 may be integrated as one SoC; in still another example, baseband chip 202, RF chip 204, and host chip 206 may be integrated as one SoC, as described above.

[0048] In the uplink, host chip 206 may generate raw data and send it to baseband chip 202 for encoding, modulation, and mapping. Interface 214 of baseband chip 202 may receive the data from host chip 206. Baseband chip 202 may also access the raw data generated by host chip 206 and stored in external memory 208, for example, using the direct memory access (DMA). Baseband chip 202 may first encode (e.g., by source coding and/or channel coding) the raw data and modulate the coded data using any suitable modulation techniques, such as multi-phase shift keying (MPSK) modulation or quadrature amplitude modulation (QAM). Baseband chip 202 may perform any other functions, such as symbol or layer mapping, to convert the raw data into a signal that can be used to modulate the carrier frequency for transmission. In the uplink, baseband chip 202 may send the modulated signal to RF chip 204 via interface 214. RF chip 204, through the transmitter, may convert the modulated signal in the digital form into analog signals, i.e., RF signals, and perform any suitable front-end RF functions, such as filtering, digital pre-distortion, up-conversion, or sample-rate conversion. Antenna 210 (e.g., an antenna array) may transmit the RF signals provided by the transmitter of RF chip 204.

[0049] In the downlink, antenna 210 may receive RF signals from an access node or other wireless device. For example, the RF signals may include, among other things, information configuring apparatus 200 to monitor a search space type that includes DCI2 1, an interruption radio network temporary identifier (INT-RNTI), a transmission that includes one or more preempted/corrupted reference signals, PDSCH packets, etc. The RF signals may be passed to the receiver (Rx) of RF chip 204. RF chip 204 may perform any suitable front-end RF functions, such as filtering, IQ imbalance compensation, down-paging conversion, or sample-rate conversion, and convert the RF signals (e.g., transmission) into low-frequency digital signals (baseband signals) that can be processed by baseband chip 202.

[0050] As seen in FIG. 2, baseband chip 202 may include a determination circuit 216 configured to determine whether at least one preemption condition is met. A first preemption condition may include, e.g., determining whether an INT-RNTI was received from the base station. A second preemption condition may include, e.g., determining whether apparatus 200 is configured with a search space type that includes DCI2 1. When both the first and second preemptions conditions are met, determination circuit 216 may activate channel estimation control circuit 220. Channel estimation control circuit 220 may be activated during the reception of symbols N_INT = symbols, (where is the symbols indicated as uplink by tdd-UL-

DL-ConfigurationCommon ), from the symbol indicated by SearchSpace- >monitoringSymbolsWithinSlot. From a system timing point of view, channel estimation control circuit 220 may be activated by determination circuit 216 at initial slot boundary of N_INT symbols from the symbol indicated by SearchSpace->monitoringSymbolsWithinSlot. The rest of the time, channel estimation control circuit 220 may be deactivated to conserve power.

[0051] When activated, channel estimation control circuit 220 may receive, from an interface 214, a transmission that includes a plurality of reference signals. Knowing, a priori , the resource elements (REs) that may include reference signals, channel estimation control circuit 220 may perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption. When corrupted, these reference signals may be excluded from a channel estimation procedure. Additional details of the channel estimation control procedure performed by channel estimation control circuit 220 are provided below in connection of FIG. 3.

[0052] FIG. 3 illustrates a data flow 300 between an eMBB UE 102a, a URELC UE 102b, and a gNB 304, according to certain aspects of the present disclosure. eMBB UE 102a may correspond to, e.g., user equipment 102, apparatus 200, and/or node 500. In some embodiments, an mMTC UE (not shown) may be configured to perform the same operations described below in connection with eMBB UE 102a. URELC UE 102b may correspond to, e.g., user equipment 102, apparatus 200, and/or node 500. gNB 304 may correspond to, e.g., access node 104 or node 500. [0053] Referring to FIG. 3, gNB 304 may send (at 301) an INT-RNTI to eMBB UE 102a.

INT-RNTI may indicate to eMBB UE 102a that some transmissions may include symbols that are preempted by those of a URLLC transmission. gNB 304 may configure eMBB UE 102a to monitor interrupted transmission indications using INT-RNTI on a physical downlink control channel (PDCCH). gNB 304 may configure INT-RNTI and other parameters related to preemption in the information element (IE) DownlinkPreemption within the PDCCH-Config IE, for example. INT- RNTI may be 16-bits in length, and its value can range from 1 to 65519 (0x0001 to OxFFEF). Moreover, gNB 304 may send (at 303) information that configures eMBB UE 102a with a search space type that includes DCI2 1. Still further, gNB 304 may schedule (at 305) eMBB and/or mMTC downlink transmissions, which may include reference signals (e.g., DMRS, CRS, TRS, etc.). The scheduling of eMBB downlink transmissions may indicate to eMBB UE 102a which code blocks and/or REs (time/frequency resources) of the code blocks may include its transmissions and/or reference signals, and hence, which code blocks or REs the eMBB UE 102a should monitor.

