User Equipment and Base Stations

Abstract

To provide a method and a device for transmitting a reference signal (RS).SOLUTION: In a method 300 performed by a network device 110, a first set of RS resources is determined to perform RS transmission by the network device. The first set of the RS resources is associated with a first number of RS ports used for the RS transmission, and corresponds to a first set of resource elements (RE) interpolated by unused RE on frequency domain. In the method, a first RS configuration for the RS transmission is generated based on the first set of the RS resources, and information regarding the first RS configuration is transmitted to a terminal device 120 to be serviced by the network device.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to the field of telecommunications, and more particularly, to a method and apparatus for reference signal (RS) transmission. [Background technology]

[0002] With the development of communication technology, several types of services or traffic are proposed, such as enhanced mobile broadband (eMBB), which generally requires high data rates, massive machine type communication (mMTC), which usually requires long battery life, and ultra-reliable and low latency communication (URLLC). Meanwhile, for new radio access, multi-antenna methods such as beam management and reference signal transmission are being researched. In particular, it is agreed in the 3GPP specifications that the Channel State Information-Reference Signal (CSI-RS) can support beam sweeping within an Orthogonal Frequency Division Multiplexing (OFDM) symbol.

[0003] CSI-RS should support transmit (Tx) and receive (Rx) beam sweeping, which can help the terminal device find a good Tx-Rx beam pair. To obtain the optimal Tx-Rx beam pair, N t Tx beam and N r If there are N Rx beams, the CSI-RS will have a total of N t ×N rIf each repetition takes one symbol, then a total of N t ×N r symbols may be required. The number of antennas at a particular Tx / Rx point (e.g., NodeB for new wireless access) and terminal device may be large, which means a large number of beams to be swept. In this case, overhead and delay reduction schemes for CSI-RS transmission need to be considered. Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the exemplary embodiments of the present disclosure provide a method and apparatus for RS transmission. [Means for solving the problem]

[0005] In a first aspect, a method implemented in a network device is provided. According to the method, a first set of RS resources is determined by the network device for RS transmission. The first set of RS resources is associated with a first number of RS ports used for RS transmission and corresponds to a first set of resource elements (REs) interpolated by unused REs in the frequency domain. A first RS configuration for RS transmission is generated based on the first set of RS resources. Information regarding the first RS configuration is transmitted to a terminal device served by the network device.

[0006] In a second aspect, a method implemented in a terminal device is provided. According to the method, information regarding a first RS configuration for RS transmission by the network device is received from the network device. The first RS configuration is determined based on a first set of RS resources for the RS transmission. The first set of RS resources is associated with a first number of RS ports used for the RS transmission and corresponds to a first set of REs, which is interpolated by at least one unused RE in the frequency domain. At least one RS sequence is detected based on the first RS configuration.

[0007] In a third aspect, a network device is provided. The network device has a processor and a memory coupled to the processor. The memory stores instructions that, when executed by the processor, cause the network device to perform actions. The actions include determining a first set of RS resources for RS transmission by the network device. The first set of RS resources is associated with a first number of RS ports used for RS transmission and corresponds to a first set of REs interpolated by unused REs in the frequency domain. The actions further include generating a first RS configuration for RS transmission based on the first set of RS resources, and transmitting information about the first RS configuration to a terminal device served by the network device.

[0008] In a fourth aspect, a terminal device is provided. The terminal device has a processor and a memory coupled to the processor. The memory stores instructions that, when executed by the processor, cause the network device to perform actions. The actions include receiving, from the network device, information regarding a first reference signal (RS) configuration for RS transmission by the network device. The first RS configuration is determined based on a first set of RS resources for the RS transmission. The first set of RS resources is associated with a first number of RS ports used for the RS transmission and corresponds to a first set of resource elements (REs) interpolated by at least one unused RE in the frequency domain. The actions further include detecting at least one RS sequence based on the first RS configuration.

[0009] Other features of the present disclosure will become readily apparent from the following description. [Brief description of the drawings]

[0010] The above and other objects, features, and advantages of the present disclosure will become more apparent through a more detailed description of several embodiments of the present disclosure in the accompanying drawings.

[0011] [Figure 1] FIG. 1 is a block diagram of a communication environment in which embodiments of the present disclosure may be implemented.

[0012] [Diagram 2] FIG. 2 is a flowchart illustrating a process for RS transmission, according to some embodiments of the present disclosure.

[0013] [Diagram 3] FIG. 3 is a flowchart of an example method according to some embodiments of the present disclosure.

[0014] [Figure 4A]FIG. 4A illustrates an example of selection of a first set of RS resources from a predetermined set of RS resources in accordance with some embodiments of the disclosure. [Figure 4B] FIG. 4B illustrates an example of selection of a first set of RS resources from a predetermined set of RS resources in accordance with some embodiments of the disclosure.

[0015] [Diagram 5] FIG. 5 is a diagram illustrating an example of selection of a first set of RS resources from a predetermined set of RS resources according to another embodiment of the present disclosure.

[0016] [Figure 6] FIG. 6 is a flowchart of an example method according to some embodiments of the present disclosure.

[0017] [Figure 7] 7A-7D are diagrams illustrating examples of configuring a second set of RS resources according to some embodiments of the present disclosure.

[0018] [Figure 8A] FIG. 8A illustrates an example of an RPF indication in an RS configuration in accordance with some embodiments of the present disclosure.

[0019] [Figure 8B] FIG. 8B is a diagram illustrating example information regarding a second RS configuration, according to some embodiments of the present disclosure.

[0020] [Figure 9] FIG. 9 is a flowchart of an exemplary method according to some embodiments of the present disclosure.

[0021] [Figure 10] 10A-10B are diagrams illustrating example resource mapping of different RS sequences according to some embodiments of the present disclosure.

[0022] [Figure 11] 11A-11B are diagrams illustrating example resource mapping of different RS sequences according to some embodiments of the present disclosure.

[0023] [Figure 12] 12A-12B are diagrams illustrating examples of different power configurations for RS transmissions, according to some embodiments of the present disclosure.

[0024] [Figure 13] FIG. 13 is a diagram illustrating an example of an SRS configuration associated with a CSI-RS configuration, in accordance with some embodiments of the present disclosure.

