Multi-user demodulation reference signal configuration and indication

Abstract

Methods, systems, and devices for configuring and indicating demodulation reference signals (DMRSs) in a multi-user communication system are described herein. An exemplary wireless communication method includes a first wireless device receiving a first indication from a network node, the first indication indicating information related to a first set of demodulation reference signal (DMRS) ports of the first wireless device; determining a first group of DMRS ports indicated in the first indication; and performing a demodulation operation on the first DMRS based on the at least first group of DMRS ports.

Description

Technical Field

[0001] This disclosure generally relates to digital wireless communications. Background Technology

[0002] Mobile communication technologies are driving the world toward an increasingly interconnected and networked society. Compared to existing wireless networks, next-generation systems and wireless communication technologies need to support a wider range of use case characteristics and provide more complex and granular access requirements and flexibility.

[0003] LTE (Long Term Evolution) is a wireless communication standard for mobile devices and data terminals developed by the 3rd Generation Partnership Project (3GPP). LTE Advanced (LTE-A) is a wireless communication standard that enhances the LTE standard. The fifth-generation wireless system, known as 5G, advances the LTE and LTE-A wireless standards and aims to support higher data rates, massive connectivity, ultra-low latency, high reliability, and other emerging service requirements. Summary of the Invention

[0004] This disclosure provides techniques for configuring and indicating demodulation reference signals (DM-RS, or DMRS for short) in a multi-user communication system. The described embodiments advantageously enable the mitigation of interference between user equipments (UEs) that are being co-scheduled.

[0005] In one example aspect, a wireless communication method includes: receiving a first indication from a network node by a first wireless device, the first indication indicating information related to a first set of demodulation reference signal (DMRS) ports of the first wireless device, determining the first set of DMRS ports indicated in the first indication, and performing a demodulation operation on the first DMRS based on at least the first set of DMRS ports.

[0006] In another example aspect, a wireless communication method includes: a network node sending a first indication to a first wireless device, the first indication indicating information related to a first set of demodulation reference signal (DMRS) ports of the first wireless device. The first wireless device is instructed to determine the first set of DMRS ports indicated in the first indication, and to perform a demodulation operation on the first DMRS based on at least the first set of DMRS ports.

[0007] In yet another example, the above-described method is embodied in processor-executable code and stored in a non-transitory computer-readable storage medium. When executed by a processor, the code contained in the computer-readable storage medium causes the processor to implement the method described in this patent document.

[0008] In yet another example embodiment, a device configured or operable to perform the methods described above is disclosed.

[0009] The above and other aspects, and their implementations, are described in more detail in the accompanying drawings, specification, and claims. Attached Figure Description

[0010] Figure 1 An example of a physical resource block (PRB) binding of type 1 DMRS is shown, where the frequency domain (FD) orthogonal cover code (OCC) length is 4.

[0011] Figure 2 An example of scheduling constraints is shown.

[0012] Figure 3 Another example of scheduling constraints is shown.

[0013] Figure 4 Examples of a first group of PRBs with scheduling restrictions and a second group of PRBs without any restrictions are shown.

[0014] Figure 5A and Figure 5B Examples of PRB offsets between two user equipment (UE) for the first PRB being even and odd are shown respectively.

[0015] Figure 6A and Figure 6B An example flowchart of wireless communication is shown.

[0016] Figure 7 An example block diagram of a hardware platform is shown, which may be part of a network device or a communication device.

[0017] Figure 8 Examples of wireless communication including base stations (BS) and user equipment (UE) based on some implementations of the disclosed technology are shown. Detailed Implementation

[0018] Existing and evolving cellular systems (such as 5G NR) use a demodulation reference signal (DMRS) to generate channel estimates at the receiver for demodulation of the relevant physical channels. For example, the DMRS is specifically designed and mapped for each physical channel, such as the Physical Broadcast Channel (PBCH), Physical Downlink Control Channel (PDCCH), Physical Downlink Shared Channel (PDSCH), Physical Uplink Control Channel (PUCCH), and Physical Uplink Shared Channel (PUSCH). In some implementations, the DMRS is UE-specific and can be transmitted as needed. In other implementations, the DMRS supports massive multi-user (MU) multiple-input multiple-output (MIMO) communication.

[0019] The exemplary headings of the following sections are intended to facilitate understanding of the disclosed subject matter and do not limit the scope of the claimed subject matter in any way. Therefore, one or more features of one example section may be combined with one or more features of another example section. Furthermore, the term "5G" is used for clarity of explanation; however, the technologies disclosed in this document are not limited to 5G technology alone and can be used in wireless systems implementing other protocols.

[0020] 1 Introduction and Overview To support more Quadrature Demodulation Reference Signal (DMRS) ports for uplink and downlink transmissions, a 4-bit frequency domain (FD) orthogonal coverage code (OCC) is used for the DMRS. Furthermore, for DMRS type 1, Physical Resource Block (PRB) bonding is supported. Figure 1 As shown, two PRBs are bound together and support FD-OCC of length 4. Two code division multiplexing (CDM) groups are supported, and each CDM group uses 6 resource elements (REs). The first CDM group #0 is mapped to REs #0, 2, 4, and 6 in the first PRB, and the second CDM group #0 is mapped to REs #8 and 10 in the first PRB and REs #0 and 2 in the second PRB binding. To support PRB binding, scheduling constraints are introduced. These constraints are based on UE capabilities; for example, if the UE can handle orphan REs or PRBs, no constraints are imposed on the UE, but if the UE cannot handle orphan REs or PRBs, the scheduled PRBs are restricted. For example, the constraints require that the number of consecutively scheduled PRBs be even, and that the PRB offset of the scheduled PDSCH relative to reference point A (e.g., common resource block 0) be even. Figure 2 As shown.

