PATENT DOCUMENT

Publication Number: US-11979354-B2
Application Number: US-202017441253-A
Country: US
Kind Code: B2

Title: Adaptive applications of orthogonal cover codes on resource elements for wireless communication systems

Abstract:
Some aspects of this disclosure relate to apparatuses and methods for implementing designs for configurations of resource elements to carry reference signals for a user equipment (UE). A reference signal can be processed by the UE according to the configuration of resource elements to carry reference signals. The configurations can be determined by the base station, and received from the base station by the UE. The base station determines the configurations based on information or parameters provided by the UE, e.g., a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with channel status information reference signal, or a preference associated with demodulation reference signal for the UE.

Claims:
What is claimed is: 
     
       1. A user equipment (UE), comprising:
 a transceiver configured to wirelessly communicate with a base station through a channel between the UE and the base station; and 
 a processor communicatively coupled to the transceiver and configured to: 
 send, using the transceiver and to the base station, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with a channel status information reference signal (CSI-RS), or a preference associated with a demodulation reference signal (DMRS) for the UE; 
 receive, using the transceiver and from the base station, a configuration of resource elements to carry reference signals for the UE, wherein the configuration is responsive to the coherence bandwidth of the channel, the coherence time of the channel, 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 the DMRS for one or more antenna ports of the UE; and 
 perform DMRS or CSI-RS reference signal processing based on the configuration of resource elements to carry reference signals for the UE. 
 
     
     
       2. The UE of  claim 1 , wherein the processor is configured to assign the subset of the set of resource elements or an OCC applied to the subset of the set of resource elements to an antenna port of the one or more antenna ports of the UE. 
     
     
       3. The UE of  claim 1 , wherein the processor is configured to receive a radio resource control (RRC) signal, a medium access control (MAC) control element (CE), or a downlink control information (DCI) to indicate the configuration of resource elements to carry reference signals for the UE. 
     
     
       4. The UE of  claim 3 , wherein the one or more OCCs applied to at least the subset of the set of resource elements for the one or more antenna ports are semi-statically configured by the RRC signal, or dynamically configured by the MAC-CE or the DCI. 
     
     
       5. The UE of  claim 1 , wherein the set of resource elements includes at least two adjacent resource elements at two consecutive sub-carriers in a frequency domain and a symbol in a time domain, or at least two adjacent resource elements at two consecutive sub-carriers in the frequency domain and two adjacent symbols in the time domain. 
     
     
       6. The UE of  claim 5 , wherein the one or more OCCs include frequency domain (FD) OCCs applied to the two adjacent resource elements at two consecutive sub-carriers in the frequency domain. 
     
     
       7. The UE of  claim 5 , wherein the one or more OCCs include time domain (TD) OCCs applied to the two adjacent resource elements of two adjacent symbols in the time domain. 
     
     
       8. The UE of  claim 5 , wherein the configuration of resource elements to carry reference signals for the UE indicates that only one or more frequency domain (FD) OCCs, or one or more time domain (TD) OCCs are applied, based on a relationship between a sub-carrier spacing (SCS) interval between the two consecutive sub-carriers at the frequency domain and the coherence bandwidth of the channel. 
     
     
       9. The UE of  claim 5 , wherein the subset of the set of resource elements having the one or more OCCs applied to is empty, and the configuration indicates no OCC is applied to the set of resource elements allocated to the one or more antenna ports of the UE. 
     
     
       10. The UE of  claim 1 , wherein the channel comprises one or more frequencies above 52 GHz. 
     
     
       11. The UE of  claim 1 , further comprising at least 2 antenna ports. 
     
     
       12. A base station, comprising:
 a transceiver configured to communicate with a user equipment (UE) through a channel between the UE and the base station; and 
 a processor communicatively coupled to the transceiver and configured to: 
 receive, using the transceiver and from the UE, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with a channel status information reference signal (CSI-RS), or a preference associated with a demodulation reference signal (DMRS) for the UE; 
 determine, responsive to the coherence bandwidth of the channel, the coherence time of the channel, the preference associated with the CSI-RS, or the preference associated with the DMRS, a configuration of resource elements to carry reference signals 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 the CSI-RS or the DMRS for one or more antenna ports of the UE; and 
 transmit, using the transceiver and to the UE, the configuration of resource elements to carry reference signals for the UE. 
 
     
     
       13. The base station of  claim 12 , wherein the processor is further configured to assign the subset of the set of resource elements or an OCC applied to the subset of the set of resource elements to an antenna port of the one or more antenna ports of the UE. 
     
     
       14. The base station of  claim 12 , wherein the processor is configured to transmit a radio resource control (RRC) signal, a medium access control (MAC) control element (CE), or a downlink control information (DCI) to indicate the configuration of resource elements to carry reference signals for the UE. 
     
     
       15. The base station of  claim 14 , wherein the one or more OCCs applied to at least the subset of the set of resource elements for the one or more antenna ports are semi-statically configured by the RRC signal, or dynamically configured by the MAC-CE or the DCI. 
     
     
       16. The base station of  claim 12 , wherein the set of resource elements includes at least two adjacent resource elements at two consecutive sub-carriers in a frequency domain and a symbol in a time domain, or at least two adjacent resource elements at two consecutive sub-carriers in the frequency domain and two adjacent symbols in the time domain. 
     
     
       17. The base station of  claim 16 , wherein the one or more OCCs include only frequency domain (FD) OCCs applied to the two adjacent resource elements at two consecutive sub-carriers in the frequency domain. 
     
