Apparatus, method and computer program

Abstract

The present disclosure relates to apparatuses, methods, and computer programs. An apparatus is provided that includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least receive, from a network, an indication of a first beta value for transmitting an overlay reference signal for a first time period and a scaling factor for transmitting the overlay reference signal in a subsequent time period, and an indication of a value of the time period, where beta indicates a power allocated to the overlay reference signal, determine a number m of the time periods based on the first beta value and the scaling factor, and determine M' for a coherence block size of N subcarriers and M orthogonal frequency division multiplexing, OFDM, symbols based on the first beta value, m, the value of the time period, and the scaling factor, where M'≤M.

Description

Technical Field

[0001] Various embodiments of this disclosure generally relate to methods, apparatus, and computer programs, and specifically, but not exclusively, to superimposed reference signals. Background Technology

[0002] A communication system can be viewed as a facility that enables communication sessions between two or more communication devices or provides communication devices with access to a network. Mobile or wireless communication networks are an example of communication networks. Services can be provided to communication devices by an application server.

[0003] Mobile or wireless communication networks can operate according to multiple standards, such as those provided by 3GPP (3rd Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of mobile or wireless communication networks operating according to 3GPP standards are often referred to as 4G (fourth generation) networks, 5G (fifth generation) networks, 5G Advanced networks, and 6G networks. Summary of the Invention

[0004] Some embodiments of this disclosure will be described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the various exemplary embodiments of this disclosure, nor are they intended to limit its scope. Other features, aspects, and elements will be apparent to those skilled in the art in light of this disclosure. For example, it should be understood that additional aspects may be provided by any combination of any two or more of the aspects described herein.

[0005] In a first aspect, a method is provided, comprising: receiving from a network an indication of a first β value, a value of a time period, and a reduction factor associated with the first β value, wherein the β indication is a power allocated to a superimposed reference signal; receiving from the network a superimposed reference signal, the superimposed reference signal being transmitted for a first time period with the first β value and being transmitted in subsequent time periods with β values ​​based on the first β value and the reduction factor; and obtaining a channel estimate based on the received superimposed reference signal, the reduction factor, and the value of the time period.

[0006] The method may include receiving indications of a first β value, a time period value, and a reduction factor in a media access control (MAC), control element, or downlink control information.

[0007] Indications for the first β value and the reduction factor associated with the first β value may include an index of the normalization table.

[0008] The standardization table can be associated with the superimposed reference signal configuration type.

[0009] β can indicate the ratio between the power of the superimposed reference signal assigned to each resource element and the power of the data of each resource element without a superimposed reference signal.

[0010] The value of the time period can include the number of OFDM symbols, and the value of β is constant for OFDM symbols.

[0011] The method may include providing the network with an indication of a superimposed reference signal that supports the acquisition of channel estimation, supporting β min At least one value of β, where β min Each value has an associated K value, where K is the number of resource elements, and each resource element carries an associated β. min To obtain the reference signal required for channel estimation, and β min It is the minimum value of β.

[0012] K can be equal to 1 / β min .

[0013] Indications supporting the superimposed reference signal used to obtain channel estimation may include an index of a second normalization table.

[0014] In a second aspect, a method is provided, comprising: providing a user equipment with an indication of a first β value, a value for a time period, and a reduction factor associated with the first β value, wherein the β indication is the power allocated to a superimposed reference signal; and providing the user equipment with a superimposed reference signal for a time period at the first β value and at a β value based on the first β value and the reduction factor in subsequent time periods.

[0015] The method may include providing indications of a first β value, a time period value, and a reduction factor in the Media Access Control (MAC), control element, or downlink control information.

[0016] Indications for the first β value and the reduction factor may include an index of the normalization table.

[0017] The standardization table can be associated with the superimposed reference signal configuration type.

[0018] β can indicate the ratio between the power of the superimposed reference signal allocated to each subcarrier and the power of the data resource element without a superimposed reference signal.

[0019] The value of the time period can include the number of OFDM symbols, and the value of β is constant for OFDM symbols.

[0020] In a third aspect, a method is provided, comprising: receiving from a network an indication of a first β value for transmitting a superimposed reference signal for a first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods, and an indication of the value of the time periods, wherein β indicates the power allocated to the superimposed reference signal; determining a number m of time periods based on the first β value and the reduction factor; and determining M' for a coherent block size of N subcarriers and M orthogonal frequency division multiplexing (OFDM) symbols, based on the first β value, m, the value of the time periods, and the reduction factor, wherein M' ≤ M.

[0021] This time period can include the number of OFDM symbols, and the value of β is constant across OFDM symbols.

[0022] This method may include providing the network with indications of N and M.

[0023] Indications for N and M can be provided in the user equipment auxiliary information.

[0024] The method may include performing up to m iterations of channel estimation based on the received superimposed reference signal.

[0025] In the fourth aspect, it provides a coherent block size for determining N subcarriers and M OFDM symbols for the superimposed reference signal position; and receives β values ​​from the user equipment for the superimposed reference signal. min The at least one value of β is indicated by the superimposed reference signal to obtain the channel estimate, where β min Each value has an associated K value, where K is the number of resource elements, and each resource element carries an associated β. min To obtain the reference signal required for channel estimation, and β min It is the minimum value of β, and β indicates the power assigned to the superimposed reference signal; for a given value of β and based on M, N, at least one β min And the associated K, determine the number of time periods m; determine the value of the time period based on m and M; based on the received pair β min The instructions of K determine a first β value for transmitting a superimposed reference signal for a first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods; and provide the user equipment with instructions on the first β value, the value of the time period, and the reduction factor.

[0026] Determining the coherent block size may include receiving indications for N and M from the user equipment.

[0027] Instructions for N and M can be received in the user equipment auxiliary information.

