Adaptive application of orthogonal cover codes to resource elements in wireless communication systems

Abstract

Some aspects of the present disclosure relate to apparatus and methods for implementing a resource element configuration design for carrying reference signals for user equipment (UE). The reference signals may be processed by the UE according to the resource element configuration used to carry the reference signals. The configuration may be determined by the base station and received by the UE from the base station. The base station determines the configuration based on information or parameters provided by the UE, such as the channel coherence bandwidth, channel coherence time, preference associated with channel state information reference signals, or preference associated with demodulation reference signals for the UE.

Description

Background Art Technical Field

[0002] The described aspects generally relate to the adaptive application of orthogonal cover codes in wireless communications.

[0003] Related fields

[0004] A user equipment (UE) can communicate with a base station (e.g., an evolved NodeB (eNB), a next-generation NodeB (gNB), or other base stations) through a communication link in a wireless communication system (e.g., a new radio (NR) system, a millimeter wave (mmWave) communication system, or other communication system). In a communication system, a reference signal generally refers to a so-called "pilot signal" used by a receiver for channel-related functions (e.g., estimation, demodulation). Sometimes, a reference signal is a predefined signal transmitted via a set of predefined resource elements in a resource grid. The downlink reference signal is used by the UE for downlink channel measurement and / or coherent demodulation of downlink transmissions. In the downlink, various reference signals are defined, such as a cell-specific reference signal (CRS), a UE-specific demodulation reference signal (DMRS), a channel state information reference signal (CSI-RS), and the like. However, existing reference signal designs may not meet the diverse needs of various wireless communication systems (e.g., mmWave communication systems). Summary of the Invention

[0005] Some aspects of the present disclosure relate to apparatus and methods for adaptively configuring resource elements to carry reference signals for user equipment (UE) in a multiple-input multiple-output (MIMO) wireless communication system (e.g., a new radio (NR) MIMO system or a millimeter wave (mmWave) communication system). Based on the channel coherence bandwidth, channel coherence time, UE preference associated with a channel state information reference signal (CSI-RS), or UE preference associated with a demodulation reference signal (DMRS) between the UE and the base station, the resource element configuration for carrying the reference signal for the UE can be adaptively determined by the base station. The configuration indicates a set of resource elements and one or more orthogonal cover codes (OCCs) applied to at least a subset of the set of resource elements to carry CSI-RS or DMRS for one or more antenna ports of the UE.

[0006] Some aspects of the present disclosure relate to a UE. The UE includes: a transceiver configured to communicate with a base station via a channel between the UE and the base station; and a processor communicatively coupled to the transceiver. In some examples, the channel has one or more frequencies higher than 52 GHz (e.g., between 52.6 GHz and 71 GHz). Using the transceiver, the processor sends a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for the UE to the base station. Using the transceiver, the processor also receives a resource element configuration for carrying a reference signal for the UE from the base station. In detail, the processor may receive a radio resource control (RRC) signal, a medium access control (MAC) control element (CE), or downlink control information (DCI) to indicate a resource element configuration for carrying a reference signal for the UE. The configuration is determined by the base station based on or in response to the channel coherence bandwidth, the channel coherence time, the preference associated with the CSI-RS, or the preference associated with the DMRS. The configuration indicates a set of resource elements and one or more OCCs applied to at least a subset of the set of resource elements to carry CSI-RS or DMRS for one or more antenna ports of the UE. The one or more OCCs applied to at least a subset of the set of resource elements for one or more antenna ports may be semi-statically configured via RRC signaling or dynamically configured via MAC-CE or DCI. In some examples, the processor may allocate the subset of the set of resource elements or the OCCs applied to the subset of the set of resource elements to one of the one or more antenna ports of the UE. The UE may have multiple antenna ports, for example, 2, 4, 6, 8, 12, 16, or more antenna ports. Thereafter, based on the configuration of resource elements carrying reference signals for the UE, the processor performs DMRS or CSI-RS reference signal processing.

[0007] In some examples, a resource element configuration for carrying a reference signal for a UE indicates a set of resource elements comprising at least two adjacent resource elements at two consecutive subcarriers in the frequency domain and at one symbol in the time domain. Additionally and alternatively, the set of resource elements may comprise at least two adjacent resource elements at two consecutive subcarriers in the frequency domain and at two adjacent symbols in the time domain. Additionally, the resource element configuration for carrying a reference signal for a UE may indicate one or more OCCs comprising a frequency domain (FD) OCC applied to two adjacent resource elements at two consecutive subcarriers in the frequency domain. Similarly, the resource element configuration for carrying a reference signal for a UE may indicate one or more OCCs comprising a time domain (TD) OCC applied to two adjacent resource elements at two adjacent symbols in the time domain. In some examples, based on the relationship between a subcarrier spacing (SCS) between two consecutive subcarriers in the frequency domain and a channel coherence bandwidth, the resource element configuration for carrying a reference signal for a UE indicates that only FD-OCC or TD-OCC is applied. Additionally, in some examples, the subset of resource element sets to which one or more OCCs are applied is empty, and the configuration indicates that no OCC is applied to resource element sets allocated to one or more antenna ports of the UE.

[0008] Some aspects of the present disclosure relate to a base station. The base station includes a transceiver configured to communicate with a UE via a wireless network and a processor communicatively coupled to the transceiver. Using the transceiver, the processor receives a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for the UE from the UE. The processor also determines a resource element configuration for carrying a reference signal for the UE based on the channel coherence bandwidth, the channel coherence time, the preference associated with the CSI-RS, or the preference associated with the DMRS. The configuration indicates a resource element set and one or more OCCs applied to at least a subset of the resource element set to carry a CSI-RS or DMRS for one or more antenna ports of the UE. In a certain example, the processor may allocate a subset of the resource element set or the OCC applied to the subset of the resource element set to one of the one or more antenna ports of the UE. In addition, using the transceiver, the processor transmits a resource element configuration for carrying a reference signal for the UE to the UE. In detail, the processor transmits an RRC signal, a MAC-CE, or a DCI to indicate the resource element configuration for carrying a reference signal for the UE. One or more OCCs applied to at least a subset of resource element sets for one or more antenna ports are semi-statically configured via RRC signaling, or dynamically configured via MAC-CE or DCI.

[0009] This disclosure is provided for the purpose of illustrating some aspects only, so as to provide an understanding of the subject matter described herein. Therefore, the above features are merely examples and should not be construed as narrowing the scope or essence of the subject matter of this disclosure. Other features, aspects, and advantages of the present disclosure will become apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the disclosure and, together with the description, further serve to explain the principles of the disclosure and enable one skilled in the relevant art to make and use the disclosure.