     
       18. The base station of  claim 16 , wherein the one or more OCCs include only time domain (TD) OCCs 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 set of resource elements for the one or more antenna ports having the one or more OCCs applied is empty, and the configuration indicates no OCC is applied to the set of resource elements allocated to the one or more antenna ports of the UE. 
     
     
       20. The base station of  claim 12 , wherein the channel comprises one or more frequencies above 52 GHz.

Description:
This application is a U.S. National Phase of International Application No. PCT/CN2020/121614, filed Oct. 16, 2020, which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     Field 
     The described aspects generally relate to adaptive application of orthogonal cover codes in wireless communications. 
     Related Art 
     A user equipment (UE) can communicate with a base station (for example, an evolved Node B (eNB), a next generation node B (gNB), or other base station) over a communication link in a wireless communication system, e.g., New Radio (NR) system, a millimeter wave (mmWave) communication system, or other communication systems. In a communication system, a reference signal normally refers to the so-called “pilot signal” used for channel related functions, e.g., estimation, demodulation, by the receiver. Sometimes, a reference signal is a predefined signal transmitted over a set of predefined resource elements in a resource grid. Downlink reference signals are used by a UE for downlink channel measurement and/or coherent demodulation of downlink transmissions. There are various reference signals defined in downlink, e.g., cell-specific reference signal (CRS), UE-specific demodulation reference signal (DMRS), channel status information reference signal (CSI-RS), and more. However, existing reference signal designs may not be able to meet the diverse needs of various wireless communication systems, e.g., mmWave communication systems. 
     SUMMARY 
     Some aspects of this disclosure relate to apparatuses and methods for adaptive configurations of resource elements to carry reference signals for a user equipment (UE) in a multiple input multiple output (MIMO) wireless communication systems, e.g., a New Radio (NR) MIMO system, or a millimeter wave (mmWave) communication system. A configuration of resource elements to carry reference signals for a UE can be adaptively determined by a base station based on a coherence bandwidth of a channel between the UE and the base station, a coherence time of the channel, a preference associated with channel status information reference signal (CSI-RS) by the UE, or a preference associated with demodulation reference signal (DMRS) by the UE. 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. 
     Some aspects of this disclosure relate to a UE. The UE includes a transceiver configured to communicate with a base station through 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 above 52 GHz, e.g., between 52.6 GHz and 71 GHz. The processor sends, using the transceiver and to the base station, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE. The processor further receives, using the transceiver and from the base station, a configuration of resource elements to carry reference signals for the UE. In detail, the processor can receive a radio resource control (RRC) signal, a medium access control (MAC) control element (CE), or a downlink control information (DCI) to indicate the configuration of resource elements to carry reference signals for the UE. The configuration is determined by the base station based on or in response to the coherence bandwidth of the channel, the coherence time of the channel, the preference associated with CSI-RS, or the preference associated with 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 the CSI-RS or DMRS for one or more antenna ports of the UE. The one or more OCCs applied to at least the subset of the set of resource elements for the one or more antenna ports can be semi-statically configured by the RRC signal, or dynamically configured by the MAC-CE or the DCI. In some examples, the processor can assign the subset of the set of resource elements or an OCC applied to the subset of the set of resource elements to an antenna port of the one or more antenna ports of the UE. The UE can have multiple antenna ports, e.g., 2, 4, 6, 8, 12, 16, or more antenna ports. Afterwards, the processor performs DMRS or CSI-RS reference signal processing based on the configuration of resource elements to carry reference signals for the UE. 
     In some examples, the configuration of resource elements to carry reference signals for the UE indicates a set of resource elements including at least two adjacent resource elements at two consecutive sub-carriers in a frequency domain and a symbol in a time domain. Additionally and alternatively, the set of resource elements can include at least two adjacent resource elements at two consecutive sub-carriers in the frequency domain and two adjacent symbols in the time domain. In addition, the configuration of resource elements to carry reference signals for the UE can indicate the one or more OCCs including frequency domain (FD) OCCs applied to the two adjacent resource elements at two consecutive sub-carriers in the frequency domain. Similarly, the configuration of resource elements to carry reference signals for the UE can indicate the one or more OCCs including time domain (TD) OCCs applied to the two adjacent resource elements of two adjacent symbols in the time domain. In some examples, the configuration of resource elements to carry reference signals for the UE indicates that only FD-OCCs, or TD-OCCs are applied, based on a relationship between a sub-carrier spacing (SCS) interval between the two consecutive sub-carriers at the frequency domain and the coherence bandwidth of the channel. Further in some examples, the subset of the set of resource elements having the one or more OCCs applied to is empty, and the configuration indicates no OCC is applied to the set of resource elements allocated to the one or more antenna ports of the UE. 
     Some aspects of this disclosure relate to a base station. The base station includes a transceiver configured to communicate over a wireless network with a UE, and a processor communicatively coupled to the transceiver. The processor receives, using the transceiver and from the UE, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE. The processor further determines, based on the coherence bandwidth of the channel, the coherence time of the channel, the preference associated with CSI-RS, or the preference associated with DMRS, a configuration of resource elements to carry reference signals for the UE. 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 the CSI-RS or DMRS for one or more antenna ports of the UE. In some example, the processor can assign the subset of the set of resource elements or an OCC applied to the subset of the set of resource elements to an antenna port of the one or more antenna ports of the UE. In addition, the processor transmits, using the transceiver and to the UE, the configuration of resource elements to carry reference signals for the UE. In detail, the processor transmits a RRC signal, a MAC-CE, or a DCI to indicate the configuration of resource elements to carry reference signals for the UE. The one or more OCCs applied to at least the subset of the set of resource elements for the one or more antenna ports are semi-statically configured by the RRC signal, or dynamically configured by the MAC-CE or the DCI. 
     This Summary is provided merely for purposes of illustrating some aspects to provide an understanding of the subject matter described herein. Accordingly, the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter in this disclosure. Other features, aspects, and advantages of this disclosure will become apparent from the following Detailed Description, Figures, and Claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the disclosure and enable a person of skill in the relevant art(s) to make and use the disclosure. 
         FIG.  1    illustrates an example multiple input multiple output (MIMO) wireless system implementing designs for configurations of resource elements to carry reference signals for a user equipment (UE), according to some aspects of the disclosure. 
         FIG.  2    illustrates an example method for a system (for example a user equipment (UE)) supporting mechanisms for implementing designs for configurations of resource elements to carry reference signals for a UE, according to some aspects of the disclosure. 
         FIG.  3    illustrates an example method for a system (for example a base station) supporting mechanisms for implementing designs for configurations of resource elements to carry reference signals for a UE, according to some aspects of the disclosure. 
         FIGS.  4 A- 4 B  illustrate example configurations of resource elements to carry reference signals for a UE, according to some aspects of the disclosure. 
         FIGS.  5 A- 5 C  illustrate example configurations of resource elements to carry reference signals for a UE, according to some aspects of the disclosure. 
         FIG.  6    illustrates a block diagram of an example system of an electronic device implementing designs for configurations of resource elements to carry reference signals for a UE, according to some aspects of the disclosure. 
         FIG.  7    is an example computer system for implementing some aspects or portion(s) thereof of the disclosure provided herein. 
     