[0054] eMBB UE 102a may determine (at 306) whether the first and second preemption conditions are met. As mentioned above, the first preemption condition may include, e.g., determining whether an INT-RNTI was received from the base station. The second preemption condition may include, e.g., determining whether apparatus 200 is configured with a search space type that includes DCI2 1. When both the first and second preemptions conditions are met, eMBB UE 102a may activate (at 307) a channel estimation control circuit in its baseband chip, e.g., channel estimation control circuit 220 of FIG. 2. The channel estimation control circuit may be activated during the reception of symbols symbols, (where

N₁ is the symbols indicated as uplink by tdd-UL-DL-ConfigurationCommon ), from the symbol indicated by SearchSpace->monitoringSymbolsWithinSlot. From a system timing point of view, the channel estimation control circuit may be activated by determination circuit 216 at the initial slot boundary of N_INT symbols from the symbol indicated by SearchSpace- >monitoringSymbolsWithinSlot. The rest of the time, the channel estimation control circuit may be deactivated to conserve power.

[0055] gNB 304 may send (at 309) a transmission that includes reference signals corrupted/preempted by the URLLC transmission. When a URLLC transmission preempts a transmission for eMBB UE 102a, certain time/frequency resources originally scheduled (at 305) for eMBB 102a may be preempted by the URLLC transmission, e.g., as shown in FIG. 6. During the receipt of N_int, eMBB UE 102a may perform (at 311) a channel estimation control procedure, prior to detecting a preemption indication from gNB 304, to determine whether the reference signals include any corrupted reference signals associated with a downlink preemption. The channel estimation control procedure determines whether all or a portion of the received reference symbols are corrupted by the preemption. Whether all or a portion of the received reference symbol is corrupted depends on the timeFrequencySet= ‘setO ’ or timeFrequencySet= ‘setl If timeFrequencySet= ‘set0 then the whole received DMRS is presumed to be preempted. Only when timeFrequencySet= ‘setl ’, is a portion of corrupted received reference symbol possible. Again, the time frequency set type is configured via RRC signaling, which is not shown in FIG. 3. [0056] The channel estimation control procedure used by eMBB UE 102a may be selected from a set of channel estimation control procedures that include, e.g., a first control procedure, a second control procedure, and/or a third control procedure.

[0057] The first control procedure may be performed (at 311) when a signal -to-noise ratio

(SNR) associated with the transmission meets an SNR threshold. The first control procedure may include noise estimation based on the descrambled reference symbols. For example, the first control procedure may be performed for the first set of symbol groups that

include symbols and the last set of 14 — symbols that include

symbols, when timeFrequencySet= ‘set0

[0058] Supposed that the received resource element (RE) that includes the reference symbol is represented as:

(0-1), where r(n, Z) is the received transmission signal, is the channel frequency response,

S(n, l ) is the received reference signal,

is the channel frequency response, w(n, Z) is the Additive White Gaussian Noise (AWGN), n is a first symbol located in N_int, and Z is a second symbol not located in N_int.

[0059] Then the descrambled REs y(n, Z) can be represented as:

(0-2),

where S (n, Z) may be a known reference signal generated by channel estimation control circuit 220 for this computation and z(n, l ) may be the noise. [0060] For type-1 DMRS, eMBB UE 102a may determine the noise estimation based on the descrambled reference symbol on the same CDM group as follows:

where y (n + 2, Z) represents the third descrambled RE, y (n, Z) represents the first descrambled RE, H(n + 2, 1) is the channel associated with the third RE, H(n, 1) may be the channel associated with the first RE, z(n + 2, Z) may be the noise associated with the third RE, and z(n, Z) may be the noise associated with the first RE.

[0061] On the other hand, for type-2 DMRS, eMBB UE 102a may determine the noise estimation based on the descrambled reference symbol on the same CDM group as follows:

(0-4b).