[0011] Figure 1 An exemplary multiple-input multiple-output (MIMO) wireless system implementing a design of resource element configurations for carrying reference signals for user equipment (UE) according to aspects of the present disclosure is shown.

[0012] Figure 2

[0014] An example method is shown for a system (eg, user equipment (UE)) supporting mechanisms for implementing a design of resource element configurations for carrying reference signals for the UE, in accordance with aspects of the present disclosure.

[0013] Figure 3 An exemplary method is shown for a system (eg, a base station) supporting mechanisms for implementing a design of resource element configurations for carrying reference signals for a UE, in accordance with aspects of the present disclosure.

[0014] Figures 4A to 4B

[0026] Example resource element configurations for carrying reference signals for a UE according to some aspects of the present disclosure are shown.

[0015] Figures 5A to 5C

[0026] Example resource element configurations for carrying reference signals for a UE according to some aspects of the present disclosure are shown.

[0016] Figure 6 A block diagram of an exemplary system of an electronic device implementing a design of resource element configuration for carrying a reference signal for a UE according to some aspects of the present disclosure is shown.

[0017] Figure 7 is an exemplary computer system for implementing some aspects or portions of the disclosure provided herein.

[0018] The present disclosure is described with reference to the accompanying drawings. In the drawings, generally, like reference numerals indicate identical or functionally similar elements. Also, generally, the leftmost digit of a reference numeral identifies the drawing in which the reference numeral first appears. DETAILED DESCRIPTION

[0019] The following disclosure provides many different embodiments or examples for realizing the different features of the provided subject matter. In order to simplify the disclosure, specific examples of the various components and arrangements are described below. Of course, these are merely examples and are not intended to be limiting. In addition, in various examples, the disclosure may repeat reference numbers and / or letters. This repetition itself does not specify the relationship between the various embodiments and / or configurations discussed.

[0020] It should be noted that references to "one embodiment," "embodiment," "exemplary embodiment," "exemplary," etc. in the specification indicate that the embodiment described may include specific features, structures, or characteristics, but not every embodiment necessarily includes the specific features, structures, or characteristics. In addition, such wording does not necessarily refer to the same embodiment. In addition, when describing specific features, structures, or characteristics in conjunction with one embodiment, it would be within the knowledge of those skilled in the art to implement such features, structures, or characteristics in conjunction with other embodiments, whether explicitly described or not. In addition, the words "and" and "or" related to logical relationships may imply such logical relationships. For example, A or B may include "A and B" or "A or B."

[0021] Wireless communication networks and systems play an important role in today's society. Numerous wireless communication systems exist, such as those based on the 3rd Generation Partnership Project (3GPP) Release 16 (Rel-16), Release 17 (Rel-17), and New Radio (NR) systems. Next-generation wireless communication networks, such as NR systems, offer fast data rates and increased capacity, as well as seamless real-time interaction between humans and billions of smart devices. Millimeter wave (mmWave) communication systems operate at frequencies close to NR systems, such as one or more frequencies above 52 GHz, and can bring commercial opportunities for high-data-rate communications, such as in licensed or unlicensed spectrum between 57 GHz and 71 GHz.

[0022] Opportunities in mmWave communication systems also bring challenges. The operational design at mmWave communication systems may need to be different from that of NR systems. For example, mmWave communication systems may have different numerology, including subcarrier spacing (SCS) and channel bandwidth. Increased SCS can be used in millimeter wave communication systems to ensure the robustness of the system to phase noise. However, the increased SCS may cause the resource element spacing to be larger than the channel coherence bandwidth, causing some communication technologies to fail. In a communication system, a reference signal generally refers to a so-called "pilot signal" used by a receiver for channel functions (e.g., estimation or demodulation). Orthogonal cover codes (OCCs) have been applied to resource elements to carry various reference signals, such as UE-specific DMRS, CSI-RS. In mmWave communication systems, the OCC applied to resource elements may sometimes fail due to the increased SCS. A new design of OCC applied to resource elements to carry reference signals is expected.

[0023] Some aspects of the present disclosure provide improved solutions to the problems caused by the increase of SCS in communication systems (e.g., mmWave communication systems). Instead of using a fixed OCC applied to resource elements to carry various reference signals, a base station may determine a configuration for adaptively applying OCC to a set of resource elements to carry reference signals. The configuration may be determined based on parameters provided by the UE. For example, the UE may provide the base station with a channel coherence bandwidth, a channel coherence time, a preference associated with CSI-RS, or a preference associated with DMRS for the UE. The base station may determine a configuration for semi-statically or dynamically applying one or more OCCs to a set of resource elements. The configuration indicates a set of resource elements and one or more OCCs applied to a subset of the set of resource elements to carry CSI-RS or DMRS for one or more antenna ports of the UE. In detail, the configuration may indicate that: frequency domain (FD) OCC may be applied to at least two adjacent resource elements at two consecutive subcarriers in the frequency domain, time domain (TD) OCC may be applied to at least two adjacent resource elements of two adjacent symbols in the time domain, both FD-OCC and TD-OCC may be applied, or neither FD-OCC nor TD-OCC may be applied. When both FD-OCC and TD-OCC are applied to a resource element set, the resource element set may carry reference signals for more antenna ports. When FD-OCC and / or TD-OCC are prohibited from being applied to a resource element set, the resource element set may carry reference signals for fewer antenna ports. By weighing the number of antenna ports receiving reference signals, the technology provided herein may increase the reliability of FD-OCC and TD-OCC when applied to a resource element set.

[0024] Although some examples of configurations for carrying reference signals (eg, CSI-RS or DMRS) for UEs are provided above, aspects of the present disclosure are not limited to these examples. These examples may be applicable to other wireless communication systems.

[0025] Figure 1 An exemplary MIMO wireless system 100 is shown that implements a design for resource element configurations that carry reference signals for a UE 105, according to some aspects of the present disclosure. The wireless system 100 is provided for illustration purposes only and does not limit the disclosed aspects. The system 100 may include, but is not limited to, a network node (referred to herein as a base station) 101 and an electronic device (hereinafter referred to as a UE) 105.

[0026] According to some aspects, base station 101 may include a node configured to operate based on a variety of wireless communication technologies, such as, but not limited to, mmWave communication systems with one or more frequencies above 52 GHz or technologies based on 3GPP standards. For example, base station 101 may include a node configured to operate using Rel-16, Rel-17, or other current / future 3GPP standards. Base station 101 may be a fixed station and may also be referred to as a base transceiver system (BTS), an access point (AP), a transmit / receive point (TRP), an evolved NodeB (eNB), a next generation NodeB (gNB), or some other equivalent term.