    
    
     The present disclosure is described with reference to the accompanying drawings. In the drawings, generally, like reference numbers indicate identical or functionally similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. 
     DETAILED DESCRIPTION 
     The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
     It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” “exemplary,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phases do not necessarily refer to the same embodiment. Further, when a particular feature, structure or characteristic is described in connection with an embodiment, it would be within the knowledge of one skilled in the art to effect such feature, structure or characteristic in connection with other embodiments whether or not explicitly described. In addition, words related to logical relationship, “and,” “or” may mean the logic relationship. For example, “A or B” can include “A and B” or “A or B.” 
     Wireless communication network and systems play an important role in the current society. There are many wireless communication systems, e.g., wireless systems based on 3rd Generation Partnership Project (3GPP) release 16 (Rel-16), release 17 (Rel-17), New Radio (NR) wireless systems. The next-generation wireless communication networks, e.g., NR wireless systems, provide fast data rates and greater capacity, and seamless and real-time interaction between humans and billions of intelligent devices. Millimeter wave (mmWave) communication system can operate on frequencies close to NR systems, e.g., having one or more frequencies above 52 GHz, and can bring commercial opportunities for high data rate communications, e.g., licensed or unlicensed spectrum between 57 GHz and 71 GHz. 
     The opportunities in mmWave communication systems also bring challenges. Operations at mmWave communication systems may demand designs different from the NR systems. For example, a mmWave communication system can have a different numerology including subcarrier spacing (SCS), and channel bandwidth. Increased SCS can be used for a mmWave communication system to ensure robustness of the system to phase noise. However, increased SCS can result in resource elements having an interval larger than the coherence bandwidth of the channel, causing failures to some communication techniques. In a communication system, a reference signal normally refers to the so-called “pilot signal” used for channel functions, e.g., estimation or demodulation, by the receiver. Orthogonal cover codes (OCCs) have been applied to resource elements to carry various reference signals, e.g., UE-specific DMRS, CSI-RS. In a mmWave communication system, due to the increased SCS, OCCs applied to resource elements can fail sometimes. New designs for OCCs applied to resource elements to carry reference signals are desired. 
     Some aspects of this disclosure provide improved solutions to the problems caused by increased SCS in a communication system, e.g., a mmWave communication system. Instead of using fixed OCCs applied to resource elements to carry various reference signals, a base station can determine a configuration for adaptively applying OCCs to a set of resource elements to carry reference signals. The configuration can be determined based on parameters provided by a UE. For example, a UE can provide to a base station a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE. The base station can determine a configuration to have one or more OCCs applied to a set of resource elements semi-statically or dynamically. 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 the CSI-RS or DMRS for one or more antenna ports of the UE. In detail, the configuration can indicate that frequency domain (FD) OCCs can be applied to at least two adjacent resource elements at two consecutive sub-carriers in the frequency domain, time domain (TD) OCCs applied to at least two adjacent resource elements of two adjacent symbols in the time domain, both FD-OCCs and TD-OCCs are applied, or none of FD-OCC and TD-OCC is applied. When both FD-OCCs and TD-OCCs are applied to the set of resource elements, the set of resource elements can carry reference signals for more antenna ports. When one or both of FD-OCC and TD-OCC are disabled from being applied to the set of resource elements, the set of resource elements can carry reference signals for fewer antenna ports. By trading off the number of antenna ports to receive reference signals, techniques provided herein can increase the reliability of the FD-OCC and TD-OCC when applied to the set of resource elements. 
     Although some examples of configurations for carrying reference signals, e.g., CSI-RS or DMRS, for the UE, are presented in a mmWave communication system are provided above, the aspects of this disclosure are not limited to these examples. The examples can be applicable to other wireless communication systems. 
       FIG.  1    illustrates an example MIMO wireless system  100  implementing designs for configurations of resource elements to carry reference signals for a UE  105 , according to some aspects of the disclosure. The wireless system  100  is provided for the purpose of illustration only and does not limit the disclosed aspects. The system  100  can include, but is not limited to, a network node (herein referred to as base station)  101  and an electronic device (hereinafter referred to as UE)  105 . 
     According to some aspects, the base station  101  can include a node configured to operate based on a wide variety of wireless communication techniques such as, but not limited to, techniques for a mmWave communication system with one or more frequencies above 52 GHz, or techniques based on 3GPP standards. For example, base station  101  can include a node configured to operate using Rel-16, Rel-17, or other present/future 3GPP standards. The base station  101  can be a fixed station, and may also be called a base transceiver system (BTS), an access point (AP), a transmission/reception point (TRP), an evolved NodeB (eNB), a next generation node B (gNB), or some other equivalent terminology. 
