Method for demodulation interference estimation using empty resource elements

Abstract

Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a user equipment (UE) may receive downlink control information (DCI) including an indication of an empty resource element pattern. The empty resource element pattern may be indicated in the DCI using the value of an antenna port field that also indicates one or more demodulation reference signal (DMRS) ports for the UE and the number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals. The UE may perform one or more demodulation interference measurements based at least in part on the empty resource element pattern. The UE may demodulate downlink communications based at least in part on performing one or more demodulation interference measurements. Numerous other aspects are provided.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to the Greek patent application numbered 20190100431, filed on October 3, 2019, entitled “USING NULL RESOURCEELEMENTS FOR DEMODULATION INTERFERENCE ESTIMATION” and filed on September 28, 2020, and the U.S. non-provisional patent application numbered 17 / 035,093, entitled “USING NULL RESOURCE ELEMENTS FOR DEMODULATION INTERFERENCE ESTIMATION”, and these two applications are expressly incorporated herein by reference. Technical Field

[0003]

[0006] Aspects of the present disclosure generally relate to wireless communications, and more particularly, to techniques and apparatus for using null resource elements for demodulation interference estimation. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth or transmit power, among other examples or combinations thereof). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0005] The above multiple access technology has been adopted in various telecommunication standards to provide a common protocol that enables different user equipments (UEs) to communicate at a city level, a national level, a regional level, and even a global level. New Radio (NR), which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard released by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, making full use of new spectrum, and using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink (DL), using CP-OFDM or SC-FDMA (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL) to better integrate with other open standards, and supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0006] The slot structure used for transmission in NR is more flexible compared to that of LTE. Transmission with flexible slots may result in highly dynamic and bursty inter-cell interference. This is a problem because scheduling and demodulation performance may depend on bursty interference conditions at the transmission time. Current interference measurements using, for example, channel state information reference signals (CSI-RS) or interference measurement resources (IMR) only provide long-term measurements. These long-term measurements may result in overly conservative decisions, which reduces system throughput. In addition, although the scheduling entity can control some bursty interference through fast scheduling coordination, such coordination may take more time, cost more resources, and is insufficient for ultra-low latency applications. Summary of the invention

[0007] In some aspects, a method of wireless communication performed by a user equipment (UE) includes receiving downlink control information (DCI) including an indication of a null resource element pattern. The null resource element pattern may be indicated in the DCI using a value of an antenna port field that also indicates one or more DMRS ports for the UE and a number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals. The method may include performing one or more demodulation interference measurements based at least in part on the null resource element pattern. The method may include demodulating downlink communications based at least in part on performing one or more demodulation interference measurements.

[0008] In some aspects, a method of wireless communication performed by a UE includes sending an indication of a recommended empty resource element pattern or a recommended number of empty resource elements to a base station. The method may include receiving an indication of an empty resource element pattern from the base station based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The method may include performing one or more demodulation interference measurements based at least in part on the empty resource element pattern. The method may include demodulating downlink communications based at least in part on performing the one or more demodulation interference measurements.

[0009] In some aspects, a method of wireless communication performed by a base station includes sending a DCI including an indication of a null resource element pattern to a UE. The null resource element pattern may be indicated in the DCI using a value of an antenna port field that also indicates one or more DMRS ports for the UE and a number of DMRS code division multiplexing groups without data, or a zero-power downlink reference signal. The method may include sending downlink communications based at least in part on the null resource element pattern indicated in the DCI.

[0010] In some aspects, a method of wireless communication performed by a base station includes receiving an indication of a recommended empty resource element pattern or a recommended number of empty resource elements from a UE. The method may include sending an indication of the empty resource element pattern to the UE based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The method may include sending a downlink communication to the UE based at least in part on the empty resource element pattern.

[0011] In some aspects, a UE for wireless communication includes a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive a DCI including an indication of an empty resource element pattern. The empty resource element pattern may be indicated in the DCI using the following method: also indicating the value of the antenna port field for one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals. The memory and the one or more processors may be configured to perform one or more demodulation interference measurements based at least in part on the empty resource element pattern. The memory and the one or more processors may be configured to demodulate downlink communications based at least in part on performing one or more demodulation interference measurements.

[0012] In some aspects, a UE for wireless communication includes a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to send an indication of a recommended empty resource element pattern or a recommended number of empty resource elements to a base station. The memory and the one or more processors may be configured to receive an indication of an empty resource element pattern from a base station based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The memory and the one or more processors may be configured to perform one or more demodulation interference measurements based at least in part on the empty resource element pattern. The memory and the one or more processors may be configured to demodulate downlink communications based at least in part on performing the one or more demodulation interference measurements.

[0013] In some aspects, a base station for wireless communication includes a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to send a DCI including an indication of a null resource element pattern to a UE. The null resource element pattern may be indicated in the DCI using the value of an antenna port field that also indicates one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups without data, or a zero-power downlink reference signal. The memory and the one or more processors may be configured to send a downlink communication based at least in part on the null resource element pattern indicated in the DCI.

[0014] In some aspects, a base station for wireless communication includes a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive an indication of a recommended empty resource element pattern or a recommended number of empty resource elements from a UE. The memory and the one or more processors may be configured to send an indication of an empty resource element pattern to the UE based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The memory and the one or more processors may be configured to send a downlink communication to the UE based at least in part on the empty resource element pattern.

[0015] In some aspects, a non-transitory computer-readable medium storing an instruction set for wireless communication includes one or more instructions that, when executed by one or more processors of a UE, cause the UE to receive a DCI that includes an indication of an empty resource element pattern. The empty resource element pattern may be indicated in the DCI using a value of an antenna port field that also indicates one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals. The one or more instructions may cause the UE to perform one or more demodulation interference measurements based at least in part on the empty resource element pattern. The one or more instructions may cause the UE to demodulate downlink communications based at least in part on performing one or more demodulation interference measurements.

[0016] In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a UE, cause the UE to send an indication of a recommended empty resource element pattern or a recommended number of empty resource elements to a base station. The one or more instructions may cause the UE to receive an indication of an empty resource element pattern from the base station based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The one or more instructions may cause the UE to perform one or more demodulation interference measurements based at least in part on the empty resource element pattern. The one or more instructions may cause the UE to demodulate downlink communications based at least in part on performing the one or more demodulation interference measurements.

[0017] In some aspects, a non-transitory computer-readable medium storing an instruction set for wireless communication includes one or more instructions that, when executed by one or more processors of a base station, cause the base station to send a DCI including an indication of a null resource element pattern to a UE. The null resource element pattern may be indicated in the DCI using a value of an antenna port field that also indicates one or more DMRS ports for the UE and a number of DMRS code division multiplexing groups without data, or a zero-power downlink reference signal. The one or more instructions may cause the base station to send a downlink communication based at least in part on the null resource element pattern indicated in the DCI.

[0018] In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a base station, cause the base station to receive an indication of a recommended empty resource element pattern or a recommended number of empty resource elements from a UE. The one or more instructions may cause the base station to send an indication of an empty resource element pattern to the UE based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The one or more instructions may cause the base station to send a downlink communication to the UE based at least in part on the empty resource element pattern.

[0019] In some aspects, an apparatus for wireless communication includes: a unit for receiving a DCI including an indication of a null resource element pattern. The null resource element pattern can be indicated in the DCI using: a value of an antenna port field that also indicates one or more DMRS ports for a UE and a number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals. The apparatus may include: a unit for performing one or more demodulation interference measurements based at least in part on the null resource element pattern. The apparatus may include: a unit for demodulating downlink communications based at least in part on performing one or more demodulation interference measurements.

[0020] In some aspects, an apparatus for wireless communication includes means for sending an indication of a recommended empty resource element pattern or a recommended number of empty resource elements to a base station. The apparatus may include means for receiving an indication of an empty resource element pattern from a base station based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The apparatus may include means for performing one or more demodulation interference measurements based at least in part on the empty resource element pattern. The apparatus may include means for demodulating downlink communications based at least in part on performing the one or more demodulation interference measurements.

[0021] In some aspects, an apparatus for wireless communication includes: a unit for sending a DCI including an indication of a null resource element pattern to a UE. The null resource element pattern can be indicated in the DCI using: a value of an antenna port field that also indicates one or more DMRS ports for the UE and a number of DMRS code division multiplexing groups without data, or a zero-power downlink reference signal. The apparatus may include: a unit for sending a downlink communication based at least in part on the null resource element pattern indicated in the DCI.

[0022] In some aspects, an apparatus for wireless communication includes means for receiving an indication of a recommended empty resource element pattern or a recommended number of empty resource elements from a UE. The apparatus may include means for sending an indication of the empty resource element pattern to the UE based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The apparatus may include means for sending a downlink communication to the UE based at least in part on the empty resource element pattern.

[0023] Aspects generally include methods, apparatus, systems, computer program products, non-transitory computer readable media, user equipment, base stations, wireless communication devices, and processing systems as fully described with reference to and as illustrated by the accompanying drawings and description.

[0024] In order to better understand the specific embodiments below, the features and technical advantages of the examples according to the present disclosure have been summarized to a considerable extent above. Additional features and advantages will be described below. The disclosed concepts and specific examples can be easily utilized as the basis for modifying or designing other structures for the same purpose of performing the present disclosure. Such equivalent constructions do not deviate from the scope of protection of the attached claims. When considered in conjunction with the accompanying drawings, the characteristics of the concepts disclosed herein (both about their organization and operation methods) together with the associated advantages will be better understood according to the description below. Each of the figures in the accompanying drawings is provided for illustration and description purposes, and not as a limitation to the limits of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order that the manner in which the above-mentioned features of the present disclosure may be understood in detail, the contents briefly summarized above may be described in more detail by reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present disclosure, and since the description may allow for other equally effective aspects, they should not be considered as limiting the scope of protection thereof. The same reference numerals in different drawings may identify the same or similar elements.

[0026] Figure 1 is a block diagram illustrating an example wireless network in accordance with various aspects of the present disclosure.

[0027] Figure 2 is a block diagram illustrating an example base station in communication with a user equipment (UE) in a wireless network in accordance with various aspects of the present disclosure.

[0028] Figure 3 is a block diagram illustrating a time slot format in accordance with various aspects of the present disclosure.