[0021] In some implementations, for an FD-OCC of length 4, different FD-OCCs can be associated with different DMRS ports. Examples of FD-OCCs of length 4 are shown in Tables 1-1 and 1-2 below.

[0022] Table 1-1: Walsh matrix (Hadamard code) for FD-OCC of length 4

[0023] Table 1-2: Cyclic shifts with {0, π, π / 2, 3π / 2} for FD-OCC of length 4

[0024] However, existing systems cannot coordinate scheduling between UEs that support the constraints and co-scheduled UEs that do not. Systems with both types of UEs typically lead to increased interference, which reduces link reliability and throughput requirements, especially for high-throughput, low-latency applications. Embodiments of the disclosed technology provide methods and mechanisms for coordinating scheduling between UEs that support the constraints and UEs that do not, thereby reducing (or eliminating) interference between co-scheduled UEs.

[0025] 2. Example of adding multi-user scheduling constraints In some embodiments, the constraints may specify that all co-scheduled UEs should follow the same constraint rules. For example, all co-scheduled UEs should have the same ability to determine whether it is necessary to use a DMRS of length 4 to implement scheduling constraints.

[0026] Figure 3 An example of this constraint rule is shown. As illustrated, if UEs follow the same constraint rule, an even number of consecutive PRBs are scheduled for each co-scheduled UE, and the offsets between scheduled PRBs for different UEs are also even numbers. For example, UE1 has an offset of N PRBs relative to reference point A, and UE2 has an offset of N+2 PRBs relative to reference point A. This constraint significantly mitigates the impact of interference on DMRS demodulation, thus allowing UEs to utilize this constraint rule for co-scheduling.

[0027] In some embodiments, the constraint may specify that all co-scheduled UEs should not schedule their DMRS ports in the same CDM group on overlapping PRBs. For example, if the DMRS ports are not scheduled in the same CDM group, and different CDM groups are mapped to different REs, the impact of interference from different CDM groups on DMRS demodulation is significantly mitigated. In another example, this constraint may also be applied to a UE with an FD-OCC of length 4 and another UE with an FD-OCC of length 4 or 2.

[0028] 3. Example of defining scheduling granularity for multi-user scheduling In cellular communication systems, granularity refers to the level of detail and finesse in resource allocation and distribution. It allows the system to adjust its behavior according to the specific needs of various services and users, thereby improving efficiency, quality of service, and overall performance. Granularity plays a crucial role in optimizing the performance and efficiency of 5G systems. Fine-grained control over QoS and resource allocation enables the network to allocate resources more accurately based on the specific needs of each application or user. This helps prevent resources from being over-allocated to low-priority services and ensures that critical services receive the necessary resources.

[0029] Granularity enables networks to differentiate between different types of data streams or services, providing users with a better quality of experience. For example, latency-sensitive applications can be prioritized over less time-sensitive traffic.

[0030] Granular control over resource allocation helps networks make efficient use of available resources, preventing underutilization or waste of valuable spectrum and bandwidth.

[0031] In some embodiments, granularity can be defined for overlapping UEs that can be divided into multiple groups, wherein UEs in each group are scheduled to DMRS ports in the same CDM group. Here, UEs with scheduling restrictions requiring an even number of PRBs (as described in Section 2) and UEs without such scheduling restrictions should not be scheduled in the same CDM group.

[0032] Figure 4 An example of this scenario is illustrated. As shown, two UEs are scheduled for multi-user communication, where UE1 is scheduled under an even-numbered PRB constraint, and UE2 is scheduled without such a constraint. For UE1's second scheduling PRB, the first two REs of this PRB are bound together with the last two REs of the first scheduling PRB, for example, DMRS port #0 uses FD-OCC [1, 1, 1, 1]. UE2's first scheduling PRB overlaps with UE1's second scheduling PRB, and the first four REs of UE2's first scheduling PRB are used to map DMRS port #1, using FD-OCC [1, –1, 1, –1]. For DMRS demodulation, the FD-OCC can be viewed as having two parts, each with two REs. For each of these two REs, the FD-OCC between the two UEs is orthogonal, so the two UEs can demodulate the corresponding DMRS ports. However, if the UE is scheduled to use DMRS port #8 with FD-OCC [1, 1, –1, –1], then the first two REs of UE2 will no longer be orthogonal to the two REs of the second PRB of UE1, which will introduce interference. In this case, the system must restrict the first two codes of FD-OCC length 4 to make them orthogonal for multiple users with different consecutive PRB scheduling restrictions and whether the starting PRB is even.

[0033] In one example, when the difference between the PRBs of different UEs and reference point A is odd and the scheduled PRBs partially or completely overlap, some scheduling constraints should be applied to the DMRS port indication. For example, crossed FD-OCCs should be orthogonal. A crossed FD-OCC corresponds to UE1 being configured or indicated to use a 4-length FD-OCC, but some codewords or mapped REs overlap with a 4-length FD-OCC of another UE2 in the same CDM group.

[0034] As shown in Table 2, the indicated DMRS ports are the DMRS ports of the target UE, the DMRS ports used for the MU are the DMRS ports indicated in the same DMRS CDM group, and the restricted DMRS ports are the DMRS ports that should not be indicated to other co-scheduled UEs in the same CDM group. If the target UE is instructed to use a DMRS port from one of the DMRS port combinations in Tables 2 and 3, the number of usable or restricted DMRS ports can be reduced according to the indicated DMRS ports.

