Base Station Signaling for Enhanced Channel Estimation for New Radio Coverage

Abstract

Various techniques are provided for improving channel estimation in a wireless system, the techniques including: transmitting an indication of a physical downlink channel configuration, the physical downlink channel transmission including a demodulation reference signal (DMRS); receiving an indication that the wireless device supports bundling of DMRS signals across multiple time slots; transmitting the DMRS configuration, the DMRS configuration including a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; transmitting a set of DMRS signals within the channel estimation bundling window, wherein a first DMRS signal in the set of DMRS signals is transmitted in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is transmitted in a second time slot, and wherein the first DMRS signal and the second DMRS signal are configured to be used by the wireless device to estimate a radio channel.

Description

Technical Field

[0001] The present application relates to wireless devices, and more particularly, to an apparatus, system, and method for estimating a radio channel of a New Radio (NR) in a wireless communication system. Background Art

[0002] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smartphones and tablets have become increasingly sophisticated. In addition to supporting phone calls, many mobile devices now also provide access to the Internet, email, text messaging, and navigation using the Global Positioning System (GPS), and are capable of operating sophisticated applications that utilize these capabilities. In addition, there are many different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (e.g., associated with WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), BLUETOOTH, and LTE-M. TM wait.

[0003] The introduction of an ever-increasing number of features and functions in wireless communication devices also requires continuous improvements in wireless communication and wireless communication devices. In order to increase coverage and better serve the increasing demand and range of intended uses of wireless communication, in addition to the aforementioned communication standards, there are also wireless communication technologies being developed, including fifth-generation (5G) New Radio (NR) communications. Therefore, there is a need for improvements in the field that support such development and design. Summary of the Invention

[0004] Various aspects relate to apparatus, systems, and methods for channel estimation in a wireless system. For example, a first aspect addresses a technique for channel estimation in a wireless system, the technique comprising: receiving, by a wireless device, an indication of a physical downlink channel configuration for receiving a physical downlink channel transmission, the physical downlink channel transmission comprising a demodulation reference signal (DMRS); transmitting, by the wireless device, an indication that the wireless device supports bundling DMRS signals across multiple time slots; receiving, by the wireless device, a DMRS configuration, the DMRS configuration comprising a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; receiving, based on the DMRS configuration, a set of DMRS signals within the channel estimation bundling window, wherein a first DMRS signal in the set of DMRS signals is received in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is received in a second time slot; estimating a radio channel based on the first DMRS signal and the second DMRS signal; and decoding a transmission from a wireless node based on the estimated radio channel.

[0005] On the other hand, a technology for channel estimation in a wireless system is addressed, the technology comprising: receiving, by a wireless device, an indication of a physical uplink channel configuration for transmitting a physical uplink channel transmission including a demodulation reference signal (DMRS); transmitting, by the wireless device, an indication that the wireless device supports bundling DMRS signals across multiple time slots; receiving, by the wireless device, a DMRS configuration, the DMRS configuration including a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; and based on the DMRS configuration, transmitting a set of DMRS signals to a wireless node within the channel estimation bundling window, wherein a first DMRS signal in the set of DMRS signals is transmitted in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is transmitted in a second time slot, wherein the first DMRS signal and the second DMRS signal are configured to be used by the wireless node for estimating a radio channel.

[0006] Another aspect includes a technique for channel estimation in a wireless system, the technique comprising: transmitting to a wireless device an indication of a physical downlink channel configuration for receiving a physical downlink channel transmission, the physical downlink channel transmission comprising a demodulation reference signal (DMRS); receiving from the wireless device an indication that the wireless device supports bundling of DMRS signals across multiple time slots; transmitting to the wireless device a DMRS configuration comprising a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; transmitting, by a wireless node and based on the DMRS configuration, a set of DMRS signals within the channel estimation bundling window, wherein a first DMRS signal in the set of DMRS signals is transmitted in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is transmitted in a second time slot, and wherein the first DMRS signal and the second DMRS signal are configured to be used by the wireless device to estimate a radio channel based on the first DMRS signal and the second DMRS signal.

[0007] Another aspect includes a technique for channel estimation in a wireless system, the technique comprising: transmitting an indication of a physical uplink channel configuration for transmitting a physical uplink channel transmission to a wireless device, the physical uplink channel transmission including a demodulation reference signal (DMRS) scheduling; receiving an indication from the wireless device that the wireless device supports bundling of DMRS signals across multiple time slots; transmitting a DMRS configuration to the wireless device, the DMRS configuration including channel estimation bundling, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; receiving, by a wireless node based on the DMRS configuration and within the channel estimation bundling window, a set of DMRS signals, wherein a first DMRS signal in the set of DMRS signals is received in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is received in a second time slot; estimating a radio channel based on the first DMRS signal and the second DMRS signal; and decoding a transmission from the wireless device based on the estimated radio channel.

[0008] The techniques described herein may be implemented in and / or used with a number of different types of devices, including, but not limited to, any of cellular telephones, wireless devices, tablet computers, wearable computing devices, portable media players, and various other computing devices.

[0009] This summary is intended to provide a brief overview of some of the subject matter described in this document. Therefore, it should be understood that the above-described features are merely examples and should not be construed as narrowing the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, accompanying drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A better understanding of the present subject matter may be obtained when the following detailed description of the various aspects is considered in conjunction with the following drawings, in which:

[0011] Figure 1 An exemplary wireless communication system according to some aspects is shown;

[0012] Figure 2 A base station (BS) in communication with a user equipment (UE) device is shown according to some aspects;

[0013] Figure 3 An exemplary block diagram of a UE according to some aspects is shown;

[0014] Figure 4 An exemplary block diagram of a BS according to some aspects is shown;

[0015] Figure 5 An exemplary block diagram of a cellular communication circuit according to some aspects is shown;

[0016] Figure 6 illustrates an exemplary block diagram of a network element according to some aspects;

[0017] Figure 7 is a radio frame diagram illustrating an example of channel estimation for a time slot using DMRS according to aspects of the present disclosure;

[0018] Figure 8 is a radio frame diagram illustrating an example of cross-slot channel estimation according to aspects of the present disclosure;

[0019] Figure 9 is a radio frame diagram illustrating an example of cross-slot channel estimation with a fixed channel estimation bundling window according to aspects of the present disclosure;

[0020] Figures 10 to 12 is a radio frame diagram illustrating an example of dynamic DMRS configuration according to aspects of the present disclosure;

[0021] Figure 13 is a radio frame diagram illustrating an example of cross-slot channel estimation for NR TDD according to aspects of the present disclosure;

[0022] Figure 14Ais a flow chart illustrating a technique for channel estimation in a wireless system according to aspects of the present disclosure;

[0023] Figure 14B is a flow chart illustrating various ways to receive an indication of a physical downlink channel configuration according to aspects of the present disclosure;

[0024] Figure 15A is a flow chart illustrating a technique for channel estimation in a wireless system according to aspects of the present disclosure;

[0025] Figure 15B is a flow chart illustrating various ways to receive a DMRS configuration for step 1506 according to aspects of the present disclosure;

[0026] Figure 15C is a flow chart illustrating various options 1524 in which a DMRS configuration indicates the number of time slots used for a channel estimation bundling window in accordance with aspects of the present disclosure;

[0027] Figure 15D is a flow chart illustrating various ways to transmit an indication 1504 that a wireless device supports bundling DMRS signals across multiple time slots in accordance with aspects of the present disclosure;

[0028] Figure 16A is a flow chart illustrating a technique for channel estimation in a wireless system according to aspects of the present disclosure;

[0029] Figure 16B is a flow chart illustrating various ways to transmit a DMRS configuration to a wireless device for step 1606 according to aspects of the present disclosure;

[0030] Figure 16C is a flow chart illustrating various manners for transmitting a set of DMRS signals in a channel estimation bundling window by a wireless node and based on a DMRS configuration for step 1608 in accordance with aspects of the present disclosure;

[0031] Figure 17A is a flow chart illustrating a technique for channel estimation in a wireless system according to aspects of the present disclosure;

[0032] Figure 17B is a flow chart for estimating a radio channel based on a first DMRS signal and a second DMRS signal for block 1714 according to aspects of the present disclosure;

[0033] Figure 17C is a flow diagram illustrating an option of block 1710 in which a DMRS configuration indicates the number of time slots used for a channel estimation bundling window in accordance with aspects of the present disclosure; and

[0034] Figure 17D is a flow chart illustrating various manners for receiving an indication that the wireless device supports bundling DMRS signals across multiple time slots at block 1706 in accordance with aspects of the present disclosure.

[0035] While the features described herein are susceptible to various modifications and alternative forms, specific aspects thereof are shown by way of example in the drawings and described in detail herein. It should be understood, however, that the drawings and detailed description thereof are not intended to limit this disclosure to the specific forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims. DETAILED DESCRIPTION

[0036] This document presents various techniques for improving DMRS performance compared to Rel-15. In particular, techniques are disclosed for cross-slot channel estimation of radio channel quality for both UL and DL channels. By estimating the channel across time slots, a more accurate channel estimate can be achieved over time. By enabling more accurate channel estimation, the DMRS density can be dynamically reduced, if appropriate, thereby facilitating more efficient use of available radio resources. Furthermore, techniques for dynamic DMRS reconfiguration are disclosed.

[0037] The following is a glossary of terms that may be used in this disclosure:

[0038] Memory medium—any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media, such as CD-ROMs, floppy disks, or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media, such as hard drives or optical storage devices; registers or other similar types of memory elements, etc. Memory media may also include other types of non-transitory memory or combinations thereof. In addition, the memory medium may be located in the first computer system executing the program, or may be located in a different second computer system connected to the first computer system via a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media that may reside in different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., represented as a computer program) that can be executed by one or more processors.

[0039] Carrier Medium—memory media as described above and physical transmission media such as a bus, network, and / or other physical transmission media that carry signals such as electrical, electromagnetic, or digital signals.

[0040] Programmable hardware elements—include various hardware devices that include multiple programmable function blocks connected via programmable interconnects. Examples include FPGAs (field programmable gate arrays), PLDs (programmable logic devices), FPOAs (field programmable object arrays), and CPLDs (complex PLDs). Programmable function blocks can range from fine-grained (combinational logic units or lookup tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as "configurable logic units."

[0041] Computer system—any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), television system, grid computing system, or other device or combination of devices. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0042] User Equipment (UE) (or "UE device") - any of various types of computer systems or devices that are mobile or portable and that perform wireless communication. Examples of UE devices include mobile phones or smartphones (e.g., iPhones, TM , based on Android TM phones), portable gaming devices (e.g., Nintendo DS TM PlayStation Portable TM 、Gameboy Advance TM , iPhone TM ), laptops, wearable devices (e.g., smart watches, smart glasses), PDAs, portable Internet devices, music players, data storage devices or other handheld devices, etc. In general, the term "UE" or "UE device" can be broadly defined to cover any electronic device, computing device and / or telecommunication device (or combination of devices) that can be easily transported by a user and capable of wireless communication.