[0025] [Figure 14] FIG. 14 is a block diagram of a network device according to some embodiments of the disclosure.

[0026] [Figure 15] FIG. 15 is a block diagram of a terminal device according to some embodiments of the disclosure.

[0027] [Figure 16] FIG. 16 is a simplified block diagram of a device suitable for practicing embodiments of the present disclosure.

[0028] Throughout the drawings, the same or similar reference numbers represent the same or similar elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The subject matter of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described solely for the purpose of enabling those skilled in the art to better understand and practice the present disclosure, without implying any limitation to the scope of the present disclosure. The disclosure described herein can be implemented in various ways other than those described below.

[0030] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0031] The term "network device" or "base station" (BS) as used herein refers to a device that can provide or host a cell or coverage through which terminal devices can communicate. Examples of network devices include, but are not limited to, a Node B (NodeB or NB), an Evolved NodeB (eNodeB or eNB), a next generation NodeB (gNB), a Remote Radio Unit (RRU), a radio head (RH), a remote radio head (RRH), and low power nodes such as femto nodes, pico nodes, etc. For purposes of discussion, some embodiments are described below with reference to a gNB as an example of a network device.

[0032] The term "terminal device" as used herein refers to any device having wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to, user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, image capture devices such as digital cameras, gaming devices, music storage and playback appliances, or Internet appliances that enable wireless or wired Internet access and browsing, etc. For purposes of discussion, some embodiments are described below with reference to a UE as an example of a terminal device.

[0033] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. The term "comprises" and variations thereof are read as open terms meaning "including, but not limited to." The term "based on" is read as "based at least in part on." The terms "one embodiment" and "embodiment" are read as "at least one embodiment." The term "another embodiment" is read as "at least one other embodiment." The terms "first," "second," and the like may refer to different objects or the same object. Other definitions, both explicit and implicit, may be included below.

[0034] In some instances, values, procedures, or devices may be referred to as "best," "lowest," "highest," "minimum," "maximum," etc. It will be understood that such descriptions are intended to illustrate that selections may be made from among many functional options available, and that no such selection is necessarily better, lesser, more expensive, or otherwise preferred than other options.

[0035] The communications discussed in this disclosure may conform to any suitable standard, including, but not limited to, New Radio Access (NR), Long Term Evolution (LTE), LTE Evolution, LTE Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), and the like. Furthermore, the communications may be performed according to any generation of communications protocols now known or developed in the future. Examples of communications protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, and fifth generation (5G) communications protocols.

[0036] FIG. 1 illustrates an exemplary communication network 100 in which embodiments of the present disclosure may be implemented. The network 100 includes a network device 110 and three terminal devices 120-1, 120-2, and 120-3 (collectively referred to as terminal devices 120 or individually referred to as terminal devices 120) served by the network device 110. The coverage of the network device 110 is also referred to as a cell 102. It should be understood that the number of base stations and terminal devices is for illustrative purposes only, without implying any limitation. The network 100 may include any suitable number of base stations and terminal devices adapted to implement embodiments of the present disclosure. Although not illustrated, it will be understood that there may be one or more neighboring cells adjacent to the cell 102, with one or more corresponding network devices serving a number of terminal devices located therein.

[0037] The network devices 110 can communicate with the terminal devices 120. Communications in the network 100 may conform to any suitable standard, including, but not limited to, Long Term Evolution (LTE), LTE Evolution, LTE Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), and the like. Furthermore, the communications may be performed according to any generation of communications protocols now known or developed in the future. Examples of communications protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, and fifth generation (5G) communications protocols.

[0038] In addition to normal data communications, the network device 110 may transmit RS in a broadcast, multicast, and / or unicast manner to one or more terminal devices 120 on the downlink. Similarly, one or more terminal devices 120 may transmit RS to the network device 110 on the uplink. As used herein, "downlink" refers to a link from a network device to a terminal device, and "uplink" refers to a link from a terminal device to a network device. For purposes of discussion and without implying limitation, the following description describes some embodiments with respect to downlink RS transmission.

[0039] For example, for downlink RS transmission, the RS may be used by the terminal device 120 for beam sweeping, channel estimation, demodulation, and other operations for communication. In general, the RS is a signal sequence (also referred to as an "RS sequence") that is known by both the network device 110 and the terminal device 120. For example, the RS sequence may be generated and transmitted by the network device 110 based on a certain rule, and the terminal device 120 may estimate the RS sequence based on the same rule. Examples of RS include, but are not limited to, a downlink or uplink Demodulation Reference Signal (DMRS), a Channel State Information-Reference Signal (CSI-RS), a Sounding Reference Signal (SRS), a Phase Tracking Reference Signal (PTRS), etc. For discussion purposes without implying any limitation, the following description will describe some embodiments with reference to the CSI-RS as an example of an RS.

[0040] For downlink and uplink RS transmissions, the network device 110 may allocate corresponding resources (also referred to as "RS resources") for the transmission and / or specify which RS sequences should be transmitted. In some scenarios, both the network device 110 and the terminal device 120 are equipped with multiple antenna ports (or multiple antenna elements) and can transmit the specified RS sequences using the antenna ports (antenna elements). A set of multiple RS resources associated with the multiple RS ports is also specified. An RS port may be referred to as a particular mapping of part or all of an RS sequence to one or more resource elements of a resource region allocated for RS transmission in the time domain, frequency domain, and / or code domain.

[0041] As mentioned above, the CSI-RS should support Tx and Rx beam sweeping within an OFDM symbol to enable the terminal device to find the optimal Tx-Rx beam pair. To obtain the optimal Tx-Rx beam pair, N t Tx beam and N r If there are N Rx beams, the CSI-RS will have a total of N t ×N r If each repetition takes one symbol, then a total of N t ×N r symbols may be required. As the number of antennas in the network device and terminal device increases, the number of beams to be swept increases. This may result in significant overhead and delay for CSI-RS transmission.