[0035] Table 2: DMRS ports used for MU scheduling

[0036] Table 3: DMRS ports used for dual-symbol DMRS MU scheduling

[0037] 4DMRS port scheduling limit example DMRS port scheduling restrictions can be applied to each Resource Block Group (RBG), Precoded Resource Block Group (PRG), and / or PRG Binding Group.

[0038] In some embodiments, if a UE is restricted to scheduling an even number of consecutive PRBs and uses an even number of PRB offsets relative to reference point A, then for a UE scheduled to have one or more consecutive PRB sets, each consecutive PRB set includes an even number of PRBs and the PRB offsets relative to reference point A are even.

[0039] In some embodiments, if a UE is not restricted to scheduling an even number of consecutive PRBs, the difference between the scheduled PRB and another scheduled UE with or without such a restriction may be odd, and the DMRSs on overlapping REs may not be orthogonal. In this case, a scheduling restriction or a DMRS port indication restriction should be implemented.

[0040] In some embodiments, for a target UE that is restricted to scheduling an even number of consecutive PRBs and has an even number of PRB offsets relative to reference point A, it is advantageous to indicate some information associated with the co-scheduled UE, as described in the following two examples.

[0041] (1) When there is a UE co-scheduled with the target UE, the co-scheduled UE is scheduled without scheduling restrictions on the number of consecutive PRBs or the PRB offset relative to reference point A. In this case, the co-scheduled UE is scheduled with an odd number of consecutive PRBs and an odd number of PRB offsets.

[0042] (2) When the granularity of the target UE partially overlaps with that of a co-scheduled UE, the difference in the scheduled PRBs is odd and the PRB offset relative to reference point A is odd. Here, granularity is the number of consecutively scheduled PRBs, or a set of PRGs, or a set of PRGs, or a set of one or more consecutively scheduled PRBs, PRGs, or RBGs that can be configured for the target UE, but not all of these sets partially overlap with the co-scheduled UE. For fully overlapping or non-overlapping granularities, the DMRS ports are orthogonal, and the interference effect on DMRS demodulation based on non-orthogonal DMRS ports will be minimal. However, for partially overlapping granularities of PRGs or RBGs (and especially for overlapping resources with odd PRB offsets from reference point A), the DMRS ports are no longer orthogonal, and the reliability of demodulation is reduced. In these scenarios, the precoding or demodulation result of the next PRG (before or after) can be used on the overlapping PRBs, PRGs, RBGs, or granularities.

[0043] In some embodiments, Media Access Control (MAC) Control Element (CE) or Downlink Control Information (DCI) signaling can be used to indicate relevant information. For example, a single bit in a new field of the MAC CE or DCI is used to indicate this information.

[0044] In some embodiments, granularity is defined as a function of PRBs. For example, the size of the granularity can be 2 PRBs, 4 PRBs, or more PRBs overlapping with co-scheduled UEs having an even number of PRB scheduling restrictions. In one example, signaling can be used to indicate which granularity overlaps with a co-scheduled UE that does not have an even number of PRB scheduling restrictions. The signaling can have the same size as the granularity; for example, a bitmap can be associated with each granularity, and the signaling can indicate whether the relevant granularity overlaps with the aforementioned co-scheduled UE. Alternatively, the signaling can have a size, This indicates which granularity overlaps with the co-scheduled UE.

[0045] In some embodiments, the granularity can be at least one RBG or PRG. If more than one PRG or RBG is configured or indicated, PRG binding or RBG binding can be used.

[0046] In some embodiments, and in the case of PRG binding, at least two PRGs are bound together, wherein if at least one PRG overlaps with a co-scheduled UE, the precoding or DMRS demodulation result can be used for the overlapping PRG.

[0047] In some embodiments, and for the case of fully overlapping PRBs, at least one of the bound PRBs overlaps with the co-scheduled UE, and an odd-valued PRB offset is used, calculated from the start of the scheduled PRB of the target UE, wherein multiple bound PRBs overlap with the co-scheduled UE.

[0048] In some embodiments, for cases where PRBs partially overlap, at least one PRB in the RBG or PRG overlaps with at least one co-scheduled UE, and the UE uses an odd-value PRB offset relative to the starting position of the scheduled PRB of the target UE.

[0049] In the frequency domain, the offset of the first PRB in consecutive scheduling between two scheduling UEs is an even number, such as... Figure 5A As shown. Since two PRBs are bound for eType1 DMRS, if the offset of the first PRB of consecutively scheduled PRBs between two UEs is even, the DMRS ports in the same CDM group can be orthogonal between the two UEs in any case, so no further restrictions are needed in this case. For example, when UE1 is instructed to use DMRS port #0 with FD-OCC [1, 1, 1, 1] and UE2 is instructed to use DMRS port #8 with FD-OCC [1, 1, -1, -1], the overlapping REs {0, 2, 4, 6} of UE1 and UE2 are orthogonal due to the inherent FD-OCC of the instructed DMRS ports, and the remaining overlapping REs {8, 10} of UE1 and UE2 can be handled by the UE's UE capability regarding isolated REs.