[0043] Wireless Device—Any of various types of computer systems or devices that perform wireless communications. A wireless device may be portable (or mobile), or may be stationary or fixed in place. A UE is an example of a wireless device.

[0044] Communication Device—Any of various types of computer systems or devices that perform communication, where the communication may be wired or wireless. A communication device may be portable (or mobile), or may be stationary or fixed in place. A wireless device is one example of a communication device. A UE is another example of a communication device.

[0045] Base Station—The term “base station” or “wireless station” has the full breadth of its ordinary meaning and includes at least a wireless communication station that is installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0046] Processing element (or processor)—refers to any element or combination of elements capable of performing functions in a device such as user equipment or a cellular network device. A processing element may include, for example, a processor and associated memory, portions or circuits of individual processor cores, an entire processor core, a separate processor, an array of processors, circuits such as ASICs (application-specific integrated circuits), programmable hardware elements such as field-programmable gate arrays (FPGAs), and any of the above combinations.

[0047] Channel - the medium used to transmit information from a sender (transmitter) to a receiver. It should be noted that since the characteristics of the term "channel" may vary according to different wireless protocols, the term "channel" as used in the present invention may be considered to be used in a manner that is consistent with the standard of the type of device to which the term is used. In some standards, the channel width may be variable (e.g., depending on device capabilities, frequency band conditions, etc.). For example, LTE may support scalable channel bandwidths of 1.4 MHz to 20 MHz. In contrast, a WLAN channel may be 22 MHz wide, while a Bluetooth channel may be 1 MHz wide. Other protocols and standards may include different definitions of channels. In addition, some standards may define and use multiple types of channels, such as different channels for uplink or downlink and / or different channels for different purposes such as data, control information, etc.

[0048] Frequency band—The term “frequency band” has the full breadth of its ordinary meaning and includes at least a segment of the spectrum (eg, radio frequency spectrum) in which channels are used or set aside for the same purpose.

[0049] Automatic—refers to an action or operation being performed by a computer system (e.g., software executed by the computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without requiring user input to directly specify or execute the action or operation. Thus, the term "automatic" is in contrast to operations that are manually performed or specified by a user, where the user provides input to directly perform the operation. An automatic process may be initiated by user-provided input, but the subsequent actions performed "automatically" are not specified by the user, i.e., they are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing information, selecting checkboxes, radio selections, etc.) is not manually filling out the form, even though the computer system must update the form in response to the user's actions. The form can be automatically filled out by a computer system, where the computer system (e.g., software executing on the computer system) analyzes the fields of the form and fills it out without requiring any user input to specify the answers to the fields. As indicated above, a user can invoke the automatic filling of a form without participating in the actual filling out of the form (e.g., the user does not manually specify the answers to the fields; they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions that a user has taken.

[0050] About—refers to a value that is close to the correct or exact value. For example, about can refer to a value that is within 1% to 10% of the exact (or desired) value. However, it should be noted that the actual threshold (or tolerance) may depend on the application. For example, in some aspects, "about" may mean within 0.1% of some specified or desired value, while in various other aspects, the threshold may be, for example, 2%, 3%, 5%, etc., depending on the desires or requirements of the particular application.

[0051] Concurrency—refers to parallel execution or implementation, where tasks, processes, or programs are executed in an at least partially overlapping manner. For example, concurrency can be achieved using "strong" or strict parallelism, where tasks are executed (at least partially) in parallel on respective computing elements, or using "weak parallelism," where tasks are executed in an interleaved manner (e.g., by time multiplexing of execution threads).

[0052] Configured to—Various components may be described as being “configured to” perform one or more tasks. In such contexts, “configured to” is a broad statement that generally means “having the structure” to perform one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently performing the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, “configured to” can be a broad statement that generally means “having the circuitry” to perform one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently turned on. Generally, the circuitry that forms the structure corresponding to “configured to” may include hardware circuitry.

[0053] For ease of description, various components may be described as performing one or more tasks. Such descriptions should be interpreted as including the phrase "configured to." Representing a component as being configured to perform one or more tasks expressly intends that the component not be interpreted under 35 U.S.C. §112(f).

[0054] Exemplary Wireless Communication Systems

[0055] Now go to Figure 1 , shows a simplified example of a wireless communication system according to some aspects. Note that, Figure 1 The system is only one example of a possible system, and features of the present disclosure may be implemented in any of a variety of systems as desired.

[0056] As shown, the exemplary wireless communication system includes a base station 102A that communicates with one or more user devices 106A, 106B, 106N, etc. via a transmission medium. Each user device may be referred to herein as a "user equipment" (UE). Therefore, user device 106 is referred to as a UE or UE device.

[0057] Base station (BS) 102A may be a base transceiver station (BTS) or a cell site ("cellular base station") and may include hardware that enables wireless communications with UEs 106A through 106N.

[0058] The communication area (or coverage area) of a base station may be referred to as a "cell". The base station 102A and the UE 106 may be configured to communicate over a transmission medium using any of a variety of radio access technologies (RATs), also known as wireless communication technologies or telecommunication standards, such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), 5G New Radio (5G-NR), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), and the like. Note that if the base station 102A is implemented in the context of LTE, it may alternatively be referred to as an "eNodeB" or "eNB". Note that if the base station 102A is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB".

[0059] As shown, base station 102A may also be configured to communicate with network 100 (e.g., a cellular service provider's core network, a telecommunications network such as the Public Switched Telephone Network (PSTN), and / or the Internet, among other possibilities). Thus, base station 102A may facilitate communications between user devices and / or between user devices and network 100. In particular, cellular base station 102A may provide UE 106 with various communication capabilities, such as voice, SMS, and / or data services.

[0060] Base station 102A and other similar base stations (such as base stations 102B...102N) operating according to the same or different cellular communication standards can therefore be provided as a network of cells that can provide continuous or nearly continuous overlapping service to UEs 106A-N and similar devices over a geographic area via one or more cellular communication standards.

[0061] Thus, although base station 102A may function as Figure 1 106A-N, each UE 106 may also be capable of receiving signals from (and possibly within communication range of) one or more other cells (which may be provided by base stations 102B-N and / or any other base stations), which may be referred to as "neighboring cells." Such cells may also be capable of facilitating communications between user devices and / or between user devices and network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or cells of any other variety of granularities of service area size. For example, in Figure 1 The base stations 102A-102B shown in FIG may be macro cells, while the base station 102N may be a micro cell. Other configurations are also possible.

[0062] In some aspects, the base station 102A may be a next generation base station, such as a 5G New Radio (5GNR) base station or "gNB". In some aspects, the gNB may be connected to a legacy evolved packet core (EPC) network and / or to an NR core (NRC) / 5G core (5GC) network. In addition, a gNB cell may include one or more transition and reception points (TRPs). In addition, a UE capable of operating in accordance with 5GNR may be connected to one or more TRPs within one or more gNBs. For example, the base station 102A and one or more other base stations 102 may support joint transmissions such that the UE 106 may be able to receive transmissions from multiple base stations (and / or multiple TRPs provided by the same base station). For example, as Figure 1 As shown, base station 102A and base station 102C are both shown serving UE 106A.

[0063] It is noted that the UE 106 is capable of communicating using multiple wireless communication standards. For example, in addition to at least one cellular communication protocol (e.g., GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, 5G NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), etc.), the UE 106 can be configured to communicate using wireless networking (e.g., Wi-Fi) and / or peer-to-peer wireless communication protocols (e.g., Bluetooth, Wi-Fi peer-to-peer, etc.). If desired, the UE 106 can also or alternatively be configured to communicate using one or more global navigation satellite systems (GNSS, such as GPS or GLONASS), one or more mobile television broadcast standards (e.g., Advanced Television Systems Committee - Mobile / Handheld (ATSC-M / H)), and / or any other wireless communication protocols. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0064] Example User Equipment (UE)

[0065] Figure 2 1. User equipment 106 (e.g., one of devices 106A through 106N) is shown in accordance with some aspects in communication with base station 102. UE 106 may be a device with cellular communication capabilities, such as a mobile phone, handheld device, computer, laptop, tablet, smartwatch or other wearable device, or virtually any type of wireless device.

[0066] The UE 106 may include a processor (processing element) configured to execute program instructions stored in a memory. The UE 106 may perform any of the method aspects described herein by executing such stored instructions. Alternatively or in addition, the UE 106 may include a programmable hardware element, such as an FPGA (field programmable gate array), an integrated circuit, and / or any of various other possible hardware components configured to perform (e.g., individually or in combination) any of the method aspects described herein or any portion of any of the method aspects described herein.

[0067] The UE 106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some aspects, the UE 106 may be configured to communicate using, for example, NR or LTE using at least some shared radio components. As additional possibilities, the UE 106 may be configured to communicate using CDMA2000 (1xRTT / 1xEV-DO / HRPD / eHRPD) or LTE using a single shared radio component and / or GSM or LTE using a single shared radio component. The shared radio may be coupled to a single antenna or to multiple antennas (e.g., for MIMO) for performing wireless communications. Generally, the radio component may include any combination of a baseband processor, analog radio frequency (RF) signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, the radio component may implement one or more receive and transmit chains using the aforementioned hardware. For example, the UE 106 may share one or more portions of a receive and / or transmit chain between multiple wireless communication technologies such as those discussed above.

[0068] In some aspects, the UE 106 may include a separate transmit chain and / or receive chain (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As another possibility, the UE 106 may include one or more radio components shared between multiple wireless communication protocols, and one or more radio components used uniquely by a single wireless communication protocol. For example, the UE 106 may include a shared radio component for communicating using either LTE or 5G NR (or, in various possibilities, either LTE or 1xRTT, or either LTE or GSM), and separate radio components for communicating using each of Wi-Fi and Bluetooth. Other configurations are also possible.

[0069] Exemplary Communication Devices

[0070] Figure 31 shows an exemplary simplified block diagram of a communication device 106 according to some aspects. Figure 3 The block diagram of the communication device is only one example of a possible communication device. According to various aspects, the communication device 106 can be, among other devices, a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet computer, and / or a combination of devices. As shown, the communication device 106 may include a set of components 300 configured to perform core functions. For example, the set of components may be implemented as a system on a chip (SOC), which may include parts for various purposes. Alternatively, the set of components 300 may be implemented as individual components or groups of components for various purposes. This set of components 300 may be coupled (e.g., communicatively; directly or indirectly) to various other circuits of the communication device 106.

[0071] For example, the communication device 106 may include various types of memory (e.g., including NAND flash memory 310), input / output interfaces such as a connector I / F 320 (e.g., for connecting to a computer system; a docking station; a charging station; input devices such as a microphone, a camera, a keyboard; output devices such as a speaker; etc.), a display 360 that may be integrated with the communication device 106 or external to it, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, UMTS, GSM, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.). In some aspects, the communication device 106 may include wired communication circuitry (not shown), such as, for example, a network interface card for Ethernet.