[0042] To solve one or more of the above problems and other potential problems, a solution for RS transmission is provided according to an example embodiment of the present disclosure. The solution may provide a nested structure of RS resources based on IFDMA (Interleaved Frequency Division Multiple Access) technology. This nested structure of RS resources can support multiple repeating signals within one symbol in the time domain, so that a terminal device can detect multiple beams within one symbol. Furthermore, with this solution, multiple RS sequences can be mapped to different or the same multiple RS resources, so that a terminal device can detect multiple RS sequences simultaneously. Therefore, the solution according to the embodiment of the present disclosure can significantly reduce the overhead and latency of RS transmission.

[0043] The principles and implementations of the present disclosure are described in detail below with reference to Figures 2-14, where Figure 2 illustrates a general process 200 for RS transmission according to some embodiments of the present disclosure. For purposes of discussion, the process 200 is described with reference to Figure 1. The process 200 may include a network device 110 and one or more terminal devices 120 served by the network device 110.

[0044] The network device 110 may configure (set) some information for RS transmission (210). The information configured by the network device 110 may include configuration of at least one of the following: number of RS ports, RS resources, transmission pattern, density, at least one RS sequence, repetition factor, transmission power, etc. The network device may indicate the information to the terminal device 120 by transmitting the RS configuration (220). The terminal device 120 may receive the configured information for RS transmission from the network device 110 (230). The network device 110 may transmit an RS to the terminal device 120 based on the RS configuration (240). The terminal device 120 may receive the transmitted RS based on the RS configuration (250).

[0045] 3 shows a flowchart of an example method 300 according to some embodiments of the present disclosure. For purposes of discussion, the method 300 will be described with reference to FIG. 1. The method 300 may include a network device 110 and one or more terminal devices 120 serviced by the network device 110.

[0046] At operation 310, network device 110 determines a first set of RS resources for RS transmission by network device 110. The first set of RS resources may be associated with a first number of RS port groups used for RS transmission and correspond to a first set of REs in the frequency domain. In some embodiments, the first set of RS resources may be selected from a predetermined set of RS resources associated with a predetermined number of RS ports. In one embodiment, the first set of RS resources may be configured by the first number of RS port groups and a repetition factor.

[0047] In one embodiment, the above first number may be equal to or less than a predetermined number of RS ports. The predetermined number (represented by N) may be the same as the maximum number of supported RS ports. For example, when the maximum number of RS ports is represented by M, the above first number may be set to an integer less than or equal to M, such as 1, 2, …, M. In other embodiments, the predetermined number N may be less than the maximum number of supported RS ports, for example, N < M. And the first number of RS ports associated with the first set of RS resources may be set to an integer not greater than N (such as 1, 2, …, N).

[0048] In one embodiment, the maximum number of RS ports may be set to 8. And the above first number may be set to any one of 1, 2, 4, 8. In other embodiments, the above predetermined number may be less than the maximum number of supported RS ports, for example, 4. And the first number of the group of RS ports associated with the first set of RS resources may be set to any one of 1, 2, 4.

[0049] In one embodiment, the repetition factor may be set based on the capabilities of the terminal device 120 (for example, whether the terminal device 120 can detect multiple beams within one symbol). The repetition factor (RPF: repetition factor) may indicate the density of RS resources in the frequency domain. For example, when RPF is equal to K (K > 1), it may indicate that K - 1 unused REs are interpolated between two adjacent REs for RS transmission. As is known to those skilled in the art, the K - 1 unused REs interpolated between each two adjacent REs may result in K repeated signals within one symbol in the time domain.

[0050] In one embodiment, the network device 110 may select a first set of RS resources from a predetermined set of RS resources associated with a predetermined number of RS ports based on the first number of RS ports and the repetition factor. That is, a subset of the predetermined set of RS resources may be set to be the first set of RS resources.

[0051] In one embodiment, for example, FIG. 4A shows some examples of the selection of the first set of RS resources from a predetermined set of RS resources. FIG. 4A shows different sets of a plurality of RS resources associated with a plurality of different RS ports when the RPF is equal to K. In FIG. 4A, each element represents a RE in the frequency domain. The occupied elements (i.e., the shaded elements) represent the REs for RS transmission, while the unoccupied elements (i.e., the blank or cross-hatched elements) represent the unused REs.

[0052] As shown in FIG. 4A, for example, the predetermined set of RS resources is set such that the RPF value is K (also referred to as "RPF-K", where K is an integer and K > 1). (K - 1) unused REs are arranged between two adjacent REs for RS transmission. In one embodiment, when the first number of RS ports is Q, a resource set for Q RS ports (also abbreviated as "Q-port RS resources") may be selected as the first set of RS resources. In another embodiment, when the Q-port RS resources are determined, P-port RS resources (where P is an integer and 1 ≤ P < Q) may be selected from the Q-port RS resources. For example, Q is a multiple of P. In another embodiment, the P-port RS resources may be a subset of the Q-port RS resources, and the unselected resources may be unused for P RS ports.

[0053] In another embodiment, for example, FIG. 4B illustrates several examples of selection of a first set of RS resources from a given set of RS resources. FIG. 4B illustrates different sets of RS resources associated with different RS ports when RPF is equal to 2. In FIG. 4B, each element may represent an RE in the frequency domain. The occupied elements (i.e., elements filled with shaded or indexed with capital letters) may represent REs for RS transmission, and the unoccupied elements (i.e., elements filled with blanks or crosses) may represent unused REs. Specifically, each of the capital letters A-H may represent an index of an RS port associated with a RE for RS transmission.

[0054] As shown in FIG. 4B, for example, the predetermined set of RS resources may be represented by resource set 410 having an RPF value of 2. As shown by resource set 410, one unused RE is located between every two adjacent REs for RS transmission. If the first number of RS ports is set to be 8, 8-port RS resources 411 may be selected as the first set of RS resources. Similarly, if 8-port RS resources are determined, 4-port RS resources, such as a subset of 8-port RS resources, may be selected from the 8-port RS resources. Examples of 4-port RS resources are shown as 412-414, which are multiple subsets of 8-port RS resources 411. If 8-port RS resources and / or 4-port RS resources are determined, 2-port RS resources, such as a subset of 8-port RS resources and / or 4-port RS resources, may be selected from the 8-port RS resources and / or 4-port RS resources. Examples of 2-port RS resources are shown as 415-419, each of which is a subset of either the 8-port RS resource 411 or the 4-port RS resource 412-414. If the 8-port RS resource, the 4-port RS resource, and / or the 2-port RS resource is determined, then the 1-port RS resource may be selected from any of the 8-port RS resource, the 4-port RS resource, and / or the 2-port RS resource. For example, the 1-port RS resource may be a subset of any of the 8-port RS resource, the 4-port RS resource, and / or the 2-port RS resource. Examples of 1-port RS resources are shown as 420-427, each of which is a subset of any of the 8-port RS resource 411, the 4-port RS resource 412-414, and the 2-port RS resource 415-419. In this manner, a nested structure of RS resources based on IFDMA technology may be provided.