[0050] In one example, and as Figure 5B As shown, the PRB offset of the first scheduling PRB for the two scheduled UEs in the frequency domain is an odd number. Here, a DMRS port is indicated for each UE, for example, DMRS port #0 is indicated for UE1 and DMRS port #8 is indicated for UE2. For in Figure 5B The overlapping REs marked as shaded rectangles are misaligned for the two UEs in the FD-OCC. For an FD-OCC of length 4 for Enhancement Type 1 (or eType 1) DMRS, PRB0 and PRB1 are bound. For DMRS port #0 of CDM group #0, the last two REs in PRB0 and the first two REs in PRB1 are bound for FD-OCC [1, 1, 1, 1]. Similarly, UE2 is scheduled to use DMRS port #8 with [1, 1, –1, –1]. The first two overlapping REs of UE0 and UE1 are both associated with OCC [1, 1], which is not orthogonal in these REs and will introduce interference for DMRS demodulation in these overlapping REs.

[0051] To address the above problem, four alternative solutions were considered: (1) Restrict all scheduled UEs to use an even PRB offset relative to the first scheduled PRB. This restriction will limit the number of scheduled UEs and adversely affect the gNB scheduling flexibility.

[0052] (2) Restrict all UEs from being instructed to use DMRS ports from different CDM groups. Even if these UEs are scheduled with odd PRB offsets relative to the first scheduling PRB, UEs scheduled using DMRS ports from different CDM groups still maintain DMRS orthogonality.

[0053] (3) The target UE and the co-scheduled UE should have FD-OCC orthogonality of sub-length 2 with the target UE in the same CDM group, for example, [ w f (0) , w f (1) ]or[ w f (2) , w f (3) For overlapping REs, if the sub-length 2 of an FD-OCC of length 4 is orthogonal between the target UE and the co-scheduling UE, then the DMRS ports with an FD-OCC of length 4 are still orthogonal between these UEs, for example, the target UE uses DMRS port #0 and the co-scheduling UE uses DMRS port #1.

[0054] (4) Information about overlapping frequency resources can be indicated to the target UE. When the UE receives the relevant information, it will process the overlapping resources by, for example, ignoring DMRS ports in the overlapping resources. The relevant information can specify which parts of the frequency resources are overlapping. While the solution does not limit gNB scheduling flexibility, it will introduce additional overhead.

[0055] In some embodiments, the first DMRS port of the first wireless device is not intended to be co-scheduled with the second DMRS port of the second wireless device, the second wireless device is co-scheduled with the first wireless device, and wherein the second DMRS port is associated with an FD-OCC of length 2 or 4. In this scenario, the first and / or second DMRS ports are scheduled according to at least one of the following conditions: – The PRBs scheduled by the first radio device and its co-scheduling UE do not completely overlap; – The offset of the first scheduling PRB or consecutive scheduling PRB of the PDSCH between the first wireless device and the second wireless device is an odd number. – The same DMRS CDM group as the first DMRS port; or – These UEs have a sub-length of 4 for the FD-OCC (e.g., [ w f (0) , w f (1) ]or[ w f (2) , w f (3) ]) Not orthogonal.

[0056] In some embodiments, the second DMRS port is scheduled based on one of the above conditions or a combination of at least two of the above conditions.

[0057] In some embodiments, the following scenarios are provided for MU-MIMO with DMRS configuration enhancement type 1 (Rel-18 DMRS eType1): – If the PRBs scheduled for a UE and a co-scheduled UE do not completely overlap, then the DMRS of the target UE does not expect to be co-scheduled with the other UE. – The UE does not expect the offset of the first scheduled PRB of the PDSCH between the UE and its co-scheduled UE to be an odd number; – If the PRBs scheduled for a UE and its co-scheduling UE do not completely overlap, and their indicated DMRS ports come from the same DMRS CDM group, then the target UE's DMRS does not expect to be co-scheduled with the other UE. – If the PRBs scheduled for a UE and its co-scheduling UE do not completely overlap, and if their indicated DMRS ports come from the same DMRS CDM group, then the UE does not expect the offset of the first scheduled PRB of the PDSCH between the UE and its co-scheduling UE to be odd; and / or – If consecutive PRBs scheduled for a UE and its co-scheduling UE do not completely overlap, and if their indicated DMRS ports come from the same DMRS CDM group, the UE does not expect the offset of the first scheduled PRB of the PDSCH between the UE and its co-scheduling UE to be odd, unless the sub-length of the FD-OCC between these UEs is 4 (e.g., [ w f (0) , w f (1) ]or[ w f (2) , w f(3) The FD-OCC of ]) is orthogonal.

[0058] In some embodiments, fully overlapping scheduling PRBs between the target and co-scheduled UEs mean that the scheduling PRBs of these UEs are the same. Similarly, partially overlapping or not fully overlapping scheduling PRBs mean that the scheduling PRBs of these UEs are not exactly the same, i.e., some PRBs are scheduled to one UE but not to other UEs.

[0059] In some embodiments, the first PRB may be the first scheduled PRB of a UE (e.g., the target UE), or the first PRB of one or each of consecutive scheduled PRBs, or the first PRB in a PRG.

[0060] 5. Signaling examples for DMRS between jointly scheduled UEs In some embodiments, multiple bits in the DCI field can be used to indicate whether the co-scheduled UE and the target UE have the same DMRS sequence. In one example, the target UE and the co-scheduled UE have the same root sequence when the DMRS sequence is a root sequence associated with an allocated frequency resource, bandwidth portion, or bandwidth. In another example, the DMRS sequence is associated with a DMRS port index and a DMRS frequency location; for example, the target UE has the same DMRS sequence on the same DMRS RE or the same CDM group. In yet another example, multiple bits are associated with an indicated modulation and coding scheme (MCS).