[0072] Wireless communication circuitry 330 may be (e.g., communicatively; directly or indirectly) coupled to one or more antennas, such as one or more antennas 335 as shown. Wireless communication circuitry 330 may include cellular communication circuitry and / or short- to medium-range wireless communication circuitry, and may include multiple receive chains and / or multiple transmit chains for receiving and / or transmitting multiple spatial streams, such as in a multiple-input, multiple-output (MIMO) configuration.

[0073] In some aspects, as further described below, the cellular communication circuitry 330 can include one or more receive chains for multiple RATs (including and / or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and / or radios (e.g., a first receive chain for LTE and a second receive chain for 5G NR). Furthermore, in some aspects, the cellular communication circuitry 330 can include a single transmit chain that can switch between radios dedicated to specific RATs. For example, a first radio can be dedicated to a first RAT (e.g., LTE) and can communicate with a dedicated receive chain and a transmit chain shared with a second radio. The second radio can be dedicated to a second RAT (e.g., 5G NR). NR) and can communicate with a dedicated receive chain and a shared transmit chain. In some aspects, the second RAT can operate at millimeter wave frequencies. Because millimeter wave systems operate at higher frequencies than typical frequencies in LTE systems, signals in the millimeter wave frequency range are severely attenuated by environmental factors. To help address this attenuation issue, millimeter wave systems typically utilize beamforming and include more antennas than LTE systems. These antennas can be organized into antenna arrays or panels composed of individual antenna elements. These antenna arrays can be coupled to a radio link.

[0074] The communication device 106 may also include and / or be configured for use with one or more user interface elements. User interface elements may include various elements such as a display 360 (which may be a touch screen display), a keyboard (which may be a separate keyboard or may be implemented as part of the touch screen display), a mouse, a microphone and / or speakers, one or more cameras, one or more buttons, and / or any of a variety of other elements capable of providing information to a user and / or receiving or interpreting user input.

[0075] The communication device 106 may also include one or more smart cards 345 having SIM (Subscriber Identity Module) functionality, such as one or more UICC cards (one or more Universal Integrated Circuit Cards) 345 .

[0076] As shown, the SOC 300 may include a processor 302 that may execute program instructions for the communication device 106 and a display circuit 304 that may perform graphics processing and provide display signals to a display 360. The one or more processors 302 may also be coupled to a memory management unit (MMU) 340 (the MMU may be configured to receive addresses from the one or more processors 302 and translate those addresses into locations in memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310)), and / or to other circuits or devices such as the display circuit 304, wireless communication circuitry 330, connector I / F 320, and / or display 360. The MMU 340 may be configured to perform memory protection and page table translation or setup. In some aspects, the MMU 340 may be included as part of the processor 302.

[0077] As described above, the communication device 106 can be configured to communicate using wireless and / or wired communication circuits. As described herein, the communication device 106 may include hardware and software components for implementing any of the various features and technologies described herein. For example, by executing program instructions stored on a memory medium (e.g., a non-transient computer-readable memory medium), the processor 302 of the communication device 106 can be configured to implement part or all of the features described herein. Alternatively (or in addition thereto), the processor 302 can be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). Alternatively (or in addition thereto), in combination with one or more components in other components 300, 304, 306, 310, 320, 330, 340, 345, 350, 360, the processor 302 of the communication device 106 can be configured to implement part or all of the features described herein.

[0078] Furthermore, as described herein, processor 302 may include one or more processing elements. Thus, processor 302 may include one or more integrated circuits (ICs) configured to perform the functions of processor 302. Furthermore, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform one or more functions of processor 302.

[0079] Furthermore, as described herein, wireless communication circuitry 330 may include one or more processing elements. In other words, one or more processing elements may be included in wireless communication circuitry 330. Thus, wireless communication circuitry 330 may include one or more integrated circuits (ICs) configured to perform the functions of wireless communication circuitry 330. Furthermore, each integrated circuit may include circuitry (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of wireless communication circuitry 330.

[0080] Exemplary Base Station

[0081] Figure 4 1 shows an exemplary block diagram of a base station 102 according to some aspects. Figure 4 The base station 102 is only one example of a possible base station. As shown, the base station 102 may include a processor 404 that may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuit or device that may be configured to receive addresses from the processor 404 and translate those addresses into locations in memory (e.g., memory 460 and read-only memory (ROM) 450).

[0082] The base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide access to the telephone network as described above. Figure 1 and Figure 2 Multiple devices of the telephone network described in, such as UE device 106.

[0083] The network port 470 (or an additional network port) may also or alternatively be configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to multiple devices, such as the UE device 106. In some cases, the network port 470 may couple to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., in other UE devices served by the cellular service provider).

[0084] In some aspects, base station 102 can be a next-generation base station, such as a 5G New Radio (5GNR) base station or "gNB." In such aspects, base station 102 can connect to a legacy evolved packet core (EPC) network and / or to an NR core (NRC) / 5G core (5GC) network. Furthermore, base station 102 can be considered a 5G NR cell and can include one or more transition and reception points (TRPs). Furthermore, a UE capable of operating in accordance with 5G NR can connect to one or more TRPs within one or more gNBs.

[0085] Base station 102 may include at least one antenna 434 and possibly multiple antennas. The at least one antenna 434 may be configured to function as a wireless transceiver and may be further configured to communicate with UE device 106 via radio 430. Antenna 434 communicates with radio 430 via communication chain 432. Communication chain 432 may be a receive chain, a transmit chain, or both. Radio 430 may be configured to communicate via various wireless communication standards, including but not limited to 5G NR, LTE, LTE-A, GSM, UMTS, CDMA2000, Wi-Fi, and the like.

[0086] The base station 102 may be configured to perform wireless communications using multiple wireless communication standards. In some cases, the base station 102 may include multiple radios that enable the base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, the base station 102 may include an LTE radio component for performing communications according to LTE and a 5G NR radio component for performing communications according to 5G NR. In this case, the base station 102 may be able to operate as both an LTE base station and a 5G NR base station. When the base station 102 supports millimeter waves, the 5G NR radio component may be coupled to one or more millimeter wave antenna arrays or panels. As another possibility, the base station 102 may include a multimode radio component capable of performing communications according to any one of multiple wireless communication technologies (e.g., 5G NR and LTE, 5G NR and Wi-Fi, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0087] As further described later herein, BS 102 may include hardware and software components for implementing or supporting specific implementations of the features described herein. The processor 404 of the base station 102 may be configured to implement or support some or all of the embodiments of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 404 may be configured as a programmable hardware element such as an FPGA (field programmable gate array), or as an ASIC (application-specific integrated circuit), or a combination thereof. Alternatively (or in addition), in combination with one or more of the other components 430, 432, 434, 440, 450, 460, and 470, the processor 404 of the base station 102 may be configured to implement or support some or all of the embodiments of the features described herein.

[0088] Furthermore, as described herein, one or more processors 404 may include one or more processing elements. Thus, processor 404 may include one or more integrated circuits (ICs) configured to perform the functions of processor 404. Furthermore, each integrated circuit may include circuitry (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of one or more processors 404.

[0089] Furthermore, as described herein, radio 430 may include one or more processing elements. Thus, radio 430 may include one or more integrated circuits (ICs) configured to perform the functions of radio 430. Furthermore, each integrated circuit may include circuitry (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of radio 430.

[0090] Exemplary cellular communications circuitry

[0091] Figure 5 An exemplary simplified block diagram of a cellular communication circuit according to some aspects is shown. Note that Figure 5 The block diagram of the cellular communication circuitry is only one example of possible cellular communication circuitry; other circuitry, such as circuitry that includes or is coupled to sufficient antennas for different RATs to perform uplink activities using separate antennas, or circuitry that includes or is coupled to fewer antennas, e.g., circuitry that can be shared between multiple RATs, is also possible. According to some aspects, the cellular communication circuitry 330 can be included in a communication device such as the communication device 106 described above. As described above, the communication device 106 can be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet computer, and / or a combination of devices, among other devices.

[0092] The cellular communication circuitry 330 may be (e.g., communicatively; directly or indirectly) coupled to one or more antennas, such as antennas 335a-b and 336 as shown. In some aspects, the cellular communication circuitry 330 may include dedicated receive chains for multiple RATs (including and / or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and / or radio components (e.g., a first receive chain for LTE and a second receive chain for 5G NR). For example, Figure 5 As shown, the cellular communication circuit 330 may include a first modem 510 and a second modem 520. The first modem 510 may be configured for communication according to a first RAT (e.g., such as LTE or LTE-A), and the second modem 520 may be configured for communication according to a second RAT (e.g., such as 5G NR).

[0093] As shown, the first modem 510 may include one or more processors 512 and a memory 516 in communication with the processor 512. The modem 510 may be in communication with a radio frequency (RF) front end 530. The RF front end 530 may include circuitry for transmitting and receiving radio signals. For example, the RF front end 530 may include receive circuitry (RX) 532 and transmit circuitry (TX) 534. In some aspects, the receive circuitry 532 may be in communication with a downlink (DL) front end 550, which may include circuitry for receiving radio signals via the antenna 335a.

[0094] Similarly, the second modem 520 may include one or more processors 522 and a memory 526 in communication with the processor 522. The modem 520 may be in communication with an RF front end 540. The RF front end 540 may include circuitry for transmitting and receiving radio signals. For example, the RF front end 540 may include receive circuitry 542 and transmit circuitry 544. In some aspects, the receive circuitry 542 may be in communication with a DL front end 560, which may include circuitry for receiving radio signals via the antenna 335b.

[0095] In some aspects, the switch 570 can couple the transmit circuitry 534 to an uplink (UL) front end 572. Furthermore, the switch 570 can couple the transmit circuitry 544 to the UL front end 572. The UL front end 572 can include circuitry for transmitting radio signals via the antenna 336. Thus, when the cellular communication circuitry 330 receives an instruction to transmit according to a first RAT (e.g., via a transmit chain including the transmit circuitry 534 and the UL front end 572), the switch 570 can be switched to a first state that allows the first modem 510 to transmit signals according to the first RAT (e.g., via a transmit chain including the transmit circuitry 534 and the UL front end 572). Similarly, when the cellular communication circuitry 330 receives an instruction to transmit according to a second RAT (e.g., via a transmit chain including the transmit circuitry 544 and the UL front end 572), the switch 570 can be switched to a second state that allows the second modem 520 to transmit signals according to the second RAT (e.g., via a transmit chain including the transmit circuitry 544 and the UL front end 572).

[0096] As described herein, the first modem 510 and / or the second modem 520 may include hardware and software components for implementing any of the various features and techniques described herein. For example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), the processors 512, 522 may be configured to implement some or all of the features described herein. Alternatively (or in addition), the processors 512, 522 may be configured as programmable hardware elements, such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit). Alternatively (or in addition), in combination with one or more of the other components 530, 532, 534, 540, 542, 544, 550, 570, 572, 335, and 336, the processors 512, 522 may be configured to implement some or all of the features described herein.