     According to some aspects, the UE  105  can include an electronic device configured to operate based on a wide variety of wireless communication techniques, e.g., techniques for a mmWave communication system with one or more frequencies above 52 GHz. These techniques can also include, but are not limited to, techniques based on 3rd Generation Partnership Project (3GPP) standards. For example, the UE  105  can include an electronic device configured to operate using Rel-16, Rel-17 or other present/future 3GPP standards. The UE  105  can include, but is not limited to, a wireless communication device, a smart phone, a laptop, a desktop, a tablet, a personal assistant, a monitor, a television, a wearable device, an Internet of Things (IoTs), a vehicle&#39;s communication device, a mobile station, a subscriber station, a remote terminal, a wireless terminal, a user device, or the like. 
     In some examples, the UE  105  can include a transceiver  111  configured to wirelessly communicate with the base station  101  through a channel  103  between the UE  105  and the base station  101 . The UE  105  further includes a processor  113  communicatively coupled to the transceiver  111 . Similarly, the base station  101  can include a transceiver  121  configured to wirelessly communicate with the UE  105  through the channel  103 , and a processor  123  communicatively coupled to the transceiver  121 . More detailed operations of the transceiver  111 , the processor  113 , the transceiver  121 , and the processor  123  are shown in more details in  FIGS.  6  and  7   . In some examples, the channel  103  can have one or more frequencies above 52 GHz, e.g., between 52.6 GHz and 71 GHz. The UE  105  can include multiple antenna ports, e.g., an antenna port  102 , an antenna port  104 , an antenna port  106 , an antenna port  108 . The number of antenna ports is shown for example only, and is not limiting. For example, the UE  105  can include 2, 4, 6, 8, 12, 16, or more antenna ports. 
     The base station  101  can send various downlink reference signals to the UE  105  for downlink channel measurement and/or coherent demodulation of downlink transmission. There are various reference signals defined in downlink, e.g., cell-specific reference signal (CRS), UE-specific DMRS, CSI-RS, and more. A DMRS or CSI-RS reference signal can be processed by the UE  105  according to a configuration  115  stored in the UE  105 . In the current disclosure, a DMRS or CSI-RS signal is used as an example to describe techniques presented herein. Accordingly, these techniques can be applicable to other reference signals with little or no change. Similar techniques can be applied to uplink reference signals as well. 
     In some examples, the configuration  115  can be determined by the base station  101 , and further received from the base station  101  by the UE  105 . The configuration  115  can be adaptively determined by the base station  101  based on information or parameters provided by the UE  105 . In some detail, the UE  105  can send to the base station  101  an uplink information  107 , where the uplink information  107  can include a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE  105 . The base station  101  can receive the uplink information  107 , and further determine a configuration based on the coherence bandwidth of the channel, the coherence time of the channel, the preference associated with CSI-RS, e.g., carried in sounding reference signal (SRS), or the preference associated with DMRS. Afterwards, the base station  101  can send to the UE  105  the determined configuration. The UE  105  can receive the configuration from the base station  101 , which can be saved by the UE  105  to become the configuration  115 . 
     In some examples, the 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., the antenna port  102 , the antenna port  104 , of the UE  105 . 
     In some examples, the set of resource elements  117  includes at least two adjacent resource elements (REs) at two consecutive sub-carriers in a frequency domain and a symbol in a time domain. In other words, the set of resource elements  117  includes at least multiple adjacent REs formed of one symbol. More details of such resource elements are shown in  FIGS.  4 A- 4 B . In some other examples, the set of resource elements  117  includes at least two adjacent REs at two consecutive sub-carriers in the frequency domain and two adjacent symbols in the time domain. In other words, the set of resource elements  117  includes at least multiple adjacent REs formed of two symbols. More details of such resource elements are shown in  FIGS.  5 A- 5 C . 
     In some examples, the one or more OCCs  119  include frequency domain (FD) OCCs applied to the two adjacent resource elements at two consecutive sub-carriers in the frequency domain, or time domain (TD) OCCs applied to the at least two adjacent resource elements of two adjacent symbols in the time domain. In some examples, the configuration  115  indicates that only FD-OCCs, or only TD-OCCs are applied, based on a relationship between a sub-carrier spacing (SCS) interval between the two consecutive sub-carriers at the frequency domain and the coherence bandwidth of the channel. In some examples, there may be no OCCs applied to the set of REs  117 , and the one or more OCCs  119  will not be available. More details of the applications of OCCs are shown in  FIGS.  4 A- 4 B  and  FIGS.  5 A- 5 C . Furthermore in some examples, the number of resource elements can be adjusted to keep within the coherence bandwidth, even if the resources elements can have an interval between them. 
     In some examples, the processor  113  and the processor  123  can be configured to perform methods supporting designs for configurations of carrying reference signals for a UE, e.g., the configuration  115 . More details of the operations of the processor  113  and the processor  123  are shown in  FIG.  2    and  FIG.  3    below. 
       FIG.  2    illustrates an example method  200  for the UE  105  supporting mechanisms for implementing designs for configurations of resource elements to carry reference signals for a UE. Method  200  can be performed by the UE  105 , which can be implemented by the system  600  of  FIG.  6    and/or computer system  700  of  FIG.  7   . But 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 is to be appreciated that not all operations may be needed, and the operations may not be performed in the same order as shown in  FIG.  2   . 