[0028] The time period can include the number of OFDM symbols, and the value of β is constant across OFDM symbols.

[0029] In a fifth aspect, an apparatus is provided, comprising components for performing the method according to the first, second, third, or fourth aspect.

[0030] In a sixth aspect, an apparatus is provided, comprising at least one processor and at least one memory storing instructions, the instructions, when executed by the at least one processor, causing the apparatus to perform at least the method according to the first, second, third, or fourth aspect.

[0031] In a seventh aspect, a non-transitory computer-readable medium including instructions is provided, wherein when executed by at least one processor of the device, the instructions cause the device to perform the method according to the first, second, third, or fourth aspect.

[0032] In an eighth aspect, a computer program including instructions is provided that, when executed by a device, causes the device to perform at least the method according to the first, second, third, or fourth aspect.

[0033] Some embodiments of the present invention are defined in the dependent claims.

[0034] Many different aspects have been described above. As previously stated, it should be understood that additional aspects may be provided by combination of any two or more of the above-described aspects (or otherwise in this disclosure).

[0035] Various other aspects are also described in the following detailed description and claims.

[0036] Brief description of the attached figures Some embodiments will be described by way of non-limiting and illustrative example only with reference to the accompanying drawings, wherein: Figure 1 An example of a communication network to which the examples disclosed herein can be applied is shown; Figure 2 An example SU-RS scheme with type 2 DMRS is shown, where data and RS are superimposed on RE on a DMRS symbol; Figure 3 A PDSCH processing pipeline with a preloaded DMRS having a HARQ Ack time (K1) of 1 time slot is shown; Figure 4 A flowchart based on the example method is shown; Figure 5 A flowchart based on the example method is shown; Figure 6 A flowchart based on the example method is shown; Figure 7 A flowchart based on the example method is shown; Figure 8 An example signaling diagram between the UE and the network is shown; Figure 9 An example of the device is shown. Detailed Implementation

[0037] The following embodiments are provided by way of non-limiting and illustrative example. Although the specification may refer to "a," "an," or "some" embodiments in several places in the text, this does not necessarily mean that the same embodiment is referred to every time, or that a particular feature applies only to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is intended that such a feature, structure, or characteristic may be applied in conjunction with other embodiments, whether explicitly described or not.

[0038] It should be understood that although the terms "first," "second," etc., may be used in this document to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0039] For the purposes of this disclosure, the phrases "at least one of A or B", "at least one of A and B", and "A and / or B" mean (A), (B), or (A and B). For the purposes of this disclosure, the phrases "A, B, and / or C" mean (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0040] As used herein, the term “or” means non-exclusive “or” unless otherwise stated (e.g., “otherwise” or “or in alternatives”).

[0041] As used herein, unless explicitly stated otherwise, performing a feature, step, or function in response to A does not indicate that the feature, step, or function is performed immediately after A occurs, because one or more intermediate features, steps, or functions may be performed (at least partially) between the occurrence of the feature, step, or function and A. Similarly, performing a feature, step, or function based on A does not indicate that the feature, step, or function is performed solely based on A, because the feature, step, or function may also be based on one or more other features, steps, or functions besides A.

[0042] The embodiments described herein can be implemented in communication networks such as any of the following radio access technologies (RATs): Global Microwave Access Interoperability (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunications System based on Basic Wideband Code Division Multiple Access (W-CDMA) (UMTS, 3G), High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), Advanced LTE and Enhanced LTE (eLTE), 5G (also known as NR), or any future RAT (such as 6G). Furthermore, communication within the communication network can utilize any suitable wireless communication technology, including but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), and / or Discrete Fourier Transform Extended OFDM (DFT-s-OFDM).

[0043] As used herein, the term "network device" or "network node" refers to a node in a communications network through which user equipment can access the network and / or be configured to control radio communications and manage radio resources within a cell. A network node or network device may be referred to as a base station (BS), access point (AP), or access node. Depending on the technology applied, a network device may be, for example, a B node (B node or NB), an evolved B node (eNB), an NR NB (also known as a gNB), a remote radio unit (RRU), a radio headend (RH), a remote radio headend (RRH), a relay, an integrated access and backhaul (IAB) node, a low-power node, a non-terrestrial network (NTN) or non-terrestrial network equipment (such as satellite network equipment, low Earth orbit (LEO) satellites, and geostationary Earth orbit (GEO) satellites), or an aircraft network device.

[0044] Furthermore, in the context of split radio access networks (RAN), network equipment can refer to a centralized unit (CU) and / or a distributed unit (DU) of a base station. The interface between the CU and DU may be referred to as the F1 interface in NR. In a split RAN architecture, node operations can be performed at least partially in a central / centralized unit (CU, e.g., a server, host, or node) that is operatively coupled to a DU (e.g., a radio head / node). A CU can control one or more DUs, at least acting as a transmit / receive (Tx / Rx) node. In some embodiments, a DU may include, for example, a Radio Link Control (RLC), a Media Access Control (MAC) layer, and a Physical (PHY) layer, while a CU may include layers above the RLC layer, such as the Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC), and Internet Protocol (IP) layer. Other functional splits are also possible. In practice, any processing task can be performed in a CU or DU, and the boundaries of responsibility transfer between the CU and DU may depend on the applied implementation.

[0045] The term "terminal device" refers to any terminal device that can be configured to perform wireless communication. For example, a terminal device may be referred to as a communication device, user equipment (UE), subscriber station (SS), or mobile station (MS). Terminal devices may include mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, USB dongles, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, and so on.

[0046] As used herein, the term "resource" can refer to radio resources in the time domain, frequency domain, spatial domain, and / or code domain. Some examples of resources may include, for example, physical resource blocks (PRBs), radio frames, subframes, time slots, subbands, frequency regions, subcarriers, beams, etc. The terms "transmit" and / or "receive" can refer to wireless transmission and / or reception over radio resources via a radio propagation channel.