[0029] Figure 4is a diagram illustrating the use of null resource elements signaled in an antenna port field for demodulation interference estimation in accordance with various aspects of the present disclosure.

[0030] Figure 5 is a schematic diagram illustrating the use of empty resource elements signaled in a resource set of a zero-power channel state information reference signal in accordance with various aspects of the present disclosure.

[0031] Figure 6 is a diagram illustrating example processes performed, for example, by a UE according to various aspects of the present disclosure.

[0032] Figure 7 is a diagram illustrating example processes performed, for example, by a UE according to various aspects of the present disclosure.

[0033] Figure 8 is a diagram illustrating example processes performed, for example, by a base station according to various aspects of the present disclosure.

[0034] Fig. 9 is a diagram illustrating example processes performed, for example, by a base station according to various aspects of the present disclosure.

[0035] Figure 10-13 is a block diagram illustrating an example apparatus for wireless communications in accordance with various aspects of the present disclosure. DETAILED DESCRIPTION

[0036] Various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in a variety of different forms, and is not interpreted as being limited to any specific structure or function given throughout the present disclosure. Instead, these aspects are provided so that the present disclosure will be thorough and complete, and the protection scope of the present disclosure will be fully conveyed to those skilled in the art. Based on the teachings herein, it can be appreciated by those skilled in the art that the protection scope of the present disclosure is intended to cover any aspect of the disclosure disclosed herein, whether independently implemented or in combination with any other aspect of the present disclosure. For example, a device or method can be implemented using any number of aspects set forth herein. In addition, the protection scope of the present disclosure is intended to cover such a device or method as follows: a device or method that can be practiced using other structures, functions, or structures and functions of various aspects of the present disclosure set forth herein, or structures and functions of various aspects of the present disclosure set forth herein that are different from those set forth herein. Any aspect of the disclosure disclosed herein can be embodied by one or more elements of the claims.

[0037] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the detailed description below and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes or algorithms and other examples, or combinations thereof (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0038] In NR, the transmission slot structure is much more flexible compared to the Long Term Evolution (LTE) slot structure. This may lead to burst interference. For Burst Interference Management (BIM), the User Equipment (UE) can estimate the interference (noise) during demodulation. The UE can use the same N x N The interference is estimated by using the recurrent neural network (Rnn) matrix corresponding to each resource element. N is the number of receive antenna ports and may be referred to as the rank. For example, the UE may determine a 4x4 Rnn matrix for rank 4. The UE may calculate the inverse of the Rnn matrix and use the Rnn matrix to cancel interference. However, in the case of a higher rank (such as rank 8), the 8x8 Rnn matrix may involve four times the number of resource elements for which the UE must estimate interference. Therefore, the UE may use more computational resources and may have difficulty in correctly estimating interference.

[0039] As described herein, in some aspects a UE is configured to receive downlink control information (DCI) indicating a null resource element pattern of null resource elements from a base station (BS). The null resource elements for the UE may have null tones; that is, there is no transmission power at the time and frequency associated with the null resource elements for the UE. The null resource element pattern may indicate null resource elements scattered in a resource block over time, frequency, or both. The UE may perform demodulation interference measurements based at least in part on the null resource element pattern, and demodulate downlink communications accordingly. The UE may save processing resources because fewer calculations are involved in performing demodulation interference measurements for null resource elements. For example, for each non-null resource element, the UE determines a channel estimate, and eliminates the channel estimate before calculating interference for the non-null resource element. For null resource elements, the UE may continue to measure interference without first determining and then eliminating any channel estimates for null resource elements.

[0040] In addition, the BS may use the value of the antenna port field to indicate an empty resource element pattern in the DCI, where the antenna port field also indicates one or more demodulation reference signal (DMRS) ports for the UE and the number of DMRS code division multiplexing groups without data. Additionally or alternatively, the BS may use a zero power channel state information reference signal (ZP CSI-RS) resource set to indicate an empty resource element pattern in the DCI. Because the BS may signal an empty resource element pattern in the DCI using the antenna port field or the ZP CSI-RS resource set, the UE may save processing resources that the UE may have used to determine an empty resource element pattern and determine when to use an empty resource element pattern.

[0041] Figure 1 is a block diagram illustrating an example wireless network according to various aspects of the present disclosure. The wireless network may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network may include a certain number of BSs 110 (as indicated by BSs 110a, BSs 110b, BSs 110c, and BSs 110d) and other network entities. A BS is an entity that communicates with a UE and may also be referred to as a Node B, eNodeB (evolved Node B), eNB, gNB, NR BS, 5G Node B (NB), access point (AP), or transmit receive point (TRP), as well as other examples or combinations thereof (these terms are used interchangeably herein). Each BS may provide communication coverage for a specific geographic area. In the Third Generation Partnership Project (3GPP), the term "cell" may refer to a coverage area of ​​a BS and / or a BS subsystem serving that coverage area, depending on the context in which the term is used.

[0042] A BS may provide communication coverage for a macro cell, a micro cell, a femto cell, or another type of cell. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by a UE with a service subscription. A micro cell may cover a relatively small geographic area and may allow unrestricted access by a UE with a service subscription. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by a UE associated with a femto cell (e.g., a UE in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a micro cell may be referred to as a micro BS. A BS for a femto cell may be referred to as a femto BS or a home BS. A BS may support one or more (e.g., three) cells.

[0043] The wireless network may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, or relay BSs, as well as other examples or combinations thereof). These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in the wireless network. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts). Figure 1 In the example shown, BS 110a may be a macro BS for macro cell 102a, BS 110b may be a pico BS for pico cell 102b, and BS 110c may be a femto BS for femto cell 102c. A network controller 130 may be coupled to a set of BSs 102a, 102b, 110a, and 110b, and may provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other, for example, directly or indirectly via a wireless or wired backhaul.

[0044] In some aspects, the cell may not be stationary, but rather the geographic area of ​​the cell may move depending on the location of the mobile BS. In some aspects, the BSs may be interconnected to each other and / or to one or more other BSs or network nodes (not shown) in a wireless network through various types of backhaul interfaces (such as direct physical connections or virtual networks and other examples or combinations thereof) using any suitable transport network.

[0045] A wireless network may also include a relay station. A relay station is an entity that can receive transmissions of data from an upstream station (e.g., a BS or UE) and send transmissions of data to a downstream station (e.g., a UE or BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the illustrated example, a relay station 110d may communicate with a macro BS 110a and a UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay station may also be referred to as a relay BS, a relay base station, or a relay, among other examples or combinations thereof.

[0046] UE 120 (e.g., 120a, 120b, 120c) can be distributed throughout the wireless network, and each UE can be stationary or mobile. UE can also be referred to as an access terminal, a terminal, a mobile station, a user unit, or a station, as well as other examples or combinations thereof. UE can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet device, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, a biosensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite wireless unit), a vehicle-mounted component or sensor, a smart meter / sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless medium.

[0047] Some UEs may be considered machine type communication (MTC) or evolved or enhanced machine type communication (eMTC) UEs. For example, MTC and eMTC UEs include robots, drones, remote devices, sensors, meters, monitors, or location tags that can communicate with a base station, another device (e.g., a remote device), or some other entity, as well as other examples or combinations thereof. A wireless node may provide, for example, a connection to a network or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered customer premises equipment (CPE). UE 120 may be included inside a housing that houses components of UE 120 (e.g., a processor component, or a memory component, as well as other examples or combinations thereof).

[0048] Typically, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies or frequency channels. A frequency may also be referred to as a carrier and other examples or combinations thereof. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some examples, NR or 5G RAT networks may be deployed.

[0049] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate with each other directly (e.g., without using base station 110 as an intermediary) using one or more sidelink channels. For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocol (e.g., which may include vehicle-to-vehicle (V2V) protocol, or vehicle-to-infrastructure (V2I) protocol, and other examples or combinations thereof), or mesh network, and other examples or combinations thereof. In this example, UE 120 may perform scheduling operations, resource selection operations, or other operations described elsewhere herein as performed by BS 110.

[0050] Figure 2 is a block diagram illustrating an example base station (BS) communicating with a user equipment (UE) in a wireless network in accordance with various aspects of the present disclosure. The base station 110 may be equipped with T antennas 234a through 234t, and the UE 120 may be equipped with R antennas 252a through 252r, where generally T ≥ 1 and R ≥ 1.

[0051] At the base station 110, the transmit processor 220 may receive data for one or more UEs from a data source 212, select one or more modulation and coding schemes (MCS) for the UE based at least in part on a channel quality indicator (CQI) received from each UE, process (e.g., encode) the data for the UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and other examples or combinations thereof) and control information (e.g., CQI requests, grants, or upper layer signaling and other examples or combinations thereof), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, or reference symbols (if applicable), and transmit the data symbols to the UE. T Modulators (MODs) 232a to 232t provide TEach MOD 232 may process a respective output symbol stream (e.g., for OFDM and other embodiments or combinations thereof) to obtain an output sample stream. Each MOD 232 may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. T The downlink signals may be respectively T According to various aspects described in further detail below, the synchronization signal can be generated using position coding to convey additional information.

[0052] At UE 120, antennas 252a through 252r may receive downlink signals from base station 110 or other base stations and may provide the received signals to R Each DEMOD 254 may condition (e.g., filter, amplify, down-convert, and digitize) the received signal to obtain input samples. Each DEMOD 254 may further process the input samples (e.g., for OFDM and other embodiments or combinations thereof) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R The DEMODs 254a to 254r obtain received symbols, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. The receive processor 258 can process (e.g., decode) the detected symbols, provide decoded data for the UE 120 to the data sink 260, and provide decoded control information and system information to the controller / processor 280. The channel processor can determine a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference signal received quality (RSRQ), or a CQI, as well as other examples or combinations thereof. In some aspects, one or more components of the UE 120 may be included in a housing.

[0053] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information from a controller / processor 280 (e.g., for reporting including RSRP, RSSI, RSRQ, or CQI, among other examples or combinations thereof). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by MODs 254a through 254r (e.g., for discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM), or orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM), among other examples or combinations thereof), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the DEMOD 232, detected by the MIMO detector 236 (if any), and further processed by the receive processor 238 to obtain decoded data and control information sent by the UE 120. The receive processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and transmit to the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0054] Figure 2 The controller / processor 240 of the BS 110, the controller / processor 280 of the UE 120, or any other component may perform one or more techniques associated with using empty resource elements for demodulation interference estimation, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, or Figure 2 Any other component may perform or direct e.g. Figure 6 The process of 600 Figure 7 The process of 700 Figure 8 The process of 800 Fig. 9 The operations of process 900 or other processes as described herein. Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively. Scheduler 246 may schedule UEs for data transmission on the downlink or uplink.

