Co-scheduling interfering UE presence signaling and modulation order detection

Abstract

The invention relates to modulation order detection with respect to multiple co-scheduled UEs. An apparatus is configured to: receive, from a network node, a configuration for one or more resource elements having zero power; receiving downlink control information, wherein the downlink control information comprises at least an aperiodic indication for triggering a resource element having zero power; and determining a number of co-scheduled user equipments in the physical downlink shared channel based, at least in part, on at least one of: an index associated with the one or more resource elements, a number of the one or more resource elements, or a number of the one or more resource elements triggered with the aperiodic indication; and identifying co-scheduled UE interference information based on the number of co-scheduled UEs and the resource elements with zero power. The co-scheduled UE interference information includes a determination of MO, FDRA, and DMRS ports for each co-scheduled UE.

Description

Technical Field

[0001] The exemplary and non-limiting embodiments relate generally to detecting parameters associated with interfering co-scheduled UEs, and more particularly to modulation order detection with respect to multiple co-scheduled UEs. Background Art

[0002] In multi-user multiple-input multiple-output (MU-MMIMO) operation, a known target UE receives network-assisted signaling and performs blind detection with respect to the modulation order of the co-scheduled UE. Summary of the invention

[0003] The following summary is intended to be illustrative only. This summary is not intended to limit the scope of the claims.

[0004] According to one aspect, an apparatus includes: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receive a configuration for one or more resource elements with zero power from a network node; receive downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power; and determine the number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0005] According to one aspect, a method includes: receiving, with a user equipment, a configuration for one or more resource elements with zero power from a network node; receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering the resource elements with zero power; and determining a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of the following: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0006] According to one aspect, an apparatus includes components for: receiving a configuration for one or more resource elements with zero power from a network node; receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering the resource elements with zero power; and determining a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0007] According to one aspect, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following operations: causing reception of a configuration for one or more resource elements with zero power from a network node; causing reception of downlink control information, wherein the downlink control information includes at least an aperiodic indication for triggering resource elements with zero power; and causing determination of a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered using the aperiodic indication.

[0008] According to one aspect, an apparatus includes: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: evaluate co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; send a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and send downlink control information to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power.

[0009] According to one aspect, a method includes: evaluating, with a network node, co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; sending a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and sending downlink control information to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering the resource elements with zero power.

[0010] According to one aspect, an apparatus includes components for: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; sending a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and sending downlink control information to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power.

[0011] According to one aspect, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following operations: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; causing a configuration for one or more resource elements with zero power to be sent to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and causing downlink control information to be sent to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power.

[0012] According to some aspects, the subject matter of the independent claims is provided. Some further aspects are defined in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The foregoing aspects and other features are explained in the following description in conjunction with the accompanying drawings, in which:

[0014] Figure 1 is a block diagram of one possible and non-limiting example system in which example embodiments may be practiced;

[0015] Figure 2 is a diagram illustrating features as described herein;

[0016] Figure 3 is a diagram illustrating features as described herein;

[0017] Figure 4 is a diagram illustrating features as described herein;

[0018] Figure 5 is a diagram illustrating features as described herein;

[0019] Figure 6 is a diagram illustrating features as described herein;

[0020] Figure 7 is a diagram illustrating features as described herein;

[0021] Figure 8 is a diagram illustrating features as described herein;

[0022] Fig. 9 is a flow chart showing the steps as described herein; and

[0023] Fig.10 is a flow chart showing the steps as described herein. DETAILED DESCRIPTION

[0024] The following abbreviations that may be found in the specification and / or drawings are defined as follows: 3GPP Third Generation Partnership Project 5G Fifth Generation 5GC 5G Core Network AMF Access and Mobility Management Function BLER Block Error Rate CHBW Channel Bandwidth cRAN Cloud Radio Access Network CU Central Unit DCI Downlink Control Information DL Downlink DMRS Demodulation Reference Signal DU Distributed Unit E-MMSE-IR Interference Aware MMSE-IRC eNB (or eNodeB) Evolved Node B (e.g., LTE base station) EN-DC E-UTRA-NR Dual Connectivity en-gNB or En-gNB The node that provides NR user plane and control plane protocol termination to the UE and acts as a secondary node in EN-DC E-UTRAN Evolved Universal Terrestrial Radio Access, i.e., LTE radio access technology FDRA frequency domain resource allocation gNB (or gNodeB) is a base station for 5G / NR, i.e., a node that provides NR user plane and control plane protocol termination to the UE and is connected to the 5GC via the NG interface. I / F Interface I / Q In-Phase and Quadrature L1 Layer 1 LTE Long Term Evolution MAC Media Access Control MCS modulation and coding scheme MME Mobility Management Entity MMSE Minimum Mean Square Error MMSE-IRC Minimum Mean Square Interference Rejection Combiner MO modulation order MU-MIMO Multi-User Multiple Input Multiple Output ng or NG new generation ng-eNB or NG-eNB Next Generation eNB NR New Radio N / W or NW network NWA Network Assist O-RAN Open Radio Access Network PDCP Packet Data Convergence Protocol PDSCH Physical Downlink Shared Channel PHY Physical Layer PRB Physical Resource Block QAM Quadrature Amplitude Modulation QPSK Quadrature Phase Shift Keying QR-DM M algorithm based on QR decomposition QR-MLD Maximum Likelihood Detection Based on QR Decomposition RAN Radio Access Network RE Resource Element RF RLC Radio Link Control R-ML Reduced Complexity Maximum Likelihood RRC Radio Resource Control RRH Remote Radio Head RS reference signal RU Radio Unit Rx Receiver SD ball detection SDAP Service Data Adaptation Protocol SGW Service Gateway SMF session management functions SU-MIMO Single User Multiple Input Multiple Output TDRA Time Domain Resource Allocation Tx Transmitter UE User Equipment (e.g., wireless, usually mobile) UPF User Plane Function VNR Virtualized Network Function ZP-CSI-RS Zero Power Channel State Information Reference Signal

[0025] Steering Figure 1 , which shows a block diagram of one possible and non-limiting example in which the examples may be practiced. A user equipment (UE) 110, a radio access network (RAN) node 170 and a network element 190 are shown. Figure 1In the example of FIG. 1 , a user equipment (UE) 110 wirelessly communicates with a wireless network 100. A UE is a wireless device that can access the wireless network 100. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected by one or more buses 127. Each of the one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber or other optical communication device, etc. A "circuit" may include dedicated hardware or hardware associated with software executable thereon. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a module 140, which includes one or both of the parts 140-1 and / or 140-2 that can be implemented in a variety of ways. The module 140 may be implemented in hardware as the module 140-1, such as being implemented as part of the one or more processors 120. Module 140-1 may also be implemented as an integrated circuit or by other hardware such as a programmable gate array. In another example, module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and executed by one or more processors 120. For example, one or more memories 125 and computer program code 123 may be configured to use one or more processors 120 to cause user equipment 110 to perform one or more operations as described herein. UE 110 communicates with RAN node 170 via wireless link 111.

[0026] In this example, the RAN node 170 is a base station that provides access to the wireless network 100 through wireless devices such as UE 110. The RAN node 170 may be, for example, a base station for 5G, also known as New Radio (NR). In 5G, the RAN node 170 may be an NG-RAN node, which is defined as a gNB or ng-eNB. A gNB is a node that provides NR user plane and control plane protocol termination to the UE and is connected to the 5GC (e.g., network element 190) via an NG interface. An ng-eNB is a node that provides E-UTRA user plane and control plane protocol termination to the UE and is connected to the 5GC via an NG interface. An NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and a distributed unit (DU) (gNB-DU), DU 195 being shown. Note that the DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node that hosts the RRC, SDAP and PDCP protocols of a gNB or RRC and the PDCP protocol of an en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface connected to the gNB-DU. The F1 interface is shown at label 198, although label 198 also shows links between remote elements of the RAN node 170 and centralized elements of the RAN node 170, such as between the gNB-CU 196 and the gNB-DU 195. The gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of the gNB or en-gNB, and its operation is partially controlled by the gNB-CU. One gNB-CU supports one or more cells. A cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface 198 connected to the gNB-CU. Note that the DU 195 is considered to include the transceiver 160, for example as part of the RU, but some examples may have the transceiver 160 as part of a separate RU, for example, under the control of the DU 195 and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station for LTE (Long Term Evolution), or any other suitable base station, access point, access node or node.

[0027] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / WI / F) 161, and one or more transceivers 160 interconnected by one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor 152, the memory 155, and the network interface 161. Note that the DU 195 may also contain its own one / multiple memories and (multiple) processors and / or other hardware, but these are not shown.