[0061] In some embodiments, to achieve better downlink transmission efficiency, the MCS is indicated in the DCI field, and different modulation orders or code rates are supported for different indices. Here, multiple bits include 3 bits, as shown in Table 4.

[0062] Table 4: MU Indicators Supporting Modulation Orders of 256 QAM and / or 1024 QAM

[0063] In some embodiments, the MCS is configured without a modulation order of 256QAM or 1024QAM; that is, an MCS table without 256QAM or 1024QAM can be defined, in which case only up to 64QAM can be configured or indicated to the UE. Here, only 2 bits are needed, corresponding to bit fields 0-3 in Table 4, or as shown in Table 5.

[0064] Table 5: MU Indicators for Modulation Orders Not Supported by 256 QAM and 1024 QAM

[0065] In some embodiments, for the target UE and the co-scheduled UE, the DMRS port may be configured with an FD-OCC of length 4 or length 2.

[0066] In some embodiments, the DMRS port can be configured for multiple TRP transmissions for both the target UE and the co-scheduled UE.

[0067] In some embodiments, for a target UE and a co-scheduled UE, up to 4 or 8 DMRS ports can be indicated for a single UE.

[0068] The methods and implementations of the 6 disclosed technologies Embodiments of the disclosed technology provide an example method for wireless communication, wherein a UE is configured to receive an indication from a gNB, wherein the indication indicates information about DMRS, determine the indicated DMRS port and the DMRS port of the co-scheduled DMRS port, and perform DMRS demodulation based on the indicated information. In this example: – The number of DMRS ports that can be shared for DMRS port scheduling is limited; – Restrict all co-scheduled DMRS ports to follow the same scheduling restriction rules. For example, all co-scheduled UEs should have the same ability to restrict the scheduling of DMRS of length 4. – Restrict all other co-scheduled DMRS from scheduling in the same CDM group on overlapping PRBs; – All other co-scheduled DMRS ports in the same CDM group as the target DMRS port must have an orthogonal OCC to the target DMRS port, where the orthogonal OCC is the first two components of an FD-OCC of length 4; – The scheduling constraint is that the number of consecutive PRBs must be even, and the PRB offset from reference point A must be even. – The co-scheduled DMRS port has an odd PRB offset relative to the target DMRS.

[0069] – The information includes at least one of the following: – DMRS port index of the target DMRS port; – Does the co-scheduled DMRS port of length 4 have an odd PRB offset relative to the target DMRS port? – The granularity overlaps with other scheduled DMRS ports, where the granularity is an even number of PRBs, one or more RBGs, or one or more PRGs.

[0070] – The information includes 1 bit in MAC CE or DCI; – The information includes a bitmap, with each bit associated with a granularity; – The information includes information used to indicate a granularity. Bit; – The information includes PRG bindings configured via RRC or predefined, and the PRG bindings include at least one PRG with overlapping granularity; – The information in the DCI indicates whether the target DMRS port and the co-scheduled DMRS have the same sequence and the MCS order of the data transmission associated with the co-scheduled DMRS port; – Configure 3 bits when 256 QAM or 1024 QAM is supported; and / or – Configure 2 bits when 256 QAM or 1024 QAM is not supported.

[0071] Figure 6A A flowchart of an exemplary wireless communication method 600 is shown. Method 600 includes, at operation 602, a first wireless device receiving a first indication from a network node, the first indication indicating information related to a first set of demodulation reference signals (DMRS) ports of the first wireless device.

[0072] Method 600 includes, at operation 604, identifying the first set of DMRS ports indicated in the first instruction.

[0073] Method 600 includes, at operation 606, performing a demodulation operation of a first DMRS based on at least a first set of DMRS ports.

[0074] Figure 6B A flowchart of another exemplary wireless communication method 610 is shown. Method 610 includes, at operation 612, a network node sending a first instruction to a first wireless device, the first instruction indicating information related to a first set of demodulation reference signal (DMRS) ports of the first wireless device. As part of method 610, the wireless device is instructed to determine the first set of DMRS ports indicated in the first instruction and to perform a demodulation operation of the first DMRS based on at least the first set of DMRS ports.

[0075] Among other things, the disclosed embodiments also provide the following technical solutions: 1. A wireless communication method, comprising: a first wireless device receiving a first indication from a network node, the first indication indicating information related to a first set of demodulation reference signal (DMRS) ports of the first wireless device; determining the first set of DMRS ports indicated in the first indication; and performing a demodulation operation on the first DMRS based on at least the first set of DMRS ports.

[0076] 2. A wireless communication method, comprising: a network node sending a first instruction to a first wireless device, the first instruction indicating information related to a first set of demodulation reference signal (DMRS) ports of the first wireless device, wherein the first wireless device is instructed to: determine the first set of DMRS ports indicated in the first instruction, and perform a demodulation operation on the first DMRS based on at least the first set of DMRS ports.

[0077] 3. The method according to scheme 1 or 2, wherein the first wireless device and the second wireless device are jointly scheduled, wherein the second indication indicates information related to the second set of DMRS ports of the second wireless device, wherein the second set of DMRS ports is associated with a second DMRS, and wherein the first set of DMRS ports or the second set of DMRS ports is subject to restriction rules.

[0078] 4. The method according to Scheme 3, wherein the limiting rule specifies that the length of the frequency domain orthogonal coverage code (FD-OCC) of the first DMRS is 4 and the length of the FD-OCC of the second DMRS is 4, and wherein the first DMRS and the second DMRS are configured as type 1.