[0055] In some aspects, the UE includes: a unit for receiving a DCI that includes an indication of a null resource element pattern, wherein the null resource element pattern is indicated in the DCI using: a value of an antenna port field that also indicates one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups with no data, or one or more zero-power downlink reference signals; a unit for performing one or more demodulation interference measurements based at least in part on the null resource element pattern; and / or a unit for demodulating downlink communications based at least in part on performing the one or more demodulation interference measurements.

[0056] In some aspects, the UE includes: a unit for receiving a configuration indicating a set of empty resource element patterns, wherein the empty resource element pattern indicated in the DCI is selected from the set of empty resource element patterns. In some aspects, the UE includes: a unit for interpreting the empty resource element pattern indicated in the DCI based at least in part on a rank used by the UE, a combination of DMRS ports used by the UE, a maximum rank configured for the UE, or a combination thereof. In some aspects, the UE includes: a unit for determining that the maximum rank configured for PDSCH reception of the UE satisfies a threshold; and / or a unit for performing one or more demodulation interference measurements using the empty resource element pattern based at least in part on determining that the maximum rank configured for PDSCH reception of the UE satisfies the threshold.

[0057] In some aspects, the UE includes: means for sending an indication of a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern to a base station. In some aspects, the UE includes: means for indicating the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern in at least one of a UE capability report or a CSI report. In some aspects, the UE includes: means for receiving a CSI reporting configuration requesting the UE to report the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern in a CSI report.

[0058] In some aspects, the UE includes: means for sending an indication of a recommended empty resource element pattern or a recommended number of empty resource elements to a base station; means for receiving an indication of an empty resource element pattern from a base station based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements; means for performing one or more demodulation interference measurements based at least in part on the empty resource element pattern; and / or means for demodulating downlink communications based at least in part on performing the one or more demodulation interference measurements. In some aspects, the UE includes: means for receiving a CSI reporting configuration requesting the UE to report a recommended empty resource element pattern or a recommended number of empty resource elements in a CSI report.

[0059] In some aspects, the base station includes: a unit for sending a DCI to a UE that includes an indication of a null resource element pattern, wherein the null resource element pattern is indicated in the DCI using: a value of an antenna port field that also indicates one or more DMRS ports for the UE and a number of DMRS code division multiplexing groups with no data, or a zero-power downlink reference signal; and / or a unit for sending downlink communications based at least in part on the null resource element pattern indicated in the DCI.

[0060] In some aspects, the base station includes: a unit for sending a configuration indicating a set of empty resource element patterns, and selecting an empty resource element pattern from the set of empty resource element patterns to be indicated in a DCI. In some aspects, the base station includes: a unit for determining that the number of receive antennas reported by the UE meets a threshold; and / or a unit for indicating an empty resource element pattern based at least in part on determining that the number of receive antennas reported by the UE meets the threshold. In some aspects, the base station includes: a unit for receiving an indication of a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern from the UE.

[0061] In some aspects, the base station includes: means for determining whether to select the empty resource element pattern based at least in part on the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern. In some aspects, the base station includes: means for sending a CSI reporting configuration, the CSI reporting configuration requesting the UE to report the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern in the CSI report.

[0062] In some aspects, the base station includes: a unit for receiving an indication of a recommended empty resource element pattern or a recommended number of empty resource elements from a UE; a unit for sending an indication of the empty resource element pattern to the UE based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements; and / or a unit for sending downlink communications to the UE based at least in part on the empty resource element pattern.

[0063] Means for the UE to perform the operations described herein may include, for example, antenna 252, demodulator 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, modulator 254, controller / processor 280, and / or memory 282. Means for the base station to perform the operations described herein may include, for example, transmit processor 220, TX MIMO processor 230, modulator 232, antenna 234, demodulator 232, MIMO detector 236, receive processor 238, controller / processor 240, memory 242, and / or scheduler 246.

[0064] Figure 3 is a block diagram illustrating a slot format according to various aspects of the present disclosure. Available time-frequency resources may be divided into resource blocks. Each resource block may cover a set of subcarriers (e.g., 12 subcarriers) in a slot and may include a number of resource elements. Each resource element may cover a subcarrier in a symbol period (e.g., in time) and may be used to send a modulation symbol, which may be a real value or a complex value. Each block may have 14 symbol periods (0-13).

[0065] If through Figure 3 As indicated in the block diagram of , symbol periods 0, 1, and 2 may be a control region for control signaling, and symbol periods 3-13 may be reserved for data. Symbols for a demodulation reference signal (DMRS) may be located, for example, in symbol period 2 of the control region. A receiver may use DMRS to estimate a wireless channel for demodulation. DMRS is UE-specific and may be sent only when necessary.

[0066] The resource elements used for DMRS can be divided into multiple code division multiplexing (CDM) groups. CDM involves combining multiple signals for simultaneous transmission on a common frequency band. The DMRS in a resource block can include up to three CDM groups in symbol period 2, such as CDM group 0, CDM group 1, and CDM group 2. There are twelve subcarriers in a resource block, which means that there may be four resource elements for each CDM group. The UE can receive data for physical downlink shared channel (PDSCH) DMRS configuration in symbol period 2. For example, the resource elements in CDM group 0 in symbol period 2 may have configuration data, while the resource elements in CDM groups 1 and 2 in symbol period 2 may not have configuration data. The BS can indicate how many CDM groups do not have configuration data. In this example, the number will be two.

[0067] The BS may use an antenna port table to indicate the number of DMRS CDM groups without data and the PDSCH DMRS ports. The BS may provide the value of the antenna port table in a field of the DCI message. The value corresponds to a unique combination of the number of DMRS CDM groups without data and the DMRS ports scheduled to the UE. When one of the two codewords is enabled or when both codewords are enabled, a separate value may be applied. The PDSCH rank may be determined based at least in part on how many DMRS port indices are signaled.

[0068] As indicated above, in NR, the transmission slot structure is more flexible compared to the LTE slot structure. In fact, NR provides for mini-slots. This flexibility may result in bursty inter-cell interference. "Burst interference" may refer to interference that comes and goes quickly. For burst interference management (BIM), for resource elements for a UE, the UE may estimate the interference (caused at least in part by bursty interference) or transmission noise. The UE may estimate the interference (caused at least in part by bursty interference) for resource elements for the UE. N x N The interference of the resource elements corresponding to the recursive neural network (Rnn) matrix of the resource elements is estimated. The Rnn matrix can be, for example, a 4x4 Rnn matrix (rank 4), and the UE can calculate the interference for the resource elements in the Rnn matrix. The UE can calculate the inverse of the Rnn matrix and apply the inverse of the Rnn matrix to the resource elements to eliminate the interference for the resource elements. However, in the case of a higher rank (such as rank 8), the 8x8 Rnn matrix may involve four times as many resource elements as the 4x4 Rnn matrix. This means that the UE may have to estimate the interference for as many resource elements as four times. Therefore, the UE can use more computing resources for operations involving more resource elements. In addition, it may be difficult for the UE to correctly estimate the interference because the UE can determine the channel estimate and then eliminate the estimate from the signal in order to calculate the noise. Calculating the noise by subtraction may be inaccurate and may cause the UE to use more processing resources to explain the inaccurate calculation.

[0069] In some aspects described herein, a BS sends a DCI indicating an empty resource element pattern to a UE. The empty resource element pattern may indicate empty resource elements that are dispersed over time, frequency, or both. The UE may perform demodulation interference measurements based at least in part on the empty resource element pattern, and demodulate downlink communications accordingly. The UE may save processing resources because fewer calculations are involved in performing demodulation interference measurements for empty resource elements than for performing demodulation interference measurements for non-empty resource elements. Because the UE is not sure about the channel estimate for the empty resource element, the UE may save processing resources typically used to determine the channel estimate, eliminate the estimate, and correct the inaccuracy caused by the elimination. In some aspects, the BS may use the value of the antenna port field or the ZP CSI-RS resource set to indicate the empty resource element pattern in the DCI. Because the BS may use the antenna port field or the ZP CSI-RS to signal the empty resource element pattern in the DCI, the UE may save the processing resources that the UE may have originally used to determine the empty resource element pattern and when to use the empty resource element pattern.

[0070] Figure 41 is a diagram illustrating the use of empty resource elements signaled in an antenna port field for demodulation interference estimation in accordance with various aspects of the present disclosure. A base station (BS) 110 may be configured to communicate with a user equipment (UE) 120, but the UE 120 may be experiencing bursty interference. The UE 120 may estimate interference for the resource elements and may use N x N The recurrent neural network (RNN) matrix of resource elements (where N is the number or rank of receive antenna ports) to cancel at least some of this bursty interference. For example, BS 110 may send a transmission with a rank of 8 to UE 120. UE 120 may use an 8x8 Rnn matrix, and thus UE 120 may use more processing resources than if the UE is using an Rnn matrix smaller than 8x8 (such as 4x4).

[0071] In some aspects, the BS 110 may configure the UE 120 to use a null resource element pattern. The BS 110 may select the null resource element pattern based at least in part on information about communication conditions, measurement information, or rank, among other examples. The BS 110 may indicate the null resource element pattern to the UE 120 in downlink control information (DCI). The null resource element pattern may indicate null resource elements that are spread across a resource block over time, frequency, or both. The UE 120 may perform demodulation interference measurements based at least in part on the null resource element pattern, and demodulate downlink transmissions from the BS 110 accordingly.