[0028] The RAN node 170 includes a module 150, which includes one or both of the parts 150-1 and / or 150-2 that can be implemented in a variety of ways. The module 150 can be implemented in hardware as the module 150-1, such as being implemented as part of one or more processors 152. The module 150-1 can also be implemented as an integrated circuit or implemented by other hardware such as a programmable gate array. In another example, the module 150 can be implemented as a module 150-2, which is implemented as a computer program code 153 and executed by one or more processors 152. For example, one or more memories 155 and the computer program code 153 are configured to, together with the one or more processors 152, cause the RAN node 170 to perform one or more operations as described herein. Note that the functionality of the module 150 can be distributed, such as distributed between the DU 195 and the CU 196, or implemented only in the DU 195.

[0029] One or more network interfaces 161 communicate over a network, such as via links 176 and 131. Two or more gNBs 170 may communicate using, for example, link 176. Link 176 may be wired or wireless or both, and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

[0030] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber or other optical communication device, wireless channel, etc. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for a gNB implementation for 5G, where other elements of the RAN node 170 may be physically located at a different location from the RRH / DU, and the one or more buses 157 may be partially implemented as, for example, a fiber optic cable or other suitable network connection to connect other elements of the RAN node 170 (e.g., central unit (CU), gNB-CU) to the RRH / DU 195. Label 198 also indicates those suitable network links.

[0031] Note that the description herein indicates that a "cell" performs a function, but it should be clear that the equipment that forms the cell will perform the function. A cell constitutes part of a base station. That is, each base station can have multiple cells. For example, there may be three cells for a single carrier frequency and associated bandwidth, each covering one-third of a 360-degree area, so that the coverage area of ​​a single base station covers an approximate ellipse or circle. In addition, each cell may correspond to a single carrier, and a base station may use multiple carriers. Therefore, if there are three 120-degree cells per carrier and there are two carriers, the base station has a total of 6 cells.

[0032] The wireless network 100 may include one or more network elements 190, which may include core network functions and provide a connection to another network, such as a telephone network and / or a data communication network (e.g., the Internet), via one or more links 181. Such core network functions for 5G may include access and mobility management functions (AMF) and / or user plane functions (UPF) and / or session management functions (SMF). Such core network functions for LTE may include MME (mobility management entity) / SGW (serving gateway) functions. These are merely illustrative functions that may be supported by the network element 190, and it is noted that both 5G and LTE functions may be supported. The RAN node 170 is coupled to the network element 190 via a link 131. The link 131 may be implemented as, for example, an NG interface for 5G, or an S1 interface for LTE, or other suitable interfaces for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N / WI / F) 180 interconnected by one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to, with the one or more processors 175 , cause the network element 190 to perform one or more operations.

[0033] The wireless network 100 can implement network virtualization, which is the process of combining hardware and software network resources and network functions into a single software-based management entity, a virtual network. Network virtualization involves platform virtualization, which is usually combined with resource virtualization. Network virtualization is classified as external (combining many networks or parts of networks into virtual units), or internal (providing similar network functions to software containers on a single system). For example, a network can be deployed in a remote cloud, where virtualized network functions (VNFs) run on, for example, data center servers. For example, network core functions and / or radio access networks (e.g., CloudRAN, O-RAN, edge cloud) can be virtualized. Note that the virtualized entities resulting from network virtualization are still implemented to some extent using hardware such as processors 152 or 175 and memories 155 and 171, and such virtualized entities also produce technical effects.

[0034] It may also be noted that the operations of the example embodiments of the present disclosure may be performed by multiple cooperating devices (eg, cRAN).

[0035] Computer readable memories 125, 155, and 171 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer readable memories 125, 155, and 171 may be components for performing storage functions. As non-limiting examples, processors 120, 152, and 175 may be of any type suitable for the local technical environment and may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Processors 120, 152, and 175 may be units for performing functions such as controlling UE 110, RAN node 170, and other functions as described herein.

[0036] In general, various example embodiments of user device 110 may include, but are not limited to, a cellular telephone (such as a smart phone), a tablet computer, a personal digital assistant (PDA) with wireless communication capabilities, a portable computer with wireless communication capabilities, an image capture device such as a digital camera with wireless communication capabilities, a gaming device with wireless communication capabilities, a music storage and playback device with wireless communication capabilities, an Internet device allowing wireless Internet access and browsing, a tablet computer with wireless communication capabilities, and portable units or terminals incorporating a combination of such functionality.

[0037] Having introduced a suitable but non-limiting technical context for practicing example embodiments of the present disclosure, the example embodiments will now be described in more detail.

[0038] Features described herein may generally relate to downlink (DL) multi-user multiple-input multiple-output (MU-MIMO). In DL MU-MIMO, multiple UEs may be spatially multiplexed on the same time / frequency resources. In ongoing discussions in 3GPP, advanced interference-aware receivers for downlink MU-MIMO detection are being studied to define minimum demodulation performance requirements.

[0039] A candidate interference-aware advanced receiver for DL ​​MU-MIMO is a Reduced Complexity Maximum Likelihood (R-ML) receiver. This type of receiver uses complexity minimization techniques to achieve near-full maximum likelihood joint detection of the target and interfering UE MIMO layers. There are several known implementations of R-ML (e.g., Sphere Detection (SD), QR-Decomposition-Based M Algorithm (QR-DM), QR-Decomposition-Based Maximum Likelihood Detection (QR-MLD), etc.).

[0040] Another advanced receiver is an Interference Aware Minimum Mean Square Error-Interference Rejection Combiner (E-MMSE-IRC) receiver. Although R-ML receivers and E-MMSE-IRC receivers are discussed in the present disclosure, this is not limiting; other receivers may be used in the case of DL MU-MIMO and / or in conjunction with the example embodiments of the present disclosure.

[0041] In the case of DL MU-MIMO, interference may always be present. In order to enable these advanced receivers for MU-MIMO, multiple parameters of the interfering UE's layer need to be known, such as: DMRS sequence, interfering DMRS port, frequency domain resource allocation (FDRA), time domain resource allocation (TDRA), precoding granularity and / or modulation order (MO). The FDRA of the co-scheduled UE may be complete or partial compared to the target UE FDRA that causes a different amount of interference in the target UE FDRA portion in the MU-MIMO scenario. The R-ML receiver may require the MO of the interfering MIMO layer. The target UE (i.e., the UE that is the interference victim) may know these parameters about itself, and may need to know one or more of these parameters about other interfering co-scheduled UEs in order to mitigate interference.

[0042] In this disclosure, the terms “target UE” and “victim UE” may be used interchangeably to refer to a UE that is detecting / experiencing interference from other signals intended for other co-scheduled UEs in a DL MU-MIMO scenario, e.g., when the target UE attempts to receive from a NW.

[0043] The features described herein may generally involve network assisted (NWA) signaling. Blind detection of MO by target UE and NWA signaling of MO are currently being discussed in 3GPP. The signaling for MO may be as follows: Table 1

[0044] As shown in Table 1, examples of MO may include Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64QAM, 256QAM, and 1024QAM. These examples are not limiting; other MOs are also possible.

[0045] As can be seen, when the gNB / scheduler has information about the MO of a co-scheduled UE, as in the example of Table 1, it can include this information in the downlink control information (DCI) with values ​​1 to 5 when there is a single MO on all interfering ports using the same DMRS sequence as the target UE.

[0046] However, in some cases other values ​​may be signaled.

[0047] For example, if the common UE MO information is not available at the gNB / scheduler (i.e., the gNB is not aware of the information), the gNB may signal a value of 6 even if there is a single co-scheduled UE.

[0048] For example, if the common UE uses another DMRS sequence, the gNB may signal a value of 0 even for a single co-scheduled UE.

[0049] For example, in the case of two common UEs in different parts of the FDRA across the target UE, if they have different modulation orders, the gNB may signal a value of 6.

[0050] For example, in the case of two common UEs occupying the entire FDRA of the target UE, but each common UE has their own DMRS port, the gNB may signal a value of 7 when they have different modulation orders.

[0051] For example, in the case of two common UEs with full FDRA and a first UE using the same DMRS sequence, when the second UE uses another DMRS sequence, values ​​of 1 to 5 may be signaled only for the first UE. The target UE may then need to blindly detect the MO of the second common UE using another DMRS sequence.

[0052] Therefore, it can be noted that this DCI NWA signaling may be useful for informing the target UE of a single UE that is causing interference, but may not provide sufficient information when there are more than one interfering UE, for example, two interfering UEs (i.e., in the case where there is one target UE and two interfering UEs co-scheduled in different frequency ports). For example, the NW may not be able to indicate to the target UE the exact MO used by each of the two interfering UEs.