[0055] Similarly, FIG. 5 illustrates several examples of selection of a first set of RS resources from a predefined set of RS resources according to another embodiment of the present disclosure. FIG. 5 illustrates different sets of RS resources associated with different RS ports when the repetition factor is equal to 4. In FIG. 5, each element represents an RE in the frequency domain. The occupied elements (i.e., elements filled with shades or indexed with capital letters) may represent REs for RS transmission, and the unoccupied elements (i.e., elements filled with blanks or crosses) may represent unused REs. Specifically, each of the capital letters A-H may represent an index of an RS port associated with a RE for RS transmission.

[0056] As shown in FIG. 5, for example, the predetermined set of RS resources may be represented by resource set 510 having an RPF value of 4. As shown by resource set 510, three unused REs are located between each two adjacent REs for RS transmission. If a first number of RS ports is configured to be eight, 8-port RS resources 511 may be selected as the first set of RS resources. Similarly, if 8-port RS resources are determined, 4-port RS resources, such as a subset of 8-port RS resources, may be selected from the 8-port RS resources. Examples of 4-port RS resources are shown as 512-513, which are subsets of 8-port RS resources 511. If 8-port RS resources and / or 4-port RS resources are determined, 2-port RS resources, such as a subset of 8-port RS resources and / or 4-port RS resources, may be selected from the 8-port RS resources and / or 4-port RS resources. Examples of 2-port RS resources are shown as 514-517, each of which is a subset of either the 8-port RS resources 511 or the 4-port RS resources 512-513. If 8-port RS resources, 4-port RS resources, and / or 2-port RS resources have been determined, then 1-port RS resources may be selected from either the 8-port RS resources, 4-port RS resources, and / or 2-port RS resources. For example, the 1-port RS resources may be a subset of any of the 8-port RS resources, 4-port RS resources, and / or 2-port RS resources. Examples of 1-port RS resources are shown as 518-525, each of which is a subset of any of the 8-port RS resources 511, the 4-port RS resources 512-513, and the 2-port RS resources 514-517.

[0057] In one embodiment, RS ports with different indices may be associated with beams. For example, one beam associated with one RS port with index A may be different from another beam associated with another RS ​​port with index B. In another embodiment, the multiple RS ports may not be multiplexed with an orthogonal cover code (OCC).

[0058] 3, the method 300 moves to operation 320, where the terminal device 110 generates an RS configuration for RS transmission (also referred to as "first RS configuration" in the following description) based on the first set of RS resources. As used herein, an RS configuration is used to specify one or more aspects of the transmission of an RS, such as the set of RS resources used for the transmission and / or at least one RS sequence to be transmitted. In some embodiments, the first RS configuration may specify the first set of RS resources to be used for the RS transmission.

[0059] At operation 330, network device 110 transmits information regarding the first RS configuration to terminal device 120. The information may indicate to terminal device 120 one or more aspects of RS transmission specified in the first RS configuration. For example, based on the first RS configuration, the information may indicate to terminal device 120 that a first set of RS resources is to be used in RS transmission.

[0060] In operation 340, the terminal device 120 receives information regarding a first RS configuration from the network device 110. The terminal device 120 may determine how RS transmission is performed from the first RS configuration. For example, the terminal device 120 may be configured with a first set of RS resources to be used for RS transmission. The terminal device 120 may be configured with the first set of RS resources, which corresponds to a first set of REs, interpolated by unused REs in the frequency domain.

[0061] In one embodiment, in addition to the set of multiple RS resources (e.g., a first set of RS resources) used for RS transmission, the network device 110 may also configure at least one RS sequence for the terminal device 120. The network device 110 may transmit at least one RS sequence based on the configuration to the terminal device 120. For example, the network device 110 may transmit at least one sequence using the configured set of RS resources. Then, on the receiving side, the terminal device 120 may detect the at least one sequence based on its RS configuration.

[0062] In some embodiments, multiple RS configurations may be configured for different purposes. The multiple RS configurations may be configured based on different RS resources and / or different RS sequences. For example, different RS resources may be used for transmission of different RSs from different TRPs, different beams, and / or different antenna panels.

[0063] To configure different RS resources for RS transmission, FIG. 6 illustrates an example method 600 for RS transmission according to some embodiments of the present disclosure. For purposes of discussion, the method 600 is described with reference to FIG. 1. The method 600 may include a network device 110 and one or more terminal devices 120 served by the network device 110. Also, additional operations (not shown) may be included and / or illustrated operations may be omitted. The scope of the present disclosure described herein is not limited in this respect.

[0064] At operation 610, the network device 110 determines a second set of RS resources for RS transmission from the predetermined set of RS resources and based at least in part on the first RS configuration, The second set of RS resources may correspond to a second set of REs in the frequency domain.

[0065] In some embodiments, the network device 110 may configure the second set of RS resources such that the second set of RS resources is associated with the same number of RS ports and repetition factor as the first set of RS resources. That is, the network device 110 may configure a different subset of the predetermined set of RS resources to be the second set of RS resources. With reference to FIG. 4B, for example, if the first number of RS ports is four and the first set of RS resources is configured to be 4-port RS resources 412, then 4-port RS resources 413 or 4-port RS resources 414 may be configured as the second set of RS resources. In some embodiments, the first set of RS resources and the second set of RS resources may be separated from each other in the frequency domain (as shown by 4-port RS resources 412 and 4-port RS resources 413). Alternatively, in other embodiments, the first set of RS resources may at least partially overlap with the second set of RS resources (as shown by 4-port RS resources 412 and 4-port RS resources 414). Similarly, if the first number of RS ports is two and the first set of RS resources is configured as 2-port RS resources 415, any of 2-port RS resources 416-419 may be configured as the second set of RS resources.