[0047] Figure 1An example of a communication network to which the examples disclosed herein can be applied is shown. The communication network, or cellular communication network, may include a network node 110 configured to provide one or more cells, such as cell 100, and a network node 112 configured to provide one or more other cells, such as cell 102. For example, each cell may be a macrocell, microcell, femtocell, or picocell. A cell may define the coverage area or service area of ​​a corresponding access node.

[0048] Network nodes (110, 112) can be configured to provide radio access to a communication network to user equipment (UE) 120 (one or more UEs). Radio access may include downlink (DL) communication from network nodes (110, 112) to UE 120 and uplink (UL) communication from UE 120 to network nodes (110, 112). Examples of uplink channels may include a Physical Uplink Control Channel (PUCCH) for transmitting control information and a Physical Uplink Shared Channel (PUSCH) for transmitting data to the network. Examples of downlink channels may include a Physical Downlink Control Channel (PDCCH) for transmitting control information and a Physical Downlink Shared Channel (PDSCH) for transmitting data to the user equipment.

[0049] Multiple UEs (120, 122) can exist in the system. Each of the multiple UEs can be served by the same or different network nodes (110, 112). UEs can be configured with dual connectivity (DC), where a UE (e.g., UE 120) can connect to multiple network nodes (110, 112). UEs (120, 122) can communicate with each other to establish a device-to-device (D2D) communication interface between them via a so-called side link (SL). For example, such D2D communication can be referred to as machine-to-machine, end-to-end (P2P) communication, or vehicle-to-vehicle (V2V) communication.

[0050] In a communication network with multiple network nodes, these nodes can connect to each other via interfaces. For example, the LTE specification refers to this interface as the X2 interface. The interface between an LTE node and a 5G node, or between two 5G nodes, can be called the Xn interface.

[0051] Network nodes 110 and 112 can also connect to the core network 116 of the communication network via another interface. The LTE specification designates the core network as the Evolved Packet Core (EPC), and the core network can include multiple entities (e.g., Mobility Management Entity (MME) and gateway nodes). The MME can handle the mobility of terminal devices in a tracking area containing multiple cells and handle signaling connections between the terminal devices and the core network. The gateway node can handle data routing in the core network to / from the terminal devices. The 5G specification designates the core network as the 5G Core (5GC). The 5GC can, for example, include Access and Mobility Management Functions (AMF) and User Plane Functions / Gateways (UPF), as well as other functions. The AMF can handle the termination of Non-Access Stratum (NAS) signaling, NAS encryption & integrity protection, registration management, connection management, mobility management, access authentication and authorization, and security context management. UPF nodes can, for example, support packet routing and forwarding, packet inspection, and Quality of Service (QoS) processing.

[0052] Traditional OFDM-based waveforms have certain subcarriers carrying a known reference signal (RS) at known frequency and time locations, which the receiver uses to estimate a multiple-input multiple-output (MIMO) channel. However, this can lead to a loss of spectral efficiency because these subcarriers are dedicated to the frequency and time resources carrying the RS.

[0053] Superimposed pilots (SP) or superimposed reference signals (SU-RS) add pilots on top of data symbols using a power control factor, thereby reducing pilot symbol overhead without requiring dedicated resources for RS and providing higher achievable throughput. Figure 2 In the example shown, the type 2 DMRS symbol also carries data (e.g., the Physical Downlink Data Sharing Channel (PDSCH) or the Physical Uplink Data Sharing Channel (PUSCH)).

[0054] The frequency domain description of the SU-RS scheme is given by the following formula. (1) in, It is an N×L matrix of symbols that modulate N subcarriers of an OFDM symbol across L layers. It is an N×N diagonal matrix, with 1s at the positions carrying SU-RS and 0s elsewhere. It is an N×N identity matrix. It is an N×L matrix of data symbols extracted from the M-QAM constellation. For each layer of RS symbols, there is an L×N matrix of L vectors, and It is the ratio between the power of the superimposed pilot allocated to each subcarrier and the power of the data RE without any SU-RS.

[0055] In the SU-RS scheme, channel estimation is affected by the superposition of data and RS. This occurs when there is power... In the case of data symbols, L layers of subcarriers Least squares estimation of the channel at point It can be given as (2) in In subcarrier The L×1 vector of the pilot signals transmitted from each layer is given. It is the received signal on a specific receiving antenna on that subcarrier, and It is the estimated thermal noise power.

[0056] Data symbols used as interference are treated as white noise. However, this is not feasible in practice and can lead to degraded channel estimation. A general approach to improving channel estimation quality is to estimate the channel based on the average power of the received signal at the resource element location associated with the RS. For example, if the same RS symbol in If an OFDM symbol is repeated, then for these... Averaging the received signals at each RS position results in averaging the data symbols at each layer, and it can be assumed that their power is the average of the M-QAM constellation used to modulate the data bits. In this case, the least squares estimate can be written as... (3) in yes The average value of the signal received at each RS location, where it can be assumed that the channel is the same. It is the average value of the M-QAM constellation used to modulate the data.

[0057] When pilot signals are superimposed, data demodulation is an iterative process requiring complex signal processing. Demodulation can be summarized into the following steps: 1) For each receiving antenna, initialize the received signal at the SP position for the next iteration, e.g., .

[0058] 2) Based on Channel estimation for each receive antenna .

[0059] 3) From Eliminating the product And by using Demodulation to obtain data The estimate.