[0079] 5. The method according to Scheme 3, wherein the limiting rule specifies that when the first group of DMRS ports and the second group of DMRS ports partially overlap on at least one physical resource block (PRB), and wherein the first DMRS and the second DMRS are scheduled in different code division multiplexing (CDM) groups.

[0080] 6. The method according to Scheme 3, wherein the limiting rule specifies that when the first DMRS and the second DMRS are in the same code division multiplexing (CDM) group, the first DMRS and the second DMRS include mutually orthogonal orthogonal covering codes, and wherein the orthogonal covering code includes the first two components or the last two components of a frequency domain orthogonal covering code of length 4.

[0081] 7. The method according to Scheme 3, wherein the limiting rule specifies that each of the first group of DMRS ports and the second group of DMRS ports is at least one of the following: scheduled with an even number of consecutive physical resource blocks (PRBs), or using a PRB offset starting from an even number of reference PRB positions for consecutive PRBs, or using an even number of PRB offsets starting from (i) the first scheduled PRB, (ii) the first scheduled PRB in a precoded resource block group (PRG), or (iii) the first PRB in one or more consecutive scheduled PRBs between the first and second wireless devices.

[0082] 8. The method according to Scheme 3, wherein the limiting rule specifies that the physical resource block (PRB) offset between the first DMRS and the second DMRS is odd, and wherein the PRB offset is compared with (i) the PRB of the first schedule, (ii) the PRB of the first schedule in a precoded resource block group (PRG), or (iii) the first PRB in one or more consecutively scheduled PRBs between the first radio device and the second radio device.

[0083] 9. The method according to scheme 1 or 2, wherein the first wireless device is not co-scheduled with the second wireless device, wherein the second indication indicates information related to a second set of DMRS ports of the second wireless device, wherein the second set of DMRS ports is associated with a second DMRS, and wherein each of the first set of DMRS ports and the second set of DMRS ports is configured as type 1 and associated with a frequency domain orthogonal coverage code (FD-OCC) of length 4.

[0084] 10. The method according to Scheme 9, wherein the second group of DMRS ports is scheduled to have at least one of the following conditions: the physical resource blocks (PRBs) scheduled or consecutively scheduled for the first and second wireless devices do not completely overlap; or the offset of the first scheduled PRB between the first and second wireless devices, the first PRB in one or more consecutively scheduled PRBs, or the first scheduled PRB in a precoded resource block group (PRG) of a physical downlink shared channel (PDSCH) is odd; or the first group of DMRS ports belongs to the same DMRS code division multiplexing (CDM) group as the first group of DMRS ports; or the sub-FD-OCC of length 4 between the first and second wireless devices is non-orthogonal to the FD-OCC of length 2.

[0085] 11. The method according to Scheme 9, wherein the second group of DMRS ports is scheduled to have: (a) the physical resource blocks (PRBs) scheduled or consecutively scheduled for the first and second wireless devices do not completely overlap; (b) the DMRS ports of the first and second wireless devices come from the same DMRS code division multiplexing (CDM) group; (c) the offset of the first scheduled PRB between the first and second wireless devices, the first PRB of consecutively scheduled PRBs, or the first scheduled PRB in a precoded resource block group (PRG) of a physical downlink shared channel (PDSCH) is odd; and (d) the sub-FD-OCC of a frequency domain (FD)-orthogonal cover code (OCC) of length 4 between the first and second wireless devices is non-orthogonal.

[0086] 12. The method according to scheme 10 or 11, wherein the FD-OCC with a sub-length of 2 includes [ w f (0), wf (1) ]or[ w f (2), w f (3) ].

[0087] 13. The method according to claim 1 or 2, wherein the information includes at least one of the following: a DMRS port index of a first DMRS, a DMRS type of enhanced DMRS type 1 having a frequency domain (FD)-orthogonal coverage code (OCC) of length 4, an indication of whether the physical resource block (PRB) offset of length 4 between the first DMRS and one of the other wireless devices is odd, a granularity specifying the amount of overlap between the first DMRS and the DMRS of another of the other wireless devices, a single bit in a media access control (MAC) control element (CE) or downlink control information (DCI), a bitmap including one or more bits, wherein each of the one or more bits is associated with a first granularity, or a predetermined number of bits indicating a second granularity.

[0088] 14. The method according to Scheme 13, wherein the granularity is at least one of the following: an even number of PRBs, one or more resource block groups (RBGs), or one or more precoded resource block groups (PRGs).

[0089] 15. The method according to scheme 13, wherein the predetermined number of bits is ,in The number of granularities supported.

[0090] 16. The method according to scheme 1 or 2, wherein the information includes precoded resource block group (PRG) bindings, which include at least one PRG with overlapping granularity.

[0091] 17. The method according to Scheme 16, wherein the PRG binding is specified or predefined in the Radio Resource Control (RRC) configuration.

[0092] 18. The method according to Scheme 1 or 2, wherein the downlink control information (DCI) or media access control (MAC) control element (CE) includes information including at least one of the following: indicating whether the first set of DMRS ports has the same sequence as the second set of DMRS ports of another wireless device, or the modulation and coding scheme (MCS) order of the data transmission associated with the second set of DMRS ports.

[0093] 19. The method according to Scheme 18, wherein when the configuration indicates that the quadrature amplitude modulation (QAM) includes 256-QAM or 1024-QAM, the information is indicated by 3 bits.