[0066] In some embodiments, the network device may configure the second set of RS resources based on the shift value in the frequency and / or time domain. For example, the network device 110 may configure the second set of RS resources by shifting at least a portion of the first set of REs with the shift value. In one embodiment, as shown in FIG. 4B, if the first set of RS resources is configured to be 4-port RS resources 412, the second set of RS resources may be configured by shifting at least a portion of the 4-port RS resources 412, and an example of the second set of RS resources may be shown as 413-414. Alternatively, if the first set of RS resources is configured to be 2-port RS resources 415, the second set of RS resources may be configured by shifting at least a portion of the 2-port RS resources 415, and an example of the second set of RS resources may be shown as 416-419. Alternatively, if the first set of RS resources is configured to be 1-port RS resources 420, then the second set of RS resources may be configured by shifting at least a portion of the 1-port RS resources 420, and an example of the second set of RS resources may be shown as 421-427.

[0067] In another embodiment, Figures 7A and 7D show examples of configuring a second set of RS resources according to some embodiments of the present disclosure. As shown in Figure 7D, if the first set of RS resources is configured to be 4-port RS resources 740, the second set of RS resources may be configured by shifting at least a portion of the 4-port RS resources 740, and an example of the second set of RS resources may be shown as 710 in Figure 7A. Alternatively, as shown in Figure 7D, if the first set of RS resources is configured to be 2-port RS resources 741, the second set of RS resources may be configured by shifting at least a portion of the 2-port RS resources 741, and an example of the second set of RS resources may be shown as 721-723 in Figure 7A. Alternatively, as shown in Figure 7D, if the first set of RS resources is configured to be 1-port RS resources 742, the second set of RS resources may be configured by shifting at least a portion of the 1-port RS resources 742, and an example of the second set of RS resources may be shown as 724-730 in Figure 7A.

[0068] In some embodiments, the network device may configure the second set of RS resources such that the second set of RS resources is associated with the same number of RS ports as the first set of RS resources and has a higher density than the first set of RS resources, e.g., the second set of RS resources may be associated with a smaller repetition factor than the first set of RS resources. In one embodiment, Figures 7B and 7D show examples of configuring the second set of RS resources according to some embodiments of the present disclosure. As shown in Figure 7B, if the first set of RS resources is configured as 4-port RS resources 710 or 740, then 4-port RS resources 731 or 732 may be configured in the second set of RS resources. If the first set of RS resources is configured as 2-port RS resources 741 or 722, then 2-port RS resources 734 may be configured in the second set of RS resources. Alternatively, if the first set of RS resources is configured as 2-port RS resources 721 or 723, then 2-port RS resources 733 or 735 may be configured in the second set of RS resources. Similarly, examples for 1-port RS resources are shown in 1-port RS resources 736 and 737.

[0069] In some embodiments, the network device may configure the second set of RS resources such that the second set of RS resources is associated with a different number of RS ports than the first set of RS resources but with the same repetition factor. For example, the second set of RS resources may be associated with a second number of RS ports, the second number being greater than the first number. In another example, the second number is a multiple of the first number. In this case, the second set of REs corresponding to the second set of RS resources in the frequency domain may include the first set of REs corresponding to the first set of REs with the same indexing. In this regard, FIG. 7C illustrates an example of configuring the second set of RS resources according to some embodiments of the present disclosure. As illustrated in FIG. 7C, if the first set of RS resources is configured to be 4-port RS resources 740, the second set of RS resources may be configured to be 8-port RS resources 738.

[0070] In some embodiments, the network device may configure the second set of REs such that the second set of RS resources is associated with a different number of RS ports than the first set of RS resources and such that the second set of RS resources is included in the first set of REs with the same index.

[0071] In one embodiment, FIG. 7D illustrates an example of configuring the second set of RS resources according to some embodiments of the present disclosure. As illustrated in FIG. 7D, if the first set of RS resources is configured to be 8-port RS resources (e.g., 8-port RS resources 739) and the second number of RS ports is four, the second set of RS resources may be configured for four RS ports. The second set of RS resources may be included in the 8-port RS resources, and the indexes of the four RS ports (i.e., the second set of RS resources) in the 4-port resources may be the same as the indexes of the four ports in the 8-port RS resources. An example of the second set of RS resources for four RS ports is illustrated as 740. Alternatively, if the second number of RS ports is two, the second set of RS resources may be configured for two RS ports, and the second set of RS resources may be included in the 8-port resources and / or the 4-port resources, and the indexes of the two RS ports may be the same as the indexes of the two ports in the 8-port resources 739 and / or the 4-port resources 740. An example of the second set of RS resources for two RS ports is illustrated as 741. Alternatively, if the second number of RS ports is one, the second set of RS resources may be configured for one RS port. The second set of RS resources may be included in the 8-port RS resources, the 4-port RS resources, and / or the 2-port RS resources, and the index for one RS port may be the same as the 8-port RS resources 739, the 4-port RS resources 740, and / or the 2-port RS resources 741. An example of the second set of RS resources for one RS port is shown as 742. It can be seen that the 1-port RS resources 740 are included in the 8-port RS resources 739 with the same index for the four RS ports. The 2-port RS resources 741 are included in the 8-port RS resources 739 and / or the 4-port RS resources 740 with the same index for the two RS ports.The 1-port RS resource 742 is included in the 8-port resource 739, the 4-port resource 740, and / or the 2-port resource 741 with the same index for one RS port.

[0072] 6, method 600 proceeds to operation 620, where terminal device 110 generates an RS configuration for RS transmission based on the second set of RS resources (also referred to as the "second RS configuration" in the following description). The second RS configuration may specify a second set of RS resources to be used for the RS transmission.

[0073] At operation 630, network device 110 transmits information regarding the second RS configuration to terminal device 120. The information may indicate to terminal device 120 one or more aspects of RS transmission specified in the second RS configuration. For example, based on the configured second RS configuration, the information may indicate to terminal device 120 that a second set of RS resources is to be used in RS transmission.