[0060] 4) Settings = Proceed to step 2 for the next iteration. In 5G NR, the DMRS symbol preceding the PDSCH allocation is placed at the very beginning of the allocation process to allow for pipelined processing for faster channel estimation and PDSCH demodulation. This reduces the time spent generating HARQ ACK / NACK responses for the next possible uplink transmission opportunity. Figure 3 An example PDSCH processing pipeline with a one-slot HARQ Ack / Nack turnaround time is shown. Downlink DCI scheduling is also in the same slot. It can be seen that channel estimation for the preceding DMRS takes a significant amount of time, and PDSCH demodulation only begins after completion. For example, by using the same TX precoder (in the case of DMRS), the presence of data and pilots can be multiplexed on the same RE. This can lead to interference, posing challenges to both channel estimation and data demodulation. Superimposing pilots may require higher SINR per layer to achieve higher throughput for a given MCS.

[0061] To mitigate interference, complex receiver architectures employing iterative data demodulation and channel estimation can reduce the SINR requirements for achieving the higher throughput achievable with the SU-RS scheme. Furthermore, recent research using machine learning (ML)-based methods has demonstrated that these techniques can further reduce the SINR required to achieve higher throughput using the SU-RS scheme.

[0062] Obtaining good channel estimation using the SP scheme can involve whitening the superimposed data at multiple pilot locations within a coherent RE block spanning a certain bandwidth and the number M OFDM symbols. However, this can introduce delays in the processing of PDSCH slots because demodulation of the data cannot begin until all M OFDM symbols associated with a PDSCH transport block in a slot have been fully received. If iterative demodulation is used, it may introduce further delays and additional computational complexity for the required number of iterations.

[0063] Figure 4 A flowchart illustrating a method according to an example is shown. This method can be performed at a device. The device can be, include, or be included in the UE.

[0064] At 401, the method includes receiving from the network an indication of a first β value, a value of a time period, and a reduction factor associated with the first β value, wherein the β indication is the power assigned to the superimposed reference signal.

[0065] At 402, the method includes receiving a superimposed reference signal from the network, the superimposed reference signal being transmitted with a first β value for a first time period and with β values ​​based on the first β value and a reduction factor in subsequent time periods.

[0066] At 403, the method includes obtaining a channel estimate based on the received superimposed reference signal, the reduction factor, and the time period.

[0067] Figure 5 A flowchart illustrating a method according to an example is shown. This method can be performed at a device. The device can be, include, or be included in a node of the network, such as a RAN node, e.g., a gNB, or a network function (NF).

[0068] At 501, the method includes providing the user equipment with an indication of a first β value, a value for a time period, and a reduction factor associated with the first β value, wherein the β indication is the power assigned to the superimposed reference signal.

[0069] At 502, the method includes providing the user equipment with a superimposed reference signal for a time period at a first β value and for subsequent time periods at a β value based on the first β value and a reduction factor.

[0070] β can indicate the ratio between the power allocated to the superimposed reference signal for each subcarrier (or resource element) and the power of the data resource element without a superimposed reference signal. Indications to the first β value and the reduction factor associated with the first β value may include an index of a normalization table.

[0071] The standardized table can be referred to as the Energy Per Resource Element (EPRE) table. Table 1 shows an example of an EPRE table, whose first column contains multiple β values ​​for the first preceding SP OFDM symbol, starting from the lowest possible value. arrive The subsequent columns contain the SP for each subsequent time block. Value reduction factor For example, if =0.5, then each subsequent BS The β value in the symbol will decrease by 3 dB.

[0072]

[0073] Table 1 The maximum value β in the table maxCorresponding to the power allocation factor, under which the channel estimate can be obtained from the minimum possible coherent block spanning one reference signal symbol.

[0074] The standardized table can be associated with the configuration type of the superimposed reference signal. For example, an EPRE table can be designed for each configuration type (e.g., type 1, type 2).

[0075] In the example, the UE is signaled with an index for the configuration type in the EPRE table. Based on this index, the UE is then able to determine the β for the first time block and the reduction factor for subsequent time blocks.

[0076] Once the ratio drops below Therefore, the UE can assume that there will be no more SU-RS in subsequent time blocks. Thus, it can use... =1 is used to define multiple reduction factors, such that After M symbols, below , where M∈(1, 2, …, the maximum TDRA size of PDSCH).

[0077] The time period value can include the number of OFDM symbols over which the value of β remains constant. For example, a time period of size TP OFDM symbols can be notified to the UE. The value of β remains constant over one TP.

[0078] For reference Figure 2 The described method may include: providing the network with an indication of a superimposed reference signal that supports the acquisition of channel estimation, the support being β. min At least one value of β, where β min Each value has an associated K value, where K is the number of resource elements, and each resource element carries an associated β. min To obtain the reference signal required for channel estimation, and β min It is the minimum value of β.

[0079] Channel estimation based on SU-RS reception involves: an average value based on a certain number of SU-RS locations. The number of these locations depends on the power allocation factor. Its control allocates power to the SU-RS. The UE can instruct it to support a certain minimum. and The capability of SU-RS.

[0080] In one example, the network obtains The value of K is the number of resource elements carrying the reference signal (or pilot position), which is specified as β. minThe minimum value of β (e.g., 0.05) is needed to obtain the channel estimation. This can be a UE capability, where the UE indicates support for SU-RS reception. K can be the default value. In the example The value of K (which can be a default value or another value) can be provided in a second normalized table. An example of such a table is given in Table 2. For each β min The first entry is the default value for K.

[0081]

[0082] Table 2 Indications supporting the superimposed reference signal used to obtain channel estimation may include an index to a second normalized table. In the example, the UE selects from a predefined table (such as the one shown in Table 2). The value is specified, and the index of the entry in the table is transmitted to the network via signaling. The UE can transmit its support for SU-RS reception via signaling by indicating the index in the normalized table.

[0083] Based on the instructions given by the UE The value and gNB can be selected with appropriate values. and This enables channel estimation within the currently determined coherent block of the PDSCH time slot.

[0084] Figure 6 A flowchart illustrating a method according to an example is shown. This method can be performed at a device. The device can be, include, or be included in a node within a network such as a UE.

[0085] At 601, the method includes receiving from the network an indication of a first β value for transmitting a superimposed reference signal for a first time period and an indication of a reduction factor for transmitting the superimposed reference signal in subsequent time periods, and an indication of the value of the time period, wherein β indicates the power allocated to the superimposed reference signal.

[0086] At 602, the method includes determining the number of time periods m based on a first β value and a reduction factor.

[0087] At 603, the method includes determining M' for the coherent block size of N subcarriers and M orthogonal frequency division multiplexing (OFDM) symbols, based on a first β value, m, the value of the time period, and a reduction factor, where M' ≤ M.

[0088] Figure 7 A flowchart illustrating a method according to an example is shown. This method can be performed at a device. The device can be, include, or be included in a node of the network, such as a RAN node, e.g., a gNB, or a network function (NF).

[0089] At 701, the method includes determining the coherent block size of N subcarriers and M OFDM symbols for the location of the superimposed reference signal.

[0090] At 702, the method includes receiving from the user equipment a β value for the superimposed reference signal. min The at least one value of β is indicated by the superimposed reference signal to obtain the channel estimate, where β min Each value has an associated K value, where K is the number of resource elements, and each resource element carries an associated β. min To obtain the reference signal required for channel estimation, and β min It is the minimum value of β, and β indicates the power allocated to the superimposed reference signal.

[0091] At 703, the method includes a given value for β and is based on M, N, and at least one β. min And the associated K, determine the number of time periods m.

[0092] At 704, the method includes determining the value of the time period based on m and M.

[0093] At 705, the method includes: based on the received pair β min The instructions of K determine the first β value for transmitting the superimposed reference signal for the first time period and the reduction factor for transmitting the superimposed reference signal in subsequent time periods.

[0094] At 706, the method includes providing the user equipment with indications of a first β value, a time period value, and a reduction factor.

[0095] In the example, gNB determines the span across N subcarriers and OFDM symbol extension, Coherent blocks of SP-RS at various locations. Blocks can be selected based on current delay spread and Doppler shift estimates.

[0096] Determining the coherent block may include receiving indications for N and M from the user equipment. These indications for N and M can be received within the user equipment auxiliary information. For example, the UE may signal parameters. M serves as auxiliary information for the user experience (UE).

[0097] In one example, for a given value of β and based on M, N, at least one β min And the associated K, determining the number of time periods m includes: for a time period of size The coherent block of M requires K SU-RS positions with a power of β. min For the UE, the number of iterations for a given β possible channel estimation is given as follows:

[0098] In the example of determining the value of the time period TP, gNB selects... and The time period value can include the number of OFDM symbols with a constant β value. A symbol. Note .

[0099] β can indicate the ratio between the power of the superimposed reference signal allocated to each subcarrier (or resource element) and the power of the data resource element without a superimposed reference signal. In the example of determining the first β value, it is based on the selected time period. Choose The first value makes the cross OFDM symbols SU-RS provides sufficient power for one iteration of channel estimation. Therefore, =

[0100] In the example, = This is so that the UE can begin data demodulation after receiving the first preload SU-RS symbol, i.e. .

[0101] In the example, = This is so that the UE can begin data demodulation after receiving all OFDM symbols in the coherent block, i.e. '.

[0102] And configuration types (Type 1, Type 2) can be defined for each SU-RS. It is the power ratio required to obtain a good channel estimate by using all SPs available in the smallest possible coherent block with a certain coherent bandwidth corresponding to the maximum delay spread in one OFDM symbol. The value is a constant for a specific configuration and can be an index of Table 1.

[0103] In the example of determining the reduction factor, the reduction factor Chosen as to make in After a certain period of time Value lower than .

[0104] In the example where the number of time periods m is determined based on the first β value and the reduction factor, upon receiving the instruction / configuration... and At that time, the UE determines the number of time blocks. , making Each time block has OFDM symbols. This time period can include the number of OFDM symbols with a constant value of β.

[0105] In the example where the coherent block size for N subcarriers and M OFDM symbols is determined based on the first β value, m, the value of the time period, and the reduction factor, the UE determines the size of the coherent block selected by the network as follows: SU-RS locations and OFDM symbols. .

[0106] The method may include performing up to m iterations of channel estimation based on the received superimposed reference signal. For signals received in the PDSCH slot... For each time block of OFDM symbols, one iteration of channel estimation for each antenna port of SU-RS can be performed as follows: Reduction factor for each antenna port of SU-RS After compensation, it will be in SU-RS The signals received at each location are included in the averaging window. That is, the received signals at those SU-RS locations associated with the antenna port need to be averaged. To scale, where It is a time period number.

[0107] Obtain the SU-RS based on the average output. Antenna port-specific channel estimation at each location, as described by equation (3).

[0108] For other subcarrier locations excluding SP-RS, cross-frequency interpolation of antenna port-specific estimated channels.

[0109] One iteration of PDSCH demodulation can be based on The antenna port-specific channel estimation for each time block of each symbol is completed afterward.

[0110] Indications for the first β value, the time period value, and the reduction factor can be provided to the UE from the network in the Media Access Control (MAC) control element or downlink control information.

[0111] Figure 8 An example signaling flow between the network and the UE is shown.

[0112] In step 1, establish a target for β at the network and UE. minStandardized SU-RS tables for K (e.g., Table 2) and standardized SU-RS tables for β and rf (e.g., Table 1).

[0113] In step 2, the network sends a UE capability query to the UE.

[0114] In step 3, the UE sends UE capability information to the network, including providing β. min And the index of the K value in the SU-RS table. This provides the network with an indication of the superimposed reference signal used to obtain channel estimation, which supports β. min At least one value of β, where β min Each value has an associated K value, and the indications supporting the superimposed reference signal used to obtain the channel estimate include an index of the normalization table.

[0115] In step 4, the network establishes or reconfigures a periodic reference signal (e.g., NZP-CSI-RS).

[0116] In step 5, the UE sends UE assistance information to the network, which includes the coherent block size (M, N). This is an example of the UE providing an indication of N and M in the UE assistance information to the network.

[0117] In step 6, the network selects a value for TP to enable m channel estimation iterations, and selects β based on the values ​​of TP, K, and N. This is an example for the following: given a value for β and based on M, N, and at least one β... min The number of time periods m is determined by the associated K; the value of time period TP is determined based on m and M; and a first β value for transmitting the superimposed reference signal for the first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods are determined based on the received indications of βmin and K.

[0118] In step 7, the network provides the TP value and an index to the normalized SU-RS table for β and rf in the MAC CE. This provides the user equipment with an indication of a first β value, a value for a time period, and a reduction factor associated with the first β value in the MAC CE, where the β indication is the power assigned to the superimposed reference signal, and the indication of the first β value and the reduction factor includes an index to the normalized table.

[0119] At step 8, the UE determines the coherent block size (M', N) from β and rf. Here is an example of the following: for a coherent block size of N subcarriers and M OFDM symbols, M' is determined based on the first β value, TP, the value of the time period, and the reduction factor, where M' ≤ M.

[0120] In step 9, the network provides DCI 1_1 for scheduling PDSCH. The DCI may include optional indexes of the normalized SU-RS table for β and rf to cover MAC CE. This is an example of providing the user equipment with indications of a first β value and a reduction factor associated with that first β value in the DCI, where the β indication is the power assigned to the superimposed reference signal, and the indications of the first β value and the reduction factor include indexes of the normalized table.

[0121] In step 10, the network provides SU_RS to the PDSCH. This is an example of providing an overlay reference signal to the user equipment. The overlay reference signal will be provided with a first β value for this time period, and with β values ​​based on the first β value and a reduction factor in subsequent time periods.

[0122] At step 11, the UE performs iterative channel estimation, where averaging and β compensation are performed over N*TP SU-RS locations. This is an example of up to m iterations of channel estimation based on the received superimposed reference signal. Figure 9 A block diagram of device 10 is shown by way of example.

[0123] The apparatus 10 includes, for example, at least one processor 12 and at least one memory 14 storing instructions 15, which, when executed by the at least one processor, cause the apparatus 10 to perform at least one or more methods (or portions thereof) as disclosed herein, and any embodiments (or corresponding portions thereof). In the example, at least one memory and instructions (e.g., computer program code, software) are configured, together with at least one processor, to cause the apparatus 10 to perform one or more methods (or portions thereof) as disclosed herein, and any embodiments (or corresponding portions thereof).

[0124] The processor 12 may include circuitry, or be configured as one or more circuits, which are configured to perform phases of the method according to the embodiments described herein.

[0125] The term "circuit system" as used in this application may refer to one or more of the following: (a) a hardware circuit implementation only (such as an implementation in analog and / or digital circuits only) and (b) a combination of hardware circuits and software, such as (if applicable): (i) a combination of (multiple) analog and / or digital hardware circuits with software / firmware and (ii) any portion of (multiple) hardware processors having software (including (multiple) digital signal processors), software, and (multiple) memories, which work together to enable a device (such as a mobile phone or server) to perform various functions and (c) (multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or portions of (multiple) microprocessors, which require software (e.g., firmware) to operate, but may be absent when the software is not required to operate. The definition of circuit system applies to all uses of the term in this application, including any claim. As yet another example, as used in this application, the term circuit system also covers an implementation of hardware circuits or processors (or multiple processors) only, or a portion of hardware circuits or processors and their accompanying software and / or firmware. The term "circuit system" also covers, for example (and if applicable to certain claim elements), baseband integrated circuits or processor integrated circuits for mobile devices or similar integrated circuits in servers, cellular network devices or other computing or networking devices.

[0126] The memory 14 can be implemented using any suitable data storage technology. The memory may include a database for storing data. The memory 14 may be, for example, at least partially external to the device 10, but accessible by the device 10.

[0127] Instruction 15 may be included in a computer-readable medium or a non-transitory computer-readable medium. As used herein, the term non-transitory is a limitation on the medium itself (i.e., tangible, not signaling), rather than a limitation on the persistence of data storage (e.g., random access memory RAM and read-only memory ROM).

[0128] For example, device 10 is a terminal device, such as a UE. As another example, the device is included in such a terminal device, for example, as a chipset configured to control the terminal device. Device 10 may be caused, configured, or include functions for at least performing... Figure 4 or Figure 6 The methods and / or components of any one or more embodiments described herein.

[0129] For example, device 10 may be a network node, such as a RAN node (e.g., gNB) or a network function. As another example, the device is included in such a function, for example, as a chipset configured as a control node. Device 10 may be caused, configured, or include functions for at least performing... Figure 5 or Figure 7 The methods and / or components of any one or more embodiments described herein.

[0130] Device 10 includes a radio interface 16. The radio interface 16 can provide communication capabilities to device 10. The radio interface 16 may include a receiver configured to receive information according to at least one cellular or non-cellular standard. The radio interface 16 may include a transmitter configured to transmit information according to at least one cellular or non-cellular standard. The receiver may include more than one receiver. The transmitter may include more than one transmitter. The radio interface 16 may include a transceiver configured to receive and transmit information according to at least one cellular or non-cellular standard. The transceiver may include more than one transceiver.

[0131] Device 10 may include a user interface 18, which includes at least one of, for example, a keyboard, microphone, touch display, monitor, speaker, etc. User interface 18 can be used to control the device by a user. User interface 18 may be external to device 10. For example, device 10 may be connected to another device, such as a computer, via a wireless or wired connection, and device 10 may be controlled by a user via the computer.

[0132] In one embodiment, at least some of the processes described herein can be performed by means including components for performing at least some of the described processes. Components for performing the method steps disclosed herein may include software and / or hardware components of means 10. For example, at least one processor 12, memory 14, and computer program code form components for performing one or more methods (or portions thereof) disclosed herein, and any embodiment (or a corresponding portion thereof). As used herein, the term “component” should be interpreted in the singular form, referring to a single element, or in the plural form, referring to a combination of single elements. Therefore, the term “component for [performing A, B, C]” should be interpreted to cover means in which only one component for performing A, B, and C exists, or in which separate components for performing A, B, and C exist, or in which components for performing A, B, and C partially or completely overlap. Furthermore, the terms “component for performing A, component for performing B, component for performing C” should be interpreted to cover an apparatus in which only one component for performing A, B and C exists, or in which separate components for performing A, B and C exist, or in which components for performing A, B and C partially or completely overlap.

[0133] Although this disclosure has been described above with reference to non-limiting and illustrative examples based on the accompanying drawings, it is clear that the scope of this disclosure is not limited thereto, and modifications can be made in many different ways. As technology advances, it will become apparent to those skilled in the art how to further implement and / or modify this disclosure in various ways. Furthermore, it will be apparent to those skilled in the art that the embodiments described herein can, but are not required to, be combined in various ways with other embodiments described herein.

[0134] Furthermore, various implementations of this disclosure can be described with reference to the following entries, and their features can be combined in any reasonable manner.

[0135] Item 1. An apparatus comprising at least one processor and at least one memory storing instructions, the instructions, when executed by the at least one processor, causing the apparatus to at least: receive from a network an indication of a first β value for transmitting a superimposed reference signal for a first time period and an indication of a reduction factor for transmitting the superimposed reference signal in a subsequent time period, and an indication of a value for the time period, wherein β indicates the power allocated to the superimposed reference signal; determine a number m of time periods based on the first β value and the reduction factor; and determine M' for a coherent block size of N subcarriers and M orthogonal frequency division multiplexing (OFDM) symbols, based on the first β value, m, the value of the time period, and the reduction factor, wherein M' ≤ M.

[0136] Item 2. The apparatus according to Item 1, wherein the time period includes the number of OFDM symbols, and the value of β is constant over the OFDM symbols.

[0137] Item 3. The means according to Item 1 or Item 2, wherein the means is caused to perform: providing instructions to the network for N and M.

[0138] Item 4. The apparatus according to Item 3, wherein indications for N and M are provided in the user equipment auxiliary information.

[0139] Item 5. An apparatus according to any one of items 1 to 4, wherein the apparatus is made to perform: performing channel estimation up to m iterations based on the received superimposed reference signal.

[0140] Item 6. An apparatus comprising at least one processor and at least one memory storing instructions, the instructions, when executed by the at least one processor, causing the apparatus to at least: determine a coherent block size of N subcarriers and M OFDM symbols for a superimposed reference signal location; receive from a user equipment a β-value for the superimposed reference signal. min The at least one value of β is indicated by the superimposed reference signal to obtain the channel estimate, where β min Each value has an associated K value, where K is the number of resource elements, and each resource element carries an associated β. minTo obtain the reference signal required for channel estimation, and β min It is the minimum value of β, and β indicates the power assigned to the superimposed reference signal; for a given value of β and based on M, N, at least one β min And the associated K, determine the number of time periods m; determine the value of the time period based on m and M; based on the received pair β min The instructions of K determine a first β value for transmitting a superimposed reference signal for a first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods; and provide the user equipment with instructions on the first β value, the value of the time period, and the reduction factor.

[0141] Item 7. The apparatus according to Item 6, wherein determining the coherent block size includes receiving instructions for N and M from the user equipment.

[0142] Item 8. The apparatus according to Item 7, wherein indications for N and M are received in user equipment auxiliary information.

[0143] Item 9. An apparatus according to any one of items 6 to 8, wherein the time period includes the number of OFDM symbols, and the value of β is constant over the OFDM symbols.

[0144] Item 10. A method comprising: receiving from a network an indication of a first β value for transmitting a superimposed reference signal for a first time period, a reduction factor for transmitting the superimposed reference signal in subsequent time periods, and an indication of a value for the time periods, wherein β indicates the power allocated to the superimposed reference signal; determining a number m of time periods based on the first β value and the reduction factor; and determining M' for a coherent block size of N subcarriers and M OFDM symbols, based on the first β value, m, the value of the time periods, and the reduction factor, wherein M' ≤ M.

[0145] Item 11. A method comprising: determining a coherent block size of N subcarriers and M OFDM symbols for a superimposed reference signal location; receiving from a user equipment a β-value for the superimposed reference signal. min The at least one value of β is indicated by the superimposed reference signal to obtain the channel estimate, where β min Each value has an associated K value, where K is the number of resource elements, and each resource element carries an associated β. min To obtain the reference signal required for channel estimation, and β min It is the minimum value of β, and β indicates the power assigned to the superimposed reference signal; for a given value of β and based on M, N, at least one β min And the associated K, determine the number of time periods m; determine the value of the time period based on m and M; based on the received pair β minThe instructions of K determine a first β value for transmitting a superimposed reference signal for a first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods; and provide the user equipment with instructions on the first β value, the value of the time period, and the reduction factor.