[0062] Then, assuming

and independent noise samples in different

REs:

(0-5), where E[\y(n + 2, 1) — y(n, 1) |²] represents a windowing summation of the difference between REs (e.g., (fourth RE - second RE) + (second RE - first RE)) and s is the noise variance. [0063] When the received signal is preempted by URLLC data, the received DMRS symbol can be represented as:

(0-6), where X(n, 1) is the URLLC data, G(n, 1) is the channel frequency response for the URLLC user. [0064] Therefore, the descrambled received signal can be represented as:

(0-7).

[0065] Then, eMBB UE 102a may perform noise estimation based on the descrambled preempted reference symbol as follows:

[0066]

[0067] Now, having a noise estimation _<7, eMBB UE 102a may determine whether a reference symbol is corrupted as follows:

D , N_RS is the number of reference signal REs in the checked symbol, then the reference signal is corrupted; otherwise the reference signal is not corrupted. eMBB UE 102a may determine D based on the reliability of the noise estimation d . Also, the 2d can be replaced with when eMBB UE 102a knows a non-preempted

DMRS reference signal is received. Here, D may be controllable by firmware at eMBB UE 102a and it depends on the estimated received SNR. Moreover, D may be determined and maintained in a lookup table that is accessed by eMBB 102a to determine this value. For example, D may be determined using a simulation that estimates the amount of bias

as compared to noise estimation d. This information can be saved in the lookup

table, which may be dependent on the SNR and number of DMRS. Hence, during operation of eMBB UE 102a, the lookup table may be fine-tuned by the firmware, for example.

[0068] Otherwise, when timeFrequencySet= ‘setl \ the first control procedure may include

7 groups of consecutive symbols, the first set of symbols that include

symbols and the last set of symbols that include symbols.

[0069] Here, the noise estimation based on the descrambled reference symbol can readily be adapted to the case timeFrequencySet= ‘setl ’, by checking whether the REs to be averaged on belong to lower or upper

is the number of reference signal REs in lower

bandwidth part, then DMRS REs in lower bandwidth part is corrupted; otherwise, reference

signal REs in lower bandwidth part are not corrupted. eMBB UE 102a may perform similar

tests for upper bandwidth part reference signal REs.

[0070] Turning to the second control procedure, the second control procedure may be performed (at 311) when the SNR does not meet the SNR threshold and when eMBB UE 102a is configured with timeFrequencySet= ‘setO ’; the second control procedure includes a time-domain correlation of the descrambled reference symbols. [0071] Depending on the dmrs-AdditionalPosition, eMBB UE 102a may calculate the time-domain correlation between a pair of received reference symbols (l₀, l₁) as follows:

[0072] When the SNR is high, the time-domain correlation can be approximated as:

where R_t,_ref is determined from a lookup table, j₀(·) is the zeroth order of Bessel function of the first kind, f_D is the estimated Doppler frequency experienced by eMBB UE 102a, and T_symboi is the OFDM symbol duration. The estimated doppler frequency f_D may be available from a circuit/unit/module other than the channel estimation control circuit 220 of FIG. 2. This other circuit/unit/module may estimate f_D from a TRS, for example. Because /₀(·) is the zeroth order of Bessel function, so a range of Bessel functions can be saved in a lookup table with f_D and DI as inputs. Using this lookup table, eMBB UE 102a can determine the amount of Δ

_t that applies to

If the reference symbol is corrupted, the correlation shall be much lower than the therefore, the following rule can be used by eMBB

UE 102a to check if the DMRS is corrupted:

, then the reference signal is corrupted; otherwise, the reference signal is good. Again, eMBB UE 102a may control Δ _t using firmware and it depends on the reliability of the time-domain correlation estimation above, the estimated received SNR estimation, etc.

[0074] When M reference symbols are received, eMBB UE 102a may have pairs to

check, for example, if dmrs-AdditionalPosition= p ’ os3 ’ is being set, eMBB UE 102a may calculate:

are low, then eMBB UE 102a may conclude l₀ is corrupted.

Similar inference can be done to check the other reference symbols.

[0075] Note, when the channel varies slowly, gNB 304 might configure dmrs-

AdditionalPosition= p ’ osO \ In this case, if the channel estimate from previous slots (history) can be assumed to be quasi-co-located with the current slot, then eMBB UE 102a may still check

[0076] Otherwise, when timeFrequencySet= ‘se/J\ eMBB UE 102a may modify the time- domain correlation between a pair of received reference symbols averaged on either lower

or upper bandwidth part, as shown below:

where N_RS is the number of reference REs within lower bandwidth part.

[0077] Turning to the third control procedure, the third control procedure may be performed (at 311) when the SNR does not meet the SNR threshold and when eMBB UE 102a is configured with timeFrequencySet= ‘setl the third control procedure includes a frequency- domain correlation of the descrambled reference symbols.