[0027] According to some aspects, the UE 105 may include an electronic device configured to operate based on a variety of wireless communication technologies (e.g., technologies for mmWave communication systems having one or more frequencies greater than 52 GHz). These technologies may also include, but are not limited to, technologies based on 3rd Generation Partnership Project (3GPP) standards. For example, the UE 105 may include an electronic device configured to operate using Rel-16, Rel-17, or other current / future 3GPP standards. The UE 105 may include, but is not limited to, a wireless communication device, a smartphone, a laptop, a desktop computer, a tablet computer, a personal assistant, a monitor, a television, a wearable device, the Internet of Things (IoT), a communication device for a vehicle, a mobile station, a user station, a remote terminal, a wireless terminal, a user equipment, and the like.

[0028] In some examples, UE 105 may include a transceiver 111 configured to wirelessly communicate with base station 101 via a channel 103 between UE 105 and base station 101. UE 105 also includes a processor 113 communicatively coupled to transceiver 111. Similarly, base station 101 may include a transceiver 121 configured to wirelessly communicate with UE 105 via channel 103, and a processor 123 communicatively coupled to transceiver 121. Figure 6 and Figure 7 , more detailed operations of transceiver 111, processor 113, transceiver 121, and processor 123 are shown in greater detail. In some examples, channel 103 may have one or more frequencies above 52 GHz (e.g., between 52.6 GHz and 71 GHz). UE 105 may include multiple antenna ports, such as antenna port 102, antenna port 104, antenna port 106, and antenna port 108. The number of antenna ports is shown by way of example only and is not intended to be limiting. For example, UE 105 may include 2, 4, 6, 8, 12, 16, or more antenna ports.

[0029] The base station 101 may send various downlink reference signals to the UE 105 for downlink channel measurement and / or coherent demodulation of downlink transmissions. In the downlink, various reference signals are defined, such as a cell-specific reference signal (CRS), a UE-specific DMRS, a CSI-RS, and the like. The DMRS or CSI-RS reference signal may be processed by the UE 105 according to a configuration 115 stored in the UE 105. In the present disclosure, the DMRS or CSI-RS signal is used as an example to describe the various techniques proposed herein. Therefore, these techniques may be applied to other reference signals without any modification or with only minor modifications. Similar techniques may also be applied to uplink reference signals.

[0030] In some examples, configuration 115 can be determined by base station 101 and further received by UE 105 from base station 101. Configuration 115 can be adaptively determined by base station 101 based on information or parameters provided by UE 105. In some details, UE 105 can send uplink information 107 to base station 101, where uplink information 107 can include a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for UE 105. Base station 101 can receive uplink information 107 and further determine a configuration based on the channel coherence bandwidth, the channel coherence time, a preference associated with a CSI-RS (e.g., carried in a sounding reference signal (SRS)), or a preference associated with a DMRS. Thereafter, base station 101 can send the determined configuration to UE 105. UE 105 can receive the configuration from base station 101, which can be saved by UE 105 to become configuration 115.

[0031] In some examples, configuration 115 can indicate a set of resource elements 117 and one or more OCCs 119 applied to at least a subset of the set of resource elements to carry reference signals (e.g., CSI-RS or DMRS) for one or more antenna ports (e.g., antenna port 102, antenna port 104) of UE 105.

[0032] In some examples, the resource element set 117 includes at least two adjacent resource elements (REs) at two consecutive subcarriers in the frequency domain and at one symbol in the time domain. In other words, the resource element set 117 includes at least a plurality of adjacent REs formed by one symbol. More details of such resource elements are given in Figures 4A to 4B In some other examples, the resource element set 117 includes at least two adjacent REs at two consecutive subcarriers in the frequency domain and at two adjacent symbols in the time domain. In other words, the resource element set 117 includes at least a plurality of adjacent REs formed by two symbols. More details of such resource elements are given in Figures 5A to 5C Shown in.

[0033] In some examples, the one or more OCCs 119 include a frequency domain (FD) OCC applied to two adjacent resource elements at two consecutive subcarriers in the frequency domain, or a time domain (TD) OCC applied to at least two adjacent resource elements of two adjacent symbols in the time domain. In some examples, based on the relationship between the subcarrier spacing (SCS) between two consecutive subcarriers in the frequency domain and the channel coherence bandwidth, the configuration 115 indicates that only FD-OCC or only TD-OCC is applied. In some examples, there may be no OCC applied to the RE set 117, and one or more OCCs 119 will not be available. More details on OCC application scenarios are provided in Figures 4A to 4B as well as Figures 5A to 5C Furthermore, in some examples, the number of resource elements may be adjusted to remain within the coherence bandwidth, even though there may be spacing between resource elements.

[0034] In some examples, processor 113 and processor 123 may be configured to perform methods that support a configuration (eg, configuration 115) designed for carrying a reference signal for a UE. Figure 2 and Figure 3 , more details of the operation of processor 113 and processor 123 are shown.

[0035] Figure 2 An exemplary method 200 for a UE 105 supporting various mechanisms for implementing a design of resource element configurations for carrying reference signals for a UE is shown. The method 200 may be performed by a UE 105, which may be Figure 6 System 600 and / or Figure 7 However, the method 200 is not limited to the specific aspects depicted in those figures, and other systems may be used to perform the method, as will be understood by those skilled in the art. It should be understood that not all operations may be required, and that these operations may not be performed in the same manner as described above. Figure 2 Execute in the same order as shown.

[0036] At 202, using a transceiver, a UE transmits a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for the UE to a base station. For example, using transceiver 101, UE 105 transmits uplink information 107 to base station 101, the uplink information including a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for UE 105, such as a preference associated with a DMRS for UE 105. Figure 1 As stated.

[0037] At 204, using a transceiver, the UE receives from a base station a configuration of resource elements carrying a reference signal for the UE, wherein the configuration is determined by the base station based on a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS. For example, UE 105 receives a configuration 115 of a CSI-RS or DMRS for the UE from base station 101, such as a configuration for a CSI-RS or DMRS for the UE. Figure 1 Configuration 115 can also be used for other reference signals.

[0038] In detail, the processor 113 of the UE 105 receives an RRC signal, a MAC-CE, or a DCI to indicate a configuration 115 of a CSI-RS or DMRS for the UE 105. The configuration 115 includes a resource element set 117 and one or more OCCs 119 applied to at least a subset of the resource element set to carry the CSI-RS or DMRS for one or more antenna ports of the UE 105. In some examples, the one or more OCCs 119 applied to at least a subset of the resource element set for the one or more antenna ports can be semi-statically configured via an RRC signal, or dynamically configured via a MAC-CE or a DCI.