[0053] Furthermore, according to 3GPP discussions, RRC signaling for indicating a modulation and coding scheme (MCS) table for a common UE may be useful.

[0054] In the present disclosure, the terms "co-scheduled UE" and "common UE" may be used interchangeably to refer to a UE whose DL signal acts as interference with respect to a DL signal received at a target UE.

[0055] The features described herein may generally relate to FDRA and MO detection with two co-scheduled UEs. For two interfering UEs, it may be difficult to determine the exact MO of each interfering UE. 3GPP is considering research on a use case in which two co-UEs each have a half-bandwidth FDRA. For example, co-UE1 may be spatially multiplexed to the first half (0-25 PRBs) of the channel bandwidth (CHBW) allocated to the target UE (52PRBs), while co-UE2 may be spatially multiplexed to the second half (26-51 PRBs) of the channel bandwidth allocated to the target UE (52PRBs). Each of co-UE1 and co-UE2 may have a different MO (i.e., QPSK, 16QAM). A DCI value of 6 may be signaled to the target UE by the gNB (see, e.g., Table 1). The target UE may then have to detect that there are two separate co-UEs in each half of its FDRA and then detect the MO of each co-UE.

[0056] Features as described herein may generally relate to assisted blind detection of MO, for example relative to an R-ML receiver. Blind MO detection is complex and in some cases, particularly at higher MOs, the performance is insufficient to guarantee a 10% block error rate (BLER). In other words, blind detection may impact throughput. T-doc R4-2307466 introduces a special zero-power channel state information reference signal (ZP-CSI-RS) that is repeated in each MU-MIMO slot to assist in blind detection of MO for a common UE.

[0057] Using resource elements (REs) with zero power can make it easier for the target UE to detect the MO of the interfering UE. ZP-CSI-RS can be transmitted periodically or aperiodically.

[0058] This special ZP-CSI-RS repeated in every MU-MIMO slot is the subject of US 63 / 461477, which is hereby incorporated by reference in its entirety.

[0059] As described above, blind co-UE FDRA detection may not be able to distinguish whether there are 1 or 2 co-UEs. In other words, the UE may not be able to determine how many interfering co-UEs there are.

[0060] As mentioned above, in some cases the gNB may not be able to signal the exact MO of the co-scheduled UEs to the target UE, but may give information about the presence of a single MO within each part of the target UE's FDRA. In these cases, if the target UE wants to use an R-ML receiver, the target UE may need to blindly detect a single MO for each part of its FDRA. This may be particularly problematic when there are two interfering co-UEs.

[0061] As mentioned above, blind MO detection is complex and the performance is not good enough to guarantee 10% BLER in all cases.

[0062] As described above, assistance in the form of ZP-CSI-RS may provide very few clean REs (ie, with zero power) to detect MO. For example, if there are two separate common UEs in each half of the FDRA, only thirteen REs may be provided.

[0063] In an example embodiment, the network node, gNB or scheduler may provide assistance for MO detection (ZP-CSI-RS) and simultaneously tell the UE the number of co-scheduled UEs present.

[0064] In an example embodiment, the gNB may provide ZP-CSI-RS. In an example embodiment, the gNB may configure one or more single-port aperiodic ZP-CSI-RS resources using RRC messaging in the PDCCH-config IE. If there is a single common UE, a single resource may be configured. If there are up to two common UEs, two resources may be configured. Aperiodic ZP-CSI-RS may be triggered using DCI in a MU-MIMO slot (e.g., using format 1_1), for example to schedule DL. Zero power transmission may be triggered. Alternatively, dual power transmission may be triggered.

[0065] In some scenarios, the DCI value may not indicate the MO of all interfering common UEs. In an example embodiment, if there is no common UE, the ZP-CSI-RS resource may not be triggered. In an example embodiment, if there is a single common UE, the first ZP-CSI-RS resource may be triggered. In an example embodiment, if there are two common UEs, the second ZP-CSI-RS resource may be triggered.

[0066] A technical effect of example embodiments of the present disclosure may be to help determine FDRAs and interference ports belonging to different co-UEs based on information about the number of co-scheduled UEs.

[0067] A technical effect of example embodiments of the present disclosure may be to help detect MO by providing information about a portion of FDRA, DMRS ports used for MO detection for each common UE.

[0068] In an example embodiment, the UE may perform MO detection using very few ZP-CSI-RS REs.In an example embodiment, the UE may determine which ports and bandwidth resources are assigned / allocated to each interfering common UE.

[0069] In an example embodiment, the target UE may use an assisted MO detection method. In an example embodiment, based on information about the number of co-scheduled UEs received by the UE, a received DCI value for the MO (e.g., 0, 6, or 7, or any value indicating that the target UE is intended to perform blind detection on the MO), and the detected FDRA, DMRS ports, the UE may determine the FDRA for each co-UE and its DMRS port.

[0070] In an example embodiment, the UE may obtain a channel estimate for the common UE DMRS port and equalize (eg, using MMSE-IRC) the REs belonging to the ZP-CSI-RS on each interfering port and its FDRA. The UE may then attempt to detect one common UE at a time.

[0071] In an example embodiment, based on information received in the RRC message(s) regarding the MCS table, the UE may construct a special custom grid corresponding to the maximum MO possible for a common UE.

[0072] In an example embodiment, the UE may slice the equalizer output for each interfering port based on a custom grid.

[0073] In an example embodiment, the UE may use a predetermined fingerprint of each possible MO to detect the most likely interfering port MO. In other words, the UE may determine which MO fingerprint best matches the custom grid.

[0074] A technical effect of example embodiments of the present disclosure may be to provide a simple, reliable, and low complexity method to detect MOs of interfering ports that only look at a few ZP-CSI-RS REs.

[0075] Reference now Figure 2, showing a sequence diagram of aperiodic provision of ZP-CSI-RS for MO detection, for example, according to an example embodiment of the present disclosure.

[0076] At 210, in addition to the target UE, there may be 2 common UEs. ZP-CSI-RS resources may be added to address this scenario. At 220, the gNB may send an RRC reconfiguration message to the target UE, which may include PDSCH-config and / or aperiodic-ZP-CSI-RS-ResourceSetsToAddModList. Thus, the target UE may be configured with up to two ZP-CSI-RS resources. The number of common UEs present may be indicated by the number of configured ZP-CSI-RS resources. For example, the RRC reconfiguration message may configure the UE with a set of resource elements that belong together and may be triggered by a single trigger. At 230, the target UE may send an RRC reconfiguration complete message to the gNB.

[0077] At 240, a non-periodic triggering may be performed. The non-periodic triggering may inform the UE about the number of co-scheduled UEs. This information may be critical for mapping the FDRA portion and DMRS port to each co-scheduled UE. At 250, the gNB may send a DCI with format 1_1 or 1_2 to the target UE. The DCI may include a ZP-CSI-RS trigger value of 0, 1, or 2. The ZP-CSI-RS trigger value may trigger one or more of the configured ZP-CSI-RS resources. The number of triggered ZP-CSI-RS resources may indicate the number of co-UEs present. Additionally or alternatively, the DCI may include an index to a set of resource elements to be triggered.

[0078] At 260, the ZP-CSI-RS resources may be removed. At 270, the gNB may send an RRC reconfiguration message to the target UE, which may include PDSCH-config and / or aperiodic-ZP-CSI-RS-ResourceSetsToReleaseList. As a result, the target UE may be configured with fewer ZP-CSI-RS resources than previously. The number of co-UEs present may be indicated by the number of configured ZP-CSI-RS resources. Figure 2 In the example of , a single ZP-CSI-RS may be removed, which may indicate that there is only one common UE. At 280, the target UE may send an RRC reconfiguration complete message to the gNB.

[0079] Optionally, at 290, aperiodic triggering may be performed after the ZP-CSI-RS resources are removed at 260. For example, at 295, the gNB may send a DCI having format 1_1 or 1_2 to the target UE. The DCI may include a ZP-CSI-RS triggering value of 0 or 1. The ZP-CSI-RS triggering value may trigger one or more of the configured ZP-CSI-RS resources. The number of triggered ZP-CSI-RS resources may indicate the number of common UEs present.

[0080] It should be noted that Figure 2 The examples are not limiting; the steps may be performed in a different order, and / or additional steps may be performed.

[0081] In an example embodiment, the UE may determine the interfering ports and FDRA associated with the co-scheduled UE.In an example embodiment, information from the received DCI regarding the MO may be combined with information regarding the co-scheduled UE and the number of detected interfering DMRS ports and FDRA portions.

[0082] For example, the UE may receive DCI indicating MO value: 0, number of common UEs: 0. The UE may determine that there is no common UE (ie, SU-MIMO). This can be distinguished from the case of common UEs with other DMRS sequences.

[0083] For example, the UE may receive a DCI indicating MO value: 1, number of common UEs: 2, detected DMRS ports of the same sequence: 1001, 1002, detected DMRS ports of other sequences: none, detected FDRA: full. The UE may determine the following parameters for two common UEs: Common UE 1 parameters: DMRS port 1001, full FDRA, use QPSK; Common UE2 parameters: DMRS port 1002, full FDRA, use QPSK.

[0084] For example, a UE may receive a DCI indicating MO value: 1, number of common UEs: 2, detected DMRS ports same sequence: 1001, detected DMRS ports other sequence: 1002, detected FDRA: full. The UE may determine the following parameters for two common UEs: Common UE 1 parameters: DMRS port 1001, full FDRA, use QPSK; Common UE2 parameters: DMRS port 1002, full FDRA, MO detection. MO detection may be performed based on zero power REs.

[0085] For example, a UE may receive a DCI indicating MO value: 6, number of common UEs: 2, detected DMRS ports same sequence: 1001, detected DMRS ports other sequences: none, detected FDRA: all. The UE may determine the following parameters for two common UEs: Common UE 1 parameters: DMRS port 1001, first half FDRA, MO detection; Common UE 2 parameters: DMRS port 1001, second half FDRA, MO detection. MO detection may be performed based on zero power REs.

[0086] For example, a UE may receive a DCI indicating MO value: 0, number of common UEs: 2, detected DMRS port same sequence: none, detected DMRS port other sequence: 1002, detected FDRA: all. The UE may determine the following parameters for two common UEs: common UE 1 parameters: DMRS port 1002, first half FDRA, MO detection; common UE 2 parameters: DMRS port 1002, second half FDRA, MO detection. MO detection may be performed based on zero power REs.

[0087] For example, a UE may receive a DCI indicating MO value: 0, number of common UEs: 1, detected DMRS ports same sequence: none, detected DMRS ports other sequence: 1002, detected FDRA: full. The UE may determine the following parameters for one common UE: Common UE 1 parameters: DMRS ports 1002, full FDRA, MO detection. MO detection may be performed based on zero power REs.

[0088] For example, a UE may receive a DCI indicating MO value: 6, number of common UEs: 1, detected DMRS ports same sequence: 1001, detected DMRS ports other sequences: none, detected FDRA: full. The UE may determine the following parameters for one common UE: Common UE 1 parameters: DMRS ports 1001, full FDRA, MO detection. MO detection may be performed based on zero power REs.

[0089] In an example embodiment, the UE may perform detection grid construction. 3GPP OFDM modulation schemes for LTE, 5G, 6G, and higher, such as QPSK (4-QAM), 16-QAM, 64-QAM, 256-QAM, etc., may be represented in a two-dimensional Cartesian plane called an in-phase and quadrature (I / Q) constellation diagram. In general, this is true for squares and any other QAM modulation scheme. Each symbol is represented by a single constellation point. These I / Q points are clustered together in the constellation diagram to form a signature or "fingerprint" that has unique characteristics for each possible M-QAM modulation scheme, where M is the order to be determined.

[0090] In order to estimate the order of the modulation scheme, a custom detection constellation grid can be constructed for identifying the constellation fingerprint of the received symbol. The custom grid can be constructed by including additional grid points located intermediate between the grid points of the specific modulation order M.

[0091] In the following, two example methods for constructing a special detection constellation grid are described.

[0092] In the first method for constructing a special detection constellation grid, for a given MCS table, M is selected as the maximum possible MO for that particular MCS table, MO max For example, when MCS table 2 is used, M is 256, corresponding to 256-QAM. Now refer to Figure 3 , shows an example constellation grid for identifying QPSK, 16-QAM, 64-QAM, and 256-QAM. In this example, the grid size is chosen to be 31x31 points. In this way, the grid can be normalized to accurately cover all 256-QAM symbols and all half-distance points between these symbols. The x-axis of the grid shows the orthogonal amplitude, while the y-axis of the grid shows the in-phase amplitude. 256-QAM symbols are yellow and constitute the smallest and most frequent cluster in the constellation grid. Example at 310. 64-QAM symbols are blue and constitute the second most frequent cluster in the constellation grid. Example at 320; the cluster in the same column is also a cluster of 64-QAM symbols. 16-QAM symbols are red and constitute the third most frequent cluster in the constellation grid. Example at 330; the cluster in the same column is also a cluster of 16-QAM symbols. QPSK symbols are green and constitute the largest and least frequent cluster in the constellation grid. Example at 340. Red uniform circles can represent complex numbers of custom grids.

[0093] In the second method for constructing a special detection constellation grid, for a given MCS table, M is selected to be a MO that is times lower than the maximum MO for that particular table, i.e., M=MO max -1. For example, when MCS table 2 is used, M is 64, corresponding to 64-QAM. The second method involves selecting an MO that is smaller than the highest MO. The intermediate point between the received signals can be equalized and can fall somewhere on the constellation grid (the nearest point can be selected).

[0094] In an example embodiment, the UE may perform modulation scheme fingerprinting. When using the first method for constructing a special detection constellation grid, a histogram representing a mapping of received I / Q data points to grid points with the shortest distances may be created. The technical effect is that modulation orders can be reliably classified. Now referring to Figure 4-Figure 7, shows the histogram fingerprint of the constellation detection grid of method 1, where the received I / Q data represent 256-QAM, 64-QAM, 16-QAM and QPSK respectively. Each histogram can be determined based on the entire MU-MIMO time slot. Figure 4 A grid histogram for 256-QAM is shown. Figure 5 A grid histogram for 64-QAM is shown. Figure 6 A grid histogram for 16-QAM is shown. Figure 7 A grid histogram for QPSK is shown.

[0095] After correlating the constellation grid histogram of the received symbols with the reference histogram of each candidate modulation scheme, the modulation order of the common UE may be detected, which corresponds to the candidate modulation scheme resulting in the highest correlation value.

[0096] The UE may monitor zero power REs (e.g., 13 REs) and map them to the constellation grid. The UE may perform slicing and then associate with each of the fingerprints of the MO. The fingerprint with the highest correlation may be selected as the most likely MO.

[0097] When the second method is used to construct the special detection constellation grid, all MOs up to M have fingerprints similar to method 1, while the largest MO has a fingerprint that is uniform over the entire grid. max The constellation fingerprint of is similar to white noise. Using method 2 may slightly reduce performance, but the custom grid is much smaller than that of method 1, thus reducing the computational load.

[0098] Reference now Figure 8 , a graph showing the throughput performance of assisted MO detection according to an example embodiment of the present disclosure is shown. Figure 8 In the example of , the following configuration is used: single port, density 0.5, ZP-CSI-RS across the entire channel bandwidth of the target UE with 52 PRBs and SCS=15kHz. This configuration results in 26 REs being evaluated when interference is present on the entire target UE FDRA, and 13 REs being evaluated when interference is present on only half of the FDRA. Assume that Genie interferes with the FDRA information, but the DMRS port is blindly detected along with the MO, which is blindly detected based on the ZP-CSI-RS. 810 shows Genie with full FDRA interference. 820 shows MO detection with full FDRA interference. 830 shows Genie with half FDRA interference. 840 shows MO detection with half FRDA interference.

[0099] A technical effect of example embodiments of the present disclosure may be to enable reliable MO detection with very little performance loss.

[0100] Fig. 9 Potential steps of an example method 900 are shown. The example method 900 may include: receiving a configuration for one or more resource elements with zero power from a network node, 910; receiving downlink control information, wherein the downlink control information includes at least an aperiodic indication for triggering resource elements with zero power, 920; and determining a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of one or more resource elements triggered with the aperiodic indication, 930; and optionally, identifying co-scheduled UE interference information based on the number of co-scheduled UEs and the resource elements with zero power. The co-scheduled UE interference information may include a determination of the MO, FDRA, and DMRS ports of each co-scheduled UE. The example method 900 may be performed, for example, using a UE or a target UE.

[0101] Fig.10 Potential steps of an example method 1000 are shown. The example method 1000 may include: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot, 1010; sending a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference, 1020; and sending downlink control information to the target user equipment, wherein the downlink control information includes at least an aperiodic indication for triggering resource elements with zero power, 1030. The example method 1000 may be performed, for example, using a network node, a base station, an eNB, a gNB, etc.

[0102] According to an example embodiment, an apparatus may include: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receive a configuration for one or more resource elements with zero power from a network node; receive downlink control information, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power; and determine the number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0103] The one or more resource elements may include a set of resource elements that belong together, and the set of resource elements are configured to be triggered with a single trigger.

[0104] The aperiodic indication may also be configured to indicate the number of co-scheduled user equipments in the physical downlink shared channel.

[0105] The example apparatus may also be configured to: determine that the number of co-scheduled user devices includes two co-scheduled user devices; detect at least one frequency domain resource allocation for the two co-scheduled user devices; detect at least one demodulation reference signal port for the two co-scheduled user devices; determine a first frequency domain resource allocation for a first co-scheduled user device among the two co-scheduled user devices based at least in part on at least one detected frequency domain resource allocation and the number of co-scheduled user devices; determine a first demodulation reference signal port for the first co-scheduled user device based at least in part on at least one detected demodulation reference signal port and the number of co-scheduled user devices; determine a second frequency domain resource allocation for a second co-scheduled user device among the two co-scheduled user devices based at least in part on at least one detected frequency domain resource allocation and the number of co-scheduled user devices; and determine a second demodulation reference signal port for the second co-scheduled user device based at least in part on at least one detected demodulation reference signal port and the number of co-scheduled user devices.

[0106] The example apparatus may also be configured to: determine a frequency domain resource allocation for a first co-scheduled user equipment among the co-scheduled user equipment; determine a demodulation reference signal port for the first co-scheduled user equipment; obtain a channel estimate for one or more demodulation reference signal ports; equalize one or more resource elements having zero power on the frequency domain resource allocation for the demodulation reference signal ports for the co-scheduled user equipment; construct a custom constellation grid for possible modulation orders for the first co-scheduled user equipment; slice one or more equalized resource elements based at least in part on the custom constellation grid; and determine the modulation order for the first co-scheduled user equipment based at least in part on a comparison of one or more predetermined modulation order fingerprints with one or more sliced ​​and equalized resource elements.

[0107] A custom constellation grid may be constructed for the maximum modulation order possible for the first co-scheduled user equipment.

[0108] The custom constellation grid may be constructed for a modulation order lower than the maximum modulation order possible for the first co-scheduled user equipment.

[0109] Determining a modulation order for a first co-scheduled user device may include the example apparatus being further configured to: correlate a histogram of a custom constellation grid with a reference histogram of one or more possible modulation orders for the first co-scheduled user device; and determine the modulation order associated with the reference histogram having the highest correlation value as the modulation order for the first co-scheduled user device.

[0110] The example apparatus may be further configured to determine that a number of co-scheduled user equipments in the physical downlink shared channel is zero in response to the number of one or more resource elements triggered by the aperiodic indication being zero.

[0111] According to one aspect, an example method may be provided, comprising: receiving, using a user equipment, a configuration for one or more resource elements with zero power from a network node; receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering the resource elements with zero power; and determining a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered using the non-periodic indication.

[0112] The one or more resource elements may include a set of resource elements that belong together, and the set of resource elements may be configured to be triggered with a single trigger.

[0113] The aperiodic indication is further configured to indicate the number of co-scheduled user equipments in the physical downlink shared channel.

[0114] The example method may also include: determining that the number of co-scheduled user devices includes two co-scheduled user devices; detecting at least one frequency domain resource allocation for the two co-scheduled user devices; detecting at least one demodulation reference signal port for the two co-scheduled user devices; determining a first frequency domain resource allocation for a first co-scheduled user device among the two co-scheduled user devices based at least in part on at least one detected frequency domain resource allocation and the number of co-scheduled user devices; determining a first demodulation reference signal port for the first co-scheduled user device based at least in part on at least one detected demodulation reference signal port and the number of co-scheduled user devices; determining a second frequency domain resource allocation for a second co-scheduled user device among the two co-scheduled user devices based at least in part on at least one detected frequency domain resource allocation and the number of co-scheduled user devices; and determining a second demodulation reference signal port for the second co-scheduled user device based at least in part on at least one detected demodulation reference signal port and the number of co-scheduled user devices.

[0115] The example method may also include: determining a frequency domain resource allocation for a first co-scheduled user device among the co-scheduled user devices; determining a demodulation reference signal port for the first co-scheduled user device; obtaining a channel estimate for one or more demodulation reference signal ports; equalizing one or more resource elements having zero power on the frequency domain resource allocation for the demodulation reference signal ports for the co-scheduled user devices; constructing a custom constellation grid for possible modulation orders for the first co-scheduled user device; slicing one or more equalized resource elements based at least in part on the custom constellation grid; and determining a modulation order for the first co-scheduled user device based at least in part on a comparison of one or more predetermined modulation order fingerprints with one or more sliced ​​and equalized resource elements.

[0116] A custom constellation grid may be constructed for a maximum modulation order possible for the first co-scheduled user equipment.

[0117] A custom constellation grid is constructed for a modulation order lower than a maximum modulation order possible for the first co-scheduled user equipment.

[0118] Determining a modulation order for a first co-scheduled user equipment includes: correlating a histogram of a custom constellation grid with a reference histogram of one or more possible modulation orders for the first co-scheduled user equipment; and determining the modulation order associated with the reference histogram having the highest correlation value as the modulation order for the first co-scheduled user equipment.

[0119] The example method may also include determining that a number of co-scheduled user equipment in a physical downlink shared channel is zero in response to the number of one or more resource elements triggered with the aperiodic indication being zero.

[0120] According to an example embodiment, an apparatus may include a circuit configured to perform the following: receive a configuration for one or more resource elements with zero power from a network node; receive downlink control information, wherein the downlink control information may include at least a non-periodic indication for triggering the resource elements with zero power; and a circuit configured to perform the following: determine the number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of the following: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0121] According to an example embodiment, an apparatus may include: a processing circuit; a memory circuit including a computer program code, the memory circuit and the computer program code being configured to, together with the processing circuit, enable the apparatus to: receive a configuration for one or more resource elements with zero power from a network node; receive downlink control information, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power; and determine a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered using the non-periodic indication.

[0122] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) hardware circuit implementations only (e.g., implementations only in analog and / or digital circuitry), and (b) a combination of hardware circuitry and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuits and software / firmware, and (ii) a hardware processor (including a digital signal processor) with software, software, and any portion of memory that work together to enable a device such as a mobile phone or server to perform various functions; and (c) a hardware circuit and / or processor that requires software (e.g., firmware) for operation, such as a microprocessor or a portion of a microprocessor, but the software may not be present when not required for operation. This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to a particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0123] According to an example embodiment, an apparatus may include components for: receiving a configuration for one or more resource elements with zero power from a network node; receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power; and determining a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered using the non-periodic indication.

[0124] The one or more resource elements may include a set of resource elements that belong together, and the set of resource elements may be configured to be triggered with a single trigger.

[0125] The aperiodic indication is further configured to indicate the number of co-scheduled user equipments in the physical downlink shared channel.

[0126] The component can also be configured to: determine that the number of co-scheduled user devices includes two co-scheduled user devices; detect at least one frequency domain resource allocation for the two co-scheduled user devices; detect at least one demodulation reference signal port for the two co-scheduled user devices; determine a first frequency domain resource allocation for a first co-scheduled user device among the two co-scheduled user devices based at least in part on at least one detected frequency domain resource allocation and the number of co-scheduled user devices; determine a first demodulation reference signal port for the first co-scheduled user device based at least in part on at least one detected demodulation reference signal port and the number of co-scheduled user devices; determine a second frequency domain resource allocation for a second co-scheduled user device among the two co-scheduled user devices based at least in part on at least one detected frequency domain resource allocation and the number of co-scheduled user devices; and determine a second demodulation reference signal port for the second co-scheduled user device based at least in part on at least one detected demodulation reference signal port and the number of co-scheduled user devices.

[0127] The component can also be configured to: determine a frequency domain resource allocation for a first co-scheduled user equipment among the co-scheduled user equipments; determine a demodulation reference signal port for the first co-scheduled user equipment; obtain a channel estimate for one or more demodulation reference signal ports; equalize one or more resource elements having zero power on the frequency domain resource allocation for the demodulation reference signal ports for the co-scheduled user equipments; construct a custom constellation grid for possible modulation orders for the first co-scheduled user equipment; slice one or more equalized resource elements based at least in part on the custom constellation grid; and determine the modulation order for the first co-scheduled user equipment based at least in part on a comparison of one or more predetermined modulation order fingerprints with one or more sliced ​​and equalized resource elements.

[0128] A custom constellation grid may be constructed for a maximum modulation order possible for the first co-scheduled user equipment.

[0129] A custom constellation grid is constructed for a modulation order lower than a maximum modulation order possible for the first co-scheduled user equipment.

[0130] A component configured to determine a modulation order for a first co-scheduled user equipment may include a component configured to: correlate a histogram of a custom constellation grid with a reference histogram of one or more possible modulation orders for the first co-scheduled user equipment; and determine the modulation order associated with the reference histogram having the highest correlation value as the modulation order for the first co-scheduled user equipment.

[0131] The component may also be configured to: in response to the number of one or more resource elements triggered by the aperiodic indication being zero, determine that the number of co-scheduled user equipments in the physical downlink shared channel is zero.

[0132] Processors, memory, and / or example algorithms (which may be encoded as instructions, programs, or codes) may be provided as example components for providing or causing the performance of operations.

[0133] According to an example embodiment, a non-transitory computer-readable medium includes instructions stored thereon, which, when executed using at least one processor, cause the at least one processor to: cause receiving a configuration for one or more resource elements with zero power from a network node; cause receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power; and cause determining a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of the following: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered using the non-periodic indication.

[0134] According to an example embodiment, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following operations: causing reception of a configuration for one or more resource elements with zero power from a network node; causing reception of downlink control information, wherein the downlink control information includes at least an aperiodic indication for triggering resource elements with zero power; and causing determination of a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered using the aperiodic indication.

[0135] According to another example embodiment, a machine-readable, non-volatile program storage device may be provided, tangibly embodying instructions executable by the machine for performing operations, the operations comprising: causing reception of a configuration for one or more resource elements with zero power from a network node; causing reception of downlink control information, wherein the downlink control information comprises at least a non-periodic indication for triggering resource elements with zero power; and causing determination of a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered using the non-periodic indication.

[0136] According to another example embodiment, a non-transitory computer-readable medium includes instructions, which when executed by an apparatus causes the apparatus to perform at least the following operations: cause receiving a configuration for one or more resource elements with zero power from a network node; cause receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power; and cause determining the number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of the following: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of one or more resource elements triggered by the non-periodic indication.

[0137] A computer-implemented system comprising: at least one processor and at least one non-volatile memory storing instructions, wherein the instructions, when executed by the at least one processor, cause the system to at least perform: cause receiving a configuration for one or more resource elements with zero power from a network node; cause receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power; and cause determining a number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of the following: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0138] A computer-implemented system comprising: means for receiving a configuration for one or more resource elements with zero power from a network node; means for receiving downlink control information, wherein the downlink control information comprises at least an aperiodic indication for triggering the resource elements with zero power; and means for determining a number of co-scheduled user equipments in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered with the aperiodic indication.

[0139] According to an example embodiment, an apparatus may include: at least one processor; and at least one non-volatile memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: evaluate co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; send a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and send downlink control information to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power.

[0140] The one or more resource elements include a set of resource elements that belong together, and the set of resource elements is configured to be triggered with a single trigger.

[0141] The aperiodic indication is further configured to indicate the number of co-scheduled user equipments in the physical downlink shared channel.

[0142] In response to a single co-scheduled user equipment being present in the multi-user MIMO time slot relative to the target user equipment, the number of the one or more resource elements having zero power is one.

[0143] In response to two co-scheduled user equipments being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements having zero power is two.

[0144] In response to no co-scheduled user equipment being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication is zero.

[0145] In response to a co-scheduled user equipment being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication may be one.

[0146] In response to two co-scheduled user equipments being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication is two.

[0147] According to one aspect, an example method may be provided, comprising: evaluating, using a network node, co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; sending a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and sending downlink control information to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering a resource element with zero power.

[0148] The one or more resource elements may include a set of resource elements that belong together, and the set of resource elements may be configured to be triggered with a single trigger.

[0149] The aperiodic indication is further configured to indicate the number of co-scheduled user equipments in the physical downlink shared channel.

[0150] In response to a single co-scheduled user equipment being present in the multi-user MIMO time slot relative to the target user equipment, the number of the one or more resource elements having zero power is one.

[0151] In response to two co-scheduled user equipments being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements having zero power is two.

[0152] In response to no co-scheduled user equipment being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication is zero.

[0153] In response to a co-scheduled user equipment being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication is one.

[0154] In response to two co-scheduled user equipments being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication is two.

[0155] According to an example embodiment, an apparatus may include: a circuit configured to perform the following: evaluate co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; a circuit configured to perform the following: send a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and a circuit configured to perform the following: send downlink control information to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering the resource elements with zero power.

[0156] According to an example embodiment, an apparatus may include: a processing circuit, a memory circuit including a computer program code, the memory circuit and the computer program code being configured to, using the processing circuit, cause the apparatus to: evaluate co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; send a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and send downlink control information to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering a resource element with zero power.

[0157] According to an example embodiment, an apparatus may include components for: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; sending a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and sending downlink control information to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power.

[0158] The one or more resource elements may include a set of resource elements that belong together, wherein the set of resource elements is configured to be triggered with a single trigger.

[0159] The aperiodic indication is further configured to indicate the number of co-scheduled user equipments in the physical downlink shared channel.

[0160] In response to the presence of a single co-scheduled user equipment relative to the target user equipment in the multi-user MIMO time slot, the number of the one or more resource elements having zero power is one.

[0161] In response to two co-scheduled user equipments being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements having zero power is two.

[0162] In response to no co-scheduled user equipment being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication is zero.

[0163] In response to a co-scheduled user equipment being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication is one.

[0164] In response to two co-scheduled user equipments being present in the MU-MIMO time slot relative to the target user equipment, the number of the one or more resource elements triggered by the aperiodic indication is two.

[0165] According to an example embodiment, a non-transitory computer-readable medium includes instructions stored thereon, which, when executed using at least one processor, cause the at least one processor to: evaluate co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; cause a configuration for one or more resource elements with zero power to be sent to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and cause downlink control information to be sent to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power.

[0166] According to an example embodiment, a non-transitory computer-readable medium includes instructions stored thereon for performing at least the following: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; causing a configuration for one or more resource elements with zero power to be sent to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and causing downlink control information to be sent to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power.

[0167] According to another example embodiment, a machine-readable, non-volatile program storage device may be provided, tangibly embodying instructions executable by the machine for performing operations, the operations comprising: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; causing a configuration for one or more resource elements with zero power to be sent to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and causing downlink control information to be sent to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering a resource element with zero power.

[0168] According to another example embodiment, a non-transitory computer-readable medium includes instructions, which when executed by an apparatus causes the apparatus to perform at least the following operations: evaluate co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; cause a configuration for one or more resource elements with zero power to be sent to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and cause downlink control information to be sent to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power.

[0169] A computer-implemented system comprises: at least one processor and at least one non-volatile memory storing instructions, wherein the instructions, when executed by the at least one processor, cause the system to at least perform: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; causing a configuration for one or more resource elements with zero power to be sent to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and causing downlink control information to be sent to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power.

[0170] A computer-implemented system comprising: a component for evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; a component for causing a configuration for one or more resource elements with zero power to be sent to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and a component for causing downlink control information to be sent to the target user equipment, wherein the downlink control information may include at least a non-periodic indication for triggering resource elements with zero power.

[0171] As used herein, the term "non-transitory" is a limitation of the medium itself (ie, tangible, but not a signal), not a limitation on data storage persistence (eg, RAM versus ROM).

[0172] It should be understood that the above description is illustrative only. Various alternatives and modifications may be devised by those skilled in the art. For example, the features described in the various dependent claims may be combined with each other in any suitable combination. In addition, features from the different embodiments described above may be selectively combined into new embodiments. Therefore, this description is intended to cover all such alternatives, modifications and variations that fall within the scope of the appended claims.

[0173] Some examples of this application are provided below.

[0174] Example 1. An apparatus for communication, comprising: at least one processor; and at least one non-volatile memory storing instructions, wherein the instructions, when executed by the at least one processor, cause the apparatus to at least: receive a configuration for one or more resource elements with zero power from a network node; receive downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power; and determine the number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0175] Example 2. An apparatus according to Example 1, wherein the one or more resource elements include a set of resource elements that belong together, wherein the set of resource elements is configured to be triggered using a single trigger.

[0176] Example 3. An apparatus according to Example 1 or 2, wherein the non-periodic indication is further configured to indicate the number of the co-scheduled user equipments in the physical downlink shared channel.