[0074] In some embodiments, the information about the RS configuration may include a corresponding RPF indication. FIG. 8A illustrates an example of an RPF indication in an RS configuration according to some embodiments of the present disclosure. For example, a network device may configure a set of multiple RPF values ​​for an RS configuration, as illustrated in FIG. 8A. The RS configuration may also include at least one configuration of time and / or frequency resources, a transmission pattern, a number of RS ports, at least one RS sequence, and the like. In another embodiment, different RPF configurations for different RS configurations may be different. In another embodiment, for some RS configurations, only one RPF value may be supported, and therefore, for the RS configuration, a corresponding RPF indication may not be required.

[0075] In another embodiment, the information about the RS configuration may include an indication of a corresponding RPF value. For example, the network device may already configure a first set of RS resources for RS transmission via a first RS configuration. In this case, the network device may further configure a second set of RS resources for RS transmission by indicating a different RPF to be applied to the first set of RS resources. For example, the information about the second RS configuration may include an optional field indicating a corresponding RPF. In this regard, FIG. 8B illustrates an example of information about a second RS configuration according to some embodiments of the present disclosure. As illustrated in FIG. 8B, if the first configuration corresponds to a 4-port RS resource 810 (i.e., a first set of RS resources) already configured in the terminal device 120, the network device 110 may indicate an RPF value of 2 or 4 to the terminal device 120 in the information about the second configuration. That is, the 4-port RS resource 810 can support different RPF values ​​for different RS configurations. However, the other three RS configurations 820-840 only support an RPF value that is 2. In this case, the information about the other three RS configurations 820-840 may not have a field to indicate the RPF value.

[0076] Returning to FIG. 6, the method 600 moves to operation 640, where the terminal device 120 receives information regarding a second RS configuration from the network device 110. The terminal device 120 may determine how RS transmission is to be performed from the second RS configuration. For example, the terminal device 120 may be configured with a second set of RS resources to be used for RS transmission. The terminal device 120 may be configured with the second set of RS resources corresponding to a second set of REs interpolated by unused REs in the frequency domain.

[0077] At operation 650, network device 110 may transmit at least one RS sequence based on the second configuration to terminal device 120. For example, network device 110 may transmit at least one sequence using the second set of configured RS resources, and at the receiving end of the RS transmission, at operation 660, terminal device 120 may detect at least the sequence based on the second RS configuration.

[0078] To simultaneously support detection of different RS sequences, FIG. 9 illustrates a process 900 for RS transmission according to some embodiments of the present disclosure. For purposes of discussion, the process 900 is described with reference to FIG. 1. The process 900 may include a network device 110 and one or more terminal devices 120 served by the network device 110. It should be understood that the process 900 may also comprise additional acts (not shown) and / or omit illustrated acts. The scope of the present disclosure described herein is not limited in this respect.

[0079] At operation 910, the network device 110 generates a third RS configuration for at least one RS sequence to be transmitted to the terminal device 120. In some embodiments, examples of the RS sequence may include, but are not limited to, a pseudorandom noise (PN) sequence, a Zadoff-Chu (ZC) sequence, or the like.

[0080] In some embodiments, the third RS configuration for at least one RS sequence may be dependent on the first RS configuration or the second RS configuration. In other embodiments, the third RS configuration may be included in the first RS configuration or the second RS configuration. That is, the first RS configuration or the second RS configuration may include configurations for both RS resources and RS sequences.

[0081] In some embodiments, the third RS configuration may indicate a number of RS sequences in the at least one RS sequence to be transmitted, or the third RS configuration may indicate which RS resources should be used to transmit different RS sequences.

[0082] In some embodiments, the third RS configuration may indicate that different RS sequences are transmitted on the same RS resource. In other embodiments, for example, the third RS configuration may indicate that different RS sequences are transmitted on different RS resources. Figures 10A and 10B are diagrams illustrating examples of resource mapping of different RS sequences according to some embodiments of the present disclosure. In Figure 10A, different RS sequences 1010 are mapped to the same RS resource. In Figure 10B, different RS sequences 1010 are mapped to different RS resources.

[0083] For example, in some embodiments, the at least one RS sequence may include at least a first RS sequence and a second RS sequence. The third RS configuration may indicate that the first RS sequence is transmitted on a first set of RS resources and the second RS sequence is transmitted on a second set of RS resources. Figures 11A and 11B show examples of resource mapping of different RS sequences according to some embodiments of the present disclosure. In Figure 11A, RS sequence 1110 and RS sequence 1120 are mapped to a 4-port RS resource 1130. In Figure 11B, RS sequence 1110 is mapped to a 4-port RS resource 1140 and RS sequence 1120 is mapped to another 4-port RS resource 1150.

[0084] Returning to FIG. 9, process 900 moves to operation 920, where the network device 110 transmits information regarding the third RS configuration to the terminal device 120.

[0085] In some embodiments, information regarding the 3RS configuration may be transmitted via high level signaling and / or dynamic signaling. Examples of high level signaling include, but are not limited to, signaling at the Radio Resource Control (RRC) layer or the Media Access Control (MAC) layer. Examples of dynamic signaling include, but are not limited to, Downlink Control Information (DCI).

[0086] In some embodiments, the network device 110 may perform multi-level configuration for multiple RS sequences. For example, the network device 110 may be configured with L (L≧1) RS sequences for the terminal devices 120 via higher layer signaling. The network device 110 may then configure G (1≦G≦L) RS sequences from the L RS sequences for some of the terminal devices 120 via higher layer signaling or dynamic signaling.

[0087] In operation 930, the terminal device 120 receives from the network device 110 a third RS configuration for at least one RS sequence. The terminal device 120 may be configured with the number of RS sequences to be transmitted. The terminal device 120 may also be configured with which RS resources are used to transmit the different RS sequences. In some embodiments, the terminal device 120 may be configured with the information that the different RS sequences are transmitted on the same RS resources. In other embodiments, the terminal device 120 may be configured with the information that the different RS sequences are transmitted on different RS resources. Specifically, in some embodiments, the at least one RS sequence may include at least a first RS sequence and a second RS sequence. The terminal device 120 may be configured with the information that the first RS sequence should be transmitted on a first set of RS resources and the second RS sequence should be transmitted on a second set of RS resources.