[0078] eMBB UE 102a may perform a frequency-domain correlation

f between a pair of received reference signals REs each belonging to lower or upper bandwidth

part, which may be calculated as:

where N_RS is total number of reference signal samples used to calculate the frequency-domain correlation.

[0079] When the SNR is high, eMBB UE 102a may approximate the frequency-domain correlation as:

[0080] When the reference signal REs are not corrupted, the calculated frequency-domain correlation shall be around:

where are the power and delay of the i-th tap channel impulse response, D/ is the

subcarrier spacing, ri_Q. n-^ are the two sub-carriers for which the correlation is calculated. In practice, eMBB UE 102a may estimate/approximate parameters

We assumed that this frequency-domain correlation is available to the firmware to perform channel estimation real time control.

[0081] In some embodiments, eMBB UE 102a may use the following procedure to calculate the frequency-domain correlation using an increased number of samples for averaging:

where N_DMRS is the total number of DMRS samples used to calculate the frequency-domain correlation.

[0082] Therefore, eMBB UE 102a may use the following rule to check if part of a reference signal symbol is corrupted: if then the reference signal is corrupted; otherwise,

the reference signal is not corrupted. Similarly, eMBB UE 102a may determine Af based on the size of the averaging and SNR on which the frequency-domain correlation is calculated.

[0083] Moreover, eMBB UE 102a may use a combination of the first control procedure, the second control procedure, and/or the third control procedure depending on channel conditions, interference level, and RRC configuration. The combination may be used to improve the accuracy of the detection under certain scenarios. For example, one reason for using the combinations of the above three control procedures is that when the SNR is low or interference is high, it may not be straightforward for eMBB UE 102a to differentiate (0-8) from (0-4). Also, the approximation in high SNR for (0-10), (0-12), and (0-14) may be inaccurate. This may result in eMBB UE 102a underestimating (the estimated correlation is lower than what is supposed to be) the time- domain/frequency-domain correlation. However, this can be mitigated by setting correct A , A_t, and Af. Each of Δ , Δ_t, and Δ_f can be saved/fme-tuned by the firmware of eMBB UE 102a by comparing the true values, for example: can be plotted and compared to the estimates

in simulation and then for different SINR, eMBB UE 102a can check the bias of the estimation, Δf is used to compensate the estimation bias.

[0084] Reference time-domain correlation, , and reference frequency-domain

correlation

, might be readily available to eMBB UE 102a, since these correlations are also commonly used in time-domain and frequency-domain interpolation. Moreover, eMBB UE 102a may use Δ_t and Δ_f to accommodate for inaccuracies of reference time-domain and frequency- domain correlation.

[0085] Based on the outcome of the channel estimation control procedure, eMBB UE 102a may exclude (at 313) corrupted reference signals from a channel estimation procedure. In this way, the channel estimation control procedure of the present disclosure prevents catastrophic inaccuracies in channel estimation, thereby increasing the performance of the device, while at the same time improving the reliability of decoded PDSCH packet

[0086] FIG. 4A illustrates a flowchart of an exemplary method 400 of wireless communication, according to embodiments of the disclosure. Exemplary method 400 may be performed by an apparatus for wireless communication, e.g., such as user equipment 102, apparatus 200, baseband chip 202, channel estimation control circuit 220, eMBB UE 102a, and/or node 500. Method 400 may include steps 402-408 as described below. It is to be appreciated that some of the steps may be optional, and some of the steps may be performed simultaneously, or in a different order than shown in FIG. 4 A.

[0087] Referring to FIG. 4A, at 402, the apparatus may determine whether preemption condition(s) have been met. For example, referring to FIG. 3, eMBB UE 102a may determine (at 306) whether the first and second preemption conditions are met. As mentioned above, the first preemption condition may include, e.g., determining whether an INT-RNTI was received from the base station. The second preemption condition may include, e.g., determining whether apparatus 200 is configured with a search space type that includes DCI2 1.

[0088] When both preemption conditions have not been met, the operation moves to 404, where the apparatus performs channel estimation without performing the channel estimation control procedure. Otherwise, when both preemption conditions are met, the operation moves to 406.

[0089] At 406, the apparatus may determine N_int. For example, referring to FIG. 3, when both the first and second preemption conditions are met, eMBB UE 102a may activate (at 307) a channel estimation control circuit in its baseband chip, e.g., channel estimation control circuit 220 of FIG. 2. The channel estimation control circuit may be activated during the reception of symbols symbols, (where N₁ is the symbols indicated as uplink by

tdd-UL-DL-ConfigurationCommon ), from the symbol indicated by SearchSpace- >monitoringSymbolsWithinSlot. From a system timing point of view, the channel estimation control circuit may be activated by determination circuit 216 at the initial slot boundary of N_INT symbols from the symbol indicated by SearchSpace->monitoringSymbolsWithinSlot. The rest of the time, the channel estimation control circuit may be deactivated to conserve power.

[0090] At 408, the apparatus may activate the channel estimation control circuit. For example, referring to FIG. 3, when both the first and second preemption conditions are met, eMBB UE 102a may activate (at 307) a channel estimation control circuit in its baseband chip, e.g., channel estimation control circuit 220 of FIG. 2. The channel estimation control circuit may be activated during the reception of symbols symbols, (where

[0091] FIG. 4B illustrates a flowchart of an exemplary method 401 of wireless communication, according to embodiments of the disclosure. Exemplary method 401 may be performed by a baseband chip, e.g., such as baseband chip 202, determination circuit 216, and/or channel estimation control circuit 220. Method 401 may include steps 410-418 as described below. It is to be appreciated that some of the steps may be optional, and some of the steps may be performed simultaneously, or in a different order than shown in FIG. 4B.

[0092] At 410, the baseband chip may determine whether at least one downlink preemption condition is met. For example, referring to FIG. 2, baseband chip 202 may include a determination circuit 216 configured to determine whether at least one preemption condition is met. A first preemption condition may include, e.g., determining whether an INT-RNTI was received from the base station. A second preemption condition may include, e.g., determining whether apparatus 200 is configured with a search space type that includes DCI2 1.

[0093] At 412, the baseband chip may activate a channel estimation control circuit when the at least one downlink preemption condition is met. For example, referring to FIG. 2, when both the first and second preemption conditions are met, determination circuit 216 may activate channel estimation control circuit 220. Channel estimation control circuit 220 may be activated during the reception of symbols symbols, (where

is the

symbols indicated as uplink by tdd-UL-DL-ConfigurationCommon ), from the symbol indicated by SearchSpace->monitoringSymbolsWithinSlot. From a system timing point of view, channel estimation control circuit 220 may be activated by determination circuit 216 at the initial slot boundary of N_INT symbols from the symbol indicated by SearchSpace- >monitoringSymbolsWithinSlot. The rest of the time, channel estimation control circuit 220 may be deactivated to conserve power.

[0094] At 414, the baseband chip may receive, from an interface unit, a transmission that includes a plurality of reference signals. For example, referring to FIG. 2, when activated, channel estimation control circuit 220 may receive, from an interface 214, a transmission that includes a plurality of reference signals. Knowing, a priori , the resource elements (REs) that may include reference signals, channel estimation control circuit 220 may perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption. When corrupted, these reference signals may be excluded from a channel estimation procedure.

[0095] At 416, the baseband chip may perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption. For example, referring to FIG. 3, eMBB UE 102a may perform the first, second, third control procedure (or any combination thereof) to determine whether any of the reference signals are corrupted.

[0096] At 418, the baseband chip may exclude the corrupted reference signals from a channel estimation. For example, referring to FIG. 3, based on the determination (at 311), eMBB UE 102a may exclude (at 313) corrupted reference signals from a channel estimation procedure. In this way, the channel estimation control procedure of the present disclosure prevents catastrophic inaccuracies in channel estimation, thereby increasing the performance of the device, while at the same time improving the reliability of decoded PDSCH packet.

[0097] In various aspects of the present disclosure, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or encoded as instructions or code on a non-transitory computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computing device, such as node 500 in FIG. 5 By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, HDD, such as magnetic disk storage or other magnetic storage devices, Flash drive, SSD, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a processing system, such as a mobile device or a computer. Disk and disc, as used herein, includes CD, laser disc, optical disc, digital video disc (DVD), and floppy disk where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. [0098] According to one aspect of the present disclosure, a baseband chip is disclosed. The baseband chip may include a determination circuit and a channel estimation control circuit. The determination unit may be configured to determine whether at least one downlink preemption condition is met. The determination unit may be further configured to activate a channel estimation control circuit when the at least one downlink preemption condition is met. The channel estimation control circuit may be configured to receive, from an interface unit, a transmission that includes a plurality of reference signals. The channel estimation control circuit may be further configured to perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption. The channel estimation control circuit may be configured to exclude the corrupted reference signals from a channel estimation.

[0099] In some embodiments, the channel estimation control procedure may be selected from a set of channel estimation control procedures that includes one or more of a first control procedure, a second control procedure, or a third control procedure.

[0100] In some embodiments, the first control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when an SNR associated with the transmission meets an SNR threshold. In some embodiments, the second control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a first interrupted symbol set type is configured. In some embodiments, the third control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a second interrupted symbol set type is configured.

[0101] In some embodiments, the channel estimation control circuit may be configured to perform the first control procedure by determining a noise estimation of the transmission using the plurality of reference signals. In some embodiments, the channel estimation control circuit may be configured to perform the first control procedure by comparing the noise estimation of the transmission determined using the plurality of reference signals to a noise estimation threshold. In some embodiments, the channel estimation control circuit may be configured to perform the first control procedure by determining the plurality of reference signals includes at least one corrupted reference signal when the noise estimation meets the noise estimation threshold.

[0102] In some embodiments, the first interrupted symbol set type may be configured by a timeFrequencySet= ’setO ’ information element. In some embodiments, the channel estimation control circuit may be configured to perform the second control procedure by determining a time- domain correlation based on reference signal pairs of the plurality of reference signals. In some embodiments, the channel estimation control circuit may be configured to perform the second control procedure by comparing the time-domain correlation based on reference signal pairs to a time-domain correlation threshold. In some embodiments, the channel estimation control circuit may be configured to perform the second control procedure by determining the plurality of reference signals includes at least one corrupted reference signal when the time-domain correlation is less than the time-domain correlation threshold.

[0103] In some embodiments, the first interrupted symbol set type may be configured by a timeFrequencySet= ’setl ’ information element. In some embodiments, the channel estimation control circuit may be configured to perform the third control procedure by determining a frequency-domain correlation based on reference signal pairs of the plurality of reference signals. In some embodiments, the channel estimation control circuit may be configured to perform the third control procedure by comparing the frequency-domain correlation based on reference signal pairs to a frequency-domain correlation threshold. The channel estimation control circuit may be configured to perform the third control procedure by determining the plurality of reference signals include at least one corrupted reference signal when the frequency-domain correlation is less than the frequency-domain correlation threshold.

[0104] In some embodiments, when at least one channel condition associated with the transmission is met, the channel estimation control circuit may be configured to perform the first control procedure and the second control procedure to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption.

[0105] In some embodiments, when at least one channel condition associated with the transmission is met, the channel estimation control circuit may be configured to perform the first control procedure and the third control procedure to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption.

[0106] According to one aspect of the present disclosure, an apparatus of a baseband chip is disclosed. The apparatus may include a memory and at least one processor coupled to the memory. The at least one processor may be configured to receive, from an interface unit, a transmission that includes a plurality of reference signals. The at least one processor may be configured to determine whether at least one downlink preemption condition is met. The at least one processor may be configured to perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption when it is determined that the downlink preemption condition is met. The at least one processor may be configured to exclude the corrupted reference signals from a channel estimation.

[0107] In some embodiments, the channel estimation control procedure may be selected from a set of channel estimation control procedures that includes one or more of a first control procedure, a second control procedure, or a third control procedure.

[0108] In some embodiments, the first control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when an SNR associated with the transmission meets an SNR threshold. In some embodiments, the second control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a first interrupted symbol set type is configured. In some embodiments, the third control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a second interrupted symbol set type is configured.

[0109] In some embodiments, the at least one processor may be configured to perform the first control procedure by determining a noise estimation of the transmission using the plurality of reference signals. In some embodiments, the at least one processor may be configured to perform the first control procedure by comparing the noise estimation of the transmission determined using the plurality of reference signals to a noise estimation threshold. In some embodiments, the at least one processor may be configured to perform the first control procedure by determining the plurality of reference signals includes at least one corrupted reference signal when the noise estimation meets the noise estimation threshold.

[0110] In some embodiment, the first interrupted symbol set type may be configured by a timeFrequencySet= ’setO ’ information element. In some embodiments, the at least one processor may be configured to perform the second control procedure by determining a time-domain correlation based on reference signal pairs of the plurality of reference signals. In some embodiments, the at least one processor may be configured to perform the second control procedure by comparing the time-domain correlation based on reference signal pairs to a time- domain correlation threshold. In some embodiments, the at least one processor may be configured to perform the second control procedure by determining the plurality of reference signals includes at least one corrupted reference signal when the time-domain correlation is less than the time- domain correlation threshold.

