Method and apparatus for supporting more DMRS ports for CP-OFDM waveforms

Abstract

Apparatus and methods for communicating in a wireless network are provided. In one embodiment, a communication device determines: a first demodulation reference signal (DMRS) pattern configured to support a first number of DMRS ports for a DMRS configuration type and a DMRS symbol length; and a second DMRS pattern configured to support a second number of DMRS ports for the DMRS configuration type and the DMRS symbol length. For the DMRS configuration type and the DMRS symbol length, the second number of DMRS ports is more than the first number of DMRS ports. When a first user equipment (UE) is configured to use a second DMRS mode, the communication device determines whether to apply one or more multi-user multiple-input multiple-output (MU-MIMO) scheduling restrictions for co-scheduling the first UE with one or more second UEs, and performs MU-MIMO scheduling for the first UE and the one or more second UEs.

Description

Technical Field

[0001] The present application relates generally to wireless communication systems, including systems that use cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveforms. Background Art

[0002] Wireless mobile communication technologies use various standards and protocols to send data between base stations and wireless communication devices. Wireless communication system standards and protocols may include, for example, the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and the IEEE 802.11 standard for wireless local area networks (WLANs) (commonly referred to within industry organizations as WLANs). ).

[0003] As envisioned by 3GPP, different wireless communication system standards and protocols may use various radio access networks (RANs) to communicate between base stations of the RAN (which may also sometimes be referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices referred to as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN may use one or more radio access technologies (RATs) to perform communications between base stations and UEs. For example, GERAN implements GSM and / or EDGE RAT, UTRAN implements Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RAT, E-UTRAN implements LTE RAT (sometimes referred to as LTE), and NG-RAN implements NR RAT (sometimes referred to herein as 5G RAT, 5G NR RAT, or NR). In some deployments, E-UTRAN may also implement NR RAT. In some deployments, NG-RAN may also implement LTE RAT.

[0005] The base stations used by the RAN may correspond to the RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as an evolved Node B, enhanced Node B, eNodeB, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes also referred to as a g-Node B or gNB).

[0006] The RAN provides its communication services with external entities through its connection to the Core Network (CN). For example, E-UTRAN may utilize the Evolved Packet Core (EPC) while NG-RAN may utilize the 5G Core Network (5GC). BRIEF DESCRIPTION OF THE DRAWINGS

[0007] To easily identify the discussion of any particular element or action, the most significant digit(s) in a reference number refers to the drawing number that first introduces the element.

[0008] Figure 1 Physical resource blocks (PRBs) with demodulation reference signal (DMRS) configuration type 1 and DMRS configuration type 2 are shown.

[0009] Figure 2A and Figure 2B An example DMRS port mapping is shown.

[0010] Figure 3 is a flow chart of a method for a base station in a wireless network to configure multi-user multiple input multiple output (MU-MIMO) scheduling according to one embodiment.

[0011] Figure 4 An example data structure of a Medium Access Control (MAC) Control Element (CE) for indicating a DMRS pattern to a UE according to one embodiment is shown.

[0012] Figure 5 is a flowchart of a method for a UE in a wireless network according to one embodiment

[0013] Figure 6 A method for a base station in a wireless network according to one embodiment.

[0014] Figure 7 An example architecture of a wireless communication system according to embodiments disclosed herein is shown.

[0015] Figure 8 A system for performing signaling between a wireless device and a network device according to embodiments disclosed herein is shown. DETAILED DESCRIPTION

[0016] Various embodiments are described with respect to UE. However, reference to UE is provided for illustrative purposes only. The example embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, UE as described herein is used to represent any suitable electronic component.

[0017] For CP-OFDM waveforms, some NR systems support two types of demodulation reference signal (DMRS) configurations for both downlink (DL) and uplink (UL). For example, Figure 1 Physical resource blocks (PRBs) with DMRS configuration type 1 (also referred to herein as DMRS type 1) and DMRS configuration type 2 (also referred to herein as DMRS type 2) are shown.

[0018] DMRS configuration type 1 supports up to four ports for single-symbol DMRS and up to eight ports for dual-symbol DMRS. As shown for PRB 102, DMRS type 1 may use two DMRS code division multiplexing (CDM) groups (shown as CDM group 0 and CDM group 1).

[0019] DMRS configuration type 2 supports up to six ports for single-symbol DMRS and up to 12 ports for dual-symbol DMRS. DMRS type 2 may use three DMRS CDM groups (CDM group 0, CDM group 1, and CDM group 2) as shown for PRB 104. Each DMRS CDM group is repeated in the frequency domain using the next entry in the DMRS sequence.

[0020] For DMRS type 1 and DMRS type 2, each CDM group uses two resource elements (REs) in the frequency domain and two symbols in the time domain. Each CDM group supports up to two ports for single-symbol DMRS and up to four ports for dual-symbol DMRS. The frequency domain uses 2 (e.g., +1, -1) frequency domain orthogonal cover codes (FD-OCC), and the time domain uses 2 (e.g., +1, -1) time domain orthogonal cover codes (TD-OCC).

[0021] For example, Figure 2A and Figure 2B An example DMRS port mapping for CP-OFDM with OCCs shown as "+" and "-" is shown. In a frequency selective fading channel (e.g., with a large channel delay spread), the ports separated by the cyclic shift may not be orthogonal at the receiver. Therefore, there may be some cross-port interference. However, to avoid interference, OCCs can be used to provide port separation. Different DMRSs for different antenna ports can be distinguished using different (e.g., masking each signal with a different combination of +1 or -1 in different resource elements). In some cases, two sets of DMRS may be sent in adjacent resource elements.

[0022] DMRS can be sent according to a predefined pattern. Figure 2A, DMRS port mapping is shown for DMRS type 1. Specifically, DMRS port mapping is shown for CDM group 0 corresponding to DMRS port 0, DMRS port 1, DMRS port 4, and DMRS port 5 (DMRS port {0,1,4,5}). DMRS port mapping is also shown for CDM group 1 corresponding to DMRS port 2, DMRS port 3, DMRS port 6, and DMRS port 7 (DMRS port {2,3,6,7}).

[0023] exist Figure 2B , DMRS port mapping is shown for DMRS type 2. Specifically, DMRS port mapping is shown for CDM group 0 corresponding to DMRS port 0, DMRS port 1, DMRS port 6, and DMRS port 7 (DMRS port {0,1,6,7}). DMRS port mapping is also shown for CDM group 1 corresponding to DMRS port 2, DMRS port 3, DMRS port 8, and DMRS port 9 (DMRS port {2,3,8,9}). DMRS port mapping is also shown for CDM group 2 corresponding to DMRS port 4, DMRS port 5, DMRS port 10, and DMRS port 11 (DMRS port {4,5,10,11}).

[0024] In some wireless systems (e.g., NR systems), DMRS enhancement may support a double amount of DMRS ports for CP-OFDM. For example, up to 12 orthogonal DMRS ports may be supported for DMRS type 1, and 24 orthogonal DMRS ports may be supported for DMRS type 2, where the maximum number of orthogonal ports is doubled for both single-symbol and double-symbol DMRS. In order to reduce the amount of DMRS overhead increase, or to avoid increasing DMRS overhead while doubling the amount of DMRS ports, certain embodiments disclosed herein provide one or more of the following: multi-user multiple-input multiple-output (MU-MIMO) scheduling restrictions for DMRS type 1, MU-MIMO scheduling restrictions for DMRS type 2, and / or dynamic DMRS mode indication.

[0025] MU-MIMO Scheduling Restrictions for DMRS Type 1

[0026] For DL ​​physical downlink shared channel (PDSCH), DMRS port indication is indicated by the "antenna port" field in the downlink control information (DCI). For example, 3GPP Technical Specification (TS) 38.212 DMRS configuration type 1 uses Table 7.3.1.2.2-1 / 1A / 2 / 2A, and DMRS configuration type 2 uses Table 7.3.1.2.2-3 / 3A / 4 / 4A.

[0027] In some wireless networks, MU-MIMO co-scheduling is implicitly indicated by the "Number of DMRS CDM groups without data" column from the "Antenna Ports" field in the DCI. As provided by the embodiments disclosed herein, the benefit of supporting an increased number of DMRS ports is to provide greater MU-MIMO scheduling flexibility to the wireless network.

[0028] Increasing the number of DMRS ports within a DMRS group may increase interference between different users in MU-MIMO. Therefore, in one embodiment for DMRS Type 1, when the new DMRS pattern is configured to support an increased number of DMRS ports, one or more of the following restrictions apply to MU-MIMO scheduling: a UE using the new DMRS pattern (supporting more DMRS ports) cannot be co-scheduled with another UE using the new DMRS pattern in the same CDM group; and / or a UE using the new DMRS pattern (supporting more DMRS ports) cannot be co-scheduled with another legacy UE using the legacy DMRS pattern (supporting fewer DMRS ports) in the same CDM group.

[0029] In one embodiment, when the new DMRS pattern is configured to support an increased number of DMRS ports, for DMRS configuration type 1, if the wireless network indicates one CDM group without data, a single symbol DMRS, and DMRS ports {0,1}, one or more of the following restrictions on MU-MIMO scheduling are possible: the UE is not expected to be co-scheduled with any other UE (e.g., this applies to the case when the number of CDM groups is increased to support the increased number of DMRS ports); and / or the UE is capable of being co-scheduled with other UEs (e.g., this applies to the case when the number of CDM groups is not increased to support the increased number of DMRS ports). When the UE is capable of being co-scheduled with other UEs, in one embodiment, the co-scheduled UE is configured with the new DMRS pattern (supporting more DMRS ports). When the UE is capable of being co-scheduled with other UEs, in another embodiment, the co-scheduled UE is capable of being configured with the new DMRS pattern (supporting more DMRS ports) or the legacy DMRS pattern (supporting fewer DMRS ports).

[0030] In one embodiment, when the new DMRS pattern is configured to support an increased number of DMRS ports, for DMRS configuration type 1, if the wireless network indicates two CDM groups without data, single-symbol DMRS, and DMRS ports {0, 1, 2, 3}, one or more of the following restrictions on MU-MIMO scheduling are possible: the UE is not expected to be co-scheduled with any other UE (e.g., this applies to the case when the number of CDM groups is increased to support the increased number of DMRS ports); and / or the UE is capable of being co-scheduled with other UEs (e.g., this applies to the case when the number of CDM groups is not increased to support the increased number of DMRS ports). When the UE is capable of being co-scheduled with other UEs, in one embodiment, the co-scheduled UE is configured with the new DMRS pattern (supporting more DMRS ports). When the UE is capable of being co-scheduled with other UEs, in another embodiment, the co-scheduled UE is capable of being configured with the new DMRS pattern (supporting more DMRS ports) or the legacy DMRS pattern (supporting fewer DMRS ports).

[0031] In one embodiment, when the new DMRS pattern is configured to support an increased number of DMRS ports, for DMRS configuration type 1, if the wireless network indicates two CDM groups without data, single-symbol DMRS, and DMRS ports {0,2}, one or more of the following restrictions on MU-MIMO scheduling are possible: the UE is not expected to be co-scheduled with any other UE (e.g., MU-MIMO co-scheduling can be enabled by DMRS ports {0,1} instead); and / or the UE can be co-scheduled with other UEs. When the UE can be co-scheduled with other UEs, in one embodiment, the co-scheduled UE is configured with the new DMRS pattern (supporting more DMRS ports). When the UE can be co-scheduled with other UEs, in another embodiment, the co-scheduled UE can be configured with the new DMRS pattern (supporting more DMRS ports) or the legacy DMRS pattern (supporting fewer DMRS ports).

[0032] In one embodiment, when the new DMRS pattern is configured to support an increased number of DMRS ports, for DMRS configuration type 1, if the wireless network indicates two CDM groups without data, dual-symbol DMRS, and DMRS ports {0, 2, 4, 6}, one or more of the following restrictions on MU-MIMO scheduling are possible: the UE is not expected to be co-scheduled with any other UE (e.g., MU-MIMO co-scheduling can be enabled by DMRS ports {0, 1, 4, 5} instead); and / or the UE can be co-scheduled with other UEs. When the UE can be co-scheduled with other UEs, in one embodiment, the co-scheduled UE is configured with the new DMRS pattern (supporting more DMRS ports). When the UE can be co-scheduled with other UEs, in another embodiment, the co-scheduled UE can be configured with the new DMRS pattern (supporting more DMRS ports) or the legacy DMRS pattern (supporting fewer DMRS ports).

[0033] In one embodiment, when the new DMRS pattern is configured to support an increased number of DMRS ports, for DMRS configuration type 1, if the wireless network indicates two CDM groups without data, single-symbol DMRS, and DMRS ports {0, 1, 2}, one or more of the following restrictions on MU-MIMO scheduling are possible: the UE is capable of being co-scheduled with other UEs; and / or the UE is not expected to be co-scheduled with any other UE (e.g., DMRS configuration type 2 can be used for MU-MIMO co-scheduling instead). When the UE is capable of being co-scheduled with other UEs, in one embodiment, the co-scheduled UE is configured with the new DMRS pattern (supporting more DMRS ports). When the UE is capable of being co-scheduled with other UEs, in another embodiment, the co-scheduled UE can be configured with the new DMRS pattern (supporting more DMRS ports) or the legacy DMRS pattern (supporting fewer DMRS ports).

[0034] MU-MIMO Scheduling Restrictions for DMRS Type 2

[0035] In one embodiment, when the new DMRS pattern is configured to support an increased number of DMRS ports, for DMRS configuration type 2, if the wireless network indicates one CDM group without data, a single symbol DMRS, and DMRS ports {0,1}, one or more of the following restrictions on MU-MIMO scheduling are possible: the UE is not expected to be co-scheduled with any other UE (e.g., this applies to the case when the number of CDM groups is increased to support the increased number of DMRS ports); and / or the UE is capable of being co-scheduled with other UEs (e.g., this applies to the case when the number of CDM groups is not increased to support the increased number of DMRS ports). When the UE is capable of being co-scheduled with other UEs, in one embodiment, the co-scheduled UE is configured with the new DMRS pattern (supporting more DMRS ports). When the UE is capable of being co-scheduled with other UEs, in another embodiment, the co-scheduled UE is capable of being configured with the new DMRS pattern (supporting more DMRS ports) or the legacy DMRS pattern (supporting fewer DMRS ports).

[0036] In one embodiment, when the new DMRS pattern is configured to support an increased number of DMRS ports, for DMRS configuration type 2, if the wireless network indicates two CDM groups without data, single-symbol DMRS, and DMRS ports {0, 1, 2, 3}, one or more of the following restrictions on MU-MIMO scheduling are possible: the UE is not expected to be co-scheduled with any other UE (e.g., this applies to the case when the number of CDM groups is increased to support the increased number of DMRS ports); and / or the UE is capable of being co-scheduled with other UEs (e.g., this applies to the case when the number of CDM groups is not increased to support the increased number of DMRS ports). When the UE is capable of being co-scheduled with other UEs, in one embodiment, the co-scheduled UE is configured with the new DMRS pattern (supporting more DMRS ports). When the UE is capable of being co-scheduled with other UEs, in another embodiment, the co-scheduled UE is capable of being configured with the new DMRS pattern (supporting more DMRS ports) or the legacy DMRS pattern (supporting fewer DMRS ports).

[0037] In one embodiment, when the new DMRS pattern is configured to support an increased number of DMRS ports, for DMRS configuration type 2, if the wireless network indicates two CDM groups without data, single-symbol DMRS, and DMRS ports {0,2}, one or more of the following restrictions on MU-MIMO scheduling are possible: the UE is not expected to be co-scheduled with any other UE (e.g., MU-MIMO co-scheduling can be enabled by DMRS ports {0,1}); and / or the UE can be co-scheduled with other UEs. When the UE can be co-scheduled with other UEs, in one embodiment, the co-scheduled UE is configured with the new DMRS pattern (supporting more DMRS ports). When the UE can be co-scheduled with other UEs, in another embodiment, the co-scheduled UE can be configured with the new DMRS pattern (supporting more DMRS ports) or the legacy DMRS pattern (supporting fewer DMRS ports).

[0038] In one embodiment, when a new DMRS pattern is configured to support an increased number of DMRS ports, whether for DMRS configuration type 1 or DMRS configuration type 2, if the wireless network indicates DMRS ports {0, 2, 3}, the UE is not expected to be co-scheduled with any other UE.

[0039] Figure 3 300 is a flow chart of a method 300 for configuring multi-user multiple input multiple output (MU-MIMO) scheduling for a base station in a wireless network according to one embodiment. In box 302, the method 300 includes: determining a first demodulation reference signal (DMRS) pattern, the first demodulation reference signal (DMRS) pattern being configured to support a first number of DMRS ports for a DMRS configuration type and a DMRS symbol length. In box 304, the method 300 includes: determining a second DMRS pattern, the second DMRS pattern being configured to support a second number of DMRS ports for the DMRS configuration type and the DMRS symbol length. For the DMRS configuration type and the DMRS symbol length, the second number of DMRS ports is more than the first number of DMRS ports. In box 306, when a first user equipment (UE) is configured to use the second DMRS pattern, the method 300 includes: determining whether to apply one or more MU-MIMO scheduling restrictions for co-scheduling the first UE with one or more second UEs. In box 308, the method 300 includes: performing MU-MIMO scheduling for the first UE and the one or more second UEs.

[0040] In certain embodiments of method 300, when the DMRS configuration type includes DMRS type 1, the one or more MU-MIMO scheduling restrictions include at least one of the following: the first UE cannot be co-scheduled with one or more second UEs (when the one or more second UEs are configured to use the second DMRS mode in the same code division multiplexing (CDM) group for the first UE configured with the second DMRS mode); and / or the first UE cannot be co-scheduled with one or more second UEs (when the one or more second UEs are configured to use the first DMRS mode in the same CDM group for the first UE configured with the second DMRS mode).

[0041] In certain embodiments of method 300, when the DMRS configuration type includes DMRS type 1 or DMRS type 2, and when the base station configures: a code division multiplexing (CDM) group without data; a DMRS symbol length as one symbol; and DMRS port 0 and DMRS port 1 (DMRS port {0,1}), the one or more MU-MIMO scheduling restrictions include at least one of the following: the first UE is not expected to be co-scheduled with one or more second UEs (when the total number of CDM groups is increased to support the increased number of DMRS ports); and / or the first UE can be co-scheduled with one or more second UEs (when the total number of CDM groups is not increased to support the increased number of DMRS ports). When the first UE can be co-scheduled with one or more second UEs, in one embodiment, the one or more second UEs are configured to use the second DMRS mode. When the first UE can be co-scheduled with one or more second UEs, in another embodiment, the one or more second UEs can be configured to use the first DMRS mode or the second DMRS mode.

[0042] In certain embodiments of method 300, when the DMRS configuration type includes DMRS type 1 or DMRS type 2, and wherein when the base station configures: two code division multiplexing (CDM) groups without data; a DMRS symbol length as one symbol; and DMRS port 0, DMRS port 1, DMRS port 2, and DMRS port 3 (DMRS ports {0, 1, 2, 3}), the one or more MU-MIMO scheduling restrictions include at least one of the following: the first UE is not expected to be co-scheduled with one or more second UEs (when the total number of CDM groups is increased to support the increased number of DMRS ports); and / or the first UE can be co-scheduled with one or more second UEs (when the total number of CDM groups is not increased to support the increased number of DMRS ports). When the first UE is able to be co-scheduled with one or more second UEs, in one embodiment, the one or more second UEs are configured to use the second DMRS mode. When the first UE is able to be co-scheduled with one or more second UEs, in another embodiment, the one or more second UEs can be configured to use the first DMRS mode or the second DMRS mode.

[0043] In certain embodiments of method 300, when the DMRS configuration type includes DMRS type 1 or DMRS type 2, and wherein when the base station configures: two code division multiplexing (CDM) groups without data; a DMRS symbol length as one symbol; and DMRS port 0 and DMRS port 2 (DMRS port {0,2}), the one or more MU-MIMO scheduling restrictions include that the first UE is not expected to be co-scheduled with one or more second UEs; or the first UE can be co-scheduled with one or more second UEs. When the first UE is not expected to be co-scheduled with one or more second UEs, in one embodiment, the method further includes: enabling MU-MIMO co-scheduling for the first UE by DMRS port 0 and DMRS port 1 (DMRS port {0,1}). When the first UE can be co-scheduled with one or more second UEs, in one embodiment, the one or more second UEs are configured to use the second DMRS mode. When the first UE can be co-scheduled with one or more second UEs, in another embodiment, the one or more second UEs can be configured to use the first DMRS mode or the second DMRS mode.

[0044] In certain embodiments of the method 300, when the DMRS configuration type includes DMRS type 1, and wherein when the base station configures: two code division multiplexing (CDM) groups without data; a DMRS symbol length as two symbols; and DMRS port 0, DMRS port 2, DMRS port 4, and DMRS port 6 (DMRS ports {0, 2, 4, 6}), the one or more MU-MIMO scheduling restrictions include that the first UE is not expected to be co-scheduled with one or more second UEs; or the first UE can be co-scheduled with one or more second UEs. When the first UE is not expected to be co-scheduled with one or more second UEs, in one embodiment, the method further includes: enabling MU-MIMO co-scheduling for the first UE by DMRS port 0, DMRS port 1, DMRS port 4, and DMRS port 5 (DMRS ports {0, 1, 4, 5}). When the first UE can be co-scheduled with one or more second UEs, in one embodiment, the one or more second UEs are configured to use a second DMRS mode. When the first UE can be co-scheduled with one or more second UEs, in another embodiment, the one or more second UEs can be configured to use the first DMRS mode or the second DMRS mode.

[0045] In certain embodiments of method 300, when the DMRS configuration type includes DMRS type 1, and wherein when the base station configures: two code division multiplexing (CDM) groups without data; a DMRS symbol length as one symbol; and DMRS port 0, DMRS port 1, and DMRS port 2 (DMRS port {0, 1, 2}), the one or more MU-MIMO scheduling restrictions include that the first UE is not expected to be co-scheduled with one or more second UEs; or the first UE can be co-scheduled with one or more second UEs. When the first UE is not expected to be co-scheduled with one or more second UEs, in one embodiment, the method further includes: changing the DMRS configuration type from DMRS type 1 to DMRS type 2 to co-schedule the first UE with the one or more second UEs. When the first UE can be co-scheduled with one or more second UEs, in one embodiment, the one or more second UEs are configured to use a second DMRS pattern. When the first UE can be co-scheduled with one or more second UEs, in another embodiment, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

[0046] In certain embodiments of method 300, when the DMRS configuration type includes DMRS type 1 or DMRS type 2, and wherein when the base station configures DMRS port 0, DMRS port 2, and DMRS port 3 (DMRS port {0, 2, 3}), the one or more MU-MIMO scheduling restrictions include that the first UE is not expected to be co-scheduled with one or more second UEs.

[0047] Dynamic DMRS mode indication

[0048] In some embodiments, a wireless communication system (e.g., an NR system) may use two DMRS modes. A first DMRS mode (e.g., a conventional DMRS mode) supports up to 12 DMRS ports. A second DMRS mode (e.g., an enhanced DMRS mode) supports up to 24 DMRS ports. Some such wireless communication systems may use radio resource configuration (RRC) signaling to configure the DMRS mode.

[0049] In DL, for example, a bandwidth part (BWP) downlink dedicated (BWP-DownlinkDedicated) information element (IE) may include a PDSCH configuration (PDSCH-Config) IE, which includes a DMRS downlink configuration (DRMS-DownlinkConfig) IE with DMRS configuration information to configure a DMRS mode. In UL, for example, a BWP uplink dedicated (BWP-UplinkDedicated) IE may include a physical uplink shared channel (PUSCH) configuration (PUSCH-Config) IE, which includes a DMRS uplink configuration (DMRS-UplinkConfig) IE with DMRS configuration information to configure a DMRS mode. For UL or DL, the DMRS configuration information may include at least one of the following: a DMRS configuration type (e.g., indicated by a parameter dmrs-TypeENUMERATED{type2}), a maximum number of DMRS symbols per position (e.g., indicated by a parameter maxLengthENUMERATED{len2}), a DMRS start position, and a DMRS additional position (e.g., indicated by a parameter dmrs-AdditionalPositionENUMERATED{pos0,pos1,pos3}).

[0050] In certain embodiments, the wireless network dynamically indicates the DMRS pattern to the UE. For example, the wireless network may indicate the DMRS pattern to the UE via a medium access control (MAC) control element (CE) or via a DCI.

[0051] Figure 4An example data structure 400 for a MAC CE indicating a DMRS mode to a UE according to one embodiment is shown. In this example, the data structure 400 is eight bits wide (labeled as bits 0, 1, 2, 3, 4, 5, 6, 7). The "D / U" parameter includes a single bit to indicate whether the MAC CE is for DL ​​or UL. The "Serving Cell ID" parameter, which includes five bits, indicates an identifier (ID) of the corresponding serving cell. The "BWP ID" parameter, which includes two bits, identifies the corresponding BWP. The "A / D" parameter, which includes a single bit, indicates a conventional or enhanced DMRS mode. As shown, the example also includes an "R" parameter of seven reserved bits.

[0052] In certain embodiments, the MAC CE is also configured to modify one or more of the following: modify the DMRS pattern on multiple component carriers (CCs) simultaneously, modify the DMRS pattern on multiple BWPs simultaneously, and / or modify the DMRS pattern on both DL and UL simultaneously. In addition, or in other embodiments, the MAC CE may be configured to modify the DMRS configuration information, including, for example, modifying the DMRS configuration type (i.e., type 1 or type 2), modifying the DMRS additional position (i.e., "pos0", "pos1", "pos2", "pos3"), and / or modifying the maximum number of DMRS symbols per position (i.e., 1 or 2).

[0053] As described above, in certain embodiments, the wireless network may indicate the DMRS pattern to the UE via the DCI. In one embodiment, for example, the DCI includes a single bit field to indicate whether the wireless network indicates a legacy DMRS pattern or an enhanced DMRS pattern.

[0054] Another embodiment uses the most significant bit (MSB) or the least significant bit (LSB) of the antenna port field in the DCI to indicate the DMRS mode to the UE. For example, the RRC message may first configure the DMRS mode as a "legacy" DMRS mode or an "enhanced" DMRS mode or a "dynamic" DMRS mode. The bit width of the antenna port field in the DCI depends on the DMRS mode configured by the RRC. When the RRC message configures a dynamic DMRS mode, the MSB (or LSB) of the antenna port field in the DCI dynamically indicates whether the legacy DMRS mode or the enhanced DMRS mode is indicated.

[0055] In another embodiment for dynamically indicating the DMRS mode to the UE via DCI, a column may be added to the antenna port table. For example, a column may be added to Table 7.3.1.2.2-1 / 1A / 2 / 2A / 3 / 3A / 4 / 4A in 3GPP TS 38.213. The additional column corresponds to whether a conventional DMRS mode or an enhanced DMRS mode is indicated. In other words, when the antenna port field in the DCI indicates a particular row in a new antenna port table with an additional column corresponding to the DMRS mode, the UE determines whether the enhanced DMRS mode is indicated by the wireless network based on the row indicated in the antenna port field in the DCI.

[0056] Figure 5 5 is a flow chart of a method 500 for a user equipment (UE) in a wireless network according to one embodiment. In box 502, the method 500 includes: receiving a radio resource control (RRC) message including demodulation reference signal (DMRS) configuration information from a base station at the UE, the demodulation reference signal (DMRS) configuration information including at least one of a DMRS configuration type, a maximum number of DMRS symbols per position, a DMRS start location, and a DMRS additional location. In box 504, the method 500 includes: receiving a dynamic DMRS mode indication from the base station at the UE for the UE to select one of a first DMRS mode supporting up to 12 DMRS ports and a second DMRS mode supporting up to 24 DMRS ports. In box 506, the method 500 includes: processing the DMRS at the UE based on the selection of the first DMRS mode or the second DMRS mode indicated by the dynamic DMRS mode indication from the base station.

[0057] In certain embodiments of the method 500, receiving a dynamic DMRS pattern indication includes: receiving, at a UE, a medium access control (MAC) control element (CE) from a base station, the medium access control (MAC) control element (CE) including a single bit to indicate a first DMRS pattern or a second DMRS pattern. The MAC CE may also indicate at least one of: whether the dynamic pattern indication from the base station corresponds to an uplink DMRS configuration or a downlink DMRS configuration; a serving cell identifier (ID); and a bandwidth part (BWP) ID. In addition, or in other embodiments, the MAC CE is configured to modify one or more of: modifying DMRS patterns on multiple component carriers (CCs) simultaneously, modifying DMRS patterns on multiple bandwidth parts (BWPs) simultaneously, and / or modifying DMRS patterns of both uplink DMRS configurations and downlink DMRS configurations simultaneously. In certain embodiments, the MAC CE is configured to modify DMRS configuration information.

[0058] In certain embodiments of method 500, receiving a dynamic DMRS pattern indication includes: receiving downlink control information (DCI) at the UE from a base station, the downlink control information (DCI) indicating the first DMRS pattern or the second DMRS pattern. The DCI may include a single bit field to indicate the first DMRS pattern or the second DMRS pattern.

[0059] In certain embodiments, the method 500 further includes: determining the first DMRS mode or the second DMRS mode from the most significant bit (MSB) or the least significant bit (LSB) of the antenna port field in the DCI. The RRC message may initialize the DMRS mode to one of the first DMRS mode, the second DMRS mode, or the dynamic DMRS mode. The bit width of the antenna port field in the DCI corresponds to the DMRS mode initialized by the RRC message. When the DMRS mode is initialized to the dynamic DMRS mode by the RRC, the MSB or LSB of the antenna port field indicates reselection to the first DMRS mode or the second DMRS mode.

[0060] In certain embodiments of method 500, the DCI indicates a column in the antenna port table corresponding to the first DMRS pattern or the second DMRS pattern.

[0061] Figure 6 The present invention is a method 600 for a base station in a wireless network according to one embodiment. In box 602, the method 600 includes: sending a radio resource control (RRC) message including demodulation reference signal (DMRS) configuration information to a user equipment (UE) from the base station, the demodulation reference signal (DMRS) configuration information including at least one of a DMRS configuration type, a maximum number of DMRS symbols per position, a DMRS start location, and a DMRS additional location. In box 604, the method 600 includes: selecting a selected DRMS ​​mode at the base station, the selected DRMS ​​mode including one of a first DMRS mode supporting up to 12 DMRS ports and a second DMRS mode supporting up to 24 DMRS ports. In box 606, the method 600 includes: sending a dynamic DMRS mode indication of the selected DMRS mode from the base station to the UE.

[0062] In certain embodiments of method 600, sending a dynamic DMRS pattern indication includes: sending a medium access control (MAC) control element (CE) from a base station to a UE, the medium access control (MAC) control element (CE) including a single bit to indicate a first DMRS pattern or a second DMRS pattern. The MAC CE may also indicate at least one of: whether the selected DMRS pattern corresponds to an uplink DMRS configuration or a downlink DMRS configuration; a serving cell identifier (ID); and / or a bandwidth part (BWP) ID. The MAC CE may be configured to modify one or more of: modifying the selected DMRS pattern on multiple component carriers (CCs) simultaneously, modifying the selected DMRS pattern on multiple bandwidth parts (BWPs) simultaneously, and / or modifying the selected DMRS pattern of both the uplink DMRS configuration and the downlink DMRS configuration simultaneously. In certain embodiments, the MAC CE is configured to modify the DMRS configuration information.

[0063] In certain embodiments of method 600, sending a dynamic DMRS pattern indication includes: sending downlink control information (DCI) from the base station to the UE, the downlink control information (DCI) indicating the first DMRS pattern or the second DMRS pattern. The DCI may include a single bit field to indicate whether the selected DMRS pattern is the first DMRS pattern or the second DMRS pattern.

[0064] Certain embodiments of method 600 also include: configuring the most significant bit (MSB) or the least significant bit (LSB) of the antenna port field in the DCI to indicate the first DMRS mode or the second DMRS mode. The RRC message can initialize the UE to one of the first DMRS mode, the second DMRS mode, or the dynamic DMRS mode. The bit width of the antenna port field in the DCI corresponds to the DMRS mode initialized by the RRC message. When the DMRS mode is initialized to the dynamic DMRS mode by the RRC, the MSB or LSB of the antenna port field indicates reselection to the first DMRS mode or the second DMRS mode.

[0065] In certain embodiments of method 600, the DCI indicates a column in the antenna port table corresponding to the first DMRS pattern or the second DMRS pattern.

[0066] Figure 7 An example architecture of a wireless communication system 700 according to an embodiment disclosed herein is illustrated. The following description is provided for an example wireless communication system 700 operating in conjunction with the LTE system standard and / or the 5G or NR system standard provided in the 3GPP technical specifications.

[0067] like Figure 7As shown, wireless communication system 700 includes UE 702 and UE 704 (although any number of UEs may be used). In this example, UE 702 and UE 704 are illustrated as smartphones (e.g., handheld touch screen mobile computing devices capable of connecting to one or more cellular networks), but may also include any mobile or non-mobile computing device configured for wireless communication.

[0068] UE 702 and UE 704 may be configured to be communicatively coupled to RAN 706. In an embodiment, RAN 706 may be NG-RAN, E-UTRAN, etc. UE 702 and UE 704 utilize connections (or channels) (shown as connection 708 and connection 710, respectively) with RAN 706, where each connection (or channel) includes a physical communication interface. RAN 706 may include one or more base stations (such as base station 712 and base station 714) to implement connection 708 and connection 710.

[0069] In this example, connection 708 and connection 710 are air interfaces that enable such communicative coupling and may conform to the RAT used by the RAN 706 , such as, for example, LTE and / or NR.

[0070] In some embodiments, UE 702 and UE 704 may also directly exchange communication data via side link interface 716. UE 704 is shown as being configured to access an access point (shown as AP 718) via connection 720. For example, connection 720 may include a local wireless connection, such as any connection conforming to the IEEE 802.11 protocol, wherein AP 718 may include In this example, AP 718 may not be connected to another network (eg, the Internet) through CN 724.

[0071] In an embodiment, UE 702 and UE 704 may be configured to communicate with each other or with base station 712 and / or base station 714 over a multi-carrier communication channel using orthogonal frequency division multiplexing (OFDM) communication signals according to various communication techniques, such as, but not limited to, orthogonal frequency division multiple access (OFDMA) communication techniques (e.g., for downlink communication) or single carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or sidelink communication), although the scope of the embodiment is not limited in this respect. The OFDM signal may include multiple orthogonal subcarriers.

[0072] In some embodiments, all or part of the base station 712 or the base station 714 may be implemented as one or more software entities running on a server computer as part of a virtual network. In addition, or in other embodiments, the base station 712 or the base station 714 may be configured to communicate with each other via the interface 722. In an embodiment where the wireless communication system 700 is an LTE system (e.g., when the CN 724 is an EPC), the interface 722 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to the EPC and / or between two eNBs connected to the EPC. In an embodiment where the wireless communication system 700 is an NR system (e.g., when the CN 724 is a 5GC), the interface 722 may be an Xn interface. The Xn interface is defined between two or more base stations (e.g., two or more gNBs, etc.) connected to the 5GC, between the base station 712 (e.g., gNB) and the eNB connected to the 5GC, and / or between two eNBs connected to the 5GC (e.g., CN 724).

[0073] RAN 706 is shown as being communicatively coupled to CN 724. CN 724 may include one or more network elements 726 configured to provide various data and telecommunication services to customers / subscribers (e.g., UE 702 and users of UE 704) connected to CN 724 via RAN 706. The components of CN 724 may be implemented in one physical device or separate physical devices, including components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0074] In an embodiment, CN 724 may be an EPC, and RAN 706 may be connected to CN 724 via an S1 interface 728. In an embodiment, S1 interface 728 may be divided into two parts: an S1 user plane (S1-U) interface, which carries traffic data between base station 712 or base station 714 and a serving gateway (S-GW); and an S1-MME interface, which is a signaling interface between base station 712 or base station 714 and a mobility management entity (MME).

[0075] In an embodiment, CN 724 may be a 5GC, and RAN 706 may be connected to CN 724 via an NG interface 728. In an embodiment, NG interface 728 may be divided into two parts: an NG user plane (NG-U) interface, which carries traffic data between base station 712 or base station 714 and a user plane function (UPF); and an S1 control plane (NG-C) interface, which is a signaling interface between base station 712 or base station 714 and an access and mobility management function (AMF).

[0076] In general, the application server 730 may be an element that provides applications (e.g., packet-switched data services) that use Internet Protocol (IP) bearer resources with the CN 724. The application server 730 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 702 and the UE 704 via the CN 724. The application server 730 may communicate with the CN 724 via an IP communication interface 732.

[0077] Figure 8 A system 800 for performing signaling 834 between a wireless device 802 and a network device 818 according to embodiments disclosed herein is shown. The system 800 can be part of a wireless communication system as described herein. For example, the wireless device 802 can be a UE of the wireless communication system. For example, the network device 818 can be a base station (e.g., an eNB or a gNB) of the wireless communication system.

[0078] The wireless device 802 may include one or more processors 804. The processor 804 may execute instructions to perform various operations of the wireless device 802, as described herein. The processor 804 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0079] The wireless device 802 may include a memory 806. The memory 806 may be a non-transitory computer-readable storage medium that stores instructions 808 (which may include, for example, instructions executed by the processor 804). The instructions 808 may also be referred to as program code or a computer program. The memory 806 may also store data used by the processor 804 and results computed by the processor.

[0080] The wireless device 802 may include one or more transceivers 810, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses an antenna 812 of the wireless device 802 to facilitate signaling (e.g., signaling 834) sent or received by the wireless device 802 with other devices (e.g., network device 818) according to a corresponding RAT.

[0081] The wireless device 802 may include one or more antennas 812 (e.g., one, two, four, or more). For implementations with multiple antennas 812, the wireless device 802 may take full advantage of the spatial diversity of these multiple antennas 812 to send and / or receive multiple different data streams on the same time-frequency resources. This behavior may be referred to as, for example, multiple-input multiple-output (MIMO) behavior (referring to multiple antennas used at each of the transmitting device and the receiving device to implement this aspect). MIMO transmission by the wireless device 802 may be implemented based on precoding (or digital beamforming) applied to the wireless device 802, which multiplexes data streams between the antennas 812 based on known or assumed channel characteristics, so that each data stream is received at an appropriate signal strength relative to the other streams and at a desired location in the spatial domain (e.g., the location of the receiver associated with the data stream). Certain implementations may use a single-user MIMO (SU-MIMO) approach (in which all data streams are directed to a single receiver) and / or a multi-user MIMO (MU-MIMO) approach (in which separate data streams may be directed to separate (different) receivers in different locations in the spatial domain).

[0082] In certain embodiments with multiple antennas, the wireless device 802 may implement analog beamforming techniques whereby the phases of signals transmitted by the antennas 812 are relatively adjusted such that the (joint) transmissions of the antennas 812 are directional (this is sometimes referred to as beam steering).

[0083] The wireless device 802 may include one or more interfaces 814. The interfaces 814 may be used to provide input to the wireless device 802 or output from the wireless device. For example, a wireless device 802 that is a UE may include an interface 814, such as a microphone, a speaker, a touch screen, buttons, etc., to allow a user of the UE to provide input and / or output to the UE. Other interfaces of such a UE may be composed of transmitters, receivers, and other circuits (e.g., in addition to the transceiver 810 / antenna 812 described above), which allow the UE to communicate with other devices and may communicate according to known protocols (e.g., etc.) to perform the operation.

[0084] The wireless device 802 may include a DMRS module 816. The DMRS module 816 may be implemented via hardware, software, or a combination thereof. For example, the DMRS module 816 may be implemented as a processor, circuit, and / or instruction 808 stored in the memory 806 and executed by the processor 804. In some examples, the DMRS module 816 may be integrated within the processor 804 and / or the transceiver 810. For example, the DMRS module 816 may be implemented by a combination of software components (e.g., executed by a DSP or a general purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 804 or the transceiver 810.

[0085] The DMRS module 816 may be used in various aspects of the present disclosure, such as Figure 5 all aspects.

[0086] The network device 818 may include one or more processors 820. The processor 820 may execute instructions to perform various operations of the network device 818, as described herein. The processor 820 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0087] The network device 818 may include a memory 822. The memory 822 may be a non-transitory computer-readable storage medium that stores instructions 824 (which may include, for example, instructions executed by the processor 820). The instructions 824 may also be referred to as program code or a computer program. The memory 822 may also store data used by the processor 820 and results calculated by the processor.

[0088] The network device 818 may include one or more transceivers 826, which may include RF transmitter and / or receiver circuits that use an antenna 828 of the network device 818 to facilitate signaling (e.g., signaling 834) sent or received by the network device 818 with other devices (e.g., wireless device 802) according to the corresponding RAT.

[0089] The network device 818 may include one or more antennas 828 (e.g., one, two, four, or more). In embodiments with multiple antennas 828, the network device 818 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc. as described above.

[0090] The network device 818 may include one or more interfaces 830. The interface 830 may be used to provide input to or output from the network device 818. For example, the network device 818 as a base station may include an interface 830 composed of a transmitter, a receiver and other circuits (e.g., in addition to the transceiver 826 / antenna 828 described above), which enables the base station to communicate with other equipment in the core network and / or enables the base station to communicate with external networks, computers, databases, etc., in order to achieve the purpose of performing operations, management and maintenance of the base station or other equipment operably connected thereto.

[0091] The network device 818 may include a DMRS module 832. The DMRS module 832 may be implemented via hardware, software, or a combination thereof. For example, the DMRS module 832 may be implemented as a processor, circuit, and / or instruction 824 stored in the memory 822 and executed by the processor 820. In some examples, the DMRS module 832 may be integrated within the processor 820 and / or the transceiver 826. For example, the DMRS module 832 may be implemented by a combination of software components (e.g., executed by a DSP or a general purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 820 or the transceiver 826.

[0092] The DMRS module 832 may be used in various aspects of the present disclosure, for example, Figures 3 to 6 all aspects.

[0093] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of the method 500. For example, the apparatus may be an apparatus of a UE (such as the wireless device 802 as a UE, as described herein).

[0094] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 500. For example, the non-transitory computer-readable medium may be a memory of a UE (such as memory 806 of wireless device 802 as a UE, as described herein).

[0095] Embodiments contemplated herein include an apparatus comprising logical components, modules, or circuits for performing one or more elements of the method 500. For example, the apparatus may be an apparatus of a UE (such as the wireless device 802 as a UE, as described herein).

[0096] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of the method 500. For example, the apparatus may be an apparatus of a UE (such as the wireless device 802 as a UE, as described herein).

[0097] Embodiments contemplated herein include a signal as described in or in connection with one or more elements of method 500 .

[0098] Embodiments contemplated herein include a computer program or computer program product containing instructions, wherein the program is executed by a processor to cause the processor to perform one or more elements of the method 500. The processor may be a processor of a UE (such as the processor 804 of the wireless device 802 as a UE, as described herein). For example, these instructions may be located in the processor and / or on a memory of the UE (such as the memory 806 of the wireless device 802 as a UE, as described herein).

[0099] Embodiments contemplated herein include an apparatus including means for performing one or more elements of method 300 and / or method 600. For example, the apparatus may be an apparatus of a base station (such as network device 818 as a base station, as described herein).

[0100] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 300 and / or method 600. For example, the non-transitory computer-readable medium may be a memory of a base station (such as memory 822 of network device 818 acting as a base station, as described herein).

[0101] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuits for performing one or more elements of method 300 and / or method 600. For example, the apparatus may be an apparatus of a base station (such as network device 818 as a base station, as described herein).

[0102] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 300 and / or described method 600. For example, the apparatus may be an apparatus of a base station (such as network device 818 as a base station, as described herein).

[0103] Embodiments contemplated herein include a signal as described in or associated with one or more elements of method 300 and / or method 600 .

[0104] Embodiments contemplated herein include a computer program or computer program product including instructions, wherein execution of the program by a processing element causes the processing element to perform one or more elements of method 300 or method 600. The processor may be a processor of a base station (such as processor 820 of network device 818 as a base station, as described herein). For example, these instructions may be located in a processor and / or on a memory of a base station (such as memory 822 of network device 818 as a base station, as described herein).

[0105] For one or more embodiments, at least one of the components set forth in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein. For another example, circuits associated with a UE, a base station, a network element, etc. as described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein.

[0106] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In view of the above teachings, modifications and variations are possible or can be obtained from the practice of various embodiments.

[0107] Embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine executable instructions to be executed by a computer system. A computer system may include one or more general or special purpose computers (or other electronic devices). A computer system may include hardware components that include specific logic components for performing operations; or may include a combination of hardware, software, and / or firmware.

[0108] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments may be combined into a single system, partially combined into other systems, separated into multiple systems, or otherwise divided or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of another embodiment may be used in one embodiment. For clarity, these parameters, attributes, aspects, etc. are described only in one or more embodiments, and it should be appreciated that these parameters, attributes, aspects, etc. may be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless expressly stated herein.

[0109] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0110] Although the foregoing has been described in considerable detail for the sake of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles of the invention. It should be noted that there are many alternative ways to implement both the processes and the apparatus described herein. Therefore, the embodiments of the present invention should be regarded as illustrative rather than restrictive, and the specification is not limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

1. A base station for communicating in a wireless network, the base station comprising: a memory configured to store data corresponding to one or more multi-user multiple-input multiple-output (MU-MIMO) scheduling constraints; as well as One or more processors configured to: determining a first demodulation reference signal (DMRS) pattern configured to support a first number of DMRS ports for a DMRS configuration type and a DMRS symbol length; determining a second DMRS pattern, the second DMRS pattern being configured to support a second number of DMRS ports for the DMRS configuration type and the DMRS symbol length, wherein the second number of DMRS ports is greater than the first number of DMRS ports for the DMRS configuration type and the DMRS symbol length; When a first user equipment (UE) is configured to use the second DMRS pattern, determining whether to apply the one or more MU-MIMO scheduling restrictions for co-scheduling the first UE with one or more second UEs; as well as MU-MIMO scheduling is performed for the first UE and the one or more second UEs.

2. The base station of claim 1 , wherein when the DMRS configuration type comprises DMRS type 1, the one or more MU-MIMO scheduling restrictions comprise at least one of the following: When the one or more second UEs are configured to use the second DMRS pattern in the same code division multiplexing (CDM) group as for the first UE configured with the second DMRS pattern, the first UE cannot be co-scheduled with the one or more second UEs; and When the one or more second UEs are configured to use the first DMRS pattern in the same CDM group as for the first UE configured with the second DMRS pattern, the first UE cannot be co-scheduled with the one or more second UEs.

3. The base station according to claim 1, wherein when the DMRS configuration type includes DMRS type 1 or DMRS type 2, and wherein when the base station configures: A code division multiplexing (CDM) group with no data; The DMRS symbol length is one symbol; and When DMRS port 0 and DMRS port 1 (DMRS port {0, 1}), the one or more MU-MIMO scheduling restrictions include at least one of the following: When the total number of CDM groups increases to support an increased number of DMRS ports, the first UE is not expected to be co-scheduled with the one or more second UEs; and When the total number of CDM groups is not increased to support the increased number of DMRS ports, the first UE can be co-scheduled with the one or more second UEs. 4 . The base station according to claim 3 , wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern. 5 . The base station according to claim 3 , wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

6. The base station according to claim 1, wherein when the DMRS configuration type comprises DMRS type 1 or DMRS type 2, and wherein when the base station configures: Two code division multiplexing (CDM) groups without data; The DMRS symbol length is one symbol; and DMRS port 0, DMRS port 1, DMRS port 2 and DMRS port 3 (DMRS port {0,1,2,3}), The one or more MU-MIMO scheduling restrictions include at least one of the following: When the total number of CDM groups increases to support an increased number of DMRS ports, the first UE is not expected to be co-scheduled with the one or more second UEs; and When the total number of CDM groups is not increased to support the increased number of DMRS ports, the first UE can be co-scheduled with the one or more second UEs. 7 . The base station according to claim 6 , wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern.

8. The base station according to claim 6, wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

9. The base station according to claim 1, wherein when the DMRS configuration type comprises DMRS type 1 or DMRS type 2, and wherein when the base station configures: Two code division multiplexing (CDM) groups without data; The DMRS symbol length is taken as one symbol; as well as When DMRS port 0 and DMRS port 2 (DMRS port {0, 2}), the one or more MU-MIMO scheduling restrictions include: The first UE is not expected to be co-scheduled with the one or more second UEs; or The first UE can be co-scheduled with the one or more second UEs.

10. A base station according to claim 9, wherein when the first UE is not expected to be co-scheduled with the one or more second UEs, the one or more processors are further used to: enable the MU-MIMO co-scheduling for the first UE by the DMRS port 0 and DMRS port 1 (DMRS port {0,1}). 11 . The base station according to claim 9 , wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern. 12 . The base station according to claim 9 , wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

13. The base station according to claim 1, wherein when the DMRS configuration type comprises DMRS type 1, and wherein when the base station configures: Two code division multiplexing (CDM) groups without data; The DMRS symbol length is two symbols; and DMRS port 0, DMRS port 2, DMRS port 4 and DMRS port 6 (DMRS port {0,2,4,6}), The one or more MU-MIMO scheduling restrictions include: The first UE is not expected to be co-scheduled with the one or more second UEs; or The first UE can be co-scheduled with the one or more second UEs.

14. A base station according to claim 13, wherein when the first UE is not expected to be co-scheduled with the one or more second UEs, the one or more processors are further used to: enable the MU-MIMO co-scheduling for the first UE by the DMRS port 0, DMRS port 1, the DMRS port 4 and DMRS port 5 (DMRS port {0,1,4,5}). 15 . The base station according to claim 13 , wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern. 16 . The base station according to claim 13 , wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

17. The base station according to claim 1, wherein when the DMRS configuration type includes When DMRS type 1, and wherein the base station is configured: Two code division multiplexing (CDM) groups without data; The DMRS symbol length is one symbol; and When DMRS port 0, DMRS port 1 and DMRS port 2 (DMRS port {0,1,2}), The one or more MU-MIMO scheduling restrictions include: The first UE is not expected to be co-scheduled with the one or more second UEs; or The first UE can be co-scheduled with the one or more second UEs.

18. The base station according to claim 17, wherein when the first UE is not expected to be co-scheduled with the one or more second UEs, the one or more processors are further used to: change the DMRS configuration type from DMRS type 1 to DMRS type 2 to co-schedule the first UE with the one or more second UEs. 19 . The base station according to claim 17 , wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern.

20. The base station of claim 17, wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

21. The base station of claim 1, wherein when the DMRS configuration type includes DMRS type 1 or DMRS type 2, and wherein when the base station configures DMRS port 0, DMRS port 2, and DMRS port 3 (DMRS port {0, 2, 3}), the one or more MU-MIMO scheduling restrictions include that the first UE is not expected to be co-scheduled with the one or more second UEs.

22. A method for configuring multi-user multiple input multiple output (MU-MIMO) scheduling by a base station in a wireless network, the method comprising: determining a first demodulation reference signal (DMRS) pattern configured to support a first number of DMRS ports for a DMRS configuration type and a DMRS symbol length; determining a second DMRS pattern, the second DMRS pattern being configured to support a second number of DMRS ports for the DMRS configuration type and the DMRS symbol length, wherein the second number of DMRS ports is greater than the first number of DMRS ports for the DMRS configuration type and the DMRS symbol length; When a first user equipment (UE) is configured to use the second DMRS pattern, determining whether to apply one or more MU-MIMO scheduling restrictions for co-scheduling the first UE with one or more second UEs; as well as The MU-MIMO scheduling is performed for the first UE and the one or more second UEs.

23. The method of claim 22, wherein when the DMRS configuration type comprises DMRS type 1, the one or more MU-MIMO scheduling restrictions comprise at least one of: When the one or more second UEs are configured to use the second DMRS pattern in the same code division multiplexing (CDM) group as for the first UE configured with the second DMRS pattern, the first UE cannot be co-scheduled with the one or more second UEs; and When the one or more second UEs are configured to use the first DMRS pattern in the same CDM group as for the first UE configured with the second DMRS pattern, the first UE cannot be co-scheduled with the one or more second UEs.

24. The method according to claim 22, wherein when the DMRS configuration type comprises DMRS type 1 or DMRS type 2, and wherein when the base station configures: A code division multiplexing (CDM) group with no data; The DMRS symbol length is one symbol; and When DMRS port 0 and DMRS port 1 (DMRS port {0, 1}), the one or more MU-MIMO scheduling restrictions include at least one of the following: When the total number of CDM groups increases to support an increased number of DMRS ports, the first UE is not expected to be co-scheduled with the one or more second UEs; and When the total number of CDM groups is not increased to support the increased number of DMRS ports, the first UE can be co-scheduled with the one or more second UEs.

25. The method of claim 24, wherein when the first UE is capable of being co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern.

26. The method of claim 24, wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

27. The method of claim 22, wherein when the DMRS configuration type comprises DMRS type 1 or DMRS type 2, and wherein when the base station configures: Two code division multiplexing (CDM) groups without data; The DMRS symbol length is one symbol; and DMRS port 0, DMRS port 1, DMRS port 2 and DMRS port 3 (DMRS port {0,1,2,3}), The one or more MU-MIMO scheduling restrictions include at least one of the following: When the total number of CDM groups increases to support an increased number of DMRS ports, the first UE is not expected to be co-scheduled with the one or more second UEs; and When the total number of CDM groups is not increased to support the increased number of DMRS ports, the first UE can be co-scheduled with the one or more second UEs.

28. The method of claim 27, wherein when the first UE is capable of being co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern.

29. The method of claim 27, wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

30. The method of claim 22, wherein when the DMRS configuration type comprises DMRS type 1 or DMRS type 2, and wherein when the base station configures: Two code division multiplexing (CDM) groups without data; The DMRS symbol length is taken as one symbol; as well as When DMRS port 0 and DMRS port 2 (DMRS port {0, 2}), the one or more MU-MIMO scheduling restrictions include: The first UE is not expected to be co-scheduled with the one or more second UEs; or The first UE can be co-scheduled with the one or more second UEs.

31. The method of claim 30, wherein when the first UE is not expected to be co-scheduled with the one or more second UEs, the method further comprises: The MU-MIMO co-scheduling for the first UE is enabled by the DMRS port 0 and the DMRS port 1 (DMRS port {0, 1}).

32. The method of claim 30, wherein when the first UE is capable of being co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern.

33. The method of claim 30, wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

34. The method of claim 22, wherein when the DMRS configuration type comprises DMRS type 1, and wherein when the base station configures: Two code division multiplexing (CDM) groups without data; The DMRS symbol length is two symbols; and DMRS port 0, DMRS port 2, DMRS port 4 and DMRS port 6 (DMRS port {0,2,4,6}), The one or more MU-MIMO scheduling restrictions include: The first UE is not expected to be co-scheduled with the one or more second UEs; or The first UE can be co-scheduled with the one or more second UEs.

35. The method of claim 34, wherein when the first UE is not expected to be co-scheduled with the one or more second UEs, the method further comprises: The MU-MIMO co-scheduling for the first UE is enabled by the DMRS port 0, the DMRS port 1, the DMRS port 4 and the DMRS port 5 (DMRS ports {0, 1, 4, 5}).

36. The method of claim 34, wherein when the first UE is capable of being co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern.

37. The method of claim 34, wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

38. The method of claim 22, wherein when the DMRS configuration type comprises DMRS type 1, and wherein when the base station configures: Two code division multiplexing (CDM) groups without data; The DMRS symbol length is one symbol; and When DMRS port 0, DMRS port 1 and DMRS port 2 (DMRS port {0,1,2}), The one or more MU-MIMO scheduling restrictions include: The first UE is not expected to be co-scheduled with the one or more second UEs; or The first UE can be co-scheduled with the one or more second UEs.

39. The method of claim 38, wherein when the first UE is not expected to be co-scheduled with the one or more second UEs, the method further comprises: The DMRS configuration type is changed from DMRS type 1 to DMRS type 2 to coordinately schedule the first UE and the one or more second UEs.

40. The method of claim 38, wherein when the first UE is capable of being co-scheduled with the one or more second UEs, the one or more second UEs are configured to use the second DMRS pattern.

41. The method of claim 38, wherein when the first UE can be co-scheduled with the one or more second UEs, the one or more second UEs can be configured to use the first DMRS pattern or the second DMRS pattern.

42. The method of claim 22, wherein when the DMRS configuration type includes DMRS type 1 or DMRS type 2, and wherein when the base station configures DMRS port 0, DMRS port 2, and DMRS port 3 (DMRS port {0, 2, 3}), the one or more MU-MIMO scheduling restrictions include that the first UE is not expected to be co-scheduled with the one or more second UEs.

43. An apparatus comprising means for performing the method of any one of claims 22 to 42.

44. A computer-readable medium comprising instructions which, when executed by one or more processors of an electronic device, cause the electronic device to perform the method of any one of claims 22 to 42.

Images