     At  202 , using a transceiver, a UE sends, to a base station, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE. For example, using the transceiver  101 , the UE  105  sends, to the base station  101 , the uplink information  107  that includes a coherence bandwidth of the channel, the coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE  105 , as described for  FIG.  1   . 
     At  204 , using the transceiver, the UE receives, from the base station, a configuration of resource elements to carry reference signals for the UE, where the configuration is determined by the base station based on the coherence bandwidth of the channel, the coherence time of the channel, the preference associated with CSI-RS, or the preference associated with DMRS. For example, the UE  105  receives, from the base station  101 , the configuration  115  for CSI-RS or DMRS for the UE, as described for  FIG.  1   . The configuration  115  can be used for other reference signals as well. 
     In detail, the processor  113  of the UE  105  receives a RRC signal, a MAC-CE, or a DCI to indicate the configuration  115  for CSI-RS or DMRS for the UE  105 . The configuration  115  includes the 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 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 the subset of the set of resource elements for the one or more antenna ports can be semi-statically configured by the RRC signal, or dynamically configured by the MAC-CE or the DCI. 
     At  206 , the UE assigns the subset of the set of resource elements or an OCC applied to the subset of the set of resource elements to an antenna port of the UE. For example, the UE  105  assigns the subset of the set of resource elements or an OCC applied to the subset of the set of resource elements to an antenna port of the UE, as described for  FIG.  1   . Operations at  206  can be optional. In some examples, the assignments of the resource elements or the OCCs to an antenna port can be based on a standard, or assigned by the base station instead of the UE. More detailed examples of such assignments are shown in  FIGS.  4 A- 4 B  and  FIGS.  5 A- 5 C . 
     At  208 , the UE performs DMRS or CSI-RS reference signal processing based on the configuration of resource elements to carry reference signals for the UE. For example, the UE  105  performs DMRS or CSI-RS reference signal processing based on the configuration  115  for CSI-RS or DMRS for the UE, as described for  FIG.  1   . 
       FIG.  3    illustrates an example method  300  for the base station  101  supporting mechanisms for implementing designs for configurations of resource elements to carry reference signals for a UE. Method  300  may also be performed by system  600  of  FIG.  6    and/or computer system  700  of  FIG.  7   . But 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 is to be appreciated that not all operations may be needed, and the operations may not be performed in the same order as shown in  FIG.  3   . 
     At  302 , a base station receives, using a transceiver and from the UE, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE. For example, the base station  101  receives, using the transceiver  121  and from the UE  105 , the uplink information  107  that includes a coherence bandwidth of the channel, the coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE, as described for  FIG.  1   . 
     At  304 , the base station determines, based on the coherence bandwidth of the channel, the coherence time of the channel, the preference associated with CSI-RS, or the preference associated with DMRS, a configuration of resource elements to carry reference signals for the UE. For example, the base station  101  determines, based on the coherence bandwidth of the channel, the coherence time of the channel, the preference associated with CSI-RS, or the preference associated with DMRS contained in the uplink information  107 , a configuration of resource elements to carry reference signals for the UE  105 . 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 . 
     At  306 , the base station assigns the subset of the set of resource elements or an OCC applied to the subset of the set of resource elements to an antenna port of the UE. For example, the base station  101  assigns the subset of the set of resource elements or an OCC applied to the subset of the set of resource elements to an antenna port of the UE, as described for  FIG.  1   . Operations at  306  can be optional. In some examples, the assignments of the resource elements or the OCCs to an antenna port can be based on a standard, or assigned by the UE instead of the base station  101 . More detailed examples of such assignments are shown in  FIGS.  4 A- 4 B  and  FIGS.  5 A- 5 C . 
     At  308 , the base station transmits, using the transceiver and to the UE, the configuration of resource elements to carry reference signals for the UE. For example, the base station  101  transmits, using the transceiver  121  and to the UE  105 , the configuration of resource elements to carry reference signals for the UE  105 , which is saved by the UE  105  as the configuration  115 , as described for  FIG.  1   . In detail, the processor  123  of the base station  101  can transmit a RRC signal, a MAC-CE, or a DCI to indicate the configuration  115  for CSI-RS or DMRS for the UE  105 . The configuration  115  includes the 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 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 the subset of the set of resource elements for the one or more antenna ports are semi-statically configured by the RRC signal, or dynamically configured by the MAC-CE or the DCI. 
       FIGS.  4 A- 4 B  illustrate example configurations of resource elements to carry reference signals for a UE, according to some aspects of the disclosure. The configurations can be an example of the configure  115  shown in  FIG.  1   . The configurations in  FIGS.  4 A- 4 B  indicate 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 the CSI-RS or DMRS for one or more antenna ports of the UE. 