[0097] Furthermore, as described herein, processors 512, 522 may include one or more processing elements. Thus, processors 512, 522 may include one or more integrated circuits (ICs) configured to perform the functions of processors 512, 522. Furthermore, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of processors 512, 522.

[0098] In some aspects, the cellular communication circuitry 330 may include only one transmit / receive chain. For example, the cellular communication circuitry 330 may not include the modem 520, the RF front end 540, the DL front end 560, and / or the antenna 335b. As another example, the cellular communication circuitry 330 may not include the modem 510, the RF front end 530, the DL front end 550, and / or the antenna 335a. In some aspects, the cellular communication circuitry 330 may also not include the switch 570, and the RF front end 530 or the RF front end 540 may communicate with the UL front end 572, for example, directly.

[0099] Exemplary Network Elements

[0100] Figure 6 An exemplary block diagram of a network element 600 according to some aspects is shown. According to some aspects, the network element 600 may implement one or more logical functions / entities of a cellular core network, such as a mobility management entity (MME), a serving gateway (S-GW), an access and management function (AMF), a session management function (SMF), a network slice quota management (NSQM) function, etc. It should be noted that Figure 6The network element 600 is only one example of a possible network element 600. As shown, the core network element 600 may include one or more processors 604 that may execute program instructions for the core network element 600. The processors 604 may also be coupled to a memory management unit (MMU) 640 (which may be configured to receive addresses from the processors 604 and translate these addresses into locations in memory (e.g., memory 660 and read-only memory (ROM) 650)), or to other circuits or devices.

[0101] The network element 600 may include at least one network port 670. The network port 670 may be configured to couple to one or more base stations and / or other cellular network entities and / or devices. The network element 600 may communicate with the base stations (e.g., eNB / gNB) and / or other network entities / devices using any of a variety of communication protocols and / or interfaces.

[0102] As further described later herein, network element 600 may include hardware and software components for implementing or supporting the implementation of the features described herein. The processor 604 of core network element 600 may be configured to implement or support the implementation of part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, processor 604 may be configured as a programmable hardware element such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit), or a combination thereof.

[0103] New Radio (NR) frame structure

[0104] In NR, a radio frame has a defined length of 10 milliseconds (ms) and a subframe length of 1 ms. Parameter sets and frame structures can be dynamically defined based on the subcarrier spacing (SCS) and cyclic prefix overhead. Each subframe can be divided into multiple slots. The number of slots per subframe can vary based on the SCS, typically ranging from one slot per subframe to a maximum of thirty-two or more slots per subframe. Each slot can include fourteen Orthogonal Frequency Domain Modulation (OFDM) symbols. Because the number of slots per subframe can vary, while the subframe length is fixed, the length of each slot can vary based on the number of slots per subframe. In some cases, each slot can be allocated for downlink, uplink, or mixed uplink / downlink. In some cases, NR can also support transmission based on mini-slots, which are fractions of a slot that can be used as the smallest scheduling unit. For example, a mini-slot can include fewer than fourteen symbols of a slot, and the exact number of symbols can be configured as needed. In some cases, a mini-slot can include two, four, or seven symbols. In NR, radio resource control (RRC) can be used to semi-statically configure the timeslot configuration, for example over a period of time.

[0105] Demodulation Reference Signal (DMRS)

[0106] Wireless systems such as NR systems may include separate control and data channels. For example, NR systems may include a physical uplink control channel (PUCCH) that carries uplink control information in the control region of a transmission. The data region may be allocated to a physical uplink shared channel (PUSCH) that carries user data. In NR systems, data may be transmitted from the gNB to the UE via the physical downlink shared channel (PDSCH). The physical uplink control channel (PUCCH) may be used to acknowledge receipt of data. Downlink and uplink channels or transmissions may use time division duplexing (TDD) or frequency division duplexing (FDD). DMRS is typically embedded in PUCCH, PUSCH, and PDSCH transmissions. DMRS provides data for demodulating these channels and a phase reference for channel estimation and is therefore specific to each UE. In some cases, the DMRS design may be specific to each channel and configurable as needed. For example, the gNB may transmit scheduling and configuration information for channels such as PUCCH, PUSCH, and PDSCH via RRC. The scheduling information is semi-static and may define how and when to transmit or receive PUCCH, PUSCH, and PDSCH within a period of time.

[0107] NR timeslot channel estimation example

[0108] Turning now to the diagram showing a radio frame Figure 7, which illustrates an example of channel estimation 700 for a time slot using DMRS according to aspects of the present disclosure. For clarity, the example of channel estimation 700 illustrates a subframe with two time slots (i.e., time slot 0 702 and time slot 1 704). The frequency resources may be a number of PRBs scheduled by the gNB. Each time slot includes fourteen OFDM symbols 706. The gNB may configure the UE to transmit DMRS 708 along with the PUSCH transmission based on the PUSCH schedule. The PUSCH schedule may include a repetition indication that indicates to the UE the number of times the PUSCH and DMRS should be repeated. In this example, the UE is configured to repeat the PUSCH over two time slots and transmit the PUSCH with associated DMRS four times per time slot, thus transmitting DMRS in symbols 2, 5, 8, and 11 per time slot. The configuration may also include the specific DMRS symbols to be transmitted. Channel estimation 710 may be performed by the gNB based on the repeated DMRS transmissions associated with the PUSCH transmissions from the UE. For example, channel estimation 710 may be performed by extracting pilot symbols for DMRS transmissions in symbols 2, 5, 8, and 11 of time slot 0 702; estimating the channel for the extracted pilot symbols; and averaging and / or interpolating the estimates to generate an estimate of the channel for the symbols across time slot 0 702.

[0109] Since DMRS signaling is included with PUCCH, PUSCH, and PDSCH, the amount of DMRS signaling is also semi-statically configured along with the corresponding channel. When semi-statically configured, the DMRS does not change, while the channel itself may change, for example, due to changing environmental conditions, UE movement, etc. Since the accuracy of DMRS-based channel estimation generally depends on how close the DMRS is to the channel in time, frequency, and signal-to-noise ratio (SNR) measurements, semi-statically defined DMRS may have lower spectral efficiency because the DMRS cannot be adjusted to account for rapidly changing (or suddenly static) channel conditions. In addition, DMRS-based channel estimation is performed on a per-slot basis, thereby limiting the amount of DMRS coverage that can be used for data channel transmission.

[0110] Cross-slot channel estimation

[0111] To help improve channel coverage and use available bandwidth more efficiently, channel estimation for DMRS can be performed across time slots. For example, by combining DMRS over multiple time slots, a more accurate channel estimate can be determined. By achieving more accurate channel estimates, overall DMRS overhead can be reduced or optimized while maintaining or improving channel reliability. As discussed herein, DMRS may be discussed in conjunction with specific physical channels (e.g., PUCCH, PUSCH, PDSCH, etc.), but it should be understood that the DMRS techniques discussed herein are applicable to any channel that can benefit from DMRS signals.

[0112] According to various aspects of the present disclosure, channels (e.g., PUCCH, PUSCH, PUDSCH, etc.) may be configured. For example, the gNB may transmit a channel control message to the UE, e.g., via RRC, which includes, among other configuration information, scheduling and repetition information for the control message and DMRS configuration information, such as the number of DMRS symbols to be included in the channel. The UE may also transmit, e.g., via RRC, UE capability information indicating that the UE supports enhanced channel estimation. The indication that the UE supports enhanced channel estimation may be sent as part of a UE capability report, e.g., in response to a UE capability query from the gNB. The indication that the UE supports enhanced channel estimation may indicate that the UE supports inter-slot channel estimation, dynamic DMRS configuration, both, or may be combined with any number of other capability signaling. In some cases, such as when the UE initially connects to the wireless network, the UE capability report may be transmitted in response to a channel control message or as part of a capability exchange between the UE and the wireless network. In some cases, the gNB may receive UE capability information from a source external to the UE, such as from the wireless network. If the gNB receives an indication that the UE supports inter-slot channel estimation, the gNB may configure the UE for inter-slot channel estimation. For example, the gNB may transmit DMRS configuration information indicating the channel estimation bundling window to the UE. In some cases, the DMRS configuration information may be transmitted to the UE via RRC signaling. In some cases, the DMRS configuration information may be sent to the UE using a new field added to the downlink control information (DCI) or via a medium access control (MAC) control element (MAC-CE). For example, a single bit may be added to the DCI or MAC CE to indicate whether cross-slot channel estimation is enabled or disabled. In this case, the number of timeslots on which channel estimation can be performed may be predetermined. As another example, two bits may be added to the DCI or MAC CE to indicate whether cross-slot channel estimation is enabled and, if so, the number of timeslots on which channel estimation can be performed.

[0113] The channel estimation bundling window may indicate a time period during which channel estimation may be performed based on the DMRS signal. In some cases, the channel estimation bundling window may be set to a period of time, multiple slots / mini-slots, multiple symbols, etc. The channel estimation bundling window may span two or more slots.

[0114] In some cases, if the channel is a UL channel, such as PUSCH, PUCCH, etc., the UE may use a channel estimation bundling window to determine the time period (e.g., the time required for transmission across multiple time slots) during which the UE should maintain phase continuity of its DMRS transmissions to facilitate joint processing of the DMRS transmissions by the gNB. The UE may transmit DMRS along with the associated UL channel during the time period used for the channel estimation bundling window based on the channel configuration, number of repetitions, DMRS configuration, etc.

[0115] In some cases, if the channel is a DL channel, such as PDSCH, PDCCH, etc., the UE may use a channel estimation bundling window to determine the time period during which the UE should apply joint DMRS processing for channel estimation across different DMRS repetitions (and / or transport blocks). The gNB may then transmit using the same precoding for the DL channel and associated DMRS used for the initial transmission, along with repetitions across multiple slots in the channel estimation bundling window.

[0116] After the initial and repeated DMRS signals are received by the UE or gNB, channel estimation can then be performed across one or more time slots. Channel estimation across multiple time slots can be performed in a manner similar to channel estimation within a single time slot. For example, channel estimation can be based on least squares estimation, averaging, interpolation, or any other channel estimation technique.

[0117] In some cases, the transmit power of the UE's DMRS transmissions on the UL and the gNB's DMRS transmissions on the DL may remain constant over the initial DMRS transmission and repetitions within the channel estimation bundling window. In some cases, if the UE receives a transmit power control (TPC) command during the channel estimation bundling window, the UE may ignore the TPC command for the duration of the channel estimation bundling window. In some cases, after the channel estimation bundling window ends, the UE may apply the TPC command or continue to ignore the TPC command. In some cases where minislots are used, channel estimation bundling may be configured to span two or more minislots, and channel estimation may be performed over the two or more minislots in a manner similar to that described for channel estimation across two or more slots.