[0111] In some embodiments, the first interrupted symbol set type may be configured by a timeFrequencySet= ’setl ’ information element. In some embodiments, the at least one processor may be configured to perform the third control procedure by determining a frequency-domain correlation based on reference signal pairs of the plurality of reference signals. In some embodiments, the at least one processor may be configured to perform the third control procedure by comparing the frequency-domain correlation based on reference signal pairs to a frequency- domain correlation threshold. In some embodiments, the at least one processor may be configured to perform the third control procedure by determining the plurality of reference signals include at least one corrupted reference signal when the frequency-domain correlation is less than the frequency-domain correlation threshold.

[0112] In some embodiments, when at least one channel condition associated with the transmission is met, the at least one processor may be configured to perform the first control procedure and the second control procedure to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption.

[0113] In some embodiments, when at least one channel condition associated with the transmission is met, the at least one processor may be configured to perform the first control procedure and the third control procedure to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption.

[0114] According to another aspect of the disclosure, a method of wireless communication is disclosed. The method may include determining, by a determination circuit, whether at least one downlink preemption condition is met. The method may also include activating, by the determination circuit, a channel estimation control circuit when the at least one downlink preemption condition is met. The method may also include receiving, at a channel estimation control circuit, a transmission that includes a plurality of reference signal. The method may also include performing, by the channel estimation control circuit, a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption. The method may also include excluding, by the channel estimation control circuit, the corrupted reference signals from a channel estimation.

[0115] In some embodiments, the channel estimation control procedure may be selected from a set of channel estimation control procedures that includes one or more of a first control procedure, a second control procedure, or a third control procedure.

[0116] In some embodiments, the first control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when an SNR associated with the transmission meets an SNR threshold. In some embodiments, the second control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a first interrupted symbol set type is configured. In some embodiments, the third control procedure may be performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a second interrupted symbol set type is configured.

[0117] In some embodiments, performing the first control procedure may include determining a noise estimation of the transmission using the plurality of reference signals. In some embodiments, performing the first control procedure may include comparing the noise estimation of the transmission determined using the plurality of reference signals to a noise estimation threshold. In some embodiments, performing the first control procedure may include determining the plurality of reference signals includes at least one corrupted reference signal when the noise estimation meets the noise estimation threshold.

[0118] The foregoing description of the specific embodiments will so reveal the general nature of the present disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.

[0119] Embodiments of the present disclosure have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0120] The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended claims in any way.

[0121] Various functional blocks, modules, and steps are disclosed above. The particular arrangements provided are illustrative and without limitation. Accordingly, the functional blocks, modules, and steps may be reordered or combined in different ways than in the examples provided above. Likewise, some embodiments include only a subset of the functional blocks, modules, and steps, and any such subset is permitted.

[0122] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. A baseband chip, comprising: a determination circuit configured to: determine whether at least one downlink preemption condition is met; and activate a channel estimation control circuit when the at least one downlink preemption condition is met; and the channel estimation control circuit configured to: receive, from an interface unit, a transmission that includes a plurality of reference signals; perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption; and exclude the corrupted reference signals from a channel estimation.

2. The baseband chip of claim 1, wherein the channel estimation control procedure is selected from a set of channel estimation control procedures that includes one or more of a first control procedure, a second control procedure, or a third control procedure.

3. The baseband chip of claim 2, wherein: the first control procedure is performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when a signal-to- noise ratio (SNR) associated with the transmission meets an SNR threshold, the second control procedure is performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a first interrupted symbol set type is configured, and the third control procedure is performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a second interrupted symbol set type is configured.

4. The baseband chip of claim 3, wherein the channel estimation control circuit is configured to perform the first control procedure by: determining a noise estimation of the transmission using the plurality of reference signals; comparing the noise estimation of the transmission determined using the plurality of reference signals to a noise estimation threshold; and determining the plurality of reference signals includes at least one corrupted reference signal when the noise estimation meets the noise estimation threshold.

5. The baseband chip of claim 3, wherein: the first interrupted symbol set type is configured by a timeFrequencySet= ’setO ’ information element, and the channel estimation control circuit is configured to perform the second control procedure by: determining a time-domain correlation based on reference signal pairs of the plurality of reference signals; comparing the time-domain correlation based on reference signal pairs to a time- domain correlation threshold; and determining the plurality of reference signals includes at least one corrupted reference signal when the time-domain correlation is less than the time-domain correlation threshold.

6. The baseband chip of claim 3, wherein: the first interrupted symbol set type is configured by a timeFrequencySet= ’setl ’ information element, and the channel estimation control circuit is configured to perform the third control procedure by: determining a frequency-domain correlation based on reference signal pairs of the plurality of reference signals; comparing the frequency-domain correlation based on reference signal pairs to a frequency-domain correlation threshold; and determining the plurality of reference signals include at least one corrupted reference signal when the frequency-domain correlation is less than the frequency-domain correlation threshold.