     In some examples, as shown in  FIG.  4 A , the set of resource elements  403  is a resource block (RB) of 12 resource elements (REs), where each resource element (RE) includes one orthogonal frequency division multiplexing (OFDM) symbol on one subcarrier. The set of resource elements  403  is shown in an exemplary OFDM time-frequency grid  401  in the time domain and the frequency domain. In the frequency domain, the physical resources are divided into adjacent subcarriers with a subcarrier spacing (SCS). In some example, the SCS can be 15 kHz. In a mmWave system, the SCS can be larger than 15 kHz. The number of subcarriers varies according to the allocated system bandwidth. The OFDM time-frequency grid  401  includes 12 subcarriers over 14 symbols. The 14 symbols can form a subframe of one millisecond. In some examples, a subframe can have 12 symbols if an extended cyclic prefix is used. 
     In some examples, the set of resource elements  403  is divided into multiple subsets of resource elements to carry the CSI-RS or DMRS for one or more antenna ports of the UE. For example, as shown in  FIG.  4 A , the resource elements  403  is divided into two disjoint subsets, a subset  405  of REs, and a subset  407  of REs. The subset  405  of REs includes multiple pairs of REs, e.g., a pair of REs  451 , a pair of REs  452 , and a pair of REs  453 . The pair of REs  451 , the pair of REs  452 , or the pair of REs  453  includes two adjacent resource elements at two consecutive sub-carriers in the frequency domain and a symbol in the time domain. For example, the pair of REs  451  includes two adjacent resource elements at two consecutive sub-carriers  0  and  1 , and the symbol  3  in the time domain, since the pair of REs  451  is part of the set of resource elements  403 . The subset  407  of REs has similar structures as the subset  405  of REs. 
     Without the use of OCCs, the subset  405  of REs can be assigned to an antenna port, e.g., port  1000 , while the subset  407  of REs can be assigned to another antenna port, e.g., port  1001 . However, the subset  405  of REs can only be assigned to one antenna port without the use of OCCs. Therefore, the set of resource elements  403  is split into two subsets of REs to carry the CSI-RS or DMRS for two antenna ports of the UE. 
     In some examples, an OCC can be used to maintain orthogonality between antenna ports allocated to the same REs. As shown in  FIG.  4 A , two OCCs, {1 1} and {1-1} can be applied to the subset  405  of REs in the frequency domain so that the same subset  405  of REs can carry reference signals for two antenna ports of the UE. The OCC {1 1} is represented by “+” “+” marked on two resource elements at two consecutive sub-carriers in the frequency domain, while the OCC {1 −1} is represented by “+” “−” marked on two resource elements at two consecutive sub-carriers in the frequency domain. Accordingly, the subset  405  of REs with the OCC {1 1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1000 , and the subset  405  of REs with the OCC {1 −1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1001 . The subset  405  of REs with two OCCs applied in the frequency domain form a code division multiplexing (CDM) group  402 . 
     Similarly, two OCCs, {1 1} and {1 −1} can be applied to the subset  407  of REs in the frequency domain so that the same subset  407  of REs can carry reference signals for two antenna ports of the UE. Accordingly, the subset  407  of REs with the OCC {1 1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1002 , and the subset  405  of REs with the OCC {1 −1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1003 . The assignments of a subset of REs together with an OCC to an antenna port can be performed dynamically by a UE or a base station, or by a standard known ahead of time. 
     In some examples, as shown in  FIG.  4 B , the set of resource elements  403  is divided into three subsets of resource elements, a subset  411  of REs, a subset  413  of REs, and a subset  415  of REs, to carry the CSI-RS or DMRS for one or more antenna ports of the UE. The subset  411  of REs, the subset  413  of REs, the subset  415  of REs, includes multiple pairs of resource elements, where a pair of REs includes two adjacent resource elements at two consecutive sub-carriers in the frequency domain and a symbol in the time domain. 
     Without the use of OCCs, the subset  411  of REs can be assigned to a first antenna port, e.g., port  1000 , the subset  413  of REs can be assigned to a second antenna port, e.g., port  1001 , while the subset  415  of REs can be assigned to a third antenna port, e.g., port  1002 . However, each subset of REs can only be assigned to one antenna port without the use of OCCs. 
     In some examples, an OCC can be used to maintain orthogonality between antenna ports allocated to the same DMRS REs. Two OCCs, {1 1} and {1 −1} can be applied to the subset  411  of REs in the frequency domain so that the same subset  411  of REs can carry reference signals for two antenna ports of the UE. Accordingly, the subset  411  of REs with the OCC {1 1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1000 , and the subset  411  of REs with the OCC {1 −1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1001 . The subset  411  of REs with two OCCs applied in the frequency domain form a code division multiplexing (CDM) group  421 . 
     Similarly, two OCCs, {1 1} and {1 −1} can be applied to the subset  413  of REs in the frequency domain so that the same subset  413  of REs can carry reference signals for two antenna ports of the UE. Accordingly, the subset  413  of REs with the OCC {1 1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1002 , and the subset  413  of REs with the OCC {1 −1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1003 . The subset  413  of REs with two OCCs applied in the frequency domain form a code division multiplexing (CDM) group  423 . 
     Similarly, two OCCs, {1 1} and {1 −1} can be applied to the subset  415  of REs in the frequency domain so that the same subset  415  of REs can carry reference signals for two antenna ports of the UE. Accordingly, the subset  415  of REs with the OCC {1 1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1004 , and the subset  415  of REs with the OCC {1 −1} applied to the REs can be assigned to an antenna port, e.g., antenna port  1005 . The subset  415  of REs with two OCCs applied in the frequency domain form a code division multiplexing (CDM) group  425 . 