[0088] At operation 940, the network device 110 may transmit at least one RS sequence to the terminal device 120 based on the third configuration. Then, at operation 950, terminal device 120 may detect at least one RS sequence based on the third RS configuration.

[0089] The terminal device 120 may detect at least one RS sequence using RS resources indicated by the third RS configuration. For example, in some embodiments, the third RS configuration may indicate that the at least one RS sequence is transmitted using a first set of RS resources. In this case, the terminal device 120 may detect at least one RS sequence using the first set of RS resources. In other embodiments, the at least one RS sequence may include at least a first RS sequence and a second RS sequence. The third RS configuration may indicate that the first RS sequence is transmitted on the first set of RS resources and that the second RS sequence is transmitted on the second set of RS resources. In this case, the terminal device 120 may detect the first RS sequence on the first set of RS resources and detect the second RS sequence on the third set of RS resources.

[0090] In view of the above, the proposed solution for RS transmission can provide a nested structure of RS resources based on IFDMA technology. This nested structure of RS resources can support multiple repeated signals in one symbol in the time domain, so that a terminal device can detect multiple beams in one symbol. Furthermore, with this solution, multiple RS sequences can be mapped to different or the same multiple RS resources, so that a terminal device can detect multiple RS sequences simultaneously. Therefore, the solution according to the embodiment of the present disclosure can significantly reduce the overhead and latency for RS transmission.

[0091] In addition, the proposed solution may provide consideration regarding several other aspects of RS transmission.

[0092] For example, in some embodiments, RS resources for beam management may not be used for interference measurement. For example, some RS configurations may be configured for beam management. Those RS configurations may indicate some resources for RS transmission, and the resources indicated by the RS configurations may not be configured as resources for interference measurement.

[0093] In some embodiments, the RS resource for beam management may be configured in a partial band. For frequencies outside this partial band, other signals (Physical Downlink Shared Channel, Physical Downlink Control Channel, Synchronization Signal Block, etc.) may be transmitted instead of RS. For the transmission of other signals, the same RPF value as that of RS transmission may be applied.

[0094] In some embodiments, whether multiple beams can be detected within one symbol may depend on the capabilities of the terminal device. For example, in one embodiment, the terminal device may have different capabilities for detecting the RS. The terminal device may report information about the capabilities to the network device. In other embodiments, the network device may receive information about the capabilities, and the network device may configure the RS with an RPF value K based on the information about the capabilities. In another embodiment, the terminal device may have different capabilities for detecting the RS, and the reported information may be different based on the different capabilities. For example, in one embodiment, the terminal device may have different capabilities for detecting the RS, and the terminal device may detect multiple beams within one symbol. In this case, the terminal device may select one or more beams within one symbol and report the selection to the network device.

[0095] In some embodiments, power boosting may be applied to the set of RS resources allocated for RS transmission. The power of RS transmission for beam management may be different from the power of other RS ​​transmissions, e.g., RS transmission for CSI acquisition. In some embodiments, the power of RS transmission may have different power values ​​based on the RPF value and / or the number of RS ports. In one embodiment, the power values ​​may be different for different RPF configurations, e.g., as shown in FIG. 12A. In another embodiment, the power values ​​may be different for different numbers of RS ports, e.g., as shown in FIG. 12B.

[0096] In one embodiment, the network device may configure different power parameters for the terminal device, and the different power parameters may be associated with different RPF values ​​and / or different RS port numbers. In another embodiment, the network device may configure information about a reference power for the terminal device. The network may configure different power offset values ​​for the reference power for RS transmissions with different PRF values ​​and / or different RS port numbers. For example, the information about the reference power may be used to indicate the power of the RS transmission for reference. In another example, the information about the reference power may be used for RS transmissions with a fixed RPF value K and / or a fixed RS port number H.

[0097] In some embodiments, a configuration of SRS transmission may be associated with an RS configuration. For example, at least a portion of a plurality of SRS configurations may be mapped to at least a portion of a CSI-RS configuration, where the plurality of SRS configurations may include information regarding at least one of a plurality of SRS resources, a plurality of SRS sequences, a plurality of SRS transmission bands, etc. Furthermore, the CSI-RS configuration may indicate at least one of a CSI-RS resource, a CSI-RS port index, etc. In one embodiment, for example, at least a portion of a plurality of SRS resources and / or a plurality of SRS sequences is mapped to at least a portion of a plurality of CSI-RS resources, such as one or more CSI-RS ports. For example, as shown in FIG. 13, different plurality of SRS configurations may be associated with different plurality of CSI-RS ports. For example, each CSI-RS port corresponds to one beam. For example, when a terminal device selects one beam, the terminal device can transmit an SRS using the associated CSI-RS port.

[0098] FIG. 14 illustrates a block diagram of an apparatus 1400 according to some embodiments of the present disclosure. The apparatus 1400 may be considered as an example implementation of the network device 110 illustrated in FIG. 1. As illustrated, the apparatus 1400 includes a determining module 1410 configured to determine a first set of reference signal (RS) resources for RS transmission by the network device. The first set of RS resources is associated with a first number of RS ports used for RS transmission and corresponds to a first set of resource elements (REs) interpolated with a plurality of unused REs in the frequency domain. The apparatus 1400 also includes a generating module 1420 configured to generate a first RS configuration for RS transmission based on the first set of RS resources. In addition, the apparatus 1400 may also include a transmitting module 1430 configured to transmit information regarding the first RS configuration to a terminal device served by the network device.

[0099] FIG. 15 illustrates a block diagram of an apparatus 1500 according to some embodiments of the present disclosure. The apparatus 1500 may be regarded as an example implementation of the terminal device 120 illustrated in FIG. 1. As illustrated, the apparatus 1500 includes a receiving module 1510 configured to receive information about a first reference signal (RS) configuration for RS transmission by the network device from the network device. The first RS configuration is determined based on a first set of RS resources for the RS transmission. The first set of RS resources is associated with a first number of RS ports used for the RS transmission and corresponds to a first set of resource elements (REs) interpolated with at least one unused RE in the frequency domain. The apparatus 1500 also includes a detection module 1520 configured to detect at least one RS sequence based on the first RS configuration.