7. The baseband chip of claim 3, wherein when at least one channel condition associated with the transmission is met, the channel estimation control circuit is configured to perform the first control procedure and the second control procedure to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption.

8. The baseband chip of claim 3, wherein when at least one channel condition associated with the transmission is met, the channel estimation control circuit is configured to perform the first control procedure and the third control procedure to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption.

9. An apparatus of a baseband chip, comprising: a memory; and at least one processor coupled to the memory and configured to: receive, from an interface unit, a transmission that includes a plurality of reference signals; determine whether at least one downlink preemption condition is met; perform a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption when it is determined that the downlink preemption condition is met; and exclude the corrupted reference signals from a channel estimation.

10. The apparatus of claim 9, wherein the channel estimation control procedure is selected from a set of channel estimation control procedures that includes one or more of a first control procedure, a second control procedure, or a third control procedure.

11. The apparatus of claim 10, wherein: the first control procedure is performed to determine whether the transmission includes any corrupted reference signals when a signal -to-noise ratio (SNR) associated with the transmission meets an SNR threshold, the second control procedure is performed to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a first interrupted symbol set type is configured, and the third control procedure is performed to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a second interrupted symbol set type is configured.

12. The apparatus of claim 11, wherein the at least one processor is configured to perform the first control procedure by: determining a noise estimation of the transmission using the plurality of reference signals; comparing the noise estimation of the transmission determined using the plurality of reference signals to a noise estimation threshold; and determining the plurality of reference signals includes at least one corrupted reference signal when the noise estimation meets the noise estimation threshold.

13. The apparatus of claim 11, wherein: the first interrupted symbol set type is configured by a timeFrequencySet= ’setO ’ information element, and the at least one processor is configured to perform the second control procedure by: determining a time-domain correlation based on reference signal pairs of the plurality of reference signals; comparing the time-domain correlation based on reference signal pairs to a time- domain correlation threshold; and determining the plurality of reference signals includes at least one corrupted reference signal when the time-domain correlation is less than the time-domain correlation threshold.

14. The apparatus of claim 11, wherein: the first interrupted symbol set type is configured by a timeFrequencySet= ’setl ’ information element, and the at least one processor is configured to perform the third control procedure by: determining a frequency-domain correlation based on reference signal pairs of the plurality of reference signals; comparing the frequency-domain correlation based on reference signal pairs to a frequency-domain correlation threshold; and determining the plurality of reference signals include at least one corrupted reference signal when the frequency-domain correlation is less than the frequency-domain correlation threshold.

15. The apparatus of claim 11, wherein when at least one channel condition associated with the transmission is met, the at least one processor is configured to perform the first control procedure and the second control procedure to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption.

16. The apparatus of claim 11, wherein when at least one channel condition associated with the transmission is met, the at least one processor is configured to perform the first control procedure and the third control procedure to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption.

17. A method of wireless communication, comprising: determining, by a determination circuit, whether at least one downlink preemption condition is met; activating, by the determination circuit, a channel estimation control circuit when the at least one downlink preemption condition is met; receiving, at a channel estimation control circuit, a transmission that includes a plurality of reference signals; performing, by the channel estimation control circuit, a channel estimation control procedure, prior to detecting a preemption indication from a base station, to determine whether the plurality of reference signals include any corrupted reference signals associated with downlink preemption; and excluding, by the channel estimation control circuit, the corrupted reference signals from a channel estimation.

18. The method of claim 17, wherein the channel estimation control procedure is selected from a set of channel estimation control procedures that includes one or more of a first control procedure, a second control procedure, or a third control procedure.

19. The method of claim 18, wherein: the first control procedure is performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when a signal-to- noise ratio (SNR) associated with the transmission meets an SNR threshold, the second control procedure is performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a first interrupted symbol set type is configured, and the third control procedure is performed by the channel estimation control circuit to determine whether the transmission includes any corrupted reference signals when the SNR associated with the transmission does not meet the SNR threshold and when and a second interrupted symbol set type is configured.

20. The method of claim 19, wherein performing the first control procedure comprises: determining a noise estimation of the transmission using the plurality of reference signals; comparing the noise estimation of the transmission determined using the plurality of reference signals to a noise estimation threshold; and determining the plurality of reference signals includes at least one corrupted reference signal when the noise estimation meets the noise estimation threshold.