[0094] 20. The method according to Scheme 18, wherein when the configuration does not indicate that the quadrature amplitude modulation (QAM) includes 256-QAM or 1024-QAM, the information is indicated by 2 bits.

[0095] 21. An apparatus for wireless communication, comprising a processor configured to implement one or more of the methods described in schemes 1 to 20.

[0096] 22. A non-transitory computer-readable program storage medium having code stored thereon, which, when executed by a processor, causes the processor to implement the method of any one of schemes 1 to 20.

[0097] Figure 7 An exemplary block diagram of a hardware platform 700 is shown. The hardware platform may be part of a network device (e.g., a base station) or a communication device (e.g., a user equipment (UE)). The hardware platform 700 includes at least one processor 710 and a memory 705 storing instructions. When the instructions are executed by the processor 710, the hardware platform 700 is configured to execute. Figure 6A and 6B The operation of the various embodiments described in this patent document is also described. Transmitter 715 transmits or sends information or data to another device. For example, a network device transmitter can send a message to a user equipment. Receiver 720 receives information or data transmitted or sent by another device. For example, a user equipment can receive a message from a network device.

[0098] The above implementation will be applied to wireless communication. Figure 8 An example of a wireless communication system (e.g., a 5G or NR cellular network) is illustrated, comprising a base station 820 and one or more user equipments (UEs) 811, 812, and 813. In some embodiments, the UE accesses the BS (e.g., the network) using a communication link to the network (sometimes referred to as the uplink direction, as shown by dashed arrows 831, 832, and 833), and then subsequent communication from the BS to the UE (e.g., from the network to the UE, sometimes referred to as the downlink direction, as shown by arrows 841, 842, and 843). In some embodiments, the BS sends information to the UE (sometimes referred to as the downlink direction, as shown by arrows 841, 842, and 843), and then subsequent communication from the UE to the BS (e.g., from the UE to the BS, sometimes referred to as the uplink direction, as shown by dashed arrows 831, 832, and 833). The UE may be, for example, a smartphone, tablet, mobile computer, machine-to-machine (M2M) device, Internet of Things (IoT) device, etc.

[0099] Some embodiments described herein are described in the general context of a method or process that may be implemented in one embodiment as a computer program product embodied in a computer-readable medium, including computer-executable instructions, such as program code executable by a computer in a networked environment. The computer-readable medium may include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), optical disc (CD), digital versatile optical disc (DVD), etc. Therefore, the computer-readable medium may include non-transitory storage media. Typically, program modules may include routines, programs, objects, components, data structures, etc., that perform a particular task or implement a particular abstract data type. Computer or processor-executable instructions, associated data structures, and program modules represent examples of program code for performing the method steps disclosed herein. A particular sequence of executable instructions or associated data structures represents examples of corresponding actions for implementing the functionality described in the steps or process.

[0100] Some of the disclosed embodiments can be implemented as devices or modules using hardware circuitry, software, or a combination thereof. For example, a hardware circuitry implementation may include discrete analog and / or digital components, such as those integrated as part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as application-specific integrated circuits (ASICs) and / or field-programmable gate arrays (FPGAs). Some implementations may additionally or alternatively include a digital signal processor (DSP), a special-purpose microprocessor whose architecture is optimized for the operational requirements of digital signal processing associated with the functions disclosed herein. Similarly, the various components or sub-components within each module may be implemented in software, hardware, or firmware. Interconnectivity between modules and / or between components within a module may be provided using any connectivity methods and media known in the art, including but not limited to communications via the Internet, wired, or wireless networks using appropriate protocols.

[0101] While this document contains numerous specific details, these should not be construed as limiting the scope of the claimed invention or the content that may be claimed, but rather as descriptions of specific features of particular embodiments. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, although the foregoing features may be described as operating in certain combinations, or even initially claimed in this way, in some cases one or more features may be removed from the claimed combination, and the claimed combination may point to a sub-combination or a variation of the sub-combination. Similarly, although operations are depicted in a specific order in the drawings, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or to perform all illustrated operations to achieve the desired result.

[0102] Only some implementations and examples are described. Other implementations, enhancements and variations can be made based on what is described and illustrated in this disclosure.

Claims

1. A wireless communication method, comprising: The first wireless device receives a first indication from a network node, the first indication indicating information related to a first set of demodulation reference signal (DMRS) ports of the first wireless device. Identify the first group of DMRS ports indicated in the first instruction; as well as Demodulation is performed on the first DMRS based on at least the first set of DMRS ports.

2. A wireless communication method, comprising: The network node sends a first instruction to the first wireless device, the first instruction indicating information related to the first set of demodulation reference signals (DMRS) ports of the first wireless device. The first wireless device is instructed to: Determine the first group of DMRS ports indicated in the first instruction, and Demodulation is performed on the first DMRS based on at least the first set of DMRS ports.

3. The method according to claim 1 or 2, wherein the first wireless device and the second wireless device are co-scheduled, wherein the second indication indicates information related to a second set of DMRS ports of the second wireless device, wherein the second set of DMRS ports is associated with a second DMRS, and wherein the first set of DMRS ports or the second set of DMRS ports is subject to restriction rules.

4. The method of claim 3, wherein the limiting rule specifies that the length of the frequency domain orthogonal cover code (FD-OCC) of the first DMRS is 4 and the length of the FD-OCC of the second DMRS is 4, and wherein the first DMRS and the second DMRS are configured as type 1.