       FIGS.  5 A- 5 C  illustrate example configurations of resource elements to carry reference signals for a UE, according to some aspects of the disclosure. The configurations can be an example of the configure  115  shown in  FIG.  1   . The configurations in  FIGS.  5 A- 5 C  indicate 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 the CSI-RS or DMRS for one or more antenna ports of the UE. 
     In some examples, as shown in  FIG.  5 A , the set of resource elements  503  is a resource block (RB) of 24 REs over two symbols, symbol  3  and symbol  4 . The set of resource elements  503  is shown in an exemplary OFDM time-frequency grid  501  in the time domain and the frequency domain. The OFDM time-frequency grid  501  includes 12 subcarriers over 14 symbols. The 14 symbols can form a subframe of one millisecond. In some examples, a subframe can have 12 symbols if an extended cyclic prefix is used. 
     In some examples, the set of resource elements  503  is divided into multiple subsets of resource elements to carry the CSI-RS or DMRS for one or more antenna ports of the UE. For example, as shown in  FIG.  5 A , the resource elements  503  is divided into two disjoint subsets, a subset  511  of REs, and a subset  513  of REs. The subset  511  of REs or the subset  513  of REs includes multiple pairs of REs. A pair of REs includes two adjacent resource elements at two consecutive sub-carriers in the frequency domain and two adjacent symbols in the time domain. 
     Without the use of OCCs, the subset  511  of REs can be assigned to an antenna port, e.g., port  1000 , while the subset  513  of REs can be assigned to another antenna port, e.g., port  1001 . However, the subset  511  of REs can only be assigned to one antenna port without the use of OCCs. Therefore, the set of resource elements  503  is split into two subsets of REs to carry the CSI-RS or DMRS for two antenna ports of the UE. 
     In some examples, an OCC can be used to maintain orthogonality between antenna ports allocated to the same DMRS REs. Two OCCs, {1 1} and {1 −1} can be applied to the subset  511  of REs in the frequency domain. In addition, two OCCs, {1 1} and {−1 −1} can be applied to the subset  511  of REs in the time domain. Overall, the subset  511  of REs with the 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 . 
     Similarly, two OCCs, {1 1} and {1 −1} can be applied to the subset  513  of REs in the frequency domain. In addition, two OCCs, {1 1} and {−1 −1} can be applied to the subset  513  of REs in the time domain. Overall, the subset  513  of REs with the corresponding FD-OCCs and TD-OCCs can be assigned to four antenna ports, e.g., antenna port  1002 , antenna port  1003 , antenna port  1006 , and antenna port  1007 . 
     In some examples, as shown in  FIG.  5 B , the set of resource elements  503  is divided into four disjoint subsets, a subset  521  of REs, a subset  522  of REs, a subset  523  of REs, a subset  524  of REs, each of which includes multiple pairs REs. A pair of REs includes two adjacent resource elements at two consecutive sub-carriers in the frequency domain and one symbol in the time domain. 
     Without the use of OCCs, the subset  521  of REs can be assigned to an antenna port, e.g., port  1000 . Similarly, each of the subset  522  of REs, the subset  523  of REs, and the subset  524  of REs can be assigned to an antenna port, e.g., port  1001 , port  1002 , port  1003 . Therefore, the set of resource elements  503  is split into four subsets of REs to carry the CSI-RS or DMRS for four antenna ports of the UE. 
     In some examples, an OCC can be used to maintain orthogonality between antenna ports allocated to the same DMRS REs. Two OCCs, {1 1} and {1 −1} can be applied to the subset  521  of REs in the frequency domain. Hence, the subset  521  of REs with the corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1000 , antenna port  1001 . Similarly, the subset  523  of REs with the corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1004 , antenna port  1005 ; the subset  522  of REs with the two corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1002 , antenna port  1003 ; and the subset  524  of REs with the two corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1006 , antenna port  1007 . As shown above, only FD-OCCs are applied to a subset of REs, without applying any TD-OCCs. A base station can make such a determination to apply only FD-OCCs based on a relationship between a SCS interval at the frequency domain and the coherence bandwidth of the channel. When the coherence bandwidth of the channel is small compared to the SCS interval, TD-OCCs may not be applied to the subset of REs. Similarly, the base station can make a determination to apply only TD-OCCs without FD-OCCs to some other subsets of REs, not shown. 
     In some examples, as shown in  FIG.  5 C , the set of resource elements  503  is divided into six disjoint subsets, a subset  531  of REs, a subset  532  of REs, a subset  533  of REs, a subset  534  of REs, a subset  535  of REs, and a subset  536  of REs, each of which includes multiple pairs REs. A pair of REs includes two adjacent resource elements at two consecutive sub-carriers in the frequency domain and one symbol in the time domain. 
     Without the use of OCCs, the subset  531  of REs can be assigned to an antenna port, e.g., port  1000 . Similarly, each of the subset  532  of REs, the subset  533  of REs, the subset  534  of REs, the subset  535  of REs, and the subset  536  of REs, can be assigned to an antenna port, e.g., port  1001 , port  1002 , port  1003 , port  1004 , port  1005 . Therefore, the set of resource elements  503  is split into 6 subsets of REs to carry the CSI-RS or DMRS for 6 antenna ports of the UE. 