[0118] Figure 8is a radio frame diagram illustrating an example of cross-slot channel estimation 800 according to aspects of the present disclosure. In this example, a UE may be configured by a gNB to repeatedly transmit the PUSCH on the UL, such that the same time and frequency domain resources are allocated for multiple (here, four) consecutive slots (slots 802, 804, 806, and 808). The gNB may also configure DMRS 816 for the UE, e.g., such that for a single DMRS symbol 816, dmrs-additionalPosition = 3, so that the UE transmits DMRS 816 in symbols 2, 5, 8, and 11 of each slot. The gNB may also indicate to the UE that the channel estimation bundling window is two slots long. Therefore, the UE may then transmit DMRS 816 for slot 0 802 and slot 1 804 in symbols 2, 5, 8, and 11 of each slot with the same phase continuity, so that the gNB may perform joint channel estimation 810 for the UE across slots 0 802 and 1 804.

[0119] In some cases, the channel estimation bundling window may be a sliding channel estimation bundling window. The sliding channel estimation bundling window may be considered to be sliding the channel estimation bundling window across time slots 802, 804, 806, and 808 that repeat along the PUSCH. Thus, in this example, time slot 0 802 and time slot 1 804 may be bundled, and joint channel estimation 810 may be performed on time slot 0 802 and time slot 1 804. The channel estimation bundling window may then slide over to include time slot 1 804 and time slot 2 806, and joint channel estimation 812 performed on time slot 1 804 and time slot 2 806. The channel estimation bundling window may then slide over to include time slot 2 806 and time slot 3 808, and joint channel estimation 814 performed on time slot 2 806 and time slot 3 808. For a sliding channel estimation bundling window, phase continuity can be maintained across repeated PUSCH transmissions (e.g., four consecutive time slots 802, 804, 806, and 808). Similarly, the transmit power can be kept constant across repeated PUSCH transmissions. In some cases, the timing advance of the transmission can also be kept constant across repeated PUSCH transmissions. It will be appreciated that while this example involves UL channels, the techniques described herein can be applied in a similar manner to DL channels.

[0120] Figure 9is a radio frame diagram illustrating an example of cross-slot channel estimation 900 with a fixed channel estimation bundling window according to various aspects of the present disclosure. In some cases, the channel estimation bundling window can be a fixed channel estimation bundling window. For a fixed channel estimation bundling window, the channel estimation bundling window can be defined one after another over a set number of time slots. In this example, the UE can be configured by the gNB to repeatedly transmit the PUSCH on the UL so that the same time domain and frequency domain resources are allocated for multiple (here, four) consecutive time slots (time slots 902, 904, 906, and 908). This example shows a channel estimation bundling window defined across two time slots, where time slot 0 902 and time slot 1 904 are in a first channel estimation bundling window and time slot 2 906 and time slot 3 908 are in a second channel estimation bundling window. Joint channel estimation 910 may be performed based on DMRS 914 transmissions in time slot 0 902 and time slot 1 904, and joint channel estimation 912 may be performed based on DMRS 914 transmissions in time slot 2 906 and time slot 3 908. In some cases, phase continuity of transmissions is maintained within a channel estimation bundling window. Thus, a first channel estimation bundling window may be associated with different phase continuity than a second channel estimation bundling window. Similarly, transmit power is maintained within a given channel estimation bundling window. In some cases, if a TPC command is received within a channel estimation bundling window, the TPC command may be ignored for the ongoing channel estimation bundling window and then applied to the next channel estimation bundling window. Similarly, timing advance may also be maintained within a given channel estimation bundling window. In some cases, if a timing advance command is received within a channel estimation bundling window, the timing advance command may be ignored for the ongoing channel estimation bundling window and then applied to the next channel estimation bundling window. It will be appreciated that although UL channels are involved in this example, the techniques involved herein can be applied in a similar manner to DL channels.

[0121] Dynamic DMRS configuration

[0122] To help improve DMRS efficiency, the number of DMRS transmissions for a channel can be dynamically configured. In some cases, a UE can be configured by the gNB to transmit DMRS more frequently. For example, if the UE is relatively far from the gNB and moving rapidly, or if the channel quality between the UE and the gNB changes frequently, the UE may be considered to be at or near coverage-limited, and the gNB may configure the UE to transmit DMRS more frequently. However, DMRS configuration via RRC is semi-static, and there may be significant delays between DMRS reconfiguration opportunities using RRC. Additionally, because cross-slot channel estimation helps allow for cross-slot channel estimation, the number of DMRS samples per slot can be reduced. For example, a UE can be configured by the gNB to transmit DMRS four times in a slot with a two-slot long channel estimation bundling window. Such a configuration can estimate the channel based on eight DMRS samples. In some cases, if the received channel quality is high, the gNB may determine that the channel estimate can be sufficiently determined based on fewer DMRS samples for the channel estimation bundling window. For example, if the UE is relatively far from the gNB but stationary and encounters relatively little interference, the channel may be relatively stable. In some cases, the gNB can signal the UE to reduce the number of DMRS symbols and allow the UE to transmit fewer DMRS samples. The gNB can use a new field added to the DCI or via the MAC-CE to signal the UE. For example, a bit can be added to the DCI or MAC-CE to indicate whether DMRS signaling is reduced. As another example, if multiple bits are available, the number of DMRS symbols or specific symbols to be reduced can be indicated. In this case, the UE can halve the number of transmitted DMRS symbols, for example, from four DMRS symbols per slot to two, or otherwise reduce the number of DMRS symbols by a defined amount (e.g., to reduce DMRS density). Symbols no longer used for DMRS can be used for PUSCH / PUCCH / PDSCH signaling.

[0123] In some cases, the Phase Tracking Reference Signal (PTRS) can be dynamically adjusted based on the DMRS density. For example, the PTRS density (e.g., the number of resource elements on which the PTRS signal is transmitted) can be correlated with the indicated DMRS density, such that an indication of a reduced number of DMRS symbols can result in a reduced PTRS density, and vice versa. In some cases, the DMRS port can be varied per channel estimation bundling window to help allow for greater frequency diversity. In some cases, this DMRS port hopping can be used in conjunction with a fixed or non-overlapping channel estimation bundling window. In some cases, a new bit can be added to the DL DCI to indicate the PTRS density.

[0124] Figure 101000 is a radio frame diagram illustrating an example of dynamic DMRS configuration 1000 according to aspects of the present disclosure. In this example, a UE may initially be configured by the gNB via an RRC message to transmit DMRS signals four times in slots with a two-slot long channel estimation bundling window (here, slot 0 1002 and slot 1 1004). The gNB may then determine that the DMRS for the UE is overconfigured and may need to be reduced. The gNB may then signal the UE, for example, via DCI or MAC-CE, to reduce the amount of DMRS signaling. In some cases, the DMRS density may be reduced for each slot in the bundling window. In this example, the UE may initially have been configured to transmit DMRS in symbols 2, 5, 8, and 11 of each slot. After DMRS reduction, the UE may transmit DMRS in symbols 2 1006A and 8 1006B of slot 0 1002, and symbols 2 1006C and 8 1006D of slot 1 1004. The gNB may then perform joint channel estimation for slot 0 1002 and slot 1 1004 based on the received DMRS.

[0125] Figure 111100 is a radio frame diagram illustrating an example of dynamic DMRS configuration according to various aspects of the present disclosure. In certain situations, DMRS density can be reduced by transmitting DMRS signals in specific slots of a channel estimation bundling window. In this example, the UE may initially be configured by the gNB via an RRC message to transmit DMRS signals four times in slots having a two-slot channel estimation bundling window with a fixed channel estimation bundling window. Here, slot 0 1102 and slot 1 1104 may be included in the first channel estimation bundling window, and slot 2 1110 and slot 3 1112 may be included in the second channel estimation bundling window. The UE may then receive an indication from the gNB, such as via DCI or MAC-CE signaling, to reduce the DMRS density. In this example, the DMRS density may be reduced by half. When the DMRS density is reduced, the DMRS may be front-loaded and transmitted in one or more slots preceding the channel estimation bundling window (e.g., a three-slot channel estimation bundling window may already have DMRS signaling in the first two slots when the DMRS density is reduced). DMRS signaling in later time slots (e.g., later in time) can be removed. In this example, DMRS 1106 signaling occurs in time slot 0 1102 of the first channel estimation bundling window and time slot 2 1110 of the second channel estimation bundling window. DMRS 1106 signaling does not occur in time slot 1 1104 of the first channel estimation bundling window and time slot 2 1112 of the second channel estimation bundling window. The gNB can still perform joint channel estimation 1108 for the first channel estimation bundling window spanning time slot 0 1102 and time slot 11104, and for the first channel estimation bundling window 1114 spanning time slot 2 1110 and time slot 3 1112. In some cases, DMRS can be transmitted in earlier time slots to help allow channel estimation to be performed earlier in time and avoid potential channel decoding delays.

[0126] In some cases, when DMRS density is reduced, DMRS may be transmitted in certain time slots based on a pattern. For example, DMRS may be transmitted in one time slot every two time slots, so that DMRS may be transmitted in the first, third, and fifth time slots, while DMRS may be omitted in the second, fourth, and sixth time slots. This pattern may be per channel estimation bundling window.

[0127] Figure 1212 is a radio frame diagram illustrating an example of dynamic DMRS configuration 1200 according to aspects of the present disclosure. In this example, a UE may initially be configured by the gNB via an RRC message to transmit DMRS signals four times in slots having a two-slot long channel estimation bundling window with a sliding channel estimation bundling window. Here, slot 0 1202 and slot 1 1204 may be included in a first channel estimation bundling window, slot 1 1204 and slot 2 1210 may be included in a second channel estimation bundling window, and slot 2 1210 and slot 3 1214 may be included in a third channel estimation bundling window. The UE may then receive an indication from the gNB, such as via DCI or MAC CE signaling, to reduce DMRS density. In this example, the DMRS density may be reduced by half. As the DMRS density decreases, the DMRS may be reduced based on a pattern. In this example, DMRS is transmitted every other time slot, and thus DMRS is transmitted in time slot 0 1202 and time slot 2 1210, and is omitted from time slot 1 1 204 and time slot 3 1214. Joint channel estimation 1208 may be performed on a first channel estimation bundling window across time slot 0 1202 and time slot 1 1204 based on the DMRS transmitted in time slot 0 1202. Another joint channel estimation 1212 may be performed on a second channel estimation bundling window across time slot 1 1204 and time slot 2 1210 based on the DMRS transmitted in time slot 2 1210. Another joint channel estimation 1216 may also be performed on a third channel estimation bundling window across time slot 2 1210 and time slot 3 1214 based on the DMRS transmitted in time slot 2 1210.

[0128] In some cases, when DMRS is front-loaded and / or transmitted based on the pattern, the transmit power and phase can be maintained across the channel estimation bundling window. In some cases, the sounding reference signal (SRS) can be omitted from the first time slot and / or the time slot used for transmitting DMRS. It will be understood that although the examples involve UL channels, the techniques described herein can be applied in a similar manner to DL channels.

[0129] Figure 131300 is a radio frame diagram illustrating an example of cross-slot channel estimation for NR TDD 1300 according to aspects of the present disclosure. To help maintain phase continuity, the gNB and / or network may indicate, for example, via DIC or MAC CE signaling, that the cross-slot channel estimation bundling window is contiguous UL slots in the UL-DL configuration. In this example, two UL-DL configurations are configured: DSUUD in slots 1-5 and DSUDD in slots 6-0, where D represents a DL slot, S represents a special slot containing DL symbols, and U represents an UL slot. In this UL-DL configuration, slots 2-4 and slots 7-8 are contiguous UL slots, and DMRS 1306 may be transmitted in one or more contiguous UL slots, as described above. Therefore, cross-slot channel estimation 1302 and 1304 may be performed in a manner similar to that described above for slots 2-4 and slots 7-8, respectively. It will be appreciated that although UL channels are involved in this example, the techniques described herein may be applied in a similar manner to DL channels (eg, a cross-slot channel estimation bundling window may be defined for consecutive DL slots in a UL-DL configuration).

[0130] Figure 14A14 is a flow chart illustrating a technique for channel estimation in a wireless system 1400 according to aspects of the present disclosure. At block 1402, a wireless device receives an indication of a physical downlink channel configuration for receiving a physical downlink channel transmission, the physical downlink channel transmission including a demodulation reference signal (DMRS). For example, the UE may receive a DL channel configuration message via RRC, thereby configuring the UE to receive the DL channel and the DMRS transmitted along with the DL channel from a gNB. At block 1404, the wireless device transmits an indication that the wireless device supports bundling of DMRS signals across multiple time slots. For example, the UE may indicate support for cross-slot channel estimation and / or dynamic DMRS configuration via a UE capabilities message. At block 1406, the wireless device receives a DMRS configuration including a channel estimation bundling window indicating that channel estimation may be performed across multiple time slots. For example, the wireless device may receive the DMRS configuration via a DCI or MAC CE message. At block 1408, a set of DMRS signals may be received within a channel estimation bundling window based on the DMRS configuration, wherein a first DMRS signal of the set of DMRS signals is received in a first time slot, and wherein a second DMRS signal of the set of DMRS signals is received in a second time slot. At block 1410, a radio channel may be estimated based on the first DMRS signal and the second DMRS signal. For example, the UE may estimate the downlink radio channel across multiple time slots. At block 1412, a transmission from a wireless node may be decoded based on the estimated radio channel. For example, DMRS may be used to estimate the radio channel and to decode transmissions received from a gNB over the radio channel.

[0131] Figure 14B 14 is a flow chart illustrating various ways to receive an indication of the physical downlink channel configuration of step 1406 according to various aspects of the present disclosure. At block 1452, an option is provided in which the DMRS configuration includes an indication that the DMRS signal can be estimated across different DMRS repetitions. At block 1454, an option is provided in which the DMRS configuration includes an indication that the DMRS signal can be estimated across different transport blocks. At block 1456, an option is provided in which the DMRS configuration is received via one of radio resource control signaling, within a field in the DCI, or within a MAC CE. At block 1458, an option is provided in which the same PDSCH precoding is used within the channel estimation bundling window. At block 1460, an option is provided in which the physical downlink channel includes one of a physical downlink shared channel or a physical downlink control channel.

[0132] Figure 15A1 is a flow chart illustrating a technique for channel estimation in a wireless system 1500 according to aspects of the present disclosure. At block 1502, a wireless device receives an indication of a physical uplink channel configuration for transmitting a physical uplink channel transmission including an indication of a demodulation reference signal (DMRS) schedule. For example, the UE may receive an UL channel configuration message via RRC to configure the UE to transmit an UL channel and a DMRS associated with the UL channel. At block 1504, the wireless device transmits an indication that the wireless device supports bundling of DMRS signals across multiple time slots. For example, the UE may indicate support for cross-slot channel estimation and / or dynamic DMRS configuration via a UE capability message. At block 1506, the wireless device receives a DMRS configuration including a channel estimation bundling window indicating that channel estimation may be performed across multiple time slots. At block 1508, a set of DMRS signals is transmitted to a wireless node within the channel estimation bundling window based on the DMRS configuration, wherein a first DMRS signal in the set of DMRS signals is transmitted in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is transmitted in a second time slot, and wherein the first DMRS signal and the second DMRS signal are configured to be used by the wireless node to estimate a radio channel. For example, the wireless device may receive the DMRS configuration via a DCI or MAC CE message, and the UE may transmit the DMRS signals in a plurality of time slots based on the DMRS configuration, and which are configured for the gNB to estimate the radio channel across the plurality of time slots.

[0133] Figure 15B 1 is a flow chart illustrating various ways to receive a DMRS configuration for step 1506 according to aspects of the present disclosure. At block 1522, an option is provided in which the physical uplink channel comprises one of a physical uplink shared channel or a physical uplink control channel. At block 1524, an option is provided in which the DMRS configuration indicates the number of time slots used for the channel estimation bundling window. At block 1526, an option is provided in which the first DMRS signal and the second DMRS signal are transmitted with the same power.

[0134] Figure 15Cis a flow chart illustrating various options 1524 in which a DMRS configuration indicates a number of time slots for a channel estimation bundling window in accordance with various aspects of the present disclosure. In some cases, the number of time slots may be indicated by specifying a particular time slot, mapping, and / or number of time slots. At box 1534, an option is provided in which a channel estimation bundling window is defined for a set of time slots. At box 1536, an option is provided in which DMRS signals transmitted within the channel estimation bundling window are transmitted with the same power. At box 1538, an option is provided in which the same timing advance is applied to DMRS signals transmitted within the channel estimation bundling window. At box 1540, an option is provided in which the channel estimation bundling window includes a sliding window of the number of time slots of the channel estimation bundling window. At box 1542, an option is provided in which the number of time slots of the channel estimation bundling window is the same as the number of time slots in the uplink / downlink configuration.

[0135] Figure 15D 15 is a flow chart illustrating various ways to transmit an indication 1504 that a wireless device supports bundling DMRS signals across multiple time slots, according to aspects of the present disclosure. At block 1552, the wireless device transmits an indication that the wireless device supports dynamic DMRS reconfiguration. For example, this indication may be separate from, or combined with, an indication that the wireless device supports bundling DMRS. In some cases, the indication that the wireless device supports bundling DMRS may indicate that the wireless device supports dynamic DMRS reconfiguration. At block 1554, the wireless device receives an RRC signal indicating the number of DMRS signals to be transmitted in a time slot. At block 1556, the wireless device receives a DMRS reconfiguration indication that changes the number of DMRS signals to be transmitted in a time slot, wherein the DMRS reconfiguration indication is received within a DCI or MAC CE message. At block 1558, an option is provided to reconfigure the number of DMRS signals for each time slot of a channel estimation bundling window. At block 1560, an option is provided to reconfigure the number of DMRS signals for fewer than all time slots of the channel estimation bundling window. For example, the DMRS signal may be reconfigured based on a transmission pattern across slots of the channel estimation bundling window.At block 1562, an option is provided in which the DMRS signal is reconfigured such that the DMRS signal is not transmitted in at least one slot of the channel estimation bundling window.

[0136] Figure 16A1 is a flow chart illustrating a technique for channel estimation in a wireless system 1600 according to aspects of the present disclosure. At block 1602, an indication of a physical downlink channel configuration for receiving a physical downlink channel transmission, including a demodulation reference signal (DMRS), is transmitted to a wireless node. For example, the wireless node may transmit a DL channel configuration message via RRC to configure the UE to receive the DL channel and the DMRS transmitted with the DL channel from the wireless node. At block 1604, an indication is received from the wireless device that the wireless device supports bundling of DMRS signals across multiple time slots. For example, the wireless node may receive an indication of support for cross-slot channel estimation and / or dynamic DMRS configuration from the UE via a UE capabilities message. At block 1606, a DMRS configuration is transmitted to the wireless device, the DMRS configuration including a channel estimation bundling window indicating that channel estimation may be performed across multiple time slots. For example, the wireless node may transmit the DMRS configuration to the UE via a DCI or MAC CE message. At block 1608, a set of DMRS signals is transmitted to the wireless node in a channel estimation bundling window and based on the DMRS configuration, wherein a first DMRS signal in the set of DMRS signals is transmitted in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is transmitted in a second time slot, and wherein the first DMRS signal and the second DMRS signal are configured to be used by the wireless device to estimate a radio channel based on the first DMRS signal and the second DMRS signal. For example, a gNB may transmit a signal to a UE via a DL channel in multiple time slots, the signal including the DMRS signals in the multiple time slots. The DMRS signals may be configured to be used by the UE to estimate the radio channel and decode transmissions received from the gNB over the radio channel.

[0137] Figure 16B 1 is a flow chart illustrating various ways to transmit a DMRS configuration to a wireless device for step 1606 according to various aspects of the present disclosure. At block 1652, an option is provided in which the DMRS configuration includes an indication that the DMRS signal can be estimated across different DMRS repetitions. At block 1654, an option is provided in which the DMRS configuration includes an indication that the DMRS signal can be estimated across different transport blocks. At block 1656, an option is provided in which the DMRS configuration is transmitted via one of radio resource control signaling, within a field in a DCI, or within a MAC CE. At block 1658, an option is provided in which the same PDSCH precoding is used within the channel estimation bundling window. At block 1660, an option is provided in which the physical downlink channel includes one of a physical downlink shared channel or a physical downlink control channel.

[0138] Figure 16Cis a flow chart illustrating various ways to transmit a set of DMRS signals in a channel estimation bundling window by a wireless node and based on a DMRS configuration for step 1608 in accordance with aspects of the present disclosure. At block 1662, an option is provided in which the first DMRS signal and the second DMRS signal are transmitted with the same power.

[0139] Figure 17A 17 is a flow chart illustrating a technique for channel estimation in a wireless system 1700 according to aspects of the present disclosure. At block 1702, an indication of a physical uplink channel configuration for transmitting a physical uplink channel transmission including a DMRS-scheduled physical uplink channel is transmitted to a wireless device. For example, the wireless node may transmit an UL channel configuration message via RRC to configure the UE to transmit an UL channel and a DMRS to be transmitted along with the UL channel. At block 1704, an option is provided where the physical uplink channel includes one of a physical uplink shared channel or a physical uplink control channel. At block 1706, an indication is received from the wireless device that the wireless device supports bundling of DMRS signals across multiple time slots. For example, the wireless node may receive an indication of support for cross-slot channel estimation and / or dynamic DMRS configuration from the UE via a UE capabilities message. At block 1708, a DMRS configuration is transmitted to the wireless device, the DMRS configuration including a channel estimation bundling window indicating that channel estimation may be performed across multiple time slots. For example, the wireless node may transmit the DMRS configuration to the UE via a DCI or MAC CE message. At block 1710, an option is provided in which the DMRS configuration indicates the number of time slots used for the channel estimation bundling window. At block 1712, a set of DMRS signals is received by a wireless node based on the DMRS configuration and within the channel estimation bundling window, wherein a first DMRS signal in the set of DMRS signals is received in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is received in a second time slot. For example, the gNB may receive a signal from a UE via an UL channel in multiple time slots, the signal including DMRS signals in the multiple time slots. The DMRS signals may be configured for use by the gNB in estimating a radio channel and decoding transmissions received from the UE over the radio channel. At block 1714, the radio channel is estimated based on the first DMRS signal and the second DMRS signal. For example, the radio channel may be estimated across multiple time slots. At block 1716, the transmission from the wireless device is decoded based on the estimated radio channel.

[0140] Figure 17B17 is a flowchart for estimating a radio channel based on a first DMRS signal and a second DMRS signal at block 1714 according to aspects of the present disclosure. At block 1732, an option is provided in which the radio channel is estimated based on the first DMRS signal and the second DMRS signal transmitted at the same power within a channel estimation bundling window. At block 1734, an option is provided in which the radio channel is estimated based on the first DMRS signal and the second DMRS signal transmitted at the same timing advance within the channel estimation bundling window.

[0141] Figure 17C 1 is a flow chart illustrating an option for block 1710 in which the DMRS configuration indicates the number of time slots used for the channel estimation bundling window in accordance with aspects of the present disclosure. At block 1740, an option is provided in which the channel estimation bundling window is defined for a group of time slots. At block 1742, an option is provided in which the channel estimation bundling window comprises a sliding window of the number of time slots of the channel estimation bundling window. At block 1744, an option is provided in which the number of time slots of the channel estimation bundling window is the same as the number of time slots in the uplink / downlink configuration.

[0142] Figure 17D 1 is a flow chart illustrating various ways to receive an indication that a wireless device supports bundling DMRS signals across multiple time slots at block 1706, according to aspects of the present disclosure. At block 1752, an indication is received from the wireless device that the wireless device supports dynamic DMRS reconfiguration. For example, this indication may be separate from, or combined with, an indication that the wireless device supports bundling DMRS. In some cases, the indication that the wireless device supports bundling DMRS may indicate that the wireless device supports dynamic DMRS reconfiguration. At block 1754, a radio resource control signal is transmitted to the wireless device indicating the number of DMRS signals to be transmitted in the time slot. For example, DMRS signaling may be configured based on an RRC message. At block 1756, a DMRS reconfiguration indication is transmitted to the wireless device, the DMRS reconfiguration indication changing the number of DMRS signals to be transmitted in the time slot, wherein the DMRS reconfiguration indication is transmitted within a DCI or within a MAC CE. At block 1758, an option is provided in which the number of DMRS signals is adjusted for each time slot of the channel estimation bundling window. At block 1760, an option is provided in which the number of DMRS signals is adjusted for fewer than all time slots of the channel estimation bundling window. For example, the DMRS signals may be reconfigured based on a transmission pattern across the time slots of the channel estimation bundling window. At block 1762, an option is provided in which the DMRS signals are reconfigured so that no DMRS signals are transmitted in at least one time slot of the channel estimation bundling window.

[0143] Example

[0144] In the following sections, additional exemplary aspects are provided.

[0145] According to embodiment 1, a method for channel estimation in a wireless system includes: receiving, by a wireless device, an indication of a physical downlink channel configuration for receiving a physical downlink channel transmission, the physical downlink channel transmission including a demodulation reference signal (DMRS); transmitting, by the wireless device, an indication that the wireless device supports bundling of DMRS signals across multiple time slots; receiving, by the wireless device, a DMRS configuration, the DMRS configuration including a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; receiving, based on the DMRS configuration, a group of DMRS signals within the channel estimation bundling window, wherein a first DMRS signal in the group of DMRS signals is received in a first time slot, and wherein a second DMRS signal in the group of DMRS signals is received in a second time slot; estimating a radio channel based on the first DMRS signal and the second DMRS signal; and decoding a transmission from a wireless node based on the estimated radio channel.

[0146] Embodiment 2 includes the subject matter of embodiment 1, wherein the physical downlink channel comprises one of a physical downlink shared channel (PDSCH) or a physical downlink control channel (PDCCH).

[0147] Embodiment 3 includes the subject matter of embodiment 2, wherein the same PDSCH precoding is used within the channel estimation bundling window.

[0148] Embodiment 4 includes the subject matter of embodiment 1, wherein the DMRS configuration includes an indication that the DMRS signal can be estimated across different transport blocks.

[0149] Embodiment 5 includes the subject matter of embodiment 1, wherein the DMRS configuration includes an indication that the DMRS signal can be estimated across different DMRS repetitions.

[0150] Embodiment 6 includes the subject matter of embodiment 1, wherein the DMRS configuration is received via one of radio resource control signaling, within a field in downlink control information (DCI), or within a medium access control element (MAC CE).

[0151] According to embodiment 7, a method for channel estimation in a wireless system includes: receiving an indication of a physical uplink channel configuration by a wireless device, the physical uplink channel configuration being used to transmit a physical uplink channel transmission including a demodulation reference signal (DMRS); transmitting, by the wireless device, an indication that the wireless device supports bundling DMRS signals across multiple time slots; receiving a DMRS configuration by the wireless device, the DMRS configuration including a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; and based on the DMRS configuration, transmitting a group of DMRS signals to a wireless node within the channel estimation bundling window, wherein a first DMRS signal in the group of DMRS signals is transmitted in a first time slot, and wherein a second DMRS signal in the group of DMRS signals is transmitted in a second time slot, wherein the first DMRS signal and the second DMRS signal are configured to be used by the wireless node to estimate a radio channel.

[0152] Embodiment 8 includes the subject matter of embodiment 7, wherein the first DMRS signal and the second DMRS signal are transmitted with the same power.

[0153] Embodiment 9 includes the subject matter of embodiment 7, wherein the physical uplink channel comprises one of a physical uplink shared channel or a physical uplink control channel.

[0154] Embodiment 10 includes the subject matter of embodiment 7, wherein the DMRS configuration indicates a number of time slots used for the channel estimation bundling window.

[0155] Embodiment 11 includes the subject matter of embodiment 10, wherein the channel estimation bundling window is defined for a group of time slots.

[0156] Embodiment 12 includes the subject matter of embodiment 11, wherein the DMRS signals transmitted within the channel estimation bundling window are transmitted with the same power.

[0157] Embodiment 13 includes the subject matter of embodiment 11, wherein the same timing advance is applied to the DMRS signals transmitted within the channel estimation bundling window.

[0158] Embodiment 14 includes the subject matter of embodiment 10, wherein the channel estimation bundling window comprises a sliding window of the number of time slots of the channel estimation bundling window.

[0159] Embodiment 15 includes the subject matter of embodiment 10, wherein the number of time slots of the channel estimation bundling window is the same as the number of time slots in an uplink / downlink configuration.

[0160] Embodiment 16 includes the subject matter of embodiment 7, further comprising: transmitting an indication from the wireless device that the wireless device supports dynamic DMRS reconfiguration; receiving, by the wireless device, a radio resource control signal indicating a number of DMRS signals to be transmitted in a time slot; receiving, by the wireless device, a DMRS reconfiguration indication that changes the number of DMRS signals to be transmitted in a time slot, wherein the DMRS reconfiguration indication is received within downlink control information (DCI) or within a medium access control control element (MAC CE) message.

[0161] Embodiment 17 includes the subject matter of embodiment 16, wherein the number of DMRS signals is reconfigured for each time slot of the channel estimation bundling window.

[0162] Embodiment 18 includes the subject matter of embodiment 16, wherein the number of DMRS signals is reconfigured for less than all time slots of the channel estimation bundling window.

[0163] Embodiment 19 includes the subject matter of embodiment 18, wherein the DMRS signal is reconfigured such that a DMRS signal is not transmitted in at least one time slot of the channel estimation bundling window.

[0164] Embodiment 20 includes the subject matter of embodiment 19, wherein the DMRS signal is reconfigured such that the DMRS signal is transmitted in a time slot that is transmitted earlier in time than the at least one time slot in which the DMRS signal is not transmitted.

[0165] Embodiment 21 includes the subject matter of embodiment 16, wherein the DMRS port is changed for each channel estimation bundling window.

[0166] Embodiment 22 includes the subject matter of embodiment 16, further comprising transmitting, by the wireless device, an indication that the wireless device supports DMRS reconfiguration.

[0167] According to embodiment 23, a method for channel estimation in a wireless system comprises: transmitting an indication of a physical downlink channel configuration for receiving a physical downlink channel transmission to a wireless device, the physical downlink channel transmission comprising a demodulation reference signal (DMRS); receiving an indication from the wireless device that the wireless device supports bundling of DMRS signals across multiple time slots; transmitting a DMRS configuration to the wireless device, the DMRS configuration comprising a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; transmitting, by a wireless node and based on the DMRS configuration, a group of DMRS signals in the channel estimation bundling window, wherein a first DMRS signal in the group of DMRS signals is transmitted in a first time slot, and wherein a second DMRS signal in the group of DMRS signals is transmitted in a second time slot, and wherein the first DMRS signal and the second DMRS signal are configured to be used by the wireless device to estimate a radio channel based on the first DMRS signal and the second DMRS signal.

[0168] Embodiment 24 includes the subject matter of embodiment 23, wherein the physical downlink channel comprises one of a physical downlink shared channel (PDSCH) or a physical downlink control channel (PDCCH).

[0169] Embodiment 25 includes the subject matter of embodiment 24, wherein the same PDSCH precoding is used within the channel estimation bundling window.

[0170] Embodiment 26 includes the subject matter of embodiment 23, wherein the DMRS configuration includes an indication that the DMRS signal can be estimated across different transport blocks.

[0171] Embodiment 27 includes the subject matter of embodiment 23, wherein the DMRS configuration includes an indication that the DMRS signal can be estimated across different DMRS repetitions.

[0172] Embodiment 28 includes the subject matter of embodiment 23, wherein the DMRS configuration is transmitted via one of radio resource control signaling, within a field in downlink control information (DCI), or within a medium access control control element (MAC CE).

[0173] Embodiment 29 includes the subject matter of embodiment 23, wherein the first DMRS signal and the second DMRS signal are transmitted with the same power.