[0100] For clarity, FIG. 14 and / or FIG. 15 do not show some optional modules of the apparatus 1400 and / or the apparatus 1500. However, it should be understood that various features described with reference to FIG. 1-13 are applicable to the apparatus 1400 and / or the apparatus 1500. Furthermore, each module of the apparatus 1400 and / or the apparatus 1500 may be a hardware module or a software module. For example, in some embodiments, the apparatus 1400 and / or the apparatus 1500 may be implemented partially or fully by software and / or firmware, e.g., as a computer program product embodied in a computer-readable medium. Alternatively or additionally, the apparatus 1400 and / or the apparatus 1500 may be implemented partially or fully based on hardware, e.g., as an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system on chip (SOC), a field programmable gate array (FPGA), etc. The scope of the present disclosure is not limited in this aspect.

[0101] 16 is a simplified block diagram of a device 1600 suitable for implementing embodiments of the present disclosure. The device 1600 can be considered as a further exemplary implementation of the network device 110 or the terminal device 120 shown in FIG. 1. Thus, the device 1600 can be implemented in or at least as part of the network device 110 or the terminal device 120.

[0102] As shown, the device 1600 includes a processor 1610, a memory 1620 connected to the processor 1610, a suitable transmitter (TX) and receiver (RX) 1640 connected to the processor 1610, and a communication interface connected to the TX / RX 1640. The memory 1610 stores at least a portion of a program 1630. The TX / RX 1640 is for bidirectional communication. The TX / RX 1640 has at least one antenna to facilitate communication, although in practice the access nodes referred to in this application may have multiple antennas. The communication interface may represent an interface required for communication with other network elements, such as an X2 interface for bidirectional communication between eNBs, an S1 interface for communication between a Mobility Management Entity (MME) / Serving Gateway (S-GW) and an eNB, an Un interface for communication between an eNB and a relay node (RN), or an Uu interface between an eNB and a terminal device.

[0103] The program 1630 is assumed to include program instructions that, when executed by an associated processor 1610, enable the device 1600 to operate according to embodiments of the present disclosure as described herein with reference to FIGS. 1-13. The embodiments of the present disclosure may be implemented by computer software executable by the processor 1610 of the device 1600, or by hardware, or by a combination of software and hardware. The processor 1610 may be configured to implement various embodiments of the present disclosure. Furthermore, the combination of the processor 1610 and the memory 1610 may form a processing means 1650 adapted to implement various embodiments of the present disclosure.

[0104] The memory 1610 may be of any type suitable for a local technology network and may be implemented using any suitable data storage technology, such as, by way of non-limiting example, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Although only one memory 1610 is shown in the device 1600, the device 1600 may have several physically distinct memory modules. The processor 1610 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 1600 may have multiple processors, such as application specific integrated circuit chips, time-slaved to a clock that synchronizes the main processor.

[0105] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flowcharts, or some other pictorial representations, the blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting examples, hardware, software, firmware, dedicated circuits or logic, general-purpose hardware, or controllers, or other computing devices, or some combination thereof.

[0106] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in a program module and executed on a target real or virtual processor device, to perform a process or method described above with reference to any of Figures 1-13. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. The machine-executable instructions of the program modules may be executed in local or distributed devices. In distributed devices, the program modules may be located in both local and remote storage media.

[0107] The program codes for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, a special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, perform the functions / operations identified by the flowcharts and / or block diagrams above. The program codes may be executed as a stand-alone software package, entirely on the machine, partly on the machine, partly on the machine and partly on a remote machine, or entirely on a remote machine or server.

[0108] The above program code may be embodied in a machine-readable medium, which may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples of machine-readable storage media include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0109] Additionally, although operations are shown in a particular order, this should not be understood as requiring such operations to be performed in the particular order or sequential order shown, or that all of the shown operations be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features specific to certain embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0110] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the present disclosure, as defined by the appended claims, is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A user equipment (UE), means for receiving configuration information for configuring a first resource for a channel state information reference signal (CSI-RS); means for receiving the CSI-RS in the first resource; means for transmitting a Sounding Reference Signal (SRS) in an SRS resource associated with the first resource based on reception of the CSI-RS; Equipped with the first resource comprises one or more resource elements allocated for the CSI-RS; the first resource is within a first partial frequency band; The configuration information indicates a density of the CSI-RS, The UE does not receive the CSI-RS outside the first partial frequency band, and uses a density of the CSI-RS when receiving the CSI-RS. U.E.

2. means for determining information regarding a beam for transmitting the SRS; The UE of claim 1.

3. The SRS resource is a frequency domain resource configured by an SRS resource configuration; The UE of claim 1.

4. and means for selecting a configuration for the SRS by using the configuration information based on a detected beam of the CSI-RS. The UE of claim 1.

5. The configuration information indicates a port for the CSI-RS. The UE of claim 1.

6. A base station, means for transmitting, to a user equipment (UE), configuration information for configuring a first resource for a channel state information reference signal (CSI-RS); means for transmitting the CSI-RS in the first resource to the UE; means for receiving, from the UE, a Sounding Reference Signal (SRS) in an SRS resource associated with the first resource based on the transmission of the CSI-RS; Equipped with the first resource comprises one or more resource elements allocated for the CSI-RS; the first resource is within a first partial frequency band; The configuration information indicates a density of the CSI-RS, The base station does not transmit the CSI-RS outside the first partial frequency band, and uses a density of the CSI-RS when transmitting the CSI-RS. Base station.

7. Information regarding a beam for transmitting the SRS is determined by the UE; The base station according to claim 6.

8. The SRS resource is a frequency domain resource configured by an SRS resource configuration; The base station according to claim 6.

9. The configuration of the SRS is selected based on the detected beam of the CSI-RS by the UE using the configuration information. The base station according to claim 6.

10. The configuration information indicates a port for the CSI-RS. The base station according to claim 6.

Images