[0072] In a first operation 405, the BS 110 may configure the UE 120 with a set of empty resource element (RE) patterns. For example, the BS 110 may send a configuration indicating a set of empty RE patterns to the UE 120 using radio resource control (RRC) signaling. The configuration may indicate different sets of empty RE patterns for different ranks, different combinations of DMRS ports, or different combinations of ranks and DMRS ports, as well as other examples. For example, the configuration may include one or more empty RE patterns for each rank, or one or more empty RE patterns for a specific number of empty REs for each rank. For each rank, the configuration may include different combinations of DMRS ports. As an example, one value in the configuration may indicate that the rank is 8 in the case of DMRS ports 0-3. The value may also indicate a pattern of empty REs in a resource block. In some examples, the BS 110 may indicate these values ​​in the third column of the antenna port table. As another example, another value in the configuration may indicate that the rank is 8 in the case of DMRS ports 4-5. The value may indicate different patterns of empty REs in a resource block. UE 120 may be configured with information regarding which specific REs are blanked in a specific null RE pattern based at least in part on pre-configured possible null RE patterns, configuration from BS 110, or a combination thereof.

[0073] Empty REs may be in one or more subcarriers of a resource block. Additionally or alternatively, empty REs may be in one or more symbol periods of a resource block. In some aspects, empty REs may be spread across multiple subcarriers and multiple symbol periods. Empty REs may be located in a physical data shared channel (PDSCH) region of a resource block, in a demodulation reference signal (DMRS) symbol period of a resource block, or in both regions. In some aspects, each empty RE pattern may correspond to a unique arrangement of empty REs in time and frequency within a resource block. For example, a first empty RE pattern in an empty RE pattern set may specify a first arrangement of empty REs in a resource block. Similarly, a second empty RE pattern in an empty RE pattern set may specify a different arrangement of empty REs in a resource block.

[0074] BS 110 may determine empty REs based at least in part on information about mini-time slots, cross-link interference, reference signal transmission, and other examples. BS 110 may arrange empty REs so that they are random, evenly spaced, or clustered, and other example patterns. BS 110 may become aware of an empty RE position that is more effective than other empty RE positions, or may obtain relevant information from other BSs or UEs. BS 110 may perform one or more of any combination of the operations or considerations described above to determine an empty RE position. BS 110 may place an empty RE pattern in an empty RE pattern set based at least in part on other empty RE patterns already present in the set, empty RE patterns not in the set, the number of empty RE patterns in the set, or the age of each empty RE pattern, and other examples, or a combination thereof.

[0075] In some aspects, BS 110 may determine that the number of receive antennas reported by UE 120 satisfies a threshold, and may configure a null RE pattern based at least in part on determining that the number of receive antennas reported by UE 120 satisfies the threshold. For example, if UE 120 does not use more than four antennas, BS 110 may not configure or indicate a null RE pattern for UE 120. As another example, if UE 120 does not have more than four antenna ports, BS 110 may not configure or indicate a null RE pattern for UE 120.

[0076] In some aspects, the BS 110 may determine a null RE pattern or the number of REs included in the null RE pattern based at least in part on a maximum rank configured for PDSCH reception by the UE 120, whether the UE 120 is operating in a single-user multiple-input multiple-output (SU-MIMO) mode or a multi-user multiple-input multiple-output (MU-MIMO) mode, a precoding resource block group (PRG) configuration, a DMRS bundling configuration, or a combination thereof. Typically, when using MU-MIMO, the UE 120 will use a larger number of null REs to correctly estimate the Rnn matrix to be able to cancel or null out interference relative to SU-MIMO. In some aspects, the determination of whether the UE 120 is operating in the SU-MIMO mode or the MU-MIMO mode may be based at least in part on whether the UE 120 can assume that there are no co-scheduled ports on the same resources as those scheduled for the PDSCH.

[0077] BS 110 may use PRG for granularity in the frequency domain, or facilitate channel estimation by allowing UE 120 to perform channel estimation across a set of consecutive physical resource blocks (PRBs). This may be referred to as PRB bundling. Performing joint estimation across a set of PRBs may improve performance associated with channel estimation. However, forcing the use of the same transmit precoder across a large number of consecutive PRBs may result in lower precoder gain. Therefore, BS 110 may use a variety of configurations for PRB bundling. For example, BS 110 may use a narrowband PRG configuration of 2 or 4 PRBs, or BS 110 may use a wideband PRG configuration in which the same scheduling is applied to all PRBs in a PRB group. Therefore, as PRGs increase in size, the need for additional empty REs decreases. For example, if the PRG is in a wideband PRG configuration, BS 110 may not indicate an empty RE pattern, or may indicate an empty RE pattern different from that if 2 or 4 PRGs are used.

[0078] BS 110 may select a null RE pattern from a set of null RE patterns based at least in part on communication conditions, location of UE 120, capabilities of UE 120, information about interference, reference signal measurement information, a history of communication conditions, or a history of selected null RE patterns, among other examples.

[0079] In a second operation 410, BS 110 may indicate a null RE pattern in the DCI. For example, BS 110 may indicate a value corresponding to a value or index in a table, array, or other data structure, among other examples. In some aspects, the value may correspond to an antenna port field in an antenna port table. The antenna port table may indicate one or more DMRS ports for UE 120 and the number of DMRS code division multiplexing (CDM) groups without data.

[0080] like Figure 4 As shown in , BS 110 and UE 120 may be configured such that BS 110 and UE 120 use an antenna port table with available rows, additional fields, additional columns, or reserved bits, as well as other examples, to indicate a null RE pattern. It should be noted that the third operation 415 may occur before or during operations 405 and 410, and BS 110 may configure UE 120 to use the antenna port table at operation 405.

[0081] In some aspects, the UE 120 may recommend a null RE pattern to the BS 110. For example, the UE 120 may send an indication of a recommended null RE pattern or a recommended number of REs for the null RE pattern to the BS 110. In some instances or aspects, the BS 110 may then indicate the recommended null RE pattern in the DCI based at least in part on the indication of the recommended null RE pattern or the recommended number of REs for the null RE pattern. The UE 120 may indicate the recommended null RE pattern or the recommended number of REs for the null RE pattern in at least one of a UE capability report or a channel state information (CSI) report. The UE 120 may also receive a CSI reporting configuration requesting the UE 120 to report the recommended null RE pattern or the recommended number of REs for the null RE pattern in the CSI report. The UE 120 may use additional bits in the uplink DCI to help the BS 110 configure additional null RE patterns.

[0082] In some aspects, the UE 120 may interpret the empty RE pattern indicated in the DCI based at least in part on the rank used by the UE 120, the combination of DMRS ports used by the UE 120, the maximum rank configured for the UE 120, or a combination thereof. The maximum rank configured for the UE 120 may be the highest rank for which the UE 120 is configured among all ranks available to the UE 120. It should be noted that the maximum rank for PDSCH may be different from the number of receive antenna ports. In some aspects, a "high maximum rank" may refer to a rank higher than 4. In an example, if the UE 120 is configured to receive transmissions up to rank 8 for PDSCH, the BS 110 may configure the empty RE pattern to be denser than if the UE 120 is configured to receive transmissions with rank 1 for PDSCH.

[0083] In a third operation 415, the UE 120 may perform demodulation interference measurements using the empty RE pattern indicated by the BS 110. For example, the UE 120 may determine the interference based at least in part on a measurement of interference at one or more empty REs of the empty RE pattern. In some aspects, the UE 120 may determine that a maximum rank configured for PDSCH reception of the UE 120 satisfies a threshold, and perform one or more demodulation interference measurements using the empty RE pattern indicated in the DCI based at least in part on determining that the maximum rank configured for PDSCH reception of the UE 120 satisfies the threshold. In an example, the threshold for the maximum rank may be a rank greater than 4. In another example, the threshold may be a rank of 8.

[0084] In a fourth operation 420, the UE 120 may demodulate downlink communications (such as downlink communications scheduled using DCI) from the BS 110 based at least in part on the demodulation interference measurement. For example, the UE 120 may demodulate resource blocks in which the interference is measured using the empty RE pattern. The UE 120 may use the demodulation interference measurement from the empty RE pattern to cancel or account for the interference before extracting signal information through demodulation. By doing so, the UE 120 may save processing resources by measuring interference for fewer non-empty REs or no non-empty REs.

[0085] In some aspects, BS 110 may use a zero-power channel state information reference signal (ZP CSI-RS) resource set or another type of zero-power downlink reference signal (such as a channel state information interference measurement (CSI-IM) reference signal or another downlink reference signal used for interference measurement) to indicate a null RE pattern in the DCI, rather than indicating the null RE pattern in the DCI as a value in a table. Previously, ZP CSI-RS resources may have been used only for rate matching to PDSCH and not for interference measurement. In some aspects, BS 110 and UE 120 may use ZP CSI-RS resources or ZP CSI-RS resource sets for demodulation interference measurement purposes. In some aspects, BS 110 may indicate a null RE pattern as both a value in a table and using a ZP CSI-RS resource set.

[0086] Figure 5 is a diagram illustrating the use of empty REs signaled in a resource set of ZP CSI-RS in accordance with various aspects of the present disclosure.A base station (BS) 110 may be configured to communicate with a user equipment (UE) 120, but the UE 120 may be experiencing bursty interference.

[0087] In a first operation 505, BS 110 may send a configuration indicating one or more ZP CSI-RS resource sets to UE 120, the ZP CSI-RS resource sets indicating one or more respective empty RE patterns. For example, a ZP CSI-RS resource set ID of 0 may correspond to a specific empty RE pattern in the empty RE pattern set. Although ZP CSI-RS is used as an example, another type of downlink reference signal may be used, such as a CSI-IM reference signal.

[0088] In a second operation 510, the BS 110 may use the ZP CSI-RS resource set to indicate a null RE pattern. For example, a first ZP CSI-RS resource set value of 0 may indicate a first null RE pattern, and a second ZP CSI-RS resource set value of 1 may indicate a second null RE pattern, among other examples. In some aspects, the BS 110 and the UE 120 may be configured to use an additional bit to indicate a null RE pattern using a ZP CSI-RS resource set. It should be noted that the BS 110 may use the above reference Figure 4 One or more of any combination of the considerations or options discussed may be used to configure, select or indicate the empty RE mode.

[0089] In the third operation 515, the UE 120 may use the empty RE pattern to perform demodulation interference measurement. For example, the UE 120 may perform demodulation interference measurement in a manner similar to that described above with reference to Figure 4 In the described manner, interference is determined based at least in part on a measurement of interference at one or more empty REs of the empty RE pattern. In some aspects, the UE 120 may determine that a maximum rank configured for PDSCH reception of the UE 120 satisfies a threshold, and perform one or more demodulation interference measurements using the empty RE pattern based at least in part on the determination that the maximum rank configured for PDSCH reception of the UE 120 satisfies the threshold. In an example, the threshold for the maximum rank may be a rank greater than 4. In another example, the threshold may be a rank of 8.