     In some examples, an OCC can be used to maintain orthogonality between antenna ports allocated to the same DMRS REs. Two OCCs, {1 1} and {1 −1} can be applied to the subset  531  of REs in the frequency domain. Hence, the subset  531  of REs with the corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1000 , antenna port  1001 . Similarly, the subset  532  of REs with the corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1002 , antenna port  1003 ; the subset  533  of REs with the corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1004 , antenna port  1005 ; the subset  534  of REs with the corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1006 , antenna port  1007 ; the subset  535  of REs with the corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1008 , antenna port  1009 ; the subset  536  of REs with the corresponding FD-OCCs can be assigned to two antenna ports, e.g., antenna port  1010 , antenna port  1011 . 
     The various configurations of resource elements to carry reference signals for a UE, with or without FD-OCCs or TD-OCCs, as shown in  FIGS.  4 A- 4 B  and  FIGS.  5 A- 5 C , are for examples only, and are not limiting. For example, the set of resource elements  403  or the set of resource elements  503  can be split into multiple subsets of REs in different ways. In addition, different OCCs, e.g., other length-2 OCCs, or length-4 OCCs can be assigned to a subset of REs, resulting to assignments to a number of antenna ports different from what are shown in  FIGS.  4 A- 4 B  and  FIGS.  5 A- 5 C . 
       FIG.  6    illustrates a block diagram of an example system  600  of an electronic device implementing designs for configurations of resource elements to carry reference signals for a UE, according to some aspects of the disclosure. System  600  may be any of the electronic devices (e.g., the base station  101 , the UE  105 ) of system  100 . The system  600  includes a processor  610 , one or more transceivers  620 , communication infrastructure  640 , memory  650 , operating system  652 , application  654 , and one or more antenna  660 . Illustrated systems are provided as exemplary parts of system  600 , and system  600  can include other circuit(s) and subsystem(s). Also, although the systems of system  600  are illustrated as separate components, the aspects of this disclosure can include any combination of these, less, or more components. 
     Memory  650  may include random access memory (RAM) and/or cache, and may include control logic (e.g., computer software) and/or data. Memory  650  may include other storage devices or memory such as, but not limited to, a hard disk drive and/or a removable storage device/unit. According to some examples, operating system  652  can be stored in memory  650 . Operating system  652  can manage transfer of data from memory  650  and/or one or more applications  654  to processor  610  and/or one or more transceivers  620 . In some examples, operating system  652  maintains one or more network protocol stacks (e.g., Internet protocol stack, cellular protocol stack, and the like) that can include a number of logical layers. At corresponding layers of the protocol stack, operating system  652  includes control mechanism and data structures to perform the functions associated with that layer. 
     According to some examples, application  654  can be stored in memory  650 . Application  654  can include applications (e.g., user applications) used by wireless system  600  and/or a user of wireless system  600 . The applications in application  654  can include applications such as, but not limited to, Siri™, FaceTime™, radio streaming, video streaming, remote control, and/or other user applications. 
     System  600  can also include communication infrastructure  640 . Communication infrastructure  640  provides communication between, for example, processor  610 , one or more transceivers  620 , and memory  650 . In some implementations, communication infrastructure  640  may be a bus. Processor  610  together with instructions stored in memory  650  performs operations enabling system  600  to implement mechanisms for configurations of resource elements to carry reference signals for a UE, as described herein for the system  100  as shown in  FIG.  1   . 
     One or more transceivers  620  transmit and receive communications signals that support mechanisms for configurations of resource elements to carry reference signals for a UE as shown in  FIG.  1   . Additionally, one or more transceivers  620  transmit and receive communications signals that support mechanisms for transmitting the configurations of resource elements to carry reference signals for a UE as shown in  FIG.  1   . According to some aspects, one or more transceivers  620  may be coupled to antenna  660 . Antenna  660  may include one or more antennas that may be the same or different types. One or more transceivers  620  allow system  600  to communicate with other devices that may be wired and/or wireless. In some examples, one or more transceivers  620  can include processors, controllers, radios, sockets, plugs, buffers, and like circuits/devices used for connecting to and communication on networks. According to some examples, one or more transceivers  620  include one or more circuits to connect to and communicate on wired and/or wireless networks. 
     According to some aspects of this disclosure, one or more transceivers  620  can include a cellular subsystem, a WLAN subsystem, and/or a Bluetooth™ subsystem, each including its own radio transceiver and protocol(s) as will be understood by those skilled arts based on the discussion provided herein. In some implementations, one or more transceivers  620  can include more or fewer systems for communicating with other devices. 
     In some examples, one or more transceivers  620  can include one or more circuits (including a WLAN transceiver) to enable connection(s) and communication over WLAN networks such as, but not limited to, networks based on standards described in IEEE 802.11. 
     Additionally, or alternatively, one or more transceivers  620  can include one or more circuits (including a Bluetooth™ transceiver) to enable connection(s) and communication based on, for example, Bluetooth™ protocol, the Bluetooth™ Low Energy protocol, or the Bluetooth™ Low Energy Long Range protocol. For example, one or more transceivers transceiver  620  can include a Bluetooth™ transceiver. 
     Additionally, one or more transceivers  620  can include one or more circuits (including a cellular transceiver) for connecting to and communicating on cellular networks. The cellular networks can include, but are not limited to, 3G/4G/5G networks such as Universal Mobile Telecommunications System (UMTS), