Non-codebook-based transmission of sounding reference signals

Abstract

The application relates to devices and components, including apparatuses, systems, and methods for performing non-codebook based SRS transmission. In one example, eight or more SRS resources are used for SRS transmission based on a non-codebook. In this example, the base station configures the UE to use the eight or more SRS resources. Upon receiving the SRS transmission of the UE, the base station may transmit DCI to the UE to indicate an uplink resource allocation. The allocation may depend on precoding weights for the eight or more SRS transmissions. The DCI may have a relatively reduced size for the resource allocation indication.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 336,214, filed on April 28, 2022. The contents of that application are incorporated herein by reference in their entirety for all purposes. Background Art

[0003] Cellular communications may be defined in various standards to enable communications between user equipment and cellular networks. For example, the fifth generation mobile network (5G) is a wireless standard designed to improve data transmission speeds, reliability, availability, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 An example of a network environment according to some embodiments is illustrated.

[0005] Figure 2 An example of non-codebook based transmission of a sounding reference signal (SRS) according to some embodiments is illustrated.

[0006] Figure 3 An example of an operational flow / algorithm structure of a user equipment (UE) using non-codebook based transmission of SRS according to some embodiments is illustrated.

[0007] Figure 4 An example of an operational flow / algorithm structure of a base station using non-codebook based transmission of SRS according to some embodiments is illustrated.

[0008] Figure 5 An example of using download control information (DCI) for non-codebook based SRS transmission according to some embodiments is illustrated.

[0009] Figure 6 Another example of using DCI for non-codebook based SRS transmission according to some embodiments is illustrated.

[0010] Figure 7 An example of reporting SRS resource indicator (SRI) combinations to support DCI transmissions according to some embodiments is illustrated.

[0011] Figure 8 An example of using multiple DCIs for non-codebook based SRS transmission according to some embodiments is illustrated.

[0012] Fig. 9 Examples of receiving components according to some embodiments are illustrated.

[0013] Fig.10 Examples of UEs according to some embodiments are illustrated.

[0014] Fig.11 An example of a base station according to some embodiments is illustrated. DETAILED DESCRIPTION

[0015] The following specific embodiments relate to the accompanying drawings. The same figure numbers may be used to identify the same or similar elements in different drawings. In the following description, specific details, such as specific structures, architectures, interfaces, technologies, etc., are described for the purpose of illustration and not limitation, so as to provide a thorough understanding of various aspects of various embodiments. However, it will be apparent to those skilled in the art who benefit from the present disclosure that various aspects of various embodiments may be practiced in other examples that deviate from these specific details. In some cases, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of various embodiments due to unnecessary details. For the purposes of this document, the phrase "A or B" refers to (A), (B), or (A and B).

[0016] In general, a user equipment (UE) may transmit a sounding reference signal (SRS) to a base station so that the base station can estimate the uplink channel quality and at least manage uplink communications from the UE. SRS resources are configured by the base station for the UE. The UE may use SRS resources for non-codebook based SRS transmissions. According to this transmission scheme, the UE does not receive information about pre-coding weights from the base station, but generates such pre-coding weights based on downlink measurements (e.g., based on a channel state information reference signal (CSI-RS)). Based on the SRS transmission, the base station determines resource allocations for the uplink channel and indicates the allocations to the UE by transmitting downlink control information (DCI) to the UE. The resource allocation may at least partially take the form of an SRS resource indicator (SRI).

[0017] In one example, eight or more SRS resources may be configured by the base station. In this example, the size of the SRI indicated in the DCI may become larger (e.g., 8 or more bits). Embodiments of the present disclosure relate to using a DCI with a relatively reduced size (e.g., using less than eight bits for SRI information). In one example, the DCI indicates the number of demodulation reference signal (DMRS) ports, rather than directly indicating the SRI, wherein the number is associated with the corresponding SRI in a predefined manner. In another example, the DCI indicates the number of DMRS ports, and the number is associated with the number of SRI combinations. In this case, the DCI may also indicate the SRI for selecting the corresponding SRI combination. In yet another example, the UE may report possible SRI combinations for each number of DMRS ports. In this example, the DCI may indicate a number of DMRS ports and / or an SRI corresponding to a SRI combination in a possible SRI combination. In another example, the SRI indicated in a first DCI having a first format may be based on an SRS resource configured for a second DCI having a second format.

[0018] For clarity of explanation, this document describes SRS transmission using 8 SRS ports. However, the embodiments of the present disclosure are not limited thereto, but are equally applicable to a larger number of SRS ports (e.g., twelve, sixteen, etc.). In addition, the embodiments are described in conjunction with a 5G network. However, the embodiments are not limited thereto, and are similarly applicable to other types of communication networks including other types of cellular networks.

[0019] The following is a glossary of terms that may be used in this disclosure.

[0020] As used herein, the term "circuit" refers to, is part of, or includes a hardware component such as an electronic circuit, a logic circuit, a processor (shared, dedicated, or group) or a memory (shared, dedicated, or group) configured to provide the described functions, an application specific integrated circuit (ASIC), a field programmable device (FPD) (e.g., a field programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high capacity PLD (HCPLD), a structured ASIC, or a programmable system on chip (SoC)), a digital signal processor (DSP), etc. In some embodiments, the circuit may execute one or more software or firmware programs to provide at least some of the described functions. The term "circuit" may also refer to a combination of one or more hardware elements and a program code for performing the functions of the program code (or a combination of circuits used in an electrical or electronic system). In these embodiments, the combination of hardware elements and program code may be referred to as a specific type of circuit.

[0021] As used herein, the term "processor circuit" refers to, is part of, or includes a circuit capable of sequentially and automatically performing a series of arithmetic or logical operations or recording, storing, or transferring digital data. The term "processor circuit" may refer to an application processor, a baseband processor, a central processing unit (CPU), a graphics processing unit, a single-core processor, a dual-core processor, a triple-core processor, a quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions such as program code, software modules, and / or functional processes.

[0022] As used herein, the term "interface circuit" refers to a circuit that enables, is a part of, or includes information exchange between two or more components or devices. The term "interface circuit" may refer to one or more hardware interfaces, such as a bus, an I / O interface, a peripheral component interface, a network interface card, etc.

[0023] As used herein, the term "user equipment" or "UE" refers to a device that has radio communication capabilities and can describe a remote user of network resources in a communication network. In addition, the terms "user equipment" or "UE" may be considered synonymous and may be referred to as a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, reconfigurable mobile device, etc. In addition, the term "user equipment" or "UE" may include any type of wireless / wired device or any computing device that includes a wireless communication interface.

[0024] As used herein, the term "base station" refers to a device with radio communication capabilities, which is a network component of a communication network (or more concisely, a network) and can be configured as an access node in the communication network. The access of a UE to a communication network can be at least partially managed by a base station, whereby the UE connects to the base station to access the communication network. Depending on the radio access technology (RAT), a base station can be referred to as a gNodeB (gNB), an eNodeB (eNB), an access point, etc.

[0025] As used herein, the term "network" refers to a communication network comprising a collection of network nodes configured to provide communication functions to multiple user equipment via one or more base stations. For example, the network may be a public land mobile network (PLMN) implementing one or more communication technologies (including, for example, 5G communications).

[0026] As used herein, the term "computer system" refers to any type of interconnected electronic devices, computer devices, or components thereof. Additionally, the term "computer system" or "system" may refer to various components of a computer that are communicatively coupled to one another. Furthermore, the term "computer system" or "system" may refer to multiple computer devices or multiple computing systems that are communicatively coupled to one another and configured to share computing resources or networked resources.

[0027] As used herein, the term "resource" refers to a physical or virtual device, a physical or virtual component within a computing environment, or a physical or virtual component within a specific device, such as a computer device, a mechanical device, a memory space, a processor / CPU time, a processor / CPU usage, a processor and accelerator load, a hardware time or usage, a power supply, an input / output operation, a port or a network socket, a channel / link allocation, throughput, memory usage, storage, a network, a database and an application, a unit of work, etc. "Hardware resources" may refer to computing, storage or network resources provided by physical hardware elements. "Virtualized resources" may refer to computing, storage or network resources provided by a virtualized infrastructure to an application, device, system, etc. The term "network resources" or "communication resources" may refer to resources that a computer device / system can access via a communication network. The term "system resources" may refer to any kind of shared entity that provides a service, and may include computing resources or network resources. System resources may be considered as a set of coherent functions, network data objects or services that can be accessed through a server, wherein such system resources reside on a single host or multiple hosts and can be clearly identified.

[0028] As used herein, the term "channel" refers to any tangible or intangible transmission medium for transmitting data or data streams. The term "channel" may be synonymous or equivalent to "communication channel", "data communication channel", "transmission channel", "data transmission channel", "access channel", "data access channel", "link", "data link", "carrier", "radio frequency carrier" or any other similar term representing a path or medium through which data is transmitted. In addition, as used herein, the term "link" refers to a connection between two devices for sending and receiving information.

[0029] As used herein, the terms "instantiate," "instantiate," and the like refer to the creation of an instance. "Instance" also refers to a specific occurrence of an object, which may occur, for example, during the execution of program code.

[0030] The term "connected" may mean that two or more elements at a common communication protocol layer have an established signaling relationship with each other through a communication channel, link, interface, or reference point.

[0031] As used herein, the term "network element" refers to physical or virtualized equipment or infrastructure for providing wired or wireless communication network services. The term "network element" may be considered synonymous with or referred to as a networked computer, networking hardware, network equipment, network node, virtualized network function, etc.

[0032] The term "information element" refers to a structural element that contains one or more fields. The term "field" refers to the individual contents of an information element, or a data element that contains the contents. An information element may include one or more additional information elements.

[0033] The term "3GPP access" refers to access (e.g., radio access technology) specified by the 3GPP standards. These accesses include, but are not limited to, GSM / GPRS, LTE, LTE-A, and / or 5G NR. In general, 3GPP access refers to various types of cellular access technologies.

[0034] The term "non-3GPP access" refers to any access (e.g., radio access technology) not specified by the 3GPP standards. These accesses include, but are not limited to, WiMAX, CDMA2000, Wi-Fi, WLAN, and / or fixed networks. Non-3GPP accesses can be divided into two categories, "trusted" and "untrusted": trusted non-3GPP accesses can interact directly with the Evolved Packet Core (EPC) and / or 5G Core (5GC), while untrusted non-3GPP interoperates with the EPC / 5GC via network entities (such as Evolved Packet Data Network Gateways and / or 5G NR Network Gateways). In general, non-3GPP access refers to various types of non-cellular access technologies.

[0035] Figure 1 A network environment 100 is shown according to some embodiments. The network environment 100 may include a UE 104 and a gNB 108. The gNB 108 may be a base station that provides a wireless access cell, such as a third generation partnership project (3GPP) new radio (NR) cell through which the UE 104 can communicate with the gNB 108. The UE 104 and the gNB 108 may communicate over an air interface compatible with 3GPP technical specifications, such as those defining the fifth generation (5G) NR system standard.

[0036] The gNB 108 may send information (e.g., data and control signaling) in the downlink direction by mapping logical channels onto transport channels and mapping transport channels onto physical channels. Logical channels may transfer data between the radio link control (RLC) and MAC layers; transport channels may transfer data between the MAC and PHY layers; and physical channels may transfer information across the air interface. Physical channels may include a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), and a physical downlink shared channel (PDSCH).

[0037] The PBCH may be used to broadcast system information that the UE 104 may use to initially access a serving cell. The PBCH may be sent in a synchronization signal block (SSB) along with a physical synchronization signal (PSS) and a secondary synchronization signal (SSS). The SSB may be used by the UE 104 during a cell search process (including cell selection and reselection) and for beam selection.

[0038] The PDSCH may be used to transfer end-user application data, Signaling Radio Bearer (SRB) messages, system information messages (except for example MIB), and SI.

[0039] The PDCCH may convey DCI used by the scheduler of the gNB 108 to allocate both uplink and downlink resources. The DCI may also be used to provide uplink power control commands, configure the slot format, or indicate that preemption has occurred.

[0040] The gNB 108 may also transmit various reference signals to the UE 104. The reference signals may include demodulation reference signals (DMRS) for the PBCH, PDCCH, and PDSCH. The UE 104 may compare the received version of the DMRS with the known DMRS sequence transmitted to estimate the impact of the propagation channel. The UE 104 may then apply the inverse channel of the propagation channel during the demodulation process transmitted by the corresponding physical channel.

[0041] The reference signals may also include a channel state information reference signal (CSI-RS). CSI-RS may be a multi-purpose downlink transmission that may be used for CSI reporting, beam management, connected mode mobility, radio link failure detection, beam failure detection and recovery, and fine tuning of time and frequency synchronization.

[0042] Reference signals and information from physical channels can be mapped to resources of a resource grid. For a given antenna port, subcarrier spacing configuration, and transmission direction (e.g., downlink or uplink), there is a resource grid. The basic unit of the NR downlink resource grid can be a resource element, which can be defined by one subcarrier in the frequency domain and one orthogonal frequency division multiplexing (OFDM) symbol in the time domain. Twelve consecutive subcarriers in the frequency domain can constitute a physical resource block (PRB). A resource element group (REG) can include one PRB in the frequency domain and one OFDM symbol in the time domain, such as twelve resource elements. A control channel element (CCE) can represent a resource group used to send a PDCCH. One CCE can be mapped to multiple REGs (e.g., six REGs).

[0043] UE 104 may use physical uplink channels to send data and control information to gNB 108. Different types of physical uplink channels are possible, including, for example, a physical uplink control channel (PUCCH) and a physical uplink shared channel (PUSCH). Where PUCCH carries control information from UE 104 to gNB 108, such as uplink control information (UCI), while PUSCH carries data traffic (e.g., end-user application data) and may carry UCI.

[0044] Data transmission on the PUSCH may be non-codebook based, where the gNB 108 indicates precoding weights for use by the UE 104. In order for the gNB 108 to determine the precoding weights, the gNB 108 may have previously configured the UE 104 to transmit SRS and may have triggered the UE 104 to do so. Figure 1 As shown, gNB 108 can communicate with multiple UEs, including UE 104 and UE 112. gNB 108 can configure each of such UEs 104 and 112 to use specific SRS resources, so that gNB 108 can receive SRS sent by UE 104 and 112 to subsequently determine uplink resource allocations for each UE.

[0045] The UE 104 and the gNB 108 may perform beam management operations to identify and maintain desired beams for transmission in the uplink and downlink directions. Beam management may be applied to both PDSCH and PDCCH in the downlink direction and PUSCH and PUCCH in the uplink direction.

[0046] In one example, communications with gNB 108 and / or base stations may use channels in frequency range 1 (FR1), frequency range 2 (FR2) bands, and / or higher frequency ranges (FRH). FR1 bands include licensed bands and unlicensed bands. NR unlicensed bands (NR-U) include spectrum shared with other types of radio access technologies (RATs) (e.g., LTE-LAA, WiFi, etc.). A listen-before-talk (LBT) process may be used to avoid or minimize collisions between different RATs in NR-U, whereby devices should apply a clear channel assessment (CCA) check before using a channel.

[0047] Figure 2 An example of non-codebook based transmission 200 of an SRS according to some embodiments is illustrated. The SRS may be used for uplink channel state estimation, thereby allowing channel quality estimation to enable uplink link adaptation and / or frequency-selective scheduling. In the context of an uplink multiple-input multiple-output (MIMO) system, the SRS may also be used to determine a precoder and the number of layers that provide a particular throughput and / or signal to interference plus noise ratio (SINR). The SRS may be transmitted from a UE 104 (e.g., an example of UE 220) to a gNB 210 (e.g., an example of gNB 108) using non-codebook based transmission.

[0048] Non-codebook based transmission involves UE 220 sending data on an uplink channel (e.g., PUSCH) using precoding weights that the UE has generated based on downlink measurements. Non-codebook based transmission relies on channel reciprocity because UE 220 determines its uplink precoding weights based on downlink measurements. The gNB 210 configures UE 220 to use SRS resources and transmits CSI-RS for the UE to measure in order to generate precoding weights. UE 220 then sends SRS using the precoding weights. In response, gNB 210 determines a PUSCH resource allocation and indicates the allocation to the UE by transmitting a DCI to UE 220. Thereafter, UE 220 transmits uplink traffic using the allocated PUSCH resources.

[0049] exist Figure 2In the example of , before transmitting CSI-RS 214, gNB 210 configures UE 220 to perform non-codebook based SRS transmission. For example, gNB 210 transmits SRS configuration information 212 to UE 220. The configuration information 212 can be transmitted based on UE capability information of UE 220, which indicates that UE 220 supports non-codebook based SRS transmission. The configuration information 212 indicates to UE 220 that such transmission is to be used. The configuration information 212 also configures UE 220 to use an SRS resource set. The set can include a number "N" of SRS resources, each of which is configured with an antenna port (e.g., an SRS port) according to the UE capability. When UE 220 can support eight or more antenna ports, the number "N" can be eight or more SRS resources. Alternatively, gNB 210 can configure multiple resource sets, each of which includes four SRS resources, so that the total number of configured SRS resources is "N". In both cases, the configuration information 212 indicates that eight or more antenna ports are to be used for non-codebook based SRS transmission.

[0050] Next, gNB 210 transmits CSI-RS 214 to UE 220. UE 220 performs measurements on CSI-RS 214 to generate an SRS resource precoding weight for each of the configured SRS resources. For example, using the equation USV H =svd(H) Calculate the eigenvector based on CSI-RS. Each row of the matrix V can be applied to generate precoded SRS resources.

[0051] Based on the precoding weights and the configured SRS resources, the UE 220 transmits an SRS to the gNB 210. The SRS transmissions are illustrated as SRS1 222A to SRSk 222K and may be responsive to a trigger by the gNB 210. For example, the gNB 210 uses the PDCCH to trigger aperiodic transmissions, uses a medium access control (MAC) control element (CE) to activate semi-persistent SRS transmissions or a new cycle for periodic triggering, or uses RRC signaling to configure periodic SRS transmissions. When at least eight antenna ports are configured for use, the UE 210 may use at least eight SRS resources and corresponding at least eight antenna ports. Typically, one SRS resource is configured for each possible layer, and thus when eight or more SRS resources are used, the UE 220 may then be instructed to use eight or more layers for PUSCH.

[0052] Thereafter, gNB 210 compares the received SRS transmissions to determine the number of layers to use for PUSCH and which precoded SRS set should be selected for those layers. For example, the base station may determine that eight or more layers will be used and therefore a rank of eight or more (e.g., number of layers) and the precoding applied to the corresponding eight or more of the SRS resources will be used for PUSCH.

[0053] The gNB 210 then transmits a DCI 216 to allocate PUSCH resources. The DCI directly or indirectly indicates a set of "M" SRS resources from the "N" configured sets of SRS resources, as further described in the following figures. The DCI 216 also indicates the number of layers (or rank) and the specific precoding weights to be applied. Thereafter, the UE 220 uses the allocated resources to transmit PUSCH data (shown as PUSCH transmission 224) and other signals (e.g., DMRS) using the indicated number of layers and precoding weights.

[0054] SRS resources may be allocated for SRS transmission according to a plurality of steps, such as those defined in 3GPP TS 38.211, V16.8.0 (2022-01), section 6.4.1.4, the contents of which are incorporated herein by reference in their entirety. One step includes generating a base sequence in l′ is the symbol index, Defined in section 5.2.2 of 3GPP TS 38.211, is the cyclic shift of antenna port i, which is determined by the cyclic shift configured by RRC signaling and port index i. The maximum number of cyclic shifts The number of teeth (K) configured by the transmission comb TC ) and the association is defined in Table 6.4.1.4.2-1, which is reproduced here as Table 1 below.

[0055]

[0056] Table 1 .

[0057] Another step involves resource mapping. Specifically, the sequence of each antenna port in the antenna port for each OFDM symbol l′ and SRS resource is mapped. with amplitude scaling factor β SRS multiplied to match the specific transmit power and converted from r is mapped to antenna port p in sequence iThe mapping allocates SRS to different bandwidths (e.g., in the frequency domain) and symbols (e.g., in the time domain) based on the configured comb offset. Different antenna ports p i They can be distinguished by using different cyclic shifts. Generally speaking, uniform cyclic shifts are used for antenna ports (e.g. At the antenna port p i ) to have good separation between antenna ports. For a further example, and referring back to Table 1, for the four-antenna port case, when the cyclic shift offset is configured to be greater than half of the maximum cyclic shift compared to the first antenna port and the third antenna port, the second antenna port and the fourth antenna port may adopt different comb offsets. In addition, frequency hopping may be enabled to send SRS in different symbols with different frequency domain positions, so that the gNB 210 may obtain a wider bandwidth uplink channel, which in turn may improve the gNB 210's estimation of the uplink channel.

[0058] For example, challenges arise when the number "N" of configured SRS resources is eight or more. Specifically, some of these challenges are related to the size of the DCI 216. If the DCI 216 were to directly indicate the SRI, eight or more bits might be required for the indication because the gNB 210 may determine that the rank is eight or greater. Therefore, at least 8 bits would be required to support the different possible SRIs. Embodiments of the present disclosure enable the use of a DCI with a relatively reduced size (e.g., requiring less than 8 bits) while also enabling the configuration of "N" SRS resources, where "N" is equal to or greater than 8.

[0059] Figure 3 An example of an operational flow / algorithm structure 300 of a UE using non-codebook based transmission of SRS according to some embodiments is illustrated. The UE is an example of UE 104, UE 220, or UE 1000. Part or all of the operational flow / algorithm structure 300 may be implemented as part of non-codebook based SRS transmission 200.

[0060] In one example, the operation flow / algorithm structure 300 may include receiving configuration information indicating that at least eight SRS resources are configured for non-codebook based transmission from a base station at 302. For example, the configuration information 212 is received via RRC signaling.

[0061] In one example, the operational flow / algorithm structure 300 may include receiving a CSI-RS from a base station at 304. For example, the CSI-RS is triggered by a PDCCH.

[0062] In one example, the operation flow / algorithm structure 300 may include sending an SRS to a base station using the at least eight SRS resources based on the measurement of the CSI-RS at 306. For example, the two steps described above are performed to transmit the SRS using at least eight antenna ports, wherein each antenna port is associated with one of the configured SRS resources.