[0090] In a fourth operation 520, the UE 120 may demodulate downlink communications scheduled using the DCI based at least in part on the demodulation interference measurement. For example, the UE 120 may perform a demodulation operation similar to that described above with reference to Figure 4 In the manner described, resource blocks in which interference is measured using a null RE pattern are demodulated.

[0091] Figure 6 is a flow diagram illustrating an example process 600 performed, for example, by a UE in accordance with various aspects of the present disclosure. Example process 600 is an example of a UE (eg, UE 120) performing operations associated with using null resource elements for demodulation interference estimation.

[0092] like Figure 6 As shown in , in some aspects, process 600 may include: receiving a DCI including an indication of a null resource element pattern, the null resource element pattern being indicated in the DCI using: a value of an antenna port field that also indicates one or more DMRS ports for the UE and a number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals (block 610). For example, the UE (such as by using Fig.10The receiving component 1002 depicted in the figure can receive a DCI including an indication of a null resource element pattern, where the null resource element pattern is indicated in the DCI in the following manner: the value of the antenna port field that also indicates one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals, as described above.

[0093] like Figure 6 As further shown in FIG. 6 , in some aspects, process 600 may include performing one or more demodulation interference measurements based at least in part on the null resource element pattern (block 620). For example, a UE (e.g., by using Fig.10 The communication manager 1004 or the interference cancellation component 1010 depicted in FIG. 1004 may perform one or more demodulation interference measurements based at least in part on the null resource element pattern, as described above.

[0094] like Figure 6 As further shown in FIG. 6 , in some aspects, process 600 may include demodulating downlink communications based at least in part on performing one or more demodulation interference measurements (block 630). For example, a UE (e.g., by using Fig.10 The communication manager 1004 or the demodulation component 1012 depicted in FIG. 1004 can demodulate downlink communications based at least in part on performing one or more demodulation interference measurements, as described above.

[0095] Figure 6 Process 600 may include additional aspects, such as any single aspect or any combination of aspects described below or in combination with one or more other processes described elsewhere herein.

[0096] In a first additional aspect, process 600 includes receiving a configuration indicating a set of null resource element patterns, wherein the null resource element pattern indicated in the DCI is selected from the set of null resource element patterns.

[0097] In a second additional aspect, alone or in combination with the first aspect, the configuration indicates different sets of empty resource element patterns for at least one of different ranks or different combinations of DMRS ports.

[0098] In a third additional aspect, either alone or in combination with one or more of the first and second aspects, process 600 includes interpreting an empty resource element pattern indicated in a DCI based at least in part on a rank used by the UE, a combination of DMRS ports used by the UE, a maximum rank configured for the UE, or a combination thereof.

[0099] In a fourth additional aspect, either alone or in combination with one or more of the first to third aspects, process 600 includes determining a maximum rank satisfaction threshold for a PDSCH reception configuration for the UE, and performing one or more demodulation interference measurements using an empty resource element pattern based at least in part on the maximum rank satisfaction threshold for the PDSCH reception configuration determined for the UE.

[0100] In a fifth additional aspect, either alone or in combination with one or more of the first to fourth aspects, at least one of the empty resource element pattern or the number of resource elements included in the empty resource element pattern depends on at least one of: the maximum rank configured for the UE's PDSCH reception, whether the UE operates in SU-MIMO mode or MU-MIMO mode, the precoding resource block group configuration, the DMRS bundling configuration, or a combination thereof.

[0101] In a sixth additional aspect, either alone or in combination with one or more of the first to fifth aspects, the one or more zero-power downlink reference signals include one or more zero-power channel state information reference signals.

[0102] In a seventh additional aspect, either alone or in combination with one or more of the first to sixth aspects, the one or more zero-power downlink reference signals include one or more channel state information interference measurement reference signals or one or more downlink reference signals for interference measurement.

[0103] In an eighth additional aspect, either alone or in combination with one or more of the first to seventh aspects, process 600 includes sending an indication of a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern to a base station.

[0104] In a ninth additional aspect, either alone or in combination with one or more of the first to eighth aspects, an empty resource element pattern indicated in the DCI is based at least in part on an indication of a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern.

[0105] In a tenth additional aspect, either alone or in combination with one or more of the first to ninth aspects, process 600 includes indicating a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern in at least one of a UE capability report or a CSI report.

[0106] In an eleventh additional aspect, alone or in combination with one or more of the first to tenth aspects, process 600 includes: receiving a CSI reporting configuration, the CSI reporting configuration requesting the UE to report a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern in the CSI report.

[0107] Although Figure 6 Example blocks of process 600 are shown, but in some aspects, the same Figure 6 Compared to that depicted in , process 600 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks. Additionally or alternatively, two or more of the blocks in process 600 may be executed in parallel.

[0108] Figure 7 is a flow diagram illustrating an example process 700 performed, for example, by a UE in accordance with various aspects of the present disclosure. Example process 700 is an example of a UE (eg, UE 120) performing operations associated with using null resource elements for demodulation interference estimation.

[0109] like Figure 7 As shown in FIG. 7 , in some aspects, process 700 may include sending an indication of a recommended empty resource element pattern or a recommended number of empty resource elements to a base station (block 710). For example, a UE (e.g., by using Fig.11 The transmitting component 1106 depicted in FIG. 1104 may transmit an indication of a recommended empty resource element pattern or a recommended number of empty resource elements to a base station, as described above.

[0110] like Figure 7 As further shown in FIG. 7 , in some aspects, process 700 may include receiving an indication of a blank resource element pattern from a base station based at least in part on an indication of a recommended blank resource element pattern or a recommended number of blank resource elements (block 720). For example, a UE (e.g., by using Fig.11 The receiving component 1102 depicted in FIG. 1 can receive an indication of a null resource element pattern from a base station based at least in part on an indication of a recommended null resource element pattern or a recommended number of null resource elements, as described above.

[0111] like Figure 7 As further shown in FIG. 7 , in some aspects, process 700 may include performing one or more demodulation interference measurements based at least in part on the empty resource element pattern (block 730). For example, a UE (e.g., by using Fig.11 The communication manager 1104 or the interference cancellation component 1110 depicted in FIG. 10A may perform one or more demodulation interference measurements based at least in part on the null resource element pattern, as described above.

[0112] like Figure 7 As further shown in FIG. 7 , in some aspects, process 700 may include demodulating downlink communications based at least in part on performing one or more demodulation interference measurements (block 740). For example, a UE (e.g., by using Fig.11 The communication manager 1104 or the transmitting component 1106 depicted in FIG. 100 may demodulate downlink communications based at least in part on performing one or more demodulation interference measurements, as described above.

[0113] Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below or in combination with one or more other processes described elsewhere herein.

[0114] In a first additional aspect, an indication of an empty resource element pattern is included in the DCI, and wherein the empty resource element pattern is indicated in the DCI using: also indicating the value of the antenna port field of one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups with no data, or one or more zero-power downlink reference signals.

[0115] In a second additional aspect, alone or in combination with the first aspect, an indication of a recommended empty resource element pattern or a recommended number of empty resource elements is included in at least one of a UE capability report or a CSI report.

[0116] In a third additional aspect, alone or in combination with one or more of the first and second aspects, process 700 includes receiving a CSI reporting configuration requesting the UE to report a recommended empty resource element pattern or a recommended number of empty resource elements in a CSI report.

[0117] Although Figure 7 Example blocks of process 700 are shown, but in some aspects, the same Figure 7 Compared to that depicted in , process 700 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks. Additionally or alternatively, two or more of the blocks in process 700 may be executed in parallel.

[0118] Figure 8 is a flow diagram illustrating an example process 800 performed, for example, by a base station in accordance with various aspects of the present disclosure. Example process 800 is an example of a base station (eg, base station 110) performing operations associated with using null resource elements for demodulation interference estimation.

[0119] like Figure 8As shown in , in some aspects, process 800 may include: sending a DCI including an indication of a null resource element pattern to a UE, the null resource element pattern being indicated in the DCI using: a value of an antenna port field that also indicates one or more DMRS ports for the UE and a number of DMRS code division multiplexing groups without data, or a zero-power downlink reference signal (block 810). For example, a base station (such as by using Fig.12 The transmitting component 1206 depicted in the figure can send a DCI including an indication of a null resource element pattern to the UE, where the null resource element pattern is indicated in the DCI in the following manner: the value of the antenna port field of the number of DMRS code division multiplexing groups without data and one or more DMRS ports for the UE is also indicated, or a zero-power downlink reference signal, as described above.

[0120] like Figure 8 As further shown in FIG. 8 , in some aspects, process 800 may include sending a downlink communication based at least in part on a pattern of empty resource elements indicated in the DCI (block 820). For example, a base station (such as by using Fig.12 The transmitting component 1206 depicted in FIG. 1 may transmit a downlink communication based at least in part on the empty resource element pattern indicated in the DCI, as described above.

[0121] Figure 8 Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below or in combination with one or more other processes described elsewhere herein.

[0122] In a first additional aspect, process 800 includes sending a configuration indicating a set of null resource element patterns, and selecting a null resource element pattern from the set of null resource element patterns to be indicated in a DCI.

[0123] In a second additional aspect, alone or in combination with the first aspect, the configuration indicates different sets of empty resource element patterns for at least one of different ranks or different combinations of DMRS ports.

[0124] In a third additional aspect, either alone or in combination with one or more of the first and second aspects, process 800 includes determining that the number of receive antennas reported by the UE satisfies a threshold, and indicating an empty resource element pattern based at least in part on determining that the number of receive antennas reported by the UE satisfies the threshold.

[0125] In a fourth additional aspect, either alone or in combination with one or more of the first to third aspects, at least one of the empty resource element pattern or the number of resource elements included in the empty resource element pattern depends on at least one of: the maximum rank configured for the UE's PDSCH reception, whether the UE operates in SU-MIMO mode or MU-MIMO mode, the precoding resource block group configuration, the DMRS bundling configuration, or a combination thereof.