[0039] At 206, the UE assigns a subset of the resource element set or an OCC applied to a subset of the resource element set to the antenna port of the UE. For example, UE 105 assigns a subset of the resource element set or an OCC applied to a subset of the resource element set to the antenna port of the UE, such as for Figure 1 The operation at 206 may be optional. In some examples, the allocation of resource elements or OCCs to antenna ports may be based on a standard or may be allocated by the base station rather than the UE. A more detailed example of such allocation is provided in Figures 4A to 4B as well as Figures 5A to 5C Shown in.

[0040] At 208, based on the configuration of resource elements carrying reference signals for the UE, the UE performs DMRS or CSI-RS reference signal processing. For example, based on the configuration 115 of the CSI-RS or DMRS for the UE, the UE 105 performs DMRS or CSI-RS reference signal processing, such as for Figure 1 As stated.

[0041] Figure 3 An exemplary method 300 for a base station 101 supporting various mechanisms for implementing a design of resource element configurations for carrying reference signals for a UE is shown. The method 300 may also be implemented by Figure 6 System 600 and / or Figure 7 The method 300 is performed by the computer system 700. However, the method 300 is not limited to the specific aspects depicted in those figures, and other systems may be used to perform the method, as will be understood by those skilled in the art. It should be understood that not all operations may be required, and that these operations may not be performed in the same manner as in the examples of FIG. Figure 3 Execute in the same order as shown.

[0042] At 302, using a transceiver, a base station receives a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for a UE from a UE. For example, using transceiver 121, base station 101 receives uplink information 107 from UE 105, the uplink information including a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for a UE, such as a preference associated with a DMRS. Figure 1 As stated.

[0043] At 304, the base station determines a resource element configuration for carrying a reference signal for the UE based on the channel coherence bandwidth, the channel coherence time, the preference associated with the CSI-RS, or the preference associated with the DMRS. For example, the base station 101 determines a resource element configuration for carrying a reference signal for the UE 105 based on the channel coherence bandwidth, the channel coherence time, the preference associated with the CSI-RS, or the preference associated with the DMRS included in the uplink information 107. The configuration includes a set of resource elements and one or more OCCs applied to at least a subset of the set of resource elements to carry the CSI-RS or DMRS for one or more antenna ports of the UE 105.

[0044] At 306, the base station assigns a subset of the resource element set or an OCC applied to the subset of the resource element set to the antenna port of the UE. For example, the base station 101 assigns a subset of the resource element set or an OCC applied to the subset of the resource element set to the antenna port of the UE, such as for Figure 1 The operation at 306 may be optional. In some examples, the allocation of resource elements or OCCs to antenna ports may be based on a standard or may be allocated by the UE rather than the base station 101. More detailed examples of such allocations are described in Figures 4A to 4B as well as Figures 5A to 5C Shown in.

[0045] At 308, using the transceiver, the base station transmits to the UE a resource element configuration for carrying a reference signal for the UE. For example, using the transceiver 121, the base station 101 transmits to the UE 105 a resource element configuration for carrying a reference signal for the UE 105, which is saved by the UE 105 as configuration 115, as described for Figure 1 In detail, the processor 123 of the base station 101 may transmit an RRC signal, a MAC-CE, or a DCI to indicate a configuration 115 of a CSI-RS or DMRS for the UE 105. The configuration 115 includes a resource element set 117 and one or more OCCs 119 applied to at least a subset of the resource element set to carry the CSI-RS or DMRS for one or more antenna ports of the UE 105. In some examples, the one or more OCCs 119 applied to at least a subset of the resource element set for one or more antenna ports are semi-statically configured via an RRC signal, or dynamically configured via a MAC-CE or a DCI.

[0046] Figures 4A to 4B An exemplary resource element configuration for carrying reference signals for a UE according to some aspects of the present disclosure is shown. The configuration may be Figure 1 An example of configuration 115 is shown. Figures 4A to 4B The configuration in indicates a set of resource elements 403 and one or more OCCs applied to at least a subset of the set of resource elements 403 to carry CSI-RS or DMRS for one or more antenna ports of the UE.

[0047] In some examples, such as Figure 4A As shown, resource element set 403 is a resource block (RB) having 12 resource elements (REs), wherein each resource element (RE) comprises one orthogonal frequency division multiplexing (OFDM) symbol on one subcarrier. Resource element set 403 is shown in an exemplary OFDM time-frequency grid 401 in the time and frequency domains. In the frequency domain, physical resources are divided into adjacent subcarriers with a subcarrier spacing (SCS). In some examples, the SCS can be 15kHz. In mmWave systems, the SCS can be greater than 15kHz. The number of subcarriers varies depending on the allocated system bandwidth. OFDM time-frequency grid 401 includes 12 subcarriers across 14 symbols. 14 symbols can form a subframe of one millisecond. In some examples, if an extended cyclic prefix is ​​used, a subframe can have 12 symbols.

[0048] In some examples, the resource element set 403 is divided into multiple resource element subsets to carry CSI-RS or DMRS for one or more antenna ports of the UE. Figure 4AAs shown, resource elements 403 are divided into two disjoint subsets, RE subset 405 and RE subset 407. RE subset 405 includes multiple RE pairs, for example, RE pair 451, RE pair 452, and RE pair 453. RE pair 451, RE pair 452, or RE pair 453 includes two adjacent resource elements at two consecutive subcarriers in the frequency domain and at one symbol in the time domain. For example, RE pair 451 includes two adjacent resource elements at two consecutive subcarriers 0 and 1 and symbol 3 in the time domain because RE pair 451 is part of resource element set 403. The structure of RE subset 407 is similar to that of RE subset 405.

[0049] Without using OCC, RE subset 405 can be allocated to one antenna port, such as port 1000, while RE subset 407 can be allocated to another antenna port, such as port 1001. However, without using OCC, RE subset 405 can only be allocated to one antenna port. Therefore, resource element set 403 is divided into two RE subsets to carry CSI-RS or DMRS for two antenna ports of the UE.

[0050] In some examples, OCC can be used to maintain orthogonality between antenna ports assigned to the same RE. Figure 4A As shown, two OCCs {1 1} and {1 -1} can be applied to RE subsets 405 in the frequency domain, so that the same RE subset 405 can carry reference signals for two antenna ports of the UE. OCC {1 1} is represented by "+" and "+" marked on two resource elements at two consecutive subcarriers in the frequency domain, while OCC {1 -1} is represented by "+" and "-" marked on two resource elements at two consecutive subcarriers in the frequency domain. Therefore, when OCC {1 1} is applied to REs, RE subset 405 can be allocated to an antenna port, such as antenna port 1000, and when OCC {1 -1} is applied to REs, RE subset 405 can be allocated to an antenna port, such as antenna port 1001. When two OCCs are applied in the frequency domain, RE subsets 405 form a code division multiplexing (CDM) group 402.