[0063] In one example, the operational flow / algorithm structure 300 may include receiving a DCI indicating the set of at least eight SRS resources from a base station at 308. For example, the DCI is received on a PDCCH. Although "N" SRS resources (where "N" is equal to or greater than eight) are configured, "M" SRS resources (where "M" is equal to or less than "N") are indicated in the DCI. Each of the "M" SRS resources corresponds to a layer, and thus the DCI indicates "M" layers for uplink transmission. The DCI also indicates the precoding weights to be used, where these weights correspond to the "M" SRS resources. In order to reduce the size of the DCI, the DCI indicates the number of demodulation reference signal (DMRS) ports, rather than directly indicating the SRI, where the number is associated with the corresponding SRI in a predefined manner. In another example, the DCI indicates the number of DMRS ports, and the number is associated with the number of SRI combinations. In this case, the DCI may also indicate the SRI used to select the corresponding SRI combination. In yet another example, the UE may report possible SRI combinations for each number of DMRS ports (e.g., as part of its UE capabilities). In this example, the DCI may indicate one of the numbers of DMRS ports and / or an SRI corresponding to one of the possible SRI combinations. In another example, the SRI indicated in a first DCI having a first format may be based on an SRS resource configured for a second DCI having a second format.

[0064] Figure 4 An example of an operational flow / algorithm structure 400 of a base station using non-codebook based transmission of SRS according to some embodiments is illustrated. The base station is an example of gNB 108, gNB 210, or gNB 1100. Part or all of the operational flow / algorithm structure 400 may be implemented as part of non-codebook based SRS transmission 200.

[0065] In one example, the operation flow / algorithm structure 400 may include transmitting configuration information indicating that at least eight SRS resources are configured for non-codebook based transmission to the UE at 402. For example, the configuration information 212 is transmitted via RRC signaling.

[0066] In one example, the operational flow / algorithm structure 400 may include transmitting a CSI-RS to a UE at 404. For example, the CSI-RS is triggered by a PDCCH.

[0067] In one example, the operation flow / algorithm structure 400 may include receiving an SRS transmission using the at least eight sounding reference signal (SRS) resources from the UE based on the CSI-RS at 406. For example, the two steps described above are performed by the UE to transmit the SRS using at least eight antenna ports, wherein each antenna port is associated with one of the configured SRS resources. The base station receives the transmitted SRS on an uplink channel (e.g., PUSCH).

[0068] In one example, the operational flow / algorithm structure 400 may include transmitting a DCI indicating the set of at least eight SRS resources to the UE at 408. For example, the DCI is transmitted on the PDCCH. Although "N" SRS resources (where "N" is equal to or greater than eight) are configured, "M" SRS resources (where "M" is equal to or less than "N") are indicated in the DCI. Each of the "M" SRS resources corresponds to a layer, and therefore the DCI indicates "M" layers for uplink transmission. The DCI also indicates the precoding weights to be used, where these weights correspond to the "M" SRS resources. In order to reduce the size of the DCI, the DCI indicates the number of demodulation reference signal (DMRS) ports, rather than directly indicating the SRI, where the number is associated with the corresponding SRI in a predefined manner. In another example, the DCI indicates the number of DMRS ports, and the number is associated with the number of SRI combinations. In this case, the DCI may also indicate the SRI used to select the corresponding SRI combination. In yet another example, the UE may report possible SRI combinations for each number of DMRS ports (e.g., as part of its UE capabilities). In this example, the DCI may indicate one of the numbers of DMRS ports and / or an SRI corresponding to one of the possible SRI combinations. In another example, the SRI indicated in a first DCI having a first format may be based on an SRS resource configured for a second DCI having a second format.

[0069] Based on the received CSI-RS, the UE can determine the precoding weights for each configured SRS resource. The precoding weights can be determined by calculating the eigenvector. Therefore, information about which SRS resource should provide the best performance for each layer can be made available to the UE. Specifically, the first row in the eigenvector can provide the best performance for a single layer transmission, the first and second rows in the eigenvector can provide the best performance for two layers of transmission, and so on. This type of UE-known information can be used to reduce the size of the DCI used for PUSCH resource allocation, as further shown in the following figures.

[0070] Figure 5 An example of using DCI 510 for non-codebook based SRS transmission 500 according to some embodiments is shown. Typically, there is a one-to-one mapping between SRS resources and specific DMRS, so that the precoding applied to the SRS resources can also be applied to the corresponding DMRS. Therefore, the DCI 510 includes DMRS port information 512 instead of indicating SRI (e.g., an indicator of SRS resources). The information 512 may indicate a DMRS port and / or the number of DMRS ports. The number corresponds to the number of layers used for PUSCH transmission. The UE may store a SRI-DMRS port association 520 (e.g., a mapping between SRI and a corresponding DMRS port set). The SRI-DMRS port association 520 may be predefined or may be received from a base station via RRC signaling or a medium access control (MAC) control element (CE). Given the DMRS port information 512, the UE may look up the SRI-DRM port association 520 and determine the corresponding SRI to be used.

[0071] In one example, the first SRS resource (and the first SRI supporting single-layer transmission) is mapped to one DMRS port. In contrast, the first two SRS resources (and the corresponding second SRI supporting two-layer transmission) are mapped to two DMRS ports, and so on. This example reflects the eigenvector optimal performance method described above.

[0072] Figure 6 Another example of using DCI 610 for non-codebook based SRS transmission 600 according to some embodiments is illustrated. Figure 5Different, here each number of DMRS ports can be mapped to more than one SRI combination. For example, one DMRS port situation can be mapped to a first set of SRI combinations, two DMRS port situations can be mapped to a second set of SRI combinations, and so on. The sizes of these sets can be different or can be the same. Examples of such mappings are further shown in Tables 2 and 3 below, where each set of SRI combinations includes two combinations as in Table 2 or has different sizes as in Table 3. The DMRS port number to SRI combination method can provide the base station with some flexibility in interference management (e.g., related to communications with other UEs) and situations where the relevant CSI-RS is not configured. Specifically, each mapping can correspond to a specific combination of feature vector rows to reflect this flexibility. Because the number of DMRS ports can be mapped to more than one SRI combination, the base station may still need to indicate the SRI in the DCI to select one of the SRI combinations in the SRI combination (e.g., the SRI indicates the SRI combination instead of a specific SRI). However, the overall size of the DCI is relatively reduced.

[0073] exist Figure 6 In the example of , DCI 610 includes DMRS port information 612 (similar to DMRS port information 512) and / or SRI 614 indicating an SRI combination. The UE also stores an SRI combination-DMRS port association 620 (e.g., a mapping between an SRI combination and a corresponding DMRS port). The SRI combination-DMRS port association 620 may be predefined or may be received from a base station via RRC signaling or MACCE.

[0074] In one example, the base station includes DMRS port information 612 in the DCI 610 but does not include SRI 614. In this example, the DMRS port information 612 may indicate the number of DMRS ports (e.g., corresponding to the number or rank of layers to be used). This number may be used to look up the SRI combination-DMRS port association 620. The UE then determines the corresponding set of SRI combinations. The set may include multiple SRI combinations. If so, the UE is configured with rules that can be used to select a specific SRI combination to use. Therefore, the UE determines the number of layers to be sent (corresponding to the number of DMRS ports) and sends using the SRI indicated in the SRI combination.

[0075] In one example, the base station includes SRI 614 in DCI 610 but does not include DMRS port information 614. In this example, SRI 614 can be used to select an SRI combination. Specifically, SRI 614 can indicate an SRI combination, and the SRI combination is used to look up an SRI combination-DMRS port association 620. The lookup can result in identifying the number of DMRS ports. The identified number corresponds to the number of layers to be used in the transmission. The SRI indicated in the SRI combination is also used for transmission. In this example, the size of the SRI field in DCI 610 can be based on the total number of SRI combinations for all ranks (e.g., on the possible number of DMRS ports).

[0076] In yet another example, the base station includes DMRS port information 612 and SRI 614 in DCI 610. In this example, DMRS port information 612 may indicate the number of DMRS ports (e.g., corresponding to the number or rank of layers to be used). This number may be used to look up SRI combination-DMRS port association 620. As a result of the lookup, the UE determines a corresponding set of SRI combinations. SRI 614 is then used to select one of the SRI combinations (e.g., assuming two SRI combinations are determined, SRI 614 may be one bit long, where a "0" bit indicates that the first SRI combination will be used, and a "1" bit indicates that the second SRI combination will be used).

[0077] In addition, in one example, the base station 6110 may configure how many combinations the UE should consider for each number or over all numbers of DMRS ports in the SRI combination-DMRS port association 620 (e.g., RRC signaling for SRI restriction may be used). The use of this example is shown in Table 2 below. In another example, the base station may configure the exact SRI or candidate SRS resources for each number of DMRS ports in the SRI combination-DMRS port association 620 (e.g., through RRC signaling). The use of this example is shown in Table 3 below.

[0078] Number of DMRS ports SRS Group 1 SRI{1},{2} 2 SRI{1,2},{2,3} 3 SRI{1,2,3},{3,4,5} 4 SRI{1,2,3,4},{3,4,5,6} 5 SRI{1,2,3,4,5},{3,4,5,6,7} 6 SRI{1,2,3,4,5,6},{3,4,5,6,7,8} 7 SRI{1,2,3,4,5,6,7},{2,3,4,5,6,7,8} 8 SRI{1,2,3,4,5,6,7,8},{reserved}

[0079] Table 2 .

[0080] In Table 2 above, the size of SRI 614 is four bits to indicate sixteen SRI combinations (e.g., two combinations per the number of DMRS ports). When SRI 614 is set to, for example, "0000", the SRI value indicates the first combination {1}. Here, the UE can determine that the number of DRMS ​​ports is 1 (e.g., corresponding to a single-layer transmission) and SRI "1" will be used for single-layer transmission. In contrast, if SRI 614 is set to "0001", the value indicates the second combination {2}, and the UE can determine that a single-layer transmission will be performed based on SRI "2". In further comparison, when SRI 614 is set to, for example, "0010", the third combination {1,2} is indicated and associated with the number of DMRS ports, 2. Therefore, the UE can determine that SRI "1" and SRI "2" will be used for two-layer transmission.

[0081] The following Table 3 illustrates another example. Here, the base station may configure the exact set of SRI or candidate SRS resources for the number of DMRS ports.

[0082]

[0083]

[0084] Table 3 .

[0085] In Table 3 above, a total of thirty SRI combinations are supported, where, for example, the number of one DMRS port corresponds to six SRI combinations, and the number of eight DMRS ports corresponds to a single SRI combination. Therefore, the size of SRI 614 is five bits to indicate these thirty combinations. When SRI 614 is set to, for example, "00000" and the number of DMRS ports is indicated as one, the UE can determine that SRS resource "1" will be used. In contrast, when SRI 614 is set to, for example, "00001" and the number of DMRS ports is indicated as one, the UE can determine that SRS resource "2" is to be used, and so on.

[0086] Figure 7 An example of reporting 700 SRI combinations to support DCI transmission according to some embodiments is illustrated. Here, the base station configures the SRI combinations for the UE according to the number of DMRS ports (or equivalently, the rank) Figure 6Different, the UE can indicate to the base station the possible SRIs for each rank. The UE can report the possible SRI combinations for each number of DMRS ports. The method is similar to the method shown in Table 2 above, except that the UE can report this information. Alternatively or additionally, the UE can report the possible number of SRI combinations for each number of DMRS ports. The method is similar to the method shown in Table 3 above, except that the UE can report this information. In both cases, the reported information can be transmitted in the UE capability information (for example, before receiving the configuration information 212) or dynamically reported by being included in the uplink control information (UCI) in the PUCCH or PUSCH or by being included in the MAC CE. When transmitting DCI to the UE, the base station can transmit such as Figure 6 DMRS port information and / or SRI described in.

[0087] exist Figure 7 In the example of , the UE can report the SRI-DMRS port association 710 to the base station. In one example, the SRI-DMRS port association 710 indicates the possible SRI combinations for each number of DMRS ports. In another example, the SRI-DMRS port association 710 indicates the possible number of SRI combinations for each number of DMRS ports. In addition to being stored by the UE, the SRI-DMRS port association 710 can also be stored by the base station. In turn, the UE transmits DCI 720 including DMRS port information (similar to DMRS port information 512) and SRI 724 (similar to SRI 614). The UE can then transmit its own locally stored SRI-DMRS port association 710 to determine the resources to be used for uplink transmission.

[0088] Figure 8An example of using multiple DCIs for non-codebook based SRS transmission 800 according to some embodiments is illustrated. In one example, a first DCI 820 having a first format (e.g., format 0_2) and a second DCI 820 having a second format (e.g., format 0_1) are used. The SRI for a rank equal to or less than a specific rank threshold "X" indicated by the second DCI 820 can be based on the SRS resources configured for the first DCI 810. For example, "X" is equal to the number of first SRS resources 812 in the first resource set configured for the first DCI 810. The second SRS resource 822 in the second resource set can be configured for the second DCI 820. These two SRS resource sets can be configured for the UE by the base station (e.g., as part of configuration 212). Once the UE performs SRS transmission and the base station receives such transmission, the base station can transmit the second DCI 820 to the UE for uplink resource allocation. Here, the DCI can indicate a rank 824. The UE can compare the rank 824 with the rank threshold "X". If the rank 824 is less than or equal to "X", the second DCI 820 indicates the first SRS resource 812. Otherwise, the second DCI 820 indicates the second SRS resource 822. Here, the rank may be indicated in the SRI field of the second DCI 820. The size of this field may be based on the total number of SRI combinations of all ranks (e.g., on a different number of DMRS ports).

[0089] Fig. 9 Illustrated is a receiving component 900 of a UE 104 according to some embodiments. The receiving component 900 may include an antenna panel 904 including a plurality of antenna elements. The panel 904 is shown as having four antenna elements, but other embodiments may include other numbers.

[0090] The antenna panel 904 may be coupled to an analog beamforming (BF) assembly including a plurality of phase shifters 908(1) to 908(4). The phase shifters 908(1) to 908(4) may be coupled to a radio frequency (RF) chain 912. The RF chain 912 may amplify the received analog RF signal, down-convert the RF signal to baseband, and convert the analog baseband signal to a digital baseband signal that may be provided to a baseband processor for further processing.

[0091] In various embodiments, control circuitry that may reside in a baseband processor may provide BF weights (e.g., W1 to W4) that may represent phase shift values ​​to phase shifters 908(1) to 908(4) to provide receive beams at antenna panel 904. These BF weights may be determined based on channel-based beamforming.

[0092] Fig.10UE 1000 according to some embodiments is shown. UE 1000 may be similar to Figure 1 UE 104 and is substantially interchangeable therewith.

[0093] Similar to what is described above with respect to UE 104, UE 1000 may be any mobile or non-mobile computing device, such as a mobile phone, computer, tablet, industrial wireless sensor (e.g., microphone, carbon dioxide sensor, pressure sensor, humidity sensor, thermometer, motion sensor, accelerometer, laser scanner, fluid level sensor, inventory sensor, voltage / current meter, actuator, etc.), video surveillance / monitoring equipment (e.g., camera, camcorder, etc.), wearable device, or loose IoT device. In some embodiments, the UE may be a reduced capacity UE or an NR-Light UE.

[0094] UE 1000 may include a processor 1004, an RF interface circuit 1008, a memory / storage device 1012, a user interface 1016, a sensor 1020, a driver circuit 1022, a power management integrated circuit (PMIC) 1024, and a battery 1028. The components of UE 1000 may be implemented as an integrated circuit (IC), a portion of an integrated circuit, a discrete electronic device, or other module, logic, hardware, software, firmware, or a combination thereof. Fig.10 The block diagram of UE 1000 is intended to show a high-level view of certain of the components of UE 1000. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other implementations.

[0095] Components of UE 1000 may be coupled to various other components via one or more interconnects 1032, which may represent any type of interface, input / output, bus (local, system, or extension), transmission line, trace, optical connection, etc., which allows various circuit components (on a common or different chip or chipset) to interact with each other.

[0096] The processor 1004 may include processor circuits such as a baseband processor circuit (BB) 1004A, a central processor unit circuit (CPU) 1004B, and a graphics processor unit circuit (GPU) 1004C. The processor 1004 may include any type of circuit or processor circuit that executes or otherwise operates computer-executable instructions (such as program codes, software modules, or functional processes from the memory / storage device 1012) to cause the UE 1000 to perform operations as described herein.

[0097] In some embodiments, the baseband processor circuit 1004A can access the communication protocol stack 1036 in the memory / storage device 1012 to communicate through a 3GPP compatible network. In general, the baseband processor circuit 1004A can access the communication protocol stack to: perform user plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, SDAP layer, and PDU layer; and perform control plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and non-access layer (NAS) layer. In some embodiments, the PHY layer operations can be additionally / alternatively performed by components of the RF interface circuit 1008.

[0098] The baseband processor circuit 1004A may generate or process baseband signals or waveforms that carry information in a 3GPP-compatible network. In some embodiments, the waveforms used for NR may be based on cyclic prefix OFDM (CP-OFDM) in the uplink or downlink, and discrete Fourier transform spread OFDM (DFT-S-OFDM) in the uplink.

[0099] The baseband processor circuit 1004A may also access group information from the memory / storage 1012 to determine a search space group in which a number of repetitions of the PDCCH may be sent.

[0100] The memory / storage 1012 may include any type of volatile or non-volatile memory that may be distributed throughout the UE 1000. In some embodiments, some of the memory / storage 1012 may be located on the processor 1004 itself (e.g., L1 cache and L2 cache), while other memory / storage 1012 is external to the processor 1004 but accessible via a memory interface. The memory / storage 1012 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0101] The RF interface circuit 1008 may include a transceiver circuit and a radio frequency front end module (RFEM), which allows the UE 1000 to communicate with other devices through a radio access network. The RF interface circuit 1008 may include various elements arranged in a transmit path or a receive path. These elements may include, for example, switches, mixers, amplifiers, filters, synthesizer circuits, control circuits, etc.

[0102] In the receive path, the RFEM may receive the radiated signal from the air interface via antenna 1050 and proceed to filter and amplify the signal (using a low noise amplifier). The signal may be provided to a transceiver's receiver, which down-converts the RF signal to a baseband signal that is provided to a baseband processor of processor 1004.

[0103] In the transmit path, the transmitter of the transceiver up-converts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM may amplify the RF signal through a power amplifier before the signal is radiated across the air interface via the antenna 1050.

[0104] In various embodiments, the RF interface circuit 1008 may be configured to send / receive signals in a manner compatible with NR access technology.

[0105] Antenna 1050 may include multiple antenna elements, each of which converts electrical signals into radio waves to pass through the air and converts received radio waves into electrical signals. These antenna elements may be arranged into one or more antenna panels. Antenna 1050 may have an antenna panel that is omnidirectional, directional, or a combination thereof to achieve beamforming and multi-input, multi-output communications. Antenna 1050 may include a microstrip antenna, a printed antenna manufactured on the surface of one or more printed circuit boards, a patch antenna, a phased array antenna, etc. Antenna 1050 may have one or more panels that are designed for a specific frequency band included in a band in FR1 or FR2.

[0106] The user interface circuit 1016 includes various input / output (I / O) devices designed to enable a user to interact with the UE 1000. The user interface 1016 includes input device circuits and output device circuits. The input device circuit includes any physical or virtual components for accepting input, including in particular one or more physical or virtual buttons (e.g., reset button), physical keyboard, keypad, mouse, touch pad, touch screen, microphone, scanner, headset, etc. The output device circuit includes any physical or virtual components for displaying information or otherwise conveying information (such as sensor readings, actuator positions, or other similar information). The output device circuit may include any number or combination of audio or visual displays, including in particular one or more simple visual outputs / indicators (e.g., binary state indicators (such as light emitting diodes (LEDs)) and multi-character visual outputs) or more complex outputs (such as display devices or touch screens (e.g., liquid crystal displays (LCDs), LED displays, quantum dot displays, projectors, etc.)), where the output of characters, graphics, multimedia objects, etc. is generated or produced by the operation of the UE 1000.

[0107] Sensor 1020 may include a device, module, or subsystem whose purpose is to detect events or changes in its environment and to communicate information about the detected events (sensor data) to some other device, module, subsystem, etc. Examples of such sensors include, among others: an inertial measurement unit including an accelerometer; a gyroscope; or a magnetometer; a micro-electromechanical system or nano-electromechanical system including: a three-axis accelerometer; a three-axis gyroscope; or a magnetometer; a level sensor; a flow sensor; a temperature sensor (e.g., a thermistor); a pressure sensor; a barometric pressure sensor; a gravity meter; an altimeter; an image capture device (e.g., a camera or a lensless aperture); a light detection and ranging sensor; a proximity sensor (e.g., an infrared radiation detector, etc.); a depth sensor; an ambient light sensor; an ultrasonic transceiver; a microphone or other similar audio capture device; and the like.

[0108] The driver circuit 1022 may include software and hardware elements for controlling specific devices embedded in, attached to, or otherwise communicatively coupled to the UE 1000. The driver circuit 1022 may include various drivers to allow other components to interact with or control various input / output (I / O) devices that may be present in or connected to the UE 1000. For example, the driver circuit 1022 may include: a display driver for controlling and allowing access to a display device, a touch screen driver for controlling and allowing access to a touch screen interface, a sensor driver for obtaining sensor readings of the sensor circuit 1020 and controlling and allowing access to the sensor circuit 1020, a driver for obtaining an actuator position of an electromechanical component or controlling and allowing access to an electromechanical component, a camera driver for controlling and allowing access to an embedded image capture device, and an audio driver for controlling and allowing access to one or more audio devices.

[0109] The PMIC 1024 may manage power provided to various components of the UE 1000. Specifically, with respect to the processor 1004, the PMIC 1024 may control power source selection, voltage scaling, battery charging, or DC-DC conversion.

[0110] In some embodiments, the PMIC 1024 may control or otherwise be part of various power saving mechanisms of the UE 1000. For example, if the platform UE is in the RRC_Connected state, in which the platform is still connected to the RAN node because it expects to receive traffic soon, then after a period of inactivity, the platform may enter a state known as discontinuous reception mode (DRX). During this state, the UE 1000 may be powered off for short time intervals, thereby saving power. If there is no data traffic activity for an extended period of time, the UE 1000 may transition to the RRC_Idle state, in which the UE is disconnected from the network and no operations are performed, such as channel quality feedback, handover, etc. The UE 1000 enters a very low power state and performs paging, in which the UE wakes up again periodically to listen to the network and then powers off again. The UE 1000 may not receive data in this state; in order to receive data, the platform must transition back to the RRC_Connected state. Additional power saving modes may prevent the device from using the network for a time exceeding the paging interval (from a few seconds to a few hours). During this time, the device is completely unable to connect to the network and can be completely powered off. Any data transmitted during this time will incur significant latency, and it is assumed that latency is acceptable.

[0111] The battery 1028 can power the UE 1000, but in some examples, the UE 1000 can be installed in a fixed location and can have a power source coupled to the power grid. The battery 1028 can be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some specific implementations, such as in vehicle-based applications, the battery 1028 can be a typical lead-acid automobile battery.

[0112] Fig.11 FIG. 1 illustrates a gNB 1100 according to some embodiments. The gNB 1100 may be similar to Figure 1 The gNB 108 is similar to and essentially interchangeable with it.

[0113] gNB 1100 may include a processor 1104, a RAN interface circuit 1108, a core network (CN) interface circuit 1112, and a memory / storage device circuit 1116.

[0114] The components of gNB 1100 may be coupled to various other components via one or more interconnects 1128.

[0115] The processor 1104, RAN interface circuit 1108, memory / storage circuit 1116 (including communication protocol stack 1110), antenna 1150 and interconnect 1128 may be similar to those of reference Fig.10 Like named elements are shown and described.

[0116] The CN interface circuitry 1112 may provide connectivity to a core network, e.g., a fifth generation core network (5GC) using a 5GC-compatible network interface protocol such as a Carrier Ethernet protocol or some other suitable protocol. Network connectivity may be provided to / from the gNB 1100 via optical fiber or wireless backhaul. The CN interface circuitry 1112 may include one or more dedicated processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN interface circuitry 1112 may include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0117] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0118] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods described in the following example section. For example, the baseband circuit described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below. For another example, the circuits associated with the UE, base station, network element, etc. described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples shown in the example section below.

[0119] Example

[0120] In the following sections, additional exemplary embodiments are provided.

[0121] Embodiment 1 includes a method implemented by a user equipment (UE), the method comprising: receiving configuration information indicating that at least eight sounding reference signal (SRS) resources are configured for non-codebook based transmission from a base station; receiving a channel state information reference signal (CSI-RS) from the base station; sending SRS to the base station using the at least eight SRS resources based on measurement of the CSI-RS; and receiving downlink control information (DCI) indicating a set of the at least eight SRS resources from the base station.

[0122] Embodiment 2 includes a method according to embodiment 1, wherein the DCI indicates the number of demodulation reference signal (DMRS) ports, and wherein the method further includes: determining an SRS resource indicator (SRI) based on a predefined SRS resource indicator (SRI)-DMRS port association; and determining the set of at least eight SRS resources based on the SRI.

[0123] Embodiment 3 includes the method according to embodiment 2, wherein the predefined SRI-DMRS port association indicates a corresponding set of SRS resources for each possible number of DMRS ports.

[0124] Embodiment 4 includes a method according to any of the preceding embodiments, wherein the DCI indication corresponds to an SRS resource indicator (SRI) combination, and wherein the method further includes: determining the number of demodulation reference signal (DMRS) ports associated with the SRI combination; and determining a resource set based on the number of DMRS ports.

[0125] Embodiment 5 includes the method of embodiment 4, wherein the number of DMRS ports is determined based on an SRI combination-DMRS port association.

[0126] Embodiment 6 includes the method according to embodiment 5, wherein the SRI combination-DMRS port association indicates a corresponding SRI combination for each possible number of DMRS ports or for all possible numbers of DMRS ports.

[0127] Embodiment 7 includes the method according to embodiment 5, wherein the SRI combination-DMRS port association indicates a corresponding SRI set or a corresponding candidate SRS resource set for each possible number of DMRS ports.

[0128] Embodiment 8 includes a method according to embodiment 5, wherein the SRI combination-DMRS port association is predefined or indicated by the base station to the UE based on radio resource control (RCC) signaling or medium access control (MAC) control element (CE).

[0129] Embodiment 9 includes the method according to embodiment 5, wherein the SRI is included in an SRI field of the DCI, and wherein the size of the SRI field is based on the total number of SRI combinations of all ranks that can be used for the non-codebook based transmission.

[0130] Embodiment 10 includes the method according to any preceding embodiment, further comprising: for each possible number of demodulation reference signal (DMRS) ports, indicating a corresponding SRS resource indicator (SRI) combination to the base station.

[0131] Embodiment 11 includes a method according to embodiment 10, wherein the DCI indicates the number of DMRS ports or the SRI, and wherein the method further comprises: determining the set of at least eight SRS resources based on the number of DMRS ports or the SRI.

[0132] Embodiment 12 includes the method according to any preceding embodiment, further comprising: indicating to the base station a corresponding number of SRS resource indicator (SRI) combinations for each possible number of demodulation reference signal (DMRS) ports.

[0133] Embodiment 13 includes a method according to any of the preceding embodiments, the method further comprising: determining an SRS resource indicator (SRI) based on the DCI; and determining the set of at least eight SRS resources based on the SRI, wherein the SRI is associated with a rank less than or equal to "X", wherein "X" is a positive integer, wherein the DCI has a first DCI format, and wherein the SRI is based on SRS resources configured for a second DCI format.

[0134] Embodiment 14 includes the method of embodiment 13, wherein "X" is equal to the number of SRS resources in the resource set configured for the second DCI format.

[0135] Embodiment 15 includes a method according to any of the preceding embodiments, the method further comprising: determining an SRS resource indicator (SRI) based on the DCI; and determining the set of at least eight SRS resources based on the SRI, wherein the SRI is associated with a rank greater than "X", wherein "X" is a positive integer, wherein the DCI has a first DCI format, and wherein the SRI indicates an SRS resource configured for the first DCI format.

[0136] Embodiment 16 includes a method according to any of the preceding embodiments, the method further comprising: transmitting an indication of a corresponding number of SRS resource indicator (SRI) combinations to the base station for each possible number of demodulation reference signal (DMRS) ports, wherein the indication is transmitted based on UE capability information, uplink control information, or a medium access control (MAC) control element (CE).

[0137] Embodiment 17 includes a method implemented by a base station, the method comprising: transmitting configuration information to a user equipment (UE) indicating that at least eight sounding reference signal (SRS) resources are configured for non-codebook based transmission; transmitting a channel state information reference signal (CSI-RS) to the UE; receiving an SRS transmission using the at least eight sounding reference signal (SRS) resources from the UE based on the CSI-RS; and transmitting downlink control information (DCI) indicating a set of the at least eight SRS resources to the UE.

[0138] Embodiment 18 includes the method according to embodiment 17, and the method further includes: transmitting an SRS resource indicator (SRI) combination-DMRS port association to the UE based on radio resource control (RCC) signaling or a medium access control (MAC) control element (CE), wherein the DCI indicates an SRI for selecting an SRI combination by the UE.

[0139] Embodiment 19 includes the method of embodiment 17 or 18, wherein the DCI indicates a number of demodulation reference signal (DMRS) ports, and wherein the number of DMRS ports is pre-associated with an SRS resource indicator (SRI).

[0140] Embodiment 20 includes a UE comprising means for performing one or more elements of the method according to any one of embodiments 1 to 16 or related thereto.

[0141] Embodiment 21 includes one or more non-transitory computer-readable media, which include instructions that, when executed by one or more processors of a UE, cause the UE to perform one or more elements of a method described in or related to any one of Embodiments 1 to 16.

[0142] Embodiment 22 includes a UE comprising logic, modules or circuits for performing one or more elements of a method according to any one of embodiments 1 to 16 or related thereto.

[0143] Embodiment 23 includes a UE comprising one or more processors and one or more computer-readable media, wherein the one or more computer-readable media include instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of a method described in or related to any one of Embodiments 1 to 16.

[0144] Embodiment 24 includes a system comprising means for performing one or more elements of the method according to any one of embodiments 1 to 16 or related thereto.

[0145] Embodiment 25 includes a network including means for performing one or more elements of the method according to any one of embodiments 17 to 19 or related thereto.

[0146] Embodiment 26 includes one or more non-transitory computer-readable media, which include instructions that, when executed by one or more processors of a network, cause the network to perform one or more elements of a method described in or related to any one of Embodiments 17 to 19.

[0147] Embodiment 27 includes a network including logic, modules or circuits for performing one or more elements of the method described in or related to any one of embodiments 17 to 19.

[0148] Embodiment 28 includes a network comprising: one or more processors and one or more computer-readable media, wherein the one or more computer-readable media include instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of a method described in or related to any one of Embodiments 17 to 19.

[0149] Embodiment 29 includes a system comprising means for performing one or more elements of the method according to any one of or related to Embodiments 17 to 19.

[0150] Unless explicitly stated otherwise, any of the above examples may be combined with any other example (or combination of examples). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In view of the above teachings, modifications and variations are possible or can be obtained from the practice of various embodiments.

[0151] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to include all such variations and modifications.

Claims

1. A user equipment (UE), wherein the user equipment (UE) include: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, configure the UE to: receiving, from a base station, configuration information indicating that at least eight sounding reference signal (SRS) resources are configured for non-codebook based transmission; receiving a channel state information reference signal (CSI-RS) from the base station; Sending an SRS to the base station using the at least eight SRS resources based on the measurement of the CSI-RS; as well as Downlink control information (DCI) indicating the set of at least eight SRS resources is received from the base station.

2. The UE of claim 1 , wherein the DCI indicates a number of demodulation reference signal (DMRS) ports, and wherein executing the instructions further configures the UE to: determining an SRS resource indicator (SRI) based on a predefined SRS resource indicator (SRI)-DMRS port association; and The set of the at least eight SRS resources is determined based on the SRI. 3 . The UE according to claim 2 , wherein the predefined SRI-DMRS port association indicates a corresponding SRS resource set for each possible number of DMRS ports.

4. The UE according to any one of claims 1 to 3, wherein the DCI indicates an SRS resource indicator (SRI) corresponding to an SRI combination, and wherein executing the instructions further configures the UE to: determining a number of demodulation reference signal (DMRS) ports associated with the SRI combination; and A resource set is determined based on the number of DMRS ports. 5 . The UE of claim 4 , wherein the number of DMRS ports is determined based on an SRI combination-DMRS port association. 6 . The UE according to claim 5 , wherein the SRI combination-DMRS port association indicates a corresponding SRI combination for each possible number of DMRS ports or for all possible numbers of DMRS ports. 7 . The UE according to claim 5 , wherein the SRI combination-DMRS port association indicates a corresponding SRI set or a corresponding candidate SRS resource set for each possible number of DMRS ports.

8. The UE according to claim 5, wherein the SRI combination-DMRS port association is predefined or indicated to the UE by the base station based on radio resource control (RCC) signaling or medium access control (MAC) control element (CE).

9. The UE of claim 5, wherein the SRI is included in an SRI field of the DCI, and wherein a size of the SRI field is based on a total number of SRI combinations of all ranks that can be used for the non-codebook based transmission.

10. The UE according to any one of claims 1 to 9, wherein executing the instructions further configures the UE to: For each possible number of demodulation reference signal (DMRS) ports, a corresponding SRS resource indicator (SRI) combination is indicated to the base station.

11. The UE of claim 10, wherein the DCI indicates the number of DMRS ports or the SRI, and wherein executing the instructions further configures the UE to: The set of the at least eight SRS resources is determined based on the number of DMRS ports or the SRI.

12. The UE according to any one of claims 1 to 11, wherein executing the instructions further configures the UE to: For each possible number of demodulation reference signal (DMRS) ports, a corresponding number of SRS resource indicator (SRI) combinations is indicated to the base station.

13. The UE according to any one of claims 1 to 12, wherein executing the instructions further configures the UE to: determining an SRS resource indicator (SRI) based on the DCI; and The set of at least eight SRS resources is determined based on the SRI, wherein the SRI is associated with a rank less than or equal to "X", wherein "X" is a positive integer, wherein the DCI has a first DCI format, and wherein the SRI is based on SRS resources configured for a second DCI format.

14. The UE of claim 13, wherein "X" is equal to the number of SRS resources in the resource set configured for the second DCI format.

15. The UE according to any one of claims 1 to 14, wherein executing the instructions further configures the UE to: determining an SRS resource indicator (SRI) based on the DCI; and The set of at least eight SRS resources is determined based on the SRI, wherein the SRI is associated with a rank greater than "X", wherein "X" is a positive integer, wherein the DCI has a first DCI format, and wherein the SRI indicates an SRS resource configured for the first DCI format.

16. A method implemented by a base station, the method include: transmitting, to a user equipment (UE), configuration information indicating that at least eight sounding reference signal (SRS) resources are configured for non-codebook based transmission; transmitting a channel state information reference signal (CSI-RS) to the UE; receiving, from the UE, a sounding reference signal (SRS) transmission using the at least eight SRS resources based on the CSI-RS; as well as Downlink control information (DCI) indicating the set of at least eight SRS resources is transmitted to the UE.

17. The method according to claim 16, further comprising: include: An SRS resource indicator (SRI) combination-DMRS port association is transmitted to the UE based on radio resource control (RCC) signaling or a medium access control (MAC) control element (CE), wherein the DCI indicates an SRI for selecting an SRI combination by the UE.

18. The method according to any one of claims 16 to 17, wherein the DCI indicates a number of demodulation reference signal (DMRS) ports, and wherein the number of DMRS ports is pre-associated with an SRS resource indicator (SRI).

19. One or more computer-readable storage media storing instructions that, when executed on a user equipment (UE), cause the UE to perform operations comprising: receiving, from a base station, configuration information indicating that at least eight sounding reference signal (SRS) resources are configured for non-codebook based transmission; receiving a channel state information reference signal (CSI-RS) from the base station; sending an SRS to the base station using the at least eight SRS resources based on measurement of the CSI-RS; and Downlink control information (DCI) indicating the set of at least eight SRS resources is received from the base station.

20. The one or more computer-readable storage media of claim 19, wherein the operations further include: For each possible number of demodulation reference signal (DMRS) ports, an indication of a corresponding number of SRS resource indicator (SRI) combinations is transmitted to the base station, wherein the indication is transmitted based on UE capability information, uplink control information, or a medium access control (MAC) control element (CE).

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