[0126] In a fifth additional aspect, alone or in combination with one or more of the first to fourth aspects, the one or more zero-power downlink reference signals include one or more zero-power channel state information reference signals.

[0127] In a sixth additional aspect, either alone or in combination with one or more of the first to fifth aspects, the one or more zero-power downlink reference signals include one or more channel state information interference measurement reference signals or one or more downlink reference signals for interference measurement.

[0128] In a seventh additional aspect, alone or in combination with one or more of the first to sixth aspects, process 800 includes receiving an indication of a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern from a UE.

[0129] In an eighth additional aspect, either alone or in combination with one or more of the first to seventh aspects, process 800 includes determining whether to select an empty resource element pattern based at least in part on a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern.

[0130] In a ninth additional aspect, either alone or in combination with one or more of the first to eighth aspects, receiving an indication of a recommended empty resource element pattern or a recommended number of resource elements for an empty resource element pattern includes receiving an indication of a recommended empty resource element pattern or a recommended number of resource elements for an empty resource element pattern in at least one of a UE capability report or a CSI report.

[0131] In a tenth additional aspect, either alone or in combination with one or more of the first to ninth aspects, process 800 includes sending a CSI report configuration requesting the UE to report a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern in the CSI report.

[0132] Although Figure 8 Example blocks of process 800 are shown, but in some aspects, the same Figure 8Compared to that depicted in , process 800 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks. Additionally or alternatively, two or more blocks in the blocks of process 800 may be executed in parallel.

[0133] Fig. 9 is a flow diagram illustrating an example process 900 performed, for example, by a base station in accordance with various aspects of the present disclosure. Example process 900 is an example of a base station (eg, base station 110) performing operations associated with using null resource elements for demodulation interference estimation.

[0134] like Fig. 9 As shown in , in some aspects, process 900 may include: receiving an indication of a recommended empty resource element pattern or a recommended number of empty resource elements from a UE (block 910). For example, a base station (such as by using Fig.13 The receiving component 1302 depicted in FIG. 1 may receive an indication of a recommended empty resource element pattern or a recommended number of empty resource elements from a UE, as described above.

[0135] like Fig. 9 As further shown in FIG. 1 , in some aspects, process 900 may include sending an indication of a blank resource element pattern to a UE based at least in part on an indication of a recommended blank resource element pattern or a recommended number of blank resource elements (block 920). For example, a base station (e.g., by using Fig.13 The sending component 1306 depicted in FIG. 1 can send an indication of a blank resource element pattern to the UE based at least in part on the indication of a recommended blank resource element pattern or a recommended number of blank resource elements, as described above.

[0136] like Fig. 9 As further shown in FIG. 9 , in some aspects, process 900 may include sending a downlink communication to a UE based at least in part on a pattern of empty resource elements (block 930). For example, a base station (e.g., by using Fig.13 The transmitting component 1306 depicted in FIG. 1 can transmit a downlink communication to the UE based at least in part on the null resource element pattern, as described above.

[0137] Fig. 9 Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below or in combination with one or more other processes described elsewhere herein.

[0138] In a first additional aspect, an indication of an empty resource element pattern is included in the DCI, and wherein the empty resource element pattern is indicated in the DCI using: also indicating the value of the antenna port field of one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups with no data, or one or more zero-power downlink reference signals.

[0139] In a second additional aspect, alone or in combination with the first aspect, an indication of a recommended empty resource element pattern or a recommended number of empty resource elements is included in at least one of a UE capability report or a CSI report.

[0140] Although Fig. 9 Example blocks of process 900 are shown, but in some aspects, the same Fig. 9 Compared to that depicted in , process 900 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks. Additionally or alternatively, two or more of the blocks in process 900 may be executed in parallel.

[0141] Fig.10 1 is a block diagram of an example apparatus 1000 for wireless communication according to various aspects of the present disclosure. Apparatus 1000 may be a UE, or a UE may include apparatus 1000. In some aspects, apparatus 1000 includes a receiving component 1002, a communication manager 1004, and a sending component 1006, which may communicate with each other (e.g., via one or more buses). As shown, apparatus 1000 may communicate with another apparatus 1008 (such as a UE, a base station, or another wireless communication device) using receiving component 1002 and sending component 1006.

[0142] In some aspects, the apparatus 1000 may be configured to perform the Figure 4-Figure 5 Additionally or alternatively, the apparatus 1000 may be configured to perform one or more of the processes described herein, such as Figure 6 The process of 600 Figure 7 In some aspects, the apparatus 1000 may include the process 700 described above in combination with Figure 2 One or more components of a UE are described.

[0143] The receiving component 1002 can receive communications, such as reference signals, control information, data communications, or combinations thereof, from the apparatus 1008. The receiving component 1002 can provide the received communications to one or more other components of the apparatus 1000, such as the communications manager 1004. In some aspects, the receiving component 1002 can perform signal processing (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, among other examples) on the received communications, and can provide the processed signals to one or more other components. In some aspects, the receiving component 1002 can include the above in combination with Figure 2 One or more antennas, demodulators, MIMO detectors, receive processors, controllers / processors, memories, or combinations thereof of the described UE.

[0144] The transmission component 1006 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the device 1008. In some aspects, the communication manager 1004 may generate communications and may transmit the generated communications to the transmission component 1006 for transmission to the device 1008. In some aspects, the transmission component 1006 may perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) on the generated communications and may transmit the processed signals to the device 1008. In some aspects, the transmission component 1006 may include the above in combination with Figure 2 One or more antennas, modulators, transmit MIMO processors, transmit processors, controllers / processors, memory, or combinations thereof of the described UE. In some aspects, the transmit component 1006 can be collocated with the receive component 1002 in a transceiver.

[0145] The communication manager 1004 may receive or may cause the receiving component 1002 to receive a DCI that includes an indication of an empty resource element pattern. The empty resource element pattern may be indicated in the DCI using a value of an antenna port field that also indicates one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals. The communication manager 1004 may perform one or more demodulation interference measurements based at least in part on the empty resource element pattern. The communication manager 1004 may demodulate downlink communications based at least in part on performing one or more demodulation interference measurements. In some aspects, the communication manager 1004 may perform one or more operations described below as being performed by one or more components included in the communication manager 1004. In some aspects, the communication manager 1004 may include the above in combination with Figure 2 A controller / processor, a memory, or a combination thereof of a UE is described.

[0146] In some aspects, the communication manager 1004 may include a collection of components, such as an interference cancellation component 1010, a demodulation component 1012, an interpretation component 1014, a determination component 1016, or a combination thereof. Alternatively, the collection of components may be separate and distinct from the communication manager 1004. In some aspects, one or more of the components in the collection of components may include the above-described components. Figure 2 The controller / processor, memory or combination thereof of the UE described above, or may be in combination with Figure 2 The controller / processor, memory, or a combination thereof of the UE described herein may be implemented in the controller / processor, memory, or a combination thereof. Additionally or alternatively, one or more components in the component set may be at least partially implemented as software stored in the memory. For example, a component (or a portion of a component) may be implemented as an instruction or code stored in a non-transitory computer-readable medium and executable by a controller or processor to perform the function or operation of the component.

[0147] In some aspects, the receiving component 1002 may receive a DCI including an indication of a null resource element pattern. The null resource element pattern may be indicated in the DCI using a value of an antenna port field that also indicates one or more DMRS ports for the UE and a number of DMRS code division multiplexing groups without data, or one or more zero-power downlink reference signals. The interference cancellation component 1010 may perform one or more demodulation interference measurements based at least in part on the null resource element pattern. The demodulation component 1012 may demodulate downlink communications based at least in part on performing one or more demodulation interference measurements.

[0148] The receiving component 1002 may receive a configuration indicating a set of empty resource element patterns, wherein the empty resource element pattern indicated in the DCI is selected from the set of empty resource element patterns. The interpreting component 1014 may interpret the empty resource element pattern indicated in the DCI based at least in part on the rank used by the UE, the combination of DMRS ports used by the UE, the maximum rank configured for the UE, or a combination thereof. The determining component 1016 may determine that the maximum rank configured for the PDSCH reception of the UE satisfies a threshold. The interference cancellation component 1010 may perform one or more demodulation interference measurements using the empty resource element pattern based at least in part on the maximum rank configured for the PDSCH reception of the UE to satisfy the threshold. The sending component 1006 may send an indication of a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern to the base station. The sending component 1006 may indicate the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern in at least one of a UE capability report or a CSI report. Receiving component 1002 can receive a CSI reporting configuration requesting the UE to report a recommended null resource element pattern or a recommended number of resource elements for a null resource element pattern in a CSI report.

[0149] supply Fig.10 The number and arrangement of components shown in FIG. are provided as examples. In practice, Fig.10 There may be additional components, fewer components, different components, or differently arranged components than those shown in . Fig.10 Two or more components shown in the figure may be implemented in a single component, or Fig.10 The single component shown in can be implemented as multiple distributed components. Additionally or alternatively, Fig.10 The collection of (eg, one or more) components shown in may perform the operations described by Fig.10 One or more functions performed by another component collection shown in .

[0150] Fig.11 1 is a block diagram of an example apparatus 1100 for wireless communication according to various aspects of the present disclosure. The apparatus 1100 may be a UE, or a UE may include the apparatus 1100. In some aspects, the apparatus 1100 includes a receiving component 1102, a communication manager 1104, and a sending component 1106, which may communicate with each other (e.g., via one or more buses). As shown, the apparatus 1100 may communicate with another apparatus 1108 (such as a UE, a base station, or another wireless communication device) using the receiving component 1102 and the sending component 1106.

[0151] In some aspects, the apparatus 1100 may be configured to perform the Figure 4-Figure 5Additionally or alternatively, the apparatus 1100 may be configured to perform one or more of the processes described herein, such as Figure 6 The process of 600 Figure 7 In some aspects, the apparatus 1100 may include the process 700 described above in combination with Figure 2 One or more components of a UE are described.

[0152] The receiving component 1102 can receive communications from the apparatus 1108, such as reference signals, control information, data communications, or a combination thereof. The receiving component 1102 can provide the received communications to one or more other components of the apparatus 1100, such as the communications manager 1104. In some aspects, the receiving component 1102 can perform signal processing (e.g., filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, among other examples) on the received communications, and can provide the processed signals to one or more other components. In some aspects, the receiving component 1102 can include the above in combination with Figure 2 One or more antennas, demodulators, MIMO detectors, receive processors, controllers / processors, memories, or combinations thereof of the described UE.

[0153] The transmission component 1106 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the device 1108. In some aspects, the communication manager 1104 may generate communications and may transmit the generated communications to the transmission component 1106 for transmission to the device 1108. In some aspects, the transmission component 1106 may perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) on the generated communications and may transmit the processed signals to the device 1108. In some aspects, the transmission component 1106 may include the above in combination with Figure 2 One or more antennas, modulators, transmit MIMO processors, transmit processors, controllers / processors, memory, or combinations thereof of the described UE. In some aspects, the transmit component 1106 can be collocated with the receive component 1102 in a transceiver.

[0154] The communication manager 1104 may send, or may cause the sending component 1106 to send, to the base station an indication of a recommended empty resource element pattern or a recommended number of empty resource elements. The communication manager 1104 may receive, or may cause the receiving component 1102 to perform the following operations: receiving an indication of an empty resource element pattern from the base station based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The communication manager 1104 may perform one or more demodulation interference measurements based at least in part on the empty resource element pattern. The communication manager 1104 may demodulate downlink communications based at least in part on performing one or more demodulation interference measurements. The communication manager 1104 may receive, or may cause the receiving component 1102 to receive, a CSI reporting configuration requesting the UE to report a recommended empty resource element pattern or a recommended number of empty resource elements in a CSI report. In some aspects, the communication manager 1104 may include the above in combination with Figure 2 A controller / processor, a memory, or a combination thereof of a described UE.

[0155] In some aspects, the communication manager 1104 may include a collection of components, such as an interference cancellation component 1110, a demodulation component 1112, or a combination thereof. Alternatively, the collection of components may be separate and distinct from the communication manager 1104. In some aspects, one or more of the components in the collection of components may include the above-described components. Figure 2 The controller / processor, memory or combination thereof of the UE described above, or may be in combination with Figure 2 The controller / processor, memory, or a combination thereof of the UE described herein may be implemented in the controller / processor, memory, or a combination thereof. Additionally or alternatively, one or more components in the component set may be at least partially implemented as software stored in the memory. For example, a component (or a portion of a component) may be implemented as an instruction or code stored in a non-transitory computer-readable medium and executable by a controller or processor to perform the function or operation of the component.

[0156] The transmitting component 1106 may transmit an indication of a recommended empty resource element pattern or a recommended number of empty resource elements to the base station. The receiving component 1102 may receive an indication of an empty resource element pattern from the base station based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The interference cancellation component 1110 may perform one or more demodulation interference measurements based at least in part on the empty resource element pattern. The demodulation component 1112 may demodulate downlink communications based at least in part on performing one or more demodulation interference measurements. The receiving component 1102 may receive a CSI reporting configuration requesting the UE to report a recommended empty resource element pattern or a recommended number of empty resource elements in a CSI report.

[0157] supply Fig.11 The number and arrangement of components shown in FIG. are provided as examples. In practice, Fig.11 There may be additional components, fewer components, different components, or differently arranged components than those shown in . Fig.11 Two or more components shown in the figure may be implemented in a single component, or Fig.11 The single component shown in can be implemented as multiple distributed components. Additionally or alternatively, Fig.11 The collection of (eg, one or more) components shown in may perform the operations described by Fig.11 One or more functions performed by another component collection shown in .

[0158] Fig.12 1 is a block diagram of an example apparatus 1200 for wireless communication according to various aspects of the present disclosure. Apparatus 1200 may be a base station, or a base station may include apparatus 1200. In some aspects, apparatus 1200 includes a receiving component 1202, a communication manager 1204, and a sending component 1206, which may communicate with each other (e.g., via one or more buses). As shown, apparatus 1200 may communicate with another apparatus 1208 (such as a UE, a base station, or another wireless communication device) using receiving component 1202 and sending component 1206.

[0159] In some aspects, the apparatus 1200 may be configured to perform the Figure 4-Figure 5 Additionally or alternatively, the apparatus 1200 may be configured to perform one or more of the processes described herein (e.g. Figure 8 The process of 800 Fig. 9 In some aspects, the apparatus 1200 may include the process 900 described above in combination with Figure 2 One or more components of a base station are described.

[0160] The receiving component 1202 can receive communications from the apparatus 1208, such as reference signals, control information, data communications, or a combination thereof. The receiving component 1202 can provide the received communications to one or more other components of the apparatus 1200, such as the communications manager 1204. In some aspects, the receiving component 1202 can perform signal processing (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, among other examples) on the received communications, and can provide the processed signals to one or more other components. In some aspects, the receiving component 1202 can include the above in combination with Figure 2 One or more antennas, demodulators, MIMO detectors, receive processors, controllers / processors, memories, or combinations thereof of the described base stations.

[0161] The transmission component 1206 may transmit communications such as reference signals, control information, data communications, or a combination thereof to the device 1208. In some aspects, the communication manager 1204 may generate communications and may transmit the generated communications to the transmission component 1206 for transmission to the device 1208. In some aspects, the transmission component 1206 may perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) on the generated communications and may transmit the processed signals to the device 1208. In some aspects, the transmission component 1206 may include the above in combination with Figure 2 One or more antennas, modulators, transmit MIMO processors, transmit processors, controllers / processors, memories, or combinations thereof of the described base stations. In some aspects, the transmit component 1206 can be collocated with the receive component 1202 in a transceiver.

[0162] The communication manager 1204 may send or may cause the sending component 1206 to send a DCI including an indication of an empty resource element pattern to the UE. The empty resource element pattern may be indicated in the DCI using the value of the antenna port field that also indicates one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups without data, or a zero-power downlink reference signal. The communication manager 1204 may send downlink communications based at least in part on the empty resource element pattern indicated in the DCI, or may cause the sending component 1206 to send downlink communications based at least in part on the empty resource element pattern indicated in the DCI. The communication manager 1204 may send or may cause the sending component 1206 to send a configuration indicating a set of empty resource element patterns. The communication manager 1204 may select an empty resource element pattern to be indicated in the DCI from the set of empty resource element patterns. The communication manager 1204 may determine that the number of receive antennas reported by the UE meets a threshold. The communication manager 1204 may indicate an empty resource element pattern based at least in part on determining that the number of receive antennas reported by the UE satisfies a threshold, or may cause the sending component 1206 to indicate an empty resource element pattern based at least in part on determining that the number of receive antennas reported by the UE satisfies a threshold. The communication manager 1204 may receive or may cause the receiving component 1202 to receive an indication of a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern from the UE. The communication manager 1204 may determine whether to select an empty resource element pattern based at least in part on the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern. The communication manager 1204 may send or cause the sending component 1206 to send a CSI report configuration requesting the UE to report a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern in a CSI report. In some aspects, the communication manager 1204 may include the above in combination with Figure 2 A controller / processor, a memory, a scheduler, a communication unit, or a combination thereof of the described base station.

[0163] In some aspects, the communication manager 1204 may include a component set, such as a selection component 1210, a determination component 1212, or a combination thereof. Alternatively, the component set may be separate and distinct from the communication manager 1204. In some aspects, one or more components in the component set may include the above-mentioned combination. Figure 2 The controller / processor, memory, scheduler, communication unit or combination thereof of the base station described above, or can be combined with the above Figure 2The controller / processor, memory, scheduler, communication unit, or a combination thereof of the base station described herein may be implemented in the controller / processor, memory, scheduler, communication unit, or a combination thereof. Additionally or alternatively, one or more components in the component set may be at least partially implemented as software stored in the memory. For example, a component (or a portion of a component) may be implemented as an instruction or code stored in a non-transitory computer-readable medium and executable by a controller or processor to perform the function or operation of the component.

[0164] The sending component 1206 may send a DCI including an indication of a null resource element pattern to the UE. The null resource element pattern may be indicated in the DCI using the value of the antenna port field that also indicates one or more DMRS ports for the UE and the number of DMRS code division multiplexing groups without data, or a zero-power downlink reference signal. The sending component 1206 may send downlink communications based at least in part on the null resource element pattern indicated in the DCI. The sending component 1206 may send a configuration indicating a set of null resource element patterns. The selecting component 1210 may select a null resource element pattern to be indicated in the DCI from the set of null resource element patterns. The determining component 1212 may determine that the number of receiving antennas reported by the UE meets a threshold. The sending component 1206 may indicate a null resource element pattern based at least in part on determining that the number of receiving antennas reported by the UE meets a threshold. The receiving component 1202 may receive an indication of a recommended null resource element pattern or a recommended number of resource elements for a null resource element pattern from the UE. Determining component 1212 can determine whether to select a null resource element pattern based at least in part on a recommended null resource element pattern or a recommended number of resource elements for the null resource element pattern. Sending component 1206 can send a CSI reporting configuration requesting the UE to report a recommended null resource element pattern or a recommended number of resource elements for the null resource element pattern in a CSI report.

[0165] supply Fig.12 The number and arrangement of components shown in FIG. are provided as examples. In practice, Fig.12 There may be additional components, fewer components, different components, or differently arranged components than those shown in . Fig.12 Two or more components shown in the figure may be implemented in a single component, or Fig.12 The single component shown in can be implemented as multiple distributed components. Additionally or alternatively, Fig.12 The collection of (eg, one or more) components shown in may perform the operations described by Fig.12 One or more functions performed by another component collection shown in .

[0166] Fig.131 is a block diagram of an example apparatus 1300 for wireless communication according to various aspects of the present disclosure. Apparatus 1300 may be a base station, or a base station may include apparatus 1300. In some aspects, apparatus 1300 includes a receiving component 1302, a communication manager 1304, and a sending component 1306, which may communicate with each other (e.g., via one or more buses). As shown, apparatus 1300 may communicate with another apparatus 1308 (such as a UE, a base station, or another wireless communication device) using receiving component 1302 and sending component 1306.

[0167] In some aspects, the apparatus 1300 may be configured to perform the Figure 4-Figure 5 Additionally or alternatively, the apparatus 1300 may be configured to perform one or more of the processes described herein, such as Figure 8 The process of 800 Fig. 9 In some aspects, the apparatus 1300 may include the process 900 described above in combination with Figure 2 One or more components of a base station are described.