[0051] Similarly, two OCCs {1 1} and {1 -1} can be applied to RE subset 407 in the frequency domain, so that the same RE subset 407 can carry reference signals for two antenna ports of the UE. Therefore, when OCC {1 1} is applied to REs, RE subset 407 can be allocated to an antenna port, such as antenna port 1002, and when OCC {1 -1} is applied to REs, RE subset 405 can be allocated to an antenna port, such as antenna port 1003. Allocation of an RE subset together with an OCC to an antenna port can be performed dynamically by the UE or base station, or according to a standard known in advance.

[0052] In some examples, such as Figure 4B As shown, resource element set 403 is divided into three resource element subsets: RE subset 411, RE subset 413, and RE subset 415 to carry CSI-RS or DMRS for one or more antenna ports of the UE. RE subset 411, RE subset 413, and RE subset 415 include multiple resource element pairs, where one RE pair includes two adjacent resource elements at two consecutive subcarriers in the frequency domain and at one symbol in the time domain.

[0053] Without using OCC, RE subset 411 may be allocated to a first antenna port, such as port 1000, RE subset 413 may be allocated to a second antenna port, such as port 1001, and RE subset 415 may be allocated to a third antenna port, such as port 1002. However, without using OCC, each RE subset may be allocated to only one antenna port.

[0054] In some examples, OCCs can be used to maintain orthogonality between antenna ports assigned to the same DMRS RE. Two OCCs {1 1} and {1 -1} can be applied to RE subset 411 in the frequency domain so that the same RE subset 411 can carry reference signals for both antenna ports of the UE. Thus, when OCC {1 1} is applied to REs, RE subset 411 can be assigned to an antenna port, such as antenna port 1000, and when OCC {1 -1} is applied to REs, RE subset 411 can be assigned to an antenna port, such as antenna port 1001. When both OCCs are applied in the frequency domain, RE subset 411 forms a code division multiplexing (CDM) group 421.

[0055] Similarly, two OCCs {1 1} and {1 -1} can be applied to RE subset 413 in the frequency domain, so that the same RE subset 413 can carry reference signals for two antenna ports of the UE. Therefore, when OCC {1 1} is applied to REs, RE subset 413 can be allocated to an antenna port, such as antenna port 1002, and when OCC {1 -1} is applied to REs, RE subset 413 can be allocated to an antenna port, such as antenna port 1003. When two OCCs are applied in the frequency domain, RE subset 413 forms a code division multiplexing (CDM) group 423.

[0056] Similarly, two OCCs {1 1} and {1 -1} can be applied to RE subset 415 in the frequency domain, so that the same RE subset 415 can carry reference signals for two antenna ports of the UE. Therefore, when OCC {1 1} is applied to REs, RE subset 415 can be allocated to an antenna port, such as antenna port 1004, and when OCC {1 -1} is applied to REs, RE subset 415 can be allocated to an antenna port, such as antenna port 1005. When two OCCs are applied in the frequency domain, RE subset 415 forms a code division multiplexing (CDM) group 425.

[0057] Figures 5A to 5C An exemplary resource element configuration for carrying reference signals for a UE according to some aspects of the present disclosure is shown. The configuration may be Figure 1 An example of configuration 115 is shown. Figures 5A-5C The configuration in indicates a set of resource elements 503 and one or more OCCs applied to at least a subset of the set of resource elements to carry CSI-RS or DMRS for one or more antenna ports of the UE.

[0058] In some examples, such as Figure 5A As shown, resource element set 503 is a resource block (RB) having 24 REs spanning two symbols (symbol 3 and symbol 4). Resource element set 503 is shown in an exemplary OFDM time-frequency grid 501 in the time and frequency domains. OFDM time-frequency grid 501 includes 12 subcarriers spanning 14 symbols. 14 symbols can form a one millisecond subframe. In some examples, if an extended cyclic prefix is ​​used, a subframe can have 12 symbols.

[0059] In some examples, the resource element set 503 is divided into multiple resource element subsets to carry CSI-RS or DMRS for one or more antenna ports of the UE. Figure 5AAs shown in FIG, resource elements 503 are divided into two disjoint subsets, RE subset 511 and RE subset 513. RE subset 511 or RE subset 513 includes multiple RE pairs. An RE pair includes two adjacent resource elements at two consecutive subcarriers in the frequency domain and at two adjacent symbols in the time domain.

[0060] Without using OCC, RE subset 511 can be allocated to one antenna port, such as port 1000, while RE subset 513 can be allocated to another antenna port, such as port 1001. However, without using OCC, RE subset 511 can only be allocated to one antenna port. Therefore, resource element set 503 is divided into two RE subsets to carry CSI-RS or DMRS for two antenna ports of the UE.

[0061] In some examples, OCCs can be used to maintain orthogonality between antenna ports assigned to the same DMRS REs. Two OCCs {1 1} and {1 -1} can be applied to RE subset 511 in the frequency domain. Additionally, two OCCs {1 1} and {-1 -1} can be applied to RE subset 511 in the time domain. Overall, RE subset 511 with corresponding FD-OCCs and TD-OCCs can be assigned to four antenna ports, e.g., antenna port 1000, antenna port 1001, antenna port 1004, and antenna port 1005.

[0062] Similarly, two OCCs {1 1} and {1 -1} may be applied to the RE subset 513 in the frequency domain. In addition, two OCCs {1 1} and {-1 -1} may be applied to the RE subset 513 in the time domain. In general, the RE subset 513 with corresponding FD-OCCs and TD-OCCs may be allocated to four antenna ports, e.g., antenna port 1002, antenna port 1003, antenna port 1006, and antenna port 1007.

[0063] In some examples, such as Figure 5B As shown, resource element set 503 is divided into four disjoint subsets: RE subset 521, RE subset 522, RE subset 523, and RE subset 524, each of which includes multiple RE pairs. An RE pair includes two adjacent resource elements at two consecutive subcarriers in the frequency domain and at one symbol in the time domain.

[0064] When OCC is not used, RE subset 521 can be allocated to one antenna port, for example, port 1000. Similarly, RE subset 522, RE subset 523, and RE subset 524 can each be allocated to one antenna port, for example, port 1001, port 1002, and port 1003. Therefore, resource element set 503 is divided into four RE subsets to carry CSI-RS or DMRS for four antenna ports of the UE.

[0065] In some examples, OCCs can be used to maintain orthogonality between antenna ports assigned to the same DMRS REs. Two OCCs, {1 1} and {1 -1}, can be applied to RE subset 521 in the frequency domain. Thus, RE subset 521 with a corresponding FD-OCC can be assigned to two antenna ports, e.g., antenna port 1000 and antenna port 1001. Similarly, RE subset 523 with a corresponding FD-OCC can be assigned to two antenna ports, e.g., antenna port 1004 and antenna port 1005; RE subset 522 with a corresponding FD-OCC can be assigned to two antenna ports, e.g., antenna port 1002 and antenna port 1003; and RE subset 524 with a corresponding FD-OCC can be assigned to two antenna ports, e.g., antenna port 1006 and antenna port 1007. As shown above, only the FD-OCC is applied to the RE subsets, without any TD-OCC. The base station can make this determination to apply only the FD-OCC based on the relationship between the SCS spacing in the frequency domain and the channel coherence bandwidth. When the channel coherence bandwidth is small compared to the SCS interval, TD-OCC may not be applied to the RE subset. Similarly, the base station may make the following determination: only apply TD-OCC to some other RE subsets (not shown) without applying FD-OCC.

[0066] In some examples, such as Figure 5C As shown, resource element set 503 is divided into six disjoint subsets: RE subset 531, RE subset 532, RE subset 533, RE subset 534, RE subset 535, and RE subset 536, each of which includes multiple RE pairs. An RE pair includes two adjacent resource elements at two consecutive subcarriers in the frequency domain and at one symbol in the time domain.

[0067] When OCC is not used, RE subset 531 can be allocated to one antenna port, for example, port 1000. Similarly, RE subset 532, RE subset 533, RE subset 534, RE subset 535, and RE subset 536 can each be allocated to one antenna port, for example, port 1001, port 1002, port 1003, port 1004, and port 1005. Therefore, resource element set 503 is divided into six RE subsets to carry CSI-RS or DMRS for the six antenna ports of the UE.

[0068] In some examples, OCCs can be used to maintain orthogonality between antenna ports assigned to the same DMRS REs. Two OCCs {1 1} and {1 -1} can be applied to RE subset 531 in the frequency domain. Thus, RE subset 531 with corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port 1000 and antenna port 1001. Similarly, RE subset 532 with corresponding FD-OCC can be allocated to two antenna ports, such as antenna port 1002 and antenna port 1003; RE subset 533 with corresponding FD-OCC can be allocated to two antenna ports, such as antenna port 1004 and antenna port 1005; RE subset 534 with corresponding FD-OCC can be allocated to two antenna ports, such as antenna port 1006 and antenna port 1007; RE subset 535 with corresponding FD-OCC can be allocated to two antenna ports, such as antenna port 1008 and antenna port 1009; RE subset 536 with corresponding FD-OCC can be allocated to two antenna ports, such as antenna port 1010 and antenna port 1011.

[0069] like Figures 4A to 4B as well as Figures 5A to 5C As shown, the various resource element configurations with or without FD-OCC or TD-OCC for carrying reference signals for UEs are only used as examples and are not limiting. For example, resource element set 403 or resource element set 503 can be divided into multiple RE subsets in different ways. In addition, different OCCs (e.g., other OCCs of length 2 or OCCs of length 4) can be assigned to RE subsets, resulting in different allocation results for multiple antenna ports. Figures 4A to 4B as well as Figures 5A to 5C shown.

[0070] Figure 6A block diagram of an exemplary system 600 of an electronic device that implements a design for resource element configuration for carrying reference signals for a UE according to some aspects of the present disclosure is shown. System 600 can be any electronic device of system 100 (e.g., base station 101, UE 105). System 600 includes a processor 610, one or more transceivers 620, communication infrastructure 640, memory 650, an operating system 652, an application 654, and one or more antennas 660. The illustrated system is provided as an exemplary portion of system 600, and system 600 may include other circuits and subsystems. Moreover, although the system of system 600 is shown as individual components, aspects of the present disclosure may include any combination of these components, fewer components, or more components.

[0071] The memory 650 may include random access memory (RAM) and / or cache memory, and may include control logic components (e.g., computer software) and / or data. The memory 650 may include other storage devices or memories, such as, but not limited to, a hard drive and / or a removable storage device / unit. According to some examples, an operating system 652 may be stored in the memory 650. The operating system 652 may manage the transfer of data from the memory 650 and / or one or more application programs 654 to the processor 610 and / or one or more transceivers 620. In some examples, the operating system 652 supports one or more network protocol stacks (e.g., an Internet protocol stack and a cellular protocol stack, etc.), which may include several logical layers. At the corresponding layer of the protocol stack, the operating system 652 includes control mechanisms and data structures to perform the functions associated with that layer.

[0072] According to some examples, applications 654 may be stored in memory 650. Applications 654 may include applications used by wireless system 600 and / or a user of wireless system 600 (e.g., user applications). Applications in applications 654 may include, for example, but not limited to, Siri. TM , FaceTime TM , broadcast streaming, video streaming, remote control and / or other user applications.

[0073] The system 600 may also include a communication infrastructure 640. The communication infrastructure 640 provides, for example, communication between the processor 610, one or more transceivers 620, and the memory 650. In some implementations, the communication infrastructure 640 may be a bus. The processor 610, together with instructions stored in the memory 650, performs operations to enable the system 600 to implement a mechanism for configuring resource elements that carry reference signals for UEs, as described herein. Figure 1 The system 100 is shown.

[0074] One or more transceivers 620 transmit and receive communication signals that support mechanisms for configuring resource elements that carry reference signals for UEs, such as Figure 1 In addition, one or more transceivers 620 transmit and receive communication signals that support a mechanism for transmitting resource element configurations that carry reference signals for UEs, such as Figure 1 As shown. According to some aspects, one or more transceivers 620 may be coupled to an antenna 660. Antenna 660 may include one or more antennas that may be of the same or different types. One or more transceivers 620 allow the system 600 to communicate with other devices that may be wired and / or wireless. In some examples, one or more transceivers 620 may include circuits / devices such as processors, controllers, radio components, sockets, plugs, buffers, etc. for connecting to and communicating on a network. According to some examples, one or more transceivers 620 include one or more circuits for connecting to and communicating on a wired and / or wireless network.

[0075] According to some aspects of the present disclosure, the one or more transceivers 620 may include a cellular subsystem, a WLAN subsystem, and / or a Bluetooth subsystem. TM The subsystems each include their own radio transceiver and protocols, as will be understood by those skilled in the art based on the discussion provided herein. In some implementations, the one or more transceivers 620 may include more or fewer systems for communicating with other devices.

[0076] In some examples, transceiver(s) 620 may include one or more circuits, including a WLAN transceiver, to enable connection and communication via a WLAN network, such as, but not limited to, a network based on the standards described in IEEE 802.11.

[0077] Additionally or alternatively, the one or more transceivers 620 may include one or more circuits (including Bluetooth TM transceiver) to implement Bluetooth-based TM Protocol, Bluetooth TM Low energy protocol, or Bluetooth TM For example, one or more transceivers 620 may include Bluetooth TM transceiver.

[0078] Additionally, the one or more transceivers 620 may include one or more circuits (including cellular transceivers) for connecting to and communicating on a cellular network. Cellular networks may include, but are not limited to, 3G / 4G / 5G networks such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), millimeter wave systems, etc. For example, the one or more transceivers 220 may be configured to operate in accordance with one or more of Rel-15, Rel-16, Rel-17, or other current / future 3GPP standards.

[0079] According to some aspects of the present disclosure, the processor 610, alone or in combination with computer instructions stored in the memory 650 and / or one or more transceivers 620, implements the methods and mechanisms discussed in the present disclosure. For example, alone or in combination with computer instructions stored in the memory 650 and / or one or more transceivers 220, the processor 610 implements a mechanism for configuring resource elements that carry reference signals for UEs, such as Figure 1 According to some aspects of the present disclosure, the processor 610, alone or in combination with computer instructions stored in the memory 650 and / or one or more transceivers 620, can send a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for a UE to a base station. In addition, using the transceiver, the processor 610 can receive a resource element configuration carrying a reference signal for the UE from the base station; and further perform DMRS or CSI-RS reference signal processing based on the resource element configuration carrying the reference signal for the UE.

[0080] For example, one or more computer systems such as Figure 7 The computer system 700 shown is used to implement various aspects. The computer system 700 can be any well-known computer capable of performing the functions described herein, such as Figure 1 Device 101, 105 or Figure 6 Device 600. Computer system 700 includes one or more processors (also known as central processing units or CPUs), such as processor 704. Processor 704 is connected to a communication infrastructure 706 (e.g., a bus). Computer system 700 also includes user input / output devices 703, such as a monitor, keyboard, pointing device, etc., that communicate with communication infrastructure 706 through user input / output interface 702. Computer system 700 also includes main memory or primary storage 708, such as random access memory (RAM). Main memory 708 may include one or more levels of cache. Main memory 708 has control logic components (e.g., computer software) and / or data stored therein.

[0081] The computer system 700 may also include one or more secondary storage devices or memories 710. The secondary storage 710 may include, for example, a hard disk drive 712 and / or a removable storage device or drive 714. The removable storage drive 714 may be a floppy disk drive, a tape drive, an optical disk drive, an optical storage device, a tape backup device, and / or any other storage device / drive.

[0082] The removable storage drive 714 can interact with a removable storage unit 718. The removable storage unit 718 includes a computer-usable or readable storage device having computer software (control logic) and / or data stored thereon. The removable storage unit 718 can be a floppy disk, a magnetic tape, a compact disk, a DVD, an optical storage disk, and / or any other computer data storage device. The removable storage drive 714 reads from and / or writes to the removable storage unit 718 in a well-known manner.

[0083] According to some aspects, the secondary memory 710 may include other devices, tools, or other means for allowing the computer system 700 to access computer programs and / or other instructions and / or data. Such devices, tools, or other means may include, for example, a removable storage unit 722 and an interface 720. Examples of the removable storage unit 722 and interface 720 may include a program cartridge and cartridge interface (such as found in video game devices), a removable memory chip (such as an EPROM or PROM) and an associated socket, a memory stick and USB port, a memory card and an associated memory card slot, and / or any other removable storage unit and associated interface.

[0084] In some examples, the main memory 708, the removable storage unit 718, and the removable storage unit 722 may store instructions that, when executed by the processor 704, cause the processor 704 to perform operations for a UE (e.g., UE 105) or a base station (e.g., base station 101). In some examples, the operations include: transmitting a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for the UE to the base station; receiving a resource element configuration for carrying a reference signal for the UE from the base station; and performing DMRS or CSI-RS reference signal processing based on the resource element configuration for carrying a reference signal for the UE. In addition, the operations include: receiving a channel coherence bandwidth, a channel coherence time, a preference associated with a CSI-RS, or a preference associated with a DMRS for the UE from the UE; determining a resource element configuration for carrying a reference signal for the UE based on the channel coherence bandwidth, the preference associated with the CSI-RS, or the preference associated with the DMRS; and transmitting the resource element configuration for carrying a reference signal for the UE to the UE.

[0085] The computer system 700 may also include a communication or network interface 724. The communication interface 724 enables the computer system 700 to communicate and interact with any combination of remote devices, remote networks, remote entities, and the like (individually and collectively referenced by reference numeral 728). For example, the communication interface 724 may allow the computer system 700 to communicate with the remote device 728 via a communication path 726, which may be wired and / or wireless and may include any combination of a LAN, a WAN, the Internet, and the like. Control logic components and / or data may be transferred to and from the computer system 700 via the communication path 726.

[0086] The operations in the foregoing aspects can be implemented in various configurations and architectures. Thus, some or all of the operations in the foregoing aspects may be performed in hardware, software, or in both hardware and software. In some aspects, a tangible, non-transient device or article includes a tangible, non-transient computer-usable or readable medium on which a control logic component (software) is stored, also referred to herein as a computer program product or program storage device. This includes, but is not limited to, a computer system 700, a main memory 708, an auxiliary memory 710, and removable storage units 718 and 722, as well as tangible articles embodying any combination of the foregoing. Such control logic components, when executed by one or more data processing devices (such as computer system 700), cause such data processing devices to operate as described herein.

[0087] Based on the teachings contained in this disclosure, it will be apparent to those skilled in the relevant art how to use Figure 7 The various aspects of the present disclosure may be made and used with data processing devices, computer systems, and / or computer architectures other than those shown. In particular, the various aspects may operate with software, hardware, and / or operating system implementations other than those described herein.

[0088] It should be understood that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary aspects of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure or the appended claims in any way.

[0089] Although the present disclosure has been described herein with reference to exemplary aspects of exemplary fields and applications, it should be understood that the present disclosure is not limited thereto. Other aspects and modifications are possible and are within the scope and essence of the present disclosure. For example, and without limiting the generality of this paragraph, the various aspects are not limited to the software, hardware, firmware and / or entities shown in the figures and / or described herein. In addition, the various aspects (whether or not explicitly described herein) have significant practicality for fields and applications beyond the examples described herein.

[0090] Various aspects have been described herein with reference to functional building blocks illustrating specific implementations of specific functions and relationships thereof. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. Alternative boundaries may be defined so long as the specified functions and relationships (or their equivalents) are appropriately performed. Additionally, alternative aspects may perform functional blocks, steps, operations, methods, etc., in an order different from that described herein.

[0091] References herein to "one embodiment," "an embodiment," "an exemplary embodiment," or similar phrases indicate that the described embodiment may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of those skilled in the relevant art to incorporate such feature, structure, or characteristic into other aspects, whether or not explicitly mentioned or described herein.

[0092] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary aspects, but should be defined only in accordance with the following claims and their equivalents.

[0093] 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 authorized use should be clearly stated to users.

[0094] For one or more embodiments or examples, at least one of the components shown in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods described in the following example section. For example, circuits associated with the UE, base station, network element, etc. described above in conjunction with one or more of the preceding figures may be configured to operate according to one or more of the examples shown in the following example section.

Claims

1. A user equipment (UE), comprising: a transceiver configured to perform wireless communication with the base station via a channel between the UE and the base station; as well as a processor communicatively coupled to the transceiver and configured to: Using the transceiver, transmitting to the base station a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with a channel state information reference signal (CSI-RS), or a preference associated with a demodulation reference signal (DMRS) for the UE; receiving, using the transceiver, a resource element configuration for carrying a reference signal for the UE from the base station, wherein the configuration is responsive to the channel coherence bandwidth, the channel coherence time, the preference associated with the CSI-RS, or the preference associated with the DMRS, and the configuration indicates a set of resource elements and one or more orthogonal cover codes (OCCs) applied to at least a subset of the set of resource elements to carry the CSI-RS or DMRS for one or more antenna ports of the UE, the one or more OCCs comprising a frequency-domain FD-OCC or a time-domain TD-OCC, wherein the configuration is determined by weighing the number of antenna ports to increase reliability of the FD-OCC or the TD-OCC; as well as DMRS or CSI-RS reference signal processing is performed based on the resource element configuration carrying a reference signal for the UE.

2. The UE of claim 1 , wherein the processor is configured to allocate the subset of the set of resource elements or the OCC applied to the subset of the set of resource elements to one of the one or more antenna ports of the UE.

3. The UE according to claim 1, wherein the processor is configured to receive a radio resource control (RRC) signal, a medium access control (MAC) control element (CE), or downlink control information (DCI) to indicate the resource element configuration carrying a reference signal for the UE.

4. The UE according to claim 3, wherein the one or more OCCs applied to at least one of the subsets of the resource element set for the one or more antenna ports are semi-statically configured through the RRC signal, or dynamically configured through the MAC-CE or the DCI.

5. The UE according to claim 1, wherein the resource element set comprises at least two adjacent resource elements at two consecutive subcarriers in the frequency domain and at one symbol in the time domain, or at least two adjacent resource elements at two consecutive subcarriers in the frequency domain and at two adjacent symbols in the time domain. 6 . The UE according to claim 5 , wherein the one or more OCCs include a frequency-domain FDOCC applied to the two adjacent resource elements at two consecutive subcarriers in the frequency domain. 7 . The UE according to claim 5 , wherein the one or more OCCs include a time-domain (TD) OCC applied to the two adjacent resource elements of two adjacent symbols in the time domain.

8. The UE according to claim 5, wherein based on the relationship between the subcarrier spacing SCS between the two consecutive subcarriers in the frequency domain and the channel coherence bandwidth, the resource element configuration for the UE carrying the reference signal indicates that only one or more frequency domain FD OCCs or one or more time domain TD OCCs are applied.

9. The UE of claim 5, wherein the subset of the resource element sets to which the one or more OCCs are applied is empty, and the configuration indicates that no OCC is to be applied to the resource element sets of the one or more antenna ports allocated to the UE.

10. The UE of claim 1, wherein the channel comprises one or more frequencies above 52 GHz. The UE according to claim 1 , wherein the UE comprises at least two antenna ports.

12. A base station, comprising: a transceiver configured to communicate with user equipment (UE) via a channel between the UE and the base station; as well as a processor communicatively coupled to the transceiver and configured to: receiving, using the transceiver, from the UE a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with a channel state information reference signal (CSI-RS), or a preference associated with a demodulation reference signal (DMRS) for the UE; determining, in response to the channel coherence bandwidth, the channel coherence time, the preference associated with the CSI-RS, or the preference associated with the DMRS, a resource element configuration for carrying a reference signal for the UE, wherein the configuration indicates a set of resource elements and one or more orthogonal cover codes (OCCs) applied to at least a subset of the set of resource elements to carry a CSI-RS or a DMRS for one or more antenna ports of the UE, the one or more OCCs comprising a frequency-domain FD-OCC or a time-domain TD-OCC, wherein the configuration is determined by trading off the number of antenna ports to increase reliability of the FD-OCC or the TD-OCC; as well as The resource element configuration carrying a reference signal for the UE is transmitted to the UE using the transceiver.

13. The base station according to claim 12, wherein the processor is further configured to: allocate the subset of the resource element set or the OCC applied to the subset of the resource element set to one of the one or more antenna ports of the UE.

14. The base station according to claim 12, wherein the processor is configured to transmit a radio resource control (RRC) signal, a medium access control (MAC) control element (CE), or downlink control information (DCI) to indicate the resource element configuration carrying a reference signal for the UE.

15. The base station according to claim 14, wherein the one or more OCCs applied to at least one of the subsets of the resource element set for the one or more antenna ports are semi-statically configured through the RRC signal, or dynamically configured through the MAC-CE or the DCI.

16. The base station according to claim 12, wherein the resource element set comprises at least two adjacent resource elements at two consecutive subcarriers in the frequency domain and at one symbol in the time domain, or at least two adjacent resource elements at two consecutive subcarriers in the frequency domain and at two adjacent symbols in the time domain. 17 . The base station according to claim 16 , wherein the one or more OCCs only include frequency-domain FD OCCs applied to the two adjacent resource elements at two consecutive subcarriers in the frequency domain. 18 . The base station according to claim 16 , wherein the one or more OCCs only include a time-domain TDOCC applied to the two adjacent resource elements of two adjacent symbols in the time domain.

19. The base station of claim 16, wherein the subset of the resource element set is empty for the one or more antenna ports to which the one or more OCCs are applied, and the configuration indicates that no OCC is applied to the resource element set of the one or more antenna ports allocated to the UE.

20. The base station of claim 12, wherein the channel comprises one or more frequencies above 52 GHz.

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