[0146] Item 12. An apparatus comprising: receiving from a network an indication of a first β value for transmitting a superimposed reference signal for a first time period, a reduction factor for transmitting the superimposed reference signal in subsequent time periods, and an indication of the value of the time periods, wherein β indicates the power allocated to the superimposed reference signal; determining a number m of time periods based on the first β value and the reduction factor; and determining M' for a coherent block size of N subcarriers and M OFDM symbols, based on the first β value, m, the value of the time periods, and the reduction factor, wherein M' ≤ M.

[0147] Item 13. An apparatus comprising: determining a coherent block size of N subcarriers and M OFDM symbols for a superimposed reference signal position; receiving from a user equipment a β-value for the superimposed reference signal. min The at least one value of β is indicated by the superimposed reference signal to obtain the channel estimate, where β min Each value has an associated K value, where K is the number of resource elements, and each resource element carries an associated β. min To obtain the reference signal required for channel estimation, and β min It is the minimum value of β, and β indicates the power assigned to the superimposed reference signal; for a given value of β and based on M, N, at least one β min And the associated K, determine the number of time periods m; determine the value of the time period based on m and M; based on the received pair β min The instructions of K determine a first β value for transmitting a superimposed reference signal for a first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods; and provide the user equipment with instructions on the first β value, the value of the time period, and the reduction factor.

[0148] Item 14. A computer program comprising instructions that, when executed by a device, cause the device to perform: receiving from a network an indication of a first β value for transmitting a superimposed reference signal for a first time period, a reduction factor for transmitting the superimposed reference signal in subsequent time periods, and an indication of the value of the time periods, wherein β indicates the power allocated to the superimposed reference signal; determining a number m of time periods based on the first β value and the reduction factor; and determining M' for a coherent block size of N subcarriers and M OFDM symbols, based on the first β value, m, the value of the time periods, and the reduction factor, wherein M' ≤ M.

[0149] Item 15. A computer program comprising instructions that, when executed by a device, cause the device to: determine a coherent block size of N subcarriers and M OFDM symbols for a superimposed reference signal position; receive from a user equipment a β-value for the superimposed reference signal. min The at least one value of β is indicated by the superimposed reference signal to obtain the channel estimate, where β min Each value has an associated K value, where K is the number of resource elements, and each resource element carries an associated β. min To obtain the reference signal required for channel estimation, and β min It is the minimum value of β, and β indicates the power assigned to the superimposed reference signal; for a given value of β and based on M, N, at least one β min And the associated K, determine the number of time periods m; determine the value of the time period based on m and M; based on the received pair β min The instructions of K determine a first β value for transmitting a superimposed reference signal for a first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods; and provide the user equipment with instructions on the first β value, the value of the time period, and the reduction factor.

Claims

1. An apparatus for communication, comprising at least one processor and at least one memory storing instructions, the instructions causing the apparatus to perform at least the following when executed by the at least one processor: Receive from the network an indication of a first β value for transmitting a superimposed reference signal for a first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods, and an indication of the value of the time periods, wherein β indicates the power allocated to the superimposed reference signal; Based on the first β value and the reduction factor, the number of time periods m is determined; as well as For the coherent block size of N subcarriers and M orthogonal frequency division multiplexing (OFDM) symbols, M' is determined based on the first β value, m, the value of the time period, and the reduction factor, where M' ≤ M.

2. The apparatus of claim 1, wherein the time period includes the number of OFDM symbols, and the value of β is constant for the OFDM symbols.

3. The apparatus according to claim 1 or claim 2, wherein the apparatus is caused to perform: providing instructions for N and M to the network.

4. The apparatus of claim 3, wherein the indications for N and M are provided in the user equipment auxiliary information.

5. The apparatus according to any one of claims 1 to 4, wherein the apparatus is configured to perform: performing up to m iterations of channel estimation based on the received superimposed reference signal.

6. An apparatus for communication, comprising at least one processor and at least one memory storing instructions, the instructions causing the apparatus to perform at least the following when executed by the at least one processor: The size of the coherent block of N subcarriers and M OFDM symbols is determined based on the position of the superimposed reference signal; Receive β from user equipment for the superimposed reference signal min The superimposed reference signal is used to obtain a channel estimate, indicating at least one value of β, where β is... min Each value has an associated K value, where K is the number of resource elements, each carrying the associated β. min To obtain the reference signal required for channel estimation, and β min It is the minimum value of β, and β indicates the power allocated to the superimposed reference signal; For a given value of β and based on M, N, and at least one of β min And with the associated K, determine the number of time periods m; The value of the time period is determined based on m and M; Based on the received pair β min In accordance with the instructions of K, a first β value for transmitting the superimposed reference signal for the first time period and a reduction factor for transmitting the superimposed reference signal in subsequent time periods are determined. as well as Provide the user equipment with indications of the first β value, the value of the time period, and the reduction factor.

7. The apparatus of claim 6, wherein determining the coherence block size includes receiving instructions for N and M from the user equipment.

8. The apparatus of claim 7, wherein the indications for N and M are received in user equipment auxiliary information.

9. The apparatus according to any one of claims 6 to 8, wherein the time period includes the number of OFDM symbols, and the value of β is constant across the OFDM symbols.

10. A method for communication, comprising: Receive from the network an indication of a first β value for transmitting a superimposed reference signal for a first time period, a reduction factor for transmitting the superimposed reference signal in subsequent time periods, and an indication of the value of the time periods, wherein β indicates the power allocated to the superimposed reference signal; Based on the first β value and the reduction factor, the number of time periods m is determined; as well as For a coherent block size of N subcarriers and M OFDM symbols, M' is determined based on the first β value, m, the value of the time period, and the reduction factor, where M' ≤ M.

Images