5. The method of claim 3, wherein the limiting rule specifies that when the first group of DMRS ports and the second group of DMRS ports partially overlap on at least one physical resource block (PRB), and wherein the first DMRS and the second DMRS are scheduled in different code division multiplexing (CDM) groups.

6. The method of claim 3, wherein the limiting rule specifies that when the first DMRS and the second DMRS are in the same code division multiplexing (CDM) group, the first DMRS and the second DMRS include mutually orthogonal orthogonal covering codes, and wherein the orthogonal covering code includes the first two components or the last two components of a frequency domain orthogonal covering code of length 4.

7. The method of claim 3, wherein the limiting rule specifies that each of the first group of DMRS ports and the second group of DMRS ports is at least one of the following: Scheduled using an even number of contiguous physical resource blocks (PRBs), or For the consecutive PRBs, use an even PRB offset from the reference PRB position, or Use an even-numbered PRB offset from (i) the first scheduling PRB, (ii) the first scheduling PRB in a precoded resource block group PRG, or (iii) the first PRB in one or more consecutive scheduling PRBs between the first radio device and the second radio device.

8. The method of claim 3, wherein the limiting rule specifies that the physical resource block (PRB) offset between the first DMRS and the second DMRS is odd, and the PRB offset is compared with one of: (i) a first scheduled PRB, (ii) the first scheduled PRB in a precoded resource block group (PRG), or (iii) the first PRB of one or more consecutive scheduled PRBs between the first radio device and the second radio device.

9. The method of claim 1 or 2, wherein the first wireless device is not co-scheduled with the second wireless device, wherein the second indication indicates information related to a second set of DMRS ports of the second wireless device, wherein the second set of DMRS ports is associated with a second DMRS, and wherein each of the first set of DMRS ports and the second set of DMRS ports is configured as type 1 and associated with a frequency domain orthogonal coverage code FD-OCC of length 4.

10. The method of claim 9, wherein the second group of DMRS ports is scheduled to have at least one of the following: For scheduling or consecutive scheduling of non-fully overlapping Physical Resource Blocks (PRBs) for the first and second wireless devices, or The offset of the first scheduled PRB of the Physical Downlink Shared Channel (PDSCH) between the first wireless device and the second wireless device, the first PRB of one or more consecutive scheduled PRBs, or the offset of the first scheduled PRB in a precoded resource block group (PRG) is odd. The same DMRS code division multiplexing (CDM) group as the first DMRS port, or The sub-FD-OCCs of length 4 between the first and second wireless devices are non-orthogonal.

11. The method of claim 9, wherein the second group of DMRS ports is scheduled to have: (a) Physical Resource Blocks (PRBs) that are not fully overlapping and are scheduled or consecutively scheduled for the first and second wireless devices. (b) The DMRS ports of the first and second wireless devices originate from the same DMRS code division multiplexing (CDM) group. (c) The offset of the first scheduled PRB, the first PRB of a consecutively scheduled PRB, or the first scheduled PRB in a precoded resource block group (PRG) of the Physical Downlink Shared Channel (PDSCH) between the first and second wireless devices is odd. (d) The frequency domain orthogonal cover code (FD-OCC) with a sub-length of 2 of the FD-OCC with a length of 4 between the first and second wireless devices is non-orthogonal.

12. The method of claim 10 or 11, wherein the FD-OCC with a sub-length of 2 comprises [ w f (0), w f (1) ]or[ w f (2), w f (3) ].

13. The method according to claim 1 or 2, wherein the information includes at least one of the following: DMRS port index of the first DMRS. The DMRS type is an enhanced DMRS type 1 with a frequency domain orthogonal coverage code FD-OCC of length 4. An indication of whether the Physical Resource Block (PRB) offset between the first DMRS and one of the other radio devices with a DMRS of length 4 is odd. The granularity of the overlap between the first DMRS and the DMRS of one of the other wireless devices. A single bit in the Media Access Control (MAC) control element (CE) or Downlink Control Information (DCI). A bitmap comprising one or more bits, wherein each of the one or more bits is associated with a first granularity, or Indicates a predetermined number of bits for the second granularity.

14. The method of claim 13, wherein the granularity is at least one of the following: an even number of PRBs, one or more resource block groups (RBGs), or one or more precoded resource block groups (PRGs).

15. The method of claim 13, wherein the predetermined number of bits is ,in It represents the number of granularities supported.

16. The method of claim 1 or 2, wherein the information includes precoded resource block group (PRG) bindings, the PRG bindings including at least one PRG with overlapping granularity.

17. The method of claim 16, wherein the PRG binding is specified or predefined in the Radio Resource Control (RRC) configuration.

18. The method of claim 1 or 2, wherein the downlink control information (DCI) or media access control (MAC) control element (CE) includes the information, the information including at least one of the following: Does the first set of DMRS ports have the same sequence indication as the second set of DMRS ports of another wireless device? The modulation and coding scheme (MCS) order of the data transmission associated with the second set of DMRS ports.

19. The method of claim 18, wherein when the configuration indicates that the quadrature amplitude modulation (QAM) comprises 256-QAM or 1024-QAM, the information is indicated by 3 bits.

20. The method of claim 18, wherein when the configuration does not indicate that the quadrature amplitude modulation (QAM) comprises 256-QAM or 1024-QAM, the information is indicated by 2 bits.

21. An apparatus for wireless communication, comprising a processor configured to implement the method according to any one of claims 1 to 20.

22. A non-transitory computer-readable program storage medium having code stored thereon, which, when executed by a processor, causes the processor to perform the method according to any one of claims 1 to 20.

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