[0177] Example 4. An apparatus according to any one of Examples 1 to 3, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: determine that the number of co-scheduled user equipment includes two co-scheduled user equipment; detect at least one frequency domain resource allocation for the two co-scheduled user equipment; detect at least one demodulation reference signal port for the two co-scheduled user equipment; determine a first frequency domain resource allocation for a first co-scheduled user equipment among the two co-scheduled user equipment based at least in part on the at least one detected frequency domain resource allocation and the number of the co-scheduled user equipment; determine a first demodulation reference signal port for the first co-scheduled user equipment based at least in part on the at least one detected demodulation reference signal port and the number of the co-scheduled user equipment; determine a second frequency domain resource allocation for a second co-scheduled user equipment among the two co-scheduled user equipment based at least in part on the at least one detected frequency domain resource allocation and the number of the co-scheduled user equipment; and determine a second demodulation reference signal port for the second co-scheduled user equipment based at least in part on the at least one detected demodulation reference signal port and the number of the co-scheduled user equipment.

[0178] Example 5. An apparatus according to any one of Examples 1 to 3, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: determine a frequency domain resource allocation for a first co-scheduled user equipment among the co-scheduled user equipment; determine a demodulation reference signal port for the first co-scheduled user equipment; obtain a channel estimate for the one or more demodulation reference signal ports; equalize the one or more resource elements having zero power on the frequency domain resource allocation for the demodulation reference signal ports for the co-scheduled user equipment; construct a custom constellation grid for possible modulation orders for the first co-scheduled user equipment; slice the one or more equalized resource elements based at least in part on the custom constellation grid; and determine the modulation order for the first co-scheduled user equipment based at least in part on a comparison of one or more predetermined modulation order fingerprints with the one or more sliced ​​and equalized resource elements.

[0179] Example 6. The apparatus of Example 5, wherein the custom constellation grid is constructed for a maximum modulation order possible for the first co-scheduled user equipment.

[0180] Example 7. The apparatus of Example 5, wherein the custom constellation grid is constructed for a modulation order that is lower than a maximum modulation order possible for the first co-scheduled user equipment.

[0181] Example 8. An apparatus according to Example 5, wherein determining the modulation order for the first co-scheduled user equipment includes the at least one memory storing instructions, which, when executed by the at least one processor, causes the apparatus to: correlate a histogram of the custom constellation grid with a reference histogram of one or more possible modulation orders for the first co-scheduled user equipment; and determine the modulation order associated with the reference histogram having the highest correlation value as the modulation order for the first co-scheduled user equipment.

[0182] Example 9. An apparatus according to Example 1, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: in response to the number of the one or more resource elements triggered by the non-periodic indication being zero, determine that the number of the co-scheduled user equipment in the physical downlink shared channel is zero.

[0183] Example 10. A method comprising: receiving, using a user equipment, a configuration for one or more resource elements with zero power from a network node; receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power; and determining the number of co-scheduled user equipment in a physical downlink shared channel based at least in part on at least one of the following: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0184] Example 11. The method of Example 10, wherein the one or more resource elements comprises a set of resource elements that belong together, wherein the set of resource elements is configured to be triggered with a single trigger.

[0185] Example 12. The method of Example 10 or 11, wherein the aperiodic indication is further configured to indicate the number of the co-scheduled user equipments in the physical downlink shared channel.

[0186] Example 13. The method according to any one of Examples 10 to 12 further includes: determining that the number of the co-scheduled user devices includes two co-scheduled user devices; detecting at least one frequency domain resource allocation for the two co-scheduled user devices; detecting at least one demodulation reference signal port for the two co-scheduled user devices; determining a first frequency domain resource allocation for a first co-scheduled user device among the two co-scheduled user devices based at least in part on the at least one detected frequency domain resource allocation and the number of the co-scheduled user devices; determining a first demodulation reference signal port for the first co-scheduled user device based at least in part on the at least one detected demodulation reference signal port and the number of the co-scheduled user devices; determining a second frequency domain resource allocation for a second co-scheduled user device among the two co-scheduled user devices based at least in part on the at least one detected frequency domain resource allocation and the number of the co-scheduled user devices; and determining a second demodulation reference signal port for the second co-scheduled user device based at least in part on the at least one detected demodulation reference signal port and the number of the co-scheduled user devices.

[0187] Example 14. The method according to any one of Examples 10 to 12 further includes: determining a frequency domain resource allocation for a first co-scheduled user equipment among the co-scheduled user equipment; determining a demodulation reference signal port for the first co-scheduled user equipment; obtaining a channel estimate for the one or more demodulation reference signal ports; equalizing the one or more resource elements having zero power on the frequency domain resource allocation for the demodulation reference signal port for the co-scheduled user equipment; constructing a custom constellation grid for possible modulation orders for the first co-scheduled user equipment; slicing the one or more equalized resource elements based at least in part on the custom constellation grid; and determining the modulation order for the first co-scheduled user equipment based at least in part on a comparison of one or more predetermined modulation order fingerprints with the one or more sliced ​​and equalized resource elements.

[0188] Example 15. The method of Example 14, wherein the custom constellation grid is constructed for a maximum modulation order possible for the first co-scheduled user equipment.

[0189] Example 16. The method of Example 14, wherein the custom constellation grid is constructed for a modulation order lower than a maximum modulation order possible for the first co-scheduled user equipment.

[0190] Example 17. A method according to Example 14, wherein the determining the modulation order for the first co-scheduled user equipment includes: correlating a histogram of the custom constellation grid with a reference histogram of one or more possible modulation orders for the first co-scheduled user equipment; and determining the modulation order associated with the reference histogram having the highest correlation value as the modulation order for the first co-scheduled user equipment.

[0191] Example 18. The method according to Example 10 further includes: in response to the number of the one or more resource elements triggered by the non-periodic indication being zero, determining that the number of the co-scheduled user equipment in the physical downlink shared channel is zero.

[0192] Example 19. An apparatus comprising components for: receiving a configuration for one or more resource elements with zero power from a network node; receiving downlink control information, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power; and determining the number of co-scheduled user devices in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0193] Example 20. An apparatus according to Example 19, wherein the one or more resource elements include a set of resource elements that belong together, wherein the set of resource elements is configured to be triggered with a single trigger.

[0194] Example 21. An apparatus according to Example 19 or 20, wherein the non-periodic indication is further configured to indicate the number of the co-scheduled user equipment in the physical downlink shared channel.

[0195] Example 22. An apparatus according to any one of Examples 19 to 21, wherein the component is further configured to: determine that the number of the co-scheduled user equipment includes two co-scheduled user equipment; detect at least one frequency domain resource allocation for the two co-scheduled user equipment; detect at least one demodulation reference signal port for the two co-scheduled user equipment; determine a first frequency domain resource allocation for a first co-scheduled user equipment among the two co-scheduled user equipment based at least in part on the at least one detected frequency domain resource allocation and the number of the co-scheduled user equipment; determine a first demodulation reference signal port for the first co-scheduled user equipment based at least in part on the at least one detected demodulation reference signal port and the number of the co-scheduled user equipment; determine a second frequency domain resource allocation for a second co-scheduled user equipment among the two co-scheduled user equipment based at least in part on the at least one detected frequency domain resource allocation and the number of the co-scheduled user equipment; and determine a second demodulation reference signal port for the second co-scheduled user equipment based at least in part on the at least one detected demodulation reference signal port and the number of the co-scheduled user equipment.

[0196] Example 23. An apparatus according to any one of Examples 19 to 21, wherein the component is further configured to: determine a frequency domain resource allocation for a first co-scheduled user equipment among the co-scheduled user equipment; determine a demodulation reference signal port for the first co-scheduled user equipment; obtain a channel estimate for the one or more demodulation reference signal ports; equalize the one or more resource elements having zero power on the frequency domain resource allocation for the demodulation reference signal port for the co-scheduled user equipment; construct a custom constellation grid for possible modulation orders for the first co-scheduled user equipment; slice one or more equalized resource elements based at least in part on the custom constellation grid; and determine the modulation order for the first co-scheduled user equipment based at least in part on a comparison of one or more predetermined modulation order fingerprints with the one or more sliced ​​and equalized resource elements.

[0197] Example 24. The apparatus of Example 23, wherein the custom constellation grid is constructed for a maximum modulation order possible for the first co-scheduled user equipment.

[0198] Example 25. The apparatus of Example 23, wherein the custom constellation grid is constructed for a modulation order that is lower than a maximum modulation order possible for the first co-scheduled user equipment.

[0199] Example 26. An apparatus according to Example 23, wherein the component configured to determine the modulation order for the first co-scheduled user equipment includes a component configured to: correlate a histogram of the custom constellation grid with a reference histogram of one or more possible modulation orders for the first co-scheduled user equipment; and determine the modulation order associated with the reference histogram having the highest correlation value as the modulation order for the first co-scheduled user equipment.

[0200] Example 27. An apparatus according to Example 19, wherein the component is further configured to: in response to the number of the one or more resource elements triggered by the non-periodic indication being zero, determine that the number of the co-scheduled user equipment in the physical downlink shared channel is zero.

[0201] Example 28. A non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following operations: causing reception of a configuration for one or more resource elements with zero power from a network node; causing reception of downlink control information, wherein the downlink control information comprises at least a non-periodic indication for triggering resource elements with zero power; and causing determination of the number of co-scheduled user devices in a physical downlink shared channel based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or the number of the one or more resource elements triggered by the non-periodic indication.

[0202] Example 29. A device comprising: at least one processor; and at least one non-volatile memory storing instructions, which, when executed by the at least one processor, causes the device to at least: evaluate co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; send a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and send downlink control information to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power.

[0203] Example 30. An apparatus according to Example 29, wherein the one or more resource elements include a set of resource elements that belong together, wherein the set of resource elements is configured to be triggered with a single trigger.

[0204] Example 31. An apparatus according to Example 29 or 30, wherein the non-periodic indication is further configured to indicate a number of co-scheduled user equipments in a physical downlink shared channel.

[0205] Example 32. An apparatus according to any one of Examples 29 to 31, wherein in response to the presence of a single co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of one or more resource elements with zero power is one.

[0206] Example 33. An apparatus according to any one of Examples 29 to 31, wherein in response to the presence of two co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of one or more resource elements with zero power is two.

[0207] Example 34. An apparatus according to any one of Examples 29 to 33, wherein in response to the presence of no co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is zero.

[0208] Example 35. An apparatus according to any one of Examples 29 to 33, wherein in response to the presence of a co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is one.

[0209] Example 36. An apparatus according to any one of Examples 29 to 33, wherein in response to the presence of two co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is two.

[0210] Example 37. A method comprising: evaluating, using a network node, co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; sending a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and sending downlink control information to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering a resource element with zero power.

[0211] Example 38. The method of Example 37, wherein the one or more resource elements comprises a set of resource elements that belong together, wherein the set of resource elements is configured to be triggered using a single trigger.

[0212] Example 39. The method of Example 37 or 38, wherein the non-periodic indication is further configured to indicate a number of co-scheduled user equipments in a physical downlink shared channel.

[0213] Example 40. A method according to any one of Examples 37 to 39, wherein in response to the presence of a single co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of one or more resource elements with zero power is one.

[0214] Example 41. A method according to any one of Examples 37 to 39, wherein in response to the presence of two co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of one or more resource elements with zero power is two.

[0215] Example 42. A method according to any one of Examples 37 to 41, wherein in response to the presence of no co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is zero.

[0216] Example 43. A method according to any one of Examples 37 to 41, wherein in response to the presence of a co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is one.

[0217] Example 44. A method according to any one of Examples 37 to 41, wherein in response to the presence of two co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is two.

[0218] Example 45. An apparatus comprising components for: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; sending a configuration for one or more resource elements with zero power to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and sending downlink control information to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power.

[0219] Example 46. An apparatus according to Example 45, wherein the one or more resource elements include a set of resource elements that belong together, wherein the set of resource elements is configured to be triggered using a single trigger.

[0220] Example 47. An apparatus according to Example 45 or 46, wherein the non-periodic indication is further configured to indicate a number of co-scheduled user equipment in a physical downlink shared channel.

[0221] Example 48. An apparatus according to any one of Examples 45 to 47, wherein in response to the presence of a single co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of one or more resource elements with zero power is one.

[0222] Example 49. An apparatus according to any one of Examples 45 to 47, wherein in response to the presence of two co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of one or more resource elements with zero power is two.

[0223] Example 50. An apparatus according to any one of Examples 45 to 49, wherein in response to the presence of no co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is zero.

[0224] Example 51. An apparatus according to any one of Examples 45 to 49, wherein in response to the presence of a co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is one.

[0225] Example 52. An apparatus according to any one of Examples 45 to 49, wherein in response to the presence of two co-scheduled user equipment relative to the target user equipment in the multi-user multiple-input multiple-output time slot, the number of the one or more resource elements triggered by the non-periodic indication is two.

[0226] Example 53. A non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following operations: evaluating co-scheduled user equipment interference relative to a target user equipment in a multi-user multiple-input multiple-output time slot; causing a configuration for one or more resource elements with zero power to be sent to the target user equipment based at least in part on the evaluated co-scheduled user equipment interference; and causing downlink control information to be sent to the target user equipment, wherein the downlink control information includes at least a non-periodic indication for triggering resource elements with zero power.

Claims

1. A device for communication, comprising: at least one processor; as well as at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receiving, from a network node, a configuration for one or more resource elements having zero power; receiving downlink control information, wherein the downlink control information comprises at least an aperiodic indication for triggering resource elements with zero power; and The number of co-scheduled user equipments in the physical downlink shared channel is determined based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or The number of the one or more resource elements triggered by the aperiodic indication. 2 . The apparatus of claim 1 , wherein the one or more resource elements comprise a set of resource elements that belong together, wherein the set of resource elements is configured to be triggered using a single trigger.

3. The apparatus according to claim 1 or 2, wherein the aperiodic indication is further configured to indicate the number of the co-scheduled user equipments in the physical downlink shared channel.

4. The apparatus of claim 1 or 2, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: Determining that the number of co-scheduled user equipments includes two co-scheduled user equipments; detecting at least one frequency domain resource allocation for the two co-scheduled user equipments; detecting at least one demodulation reference signal port for the two co-scheduled user equipments; determining, based at least in part on the at least one detected frequency domain resource allocation and the number of the co-scheduled user equipments, a first frequency domain resource allocation for a first co-scheduled user equipment of the two co-scheduled user equipments; determining a first demodulation reference signal port for the first co-scheduled user equipment based at least in part on the at least one detected demodulation reference signal port and the number of the co-scheduled user equipments; determining, based at least in part on the at least one detected frequency domain resource allocation and the number of the co-scheduled user equipments, a second frequency domain resource allocation for a second co-scheduled user equipment of the two co-scheduled user equipments; as well as Based at least in part on the at least one detected demodulation reference signal port and the number of the co-scheduled user equipments, a second demodulation reference signal port for the second co-scheduled user equipment is determined.

5. The apparatus of claim 1 or 2, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: Determine frequency domain resource allocation for a first co-scheduled user equipment among the co-scheduled user equipments; Determine a demodulation reference signal port for the first co-scheduled user equipment; obtaining a channel estimate for the one or more demodulation reference signal ports; equalizing the one or more resource elements having zero power on the frequency domain resource allocation of the demodulation reference signal port for the co-scheduled user equipment; constructing a custom constellation grid for possible modulation orders for the first co-scheduled user equipment; slicing the one or more equalized resource elements based at least in part on the custom constellation grid; as well as A modulation order for the first co-scheduled user equipment is determined based at least in part on a comparison of one or more predetermined modulation order fingerprints to the one or more sliced ​​and equalized resource elements.

6. The apparatus of claim 5, wherein the custom constellation grid is constructed for a maximum modulation order possible for the first co-scheduled user equipment.

7. The apparatus of claim 5, wherein the custom constellation grid is constructed for a modulation order lower than a maximum modulation order possible for the first co-scheduled user equipment.

8. The apparatus of claim 5, wherein determining the modulation order for the first co-scheduled user equipment comprises the at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to: correlating the histogram of the custom constellation grid with a reference histogram of one or more possible modulation orders for the first co-scheduled user equipment; and A modulation order associated with a reference histogram having a highest correlation value is determined as the modulation order for the first co-scheduled user equipment.

9. The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: In response to the number of the one or more resource elements triggered by the aperiodic indication being zero, determining that the number of the co-scheduled user equipments in the physical downlink shared channel is zero.

10. A method comprising: receiving, with the user equipment, from a network node, a configuration for one or more resource elements having zero power; receiving downlink control information, wherein the downlink control information comprises at least an aperiodic indication for triggering resource elements with zero power; and The number of co-scheduled user equipments in the physical downlink shared channel is determined based at least in part on at least one of: an index associated with the one or more resource elements, the number of the one or more resource elements, or The number of the one or more resource elements triggered by the aperiodic indication.

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