[0174] According to embodiment 30, a method for channel estimation in a wireless system comprises: transmitting an indication of a physical uplink channel configuration for transmitting a physical uplink channel transmission to a wireless device, the physical uplink channel transmission including a demodulation reference signal (DMRS) scheduling; receiving an indication from the wireless device that the wireless device supports bundling of DMRS signals across multiple time slots; transmitting a DMRS configuration to the wireless device, the DMRS configuration including channel estimation bundling, the channel estimation bundling window indicating that channel estimation can be performed across multiple time slots; receiving a group of DMRS signals by a wireless node based on the DMRS configuration and within the channel estimation bundling window, wherein a first DMRS signal in the group of DMRS signals is received in a first time slot, and wherein a second DMRS signal in the group of DMRS signals is received in a second time slot; estimating a radio channel based on the first DMRS signal and the second DMRS signal; and decoding a transmission from the wireless device based on the estimated radio channel.

[0175] Embodiment 31 includes the subject matter of embodiment 30, wherein the physical uplink channel comprises one of a physical uplink shared channel or a physical uplink control channel.

[0176] Embodiment 32 includes the subject matter of embodiment 30, wherein the radio channel is estimated based on the first DMRS signal and the second DMRS signal transmitted at the same power within the channel estimation bundling window.

[0177] Embodiment 33 includes the subject matter of embodiment 30, wherein the radio channel is estimated based on the first DMRS signal and the second DMRS signal transmitted at the same timing advance within the channel estimation bundling window.

[0178] Embodiment 34 includes the subject matter of embodiment 30, wherein the DMRS configuration indicates a number of time slots used for the channel estimation bundling window.

[0179] Embodiment 35 includes the subject matter of embodiment 32, wherein the channel estimation bundling window is defined for a group of time slots.

[0180] Embodiment 36 includes the subject matter of embodiment 32, wherein the channel estimation bundling window comprises a sliding window of the number of time slots of the channel estimation bundling window.

[0181] Embodiment 37 includes the subject matter of embodiment 32, wherein the number of time slots of the channel estimation bundling window is the same as the number of time slots in an uplink / downlink configuration.

[0182] Embodiment 38 includes the subject matter of embodiment 30, further comprising: receiving an indication from the wireless device that the wireless device supports dynamic DMRS reconfiguration; transmitting a radio resource control signal to the wireless device indicating the number of DMRS signals to be transmitted in a time slot; transmitting a DMRS reconfiguration indication to the wireless device, the DMRS reconfiguration indication changing the number of DMRS signals to be transmitted in a time slot, wherein the DMRS reconfiguration indication is transmitted within downlink control information (DCI) or within a medium access control control element (MAC CE).

[0183] Embodiment 39 includes the subject matter of embodiment 38, wherein the number of DMRS signals is adjusted for each time slot of the channel estimation bundling window.

[0184] Embodiment 40 includes the subject matter of embodiment 38, wherein the number of DMRS signals is adjusted for less than all time slots of the channel estimation bundling window.

[0185] Embodiment 41 includes the subject matter of embodiment 40, wherein the DMRS signal is reconfigured such that a DMRS signal is not transmitted in at least one time slot of the channel estimation bundling window.

[0186] Embodiment 42 includes the subject matter of embodiment 41, wherein the DMRS signal is reconfigured such that the DMRS signal is transmitted in a time slot that is transmitted earlier in time than the at least one time slot in which the DMRS signal is not transmitted.

[0187] Embodiment 43 includes the subject matter of embodiment 38, wherein the DMRS port is changed for each channel estimation bundling window.

[0188] Embodiment 44 includes the subject matter of embodiment 38, further comprising receiving an indication from the wireless device that the wireless device supports DMRS reconfiguration.

[0189] Example 45 comprises a method comprising any act or combination of acts as substantially described herein in the detailed description.

[0190] Example 46 comprises a method substantially as described herein with reference to each or any combination of the figures included herein or with reference to each or any combination of the paragraphs in the detailed description.

[0191] Embodiment 47 comprises a wireless device configured to perform any action or combination of actions as substantially described herein in the detailed embodiments included in the wireless device.

[0192] Embodiment 48 comprises a wireless station configured to perform any action or combination of actions as substantially described herein in the specific embodiments included in the wireless station.

[0193] Embodiment 49 includes a non-transitory computer-readable medium storing instructions that, when executed, cause performance of any action or combination of actions as substantially described herein in the detailed description.

[0194] Embodiment 50 includes an integrated circuit configured to perform any action or combination of actions as substantially described herein in the detailed description.

[0195] Yet another exemplary aspect may include a method comprising: performing, by a device, any or all of the foregoing embodiments.

[0196] Yet another exemplary aspect may include a non-transitory computer-accessible storage medium including program instructions that, when executed at a device, cause the device to implement any or all portions of any of the aforementioned embodiments.

[0197] Yet another exemplary aspect may include a computer program comprising instructions for performing any or all of any of the aforementioned embodiments.

[0198] Yet another exemplary aspect may include an apparatus comprising means for performing any or all of the elements of any of the aforementioned embodiments.

[0199] Yet another exemplary aspect may include an apparatus comprising a processor configured to cause the device to perform any or all elements of any of the aforementioned embodiments.

[0200] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly stated to users.

[0201] Aspects of the present disclosure can be implemented in any of a variety of forms. For example, some aspects can be implemented as computer-implemented methods, computer-readable storage media, or computer systems. Other aspects can be implemented using one or more custom-designed hardware devices such as ASICs. Other aspects can be implemented using one or more programmable hardware elements such as FPGAs.

[0202] In some aspects, a non-transitory computer-readable storage medium may be configured such that it stores program instructions and / or data, wherein the program instructions, if executed by a computer system, cause the computer system to perform a method, such as any one of the method aspects described herein, or any combination of the method aspects described herein, or any subset of any method aspects described herein, or any combination of such subsets.

[0203] In some aspects, a device (e.g., UE 106, BS 102, network element 600) may be configured to include a processor (or a group of processors) and a memory medium, wherein the memory medium stores program instructions, wherein the processor is configured to read and execute the program instructions from the memory medium, wherein the program instructions are executable to implement any of the various method aspects described herein (or any combination of the method aspects described herein, or any subset of any method aspects, or any combination of such subsets). The device may be implemented in any of various forms.

[0204] Although the above aspects have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A method for channel estimation in a wireless system, comprising: transmitting, to a wireless device, an indication of a physical downlink channel configuration for receiving a physical downlink channel transmission, the physical downlink channel transmission including a demodulation reference signal (DMRS); receiving, from the wireless device, an indication that the wireless device supports bundling DMRS signals across multiple time slots and an indication that the wireless device supports dynamic DMRS reconfiguration; transmitting a DMRS configuration to the wireless device, wherein the DMRS configuration includes a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across a plurality of time slots, and wherein the DMRS configuration further indicates a number of DMRS signals to be transmitted in at least one time slot of the plurality of time slots in the channel estimation bundling window; transmitting, by the wireless node based on the DMRS configuration, a set of DMRS signals in the channel estimation bundling window, wherein a first DMRS signal in the set of DMRS signals is transmitted in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is transmitted in a second time slot, and wherein the first DMRS signal and the second DMRS signal are configured to be used by the wireless device to estimate a radio channel based on the first DMRS signal and the second DMRS signal; as well as A DMRS reconfiguration indication is transmitted that changes the number of DMRS signals to be transmitted in at least one of the plurality of time slots of the channel estimation bundling window. 2 . The method of claim 1 , wherein the physical downlink channel comprises one of a physical downlink shared channel (PDSCH) or a physical downlink control channel (PDCCH). The method according to claim 2 , wherein the same PDSCH precoding is used within the channel estimation bundling window. 4 . The method of claim 1 , wherein the DMRS configuration includes an indication that the DMRS signal can be estimated across different transport blocks. 5 . The method of claim 1 , wherein the DMRS configuration includes an indication that the DMRS signal can be estimated across different DMRS repetitions.

6. The method of claim 1, wherein the DMRS configuration is transmitted via one of radio resource control signaling, within a field in downlink control information (DCI), or within a medium access control element (MAC CE). The method according to claim 1 , wherein the first DMRS signal and the second DMRS signal are transmitted with the same power.

8. A method for channel estimation in a wireless system, comprising: transmitting, to the wireless device, an indication of a physical uplink channel configuration for transmitting a physical uplink channel transmission, the physical uplink channel transmission including a demodulation reference signal (DMRS) schedule; receiving, from the wireless device, an indication that the wireless device supports bundling DMRS signals across multiple time slots and an indication that the wireless device supports dynamic DMRS reconfiguration; transmitting a DMRS configuration to the wireless device, wherein the DMRS configuration includes a channel estimation bundling window, the channel estimation bundling window indicating that channel estimation can be performed across a plurality of time slots, and wherein the DMRS configuration further indicates a number of DMRS signals to be transmitted in at least one time slot of the plurality of time slots in the channel estimation bundling window; receiving, by a wireless node, a set of DMRS signals based on the DMRS configuration and within the channel estimation bundling window, wherein a first DMRS signal in the set of DMRS signals is received in a first time slot, and wherein a second DMRS signal in the set of DMRS signals is received in a second time slot; estimating a radio channel based on the first DMRS signal and the second DMRS signal; decoding a transmission from the wireless device based on the estimated radio channel; as well as transmitting a DMRS reconfiguration indication that changes the number of DMRS signals to be transmitted in at least one of the plurality of time slots of the channel estimation bundling window, The number of DMRS signals is reconfigured for each time slot of the channel estimation bundling window.

9. The method of claim 8, wherein the physical uplink channel comprises one of a physical uplink shared channel or a physical uplink control channel. 10 . The method according to claim 8 , wherein the radio channel is estimated based on the first DMRS signal and the second DMRS signal transmitted at the same power within the channel estimation bundling window. 11 . The method according to claim 8 , wherein the radio channel is estimated based on the first DMRS signal and the second DMRS signal transmitted with the same timing advance within the channel estimation bundling window.

12. The method of claim 8, wherein the DMRS configuration indicates a number of time slots used for the channel estimation bundling window.

13. The method of claim 10, wherein the channel estimation bundling window is defined for a group of time slots.

14. The method of claim 12, wherein the channel estimation bundling window comprises a sliding window of the number of time slots of the channel estimation bundling window.

15. The method of claim 12, wherein the number of time slots of the channel estimation bundling window is the same as the number of time slots in an uplink / downlink configuration.

16. The method of claim 8, wherein the DMRS reconfiguration indication is transmitted within downlink control information (DCI) or within a medium access control element (MAC CE). 17 . The method according to claim 8 , wherein the DMRS signal is reconfigured such that the DMRS signal is not transmitted in at least one time slot of the channel estimation bundling window. 18 . The method according to claim 17 , wherein the DMRS signal is reconfigured so that the DMRS signal is transmitted in a time slot that is transmitted earlier in time than the at least one time slot in which the DMRS signal is not transmitted. The method of claim 8 , wherein the DMRS port is changed for each channel estimation bundling window.

20. A wireless node comprising: radio components; as well as a processor operatively coupled to the radio; The processor is configured to execute the method according to any one of claims 1-19.

21. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform the method according to any one of claims 1 to 19.

22. An apparatus for channel estimation in a wireless system, comprising means for performing the method according to any one of claims 1-19.

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