[0168] The receiving component 1302 may receive communications (e.g., reference signals, control information, data communications, or combinations thereof) from the apparatus 1308. The receiving component 1302 may provide the received communications to one or more other components of the apparatus 1300, such as the communications manager 1304. In some aspects, the receiving component 1302 may perform signal processing (e.g., filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, among other examples) on the received communications, and may provide the processed signals to one or more other components. In some aspects, the receiving component 1302 may include the above in combination with Figure 2 One or more antennas, demodulators, MIMO detectors, receive processors, controllers / processors, memories, or combinations thereof of the described base stations.

[0169] The transmitting component 1306 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the device 1308. In some aspects, the communication manager 1304 may generate communications and may transmit the generated communications to the transmitting component 1306 for transmission to the device 1308. In some aspects, the transmitting component 1306 may perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) on the generated communications and may transmit the processed signals to the device 1308. In some aspects, the transmitting component 1306 may include the above in combination with Figure 2One or more antennas, modulators, transmit MIMO processors, transmit processors, controllers / processors, memories, or combinations thereof of the described base stations. In some aspects, the transmit component 1306 can be collocated with the receive component 1302 in a transceiver.

[0170] The communication manager 1304 may receive, or may cause the receiving component 1302 to receive, from the UE an indication of a recommended empty resource element pattern or a recommended number of empty resource elements. The communication manager 1304 may send an indication of an empty resource element pattern to the UE based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements, or may cause the sending component 1306 to send an indication of an empty resource element pattern to the UE based at least in part on the indication of the recommended empty resource element pattern or the recommended number of empty resource elements. The communication manager 1304 may send a downlink communication to the UE based at least in part on the empty resource element pattern, or may cause the sending component 1306 to send a downlink communication to the UE based at least in part on the empty resource element pattern. In some aspects, the communication manager 1304 may include the above in combination with Figure 2 A controller / processor, a memory, a scheduler, a communication unit, or a combination thereof of the described base station.

[0171] In some aspects, the communication manager 1304 may include a collection of components, such as those described above in conjunction with Fig.12 Alternatively, the component set may be separate and distinct from the communication manager 1304. In some aspects, one or more components in the component set may include the components described above in conjunction with Figure 2 The controller / processor, memory, scheduler, communication unit or combination thereof of the base station described above, or may be a combination of the above Figure 2 The controller / processor, memory, scheduler, communication unit, or a combination thereof of the base station described herein may be implemented in the controller / processor, memory, scheduler, communication unit, or a combination thereof. Additionally or alternatively, one or more components in the component set may be at least partially implemented as software stored in the memory. For example, a component (or a portion of a component) may be implemented as an instruction or code stored in a non-transitory computer-readable medium and executable by a controller or processor to perform the function or operation of the component.

[0172] supply Fig.13 The number and arrangement of components shown in FIG. are provided as examples. In practice, Fig.13 There may be additional components, fewer components, different components, or differently arranged components than those shown in . Fig.13 Two or more components shown in the figure may be implemented in a single component, or Fig.13The single component shown in can be implemented as multiple distributed components. Additionally or alternatively, Fig.13 The collection of (eg, one or more) components shown in may perform the operations described by Fig.13 One or more functions performed by another component collection shown in .

[0173] The above disclosure provides illustration and description, and is not intended to be exhaustive or to limit the various aspects to the precise forms disclosed. Modifications and variations may be made based on the above disclosure, or may be obtained from the practice of various aspects.

[0174] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented using hardware, firmware, or a combination of hardware and software.

[0175] Some aspects are described in conjunction with a threshold. As used herein, depending on the context, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, and other examples or combinations thereof.

[0176] It will be apparent that the systems or methods described herein can be implemented using a combination of hardware, firmware, or hardware and software in various forms. The actual dedicated control hardware or software code used to implement these systems or methods does not limit these aspects. Therefore, this paper describes the operation and behavior of the systems or methods without citing specific software codes. Software and hardware can be designed to implement these systems or methods based at least in part on the description herein.

[0177] Although the combination of features is set forth in the claims or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features can be combined in a manner that is not specifically set forth in the claims or is not disclosed in the specification. Although each dependent claim listed below directly depends on only one claim, the disclosure of various aspects includes each dependent claim of each other claim combined in the claim set. The phrase of "at least one of" the referenced item list refers to any combination of these items, including a single member. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc, and any combination (for example, aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc and ccc, or any other ordering of a, b and c) with multiple identical elements.

[0178] Any element, action or instruction used in this article should not be interpreted as being key or indispensable, unless clearly described as such. In addition, as used herein, the articles "a" and "an" are intended to include one or more projects, and can be used interchangeably with "one or more". In addition, as used herein, the terms "set" and "group" are intended to include one or more projects (e.g., related projects, unrelated projects, combinations of related projects and unrelated projects and other examples or combinations thereof), and can be used interchangeably with "one or more". In the case of wanting only one project, phrases "only one" or similar language are used. In addition, as used herein, the terms "has", "have", "having" and other examples or combinations thereof are intended to be open terms. Further, the phrase "based on" is intended to mean "based at least in part on", unless otherwise explicitly stated.

Claims

1. A method of wireless communication performed by a user equipment UE, comprising: receiving downlink control information, DCI, including an indication of a blank resource element pattern, wherein at least one of the blank resource element pattern or the number of resource elements included in the blank resource element pattern depends on at least one of: a maximum rank configured for physical downlink shared channel (PDSCH) reception of the UE, whether the UE operates in a single-user multiple-input multiple-output (SU-MIMO) mode or a multi-user multiple-input multiple-output (MU-MIMO) mode, a precoding resource block group configuration, a DMRS bundling configuration, or a combination thereof; performing one or more demodulation interference measurements based at least in part on the pattern of null resource elements; and Downlink communications are demodulated based at least in part on performing the one or more demodulation interference measurements.

2. The method according to claim 1, further comprising: A configuration indicating a set of null resource element patterns is received, wherein the null resource element pattern indicated in the DCI is selected from the set of null resource element patterns.

3. The method according to claim 2, wherein: The configuration indicates different sets of empty resource element patterns for at least one of different ranks or different combinations of DMRS ports.

4. The method according to claim 1, further comprising: The empty resource element pattern indicated in the DCI is interpreted based at least in part on a rank used by the UE, a combination of DMRS ports used by the UE, a maximum rank configured for the UE, or a combination thereof.

5. The method according to claim 1, further comprising: Determining that a maximum rank configured for receiving a physical downlink shared channel (PDSCH) of the UE satisfies a threshold; as well as The one or more demodulation interference measurements are performed using the null resource element pattern based at least in part on determining that the maximum rank configured for PDSCH reception of the UE satisfies the threshold.

6. The method according to claim 1, wherein: The empty resource element pattern is indicated in the DCI using the following method: A value of the Antenna Port field further indicating one or more demodulation reference signal (DMRS) ports for the UE and the number of DMRS code division multiplexing groups without data, or One or more zero-power downlink reference signals.

7. The method according to claim 6, wherein: The one or more zero-power downlink reference signals include one or more zero-power channel state information reference signals.

8. The method according to claim 6, wherein: The one or more zero-power downlink reference signals include one or more channel state information interference measurement reference signals or one or more downlink reference signals for interference measurement.

9. The method according to claim 1, further comprising: An indication of a recommended empty resource element pattern or a recommended number of resource elements for the empty resource element pattern is sent to a base station.

10. The method according to claim 9, wherein: The empty resource element pattern indicated in the DCI is based at least in part on the indication of the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern.

11. The method according to claim 9, further comprising: The recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern is indicated in at least one of a UE capability report or a channel state information (CSI) report.

12. The method according to claim 11, further comprising: A CSI reporting configuration is received, wherein the CSI reporting configuration requests the UE to report the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern in the CSI report.

13. A method of wireless communication performed by a base station, comprising: sending downlink control information, DCI, including an indication of a blank resource element pattern to a user equipment, UE, wherein at least one of the blank resource element pattern or the number of resource elements included in the blank resource element pattern depends on at least one of: a maximum rank configured for physical downlink shared channel, PDSCH, reception of the UE, whether the UE operates in a single-user multiple-input multiple-output, SU-MIMO mode or a multi-user multiple-input multiple-output, MU-MIMO mode, a precoding resource block group configuration, a DMRS bundling configuration, or a combination thereof; and A downlink communication is sent based at least in part on the null resource element pattern indicated in the DCI.

14. The method according to claim 13, further comprising: A configuration indicating a set of empty resource element patterns is sent, and the empty resource element pattern is selected from the set of empty resource element patterns to be indicated in the DCI.

15. The method according to claim 14, wherein: The configuration indicates different sets of empty resource element patterns for at least one of different ranks or different combinations of DMRS ports.

16. The method according to claim 13, further comprising: Determining that the number of receiving antennas reported by the UE satisfies a threshold; as well as Based at least in part on determining that the number of receive antennas reported by the UE satisfies the threshold, a null resource element pattern is indicated.

17. The method according to claim 13, wherein: The empty resource element pattern is indicated in the DCI using the following method: A value of the Antenna Port field further indicating one or more demodulation reference signal (DMRS) ports for the UE and the number of DMRS code division multiplexing groups without data, or One or more zero-power downlink reference signals.

18. The method according to claim 17, wherein: The one or more zero-power downlink reference signals include one or more zero-power channel state information reference signals.

19. The method according to claim 17, wherein: The one or more zero-power downlink reference signals include one or more channel state information interference measurement reference signals or one or more downlink reference signals for interference measurement.

20. The method of claim 13, further comprising: An indication of a recommended null resource element pattern or a recommended number of resource elements for the null resource element pattern is received from the UE.

21. The method according to claim 20, further comprising: Whether to select the null resource element pattern is determined based at least in part on the recommended null resource element pattern or the recommended number of resource elements for the null resource element pattern.

22. The method according to claim 20, wherein: Receiving the indication of the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern includes: receiving the indication of the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern in at least one of a UE capability report or a channel state information CSI report.

23. The method according to claim 22, further comprising: A CSI report configuration is sent, wherein the CSI report configuration requests the UE to report the recommended empty resource element pattern or the recommended number of resource elements for the empty resource element pattern in the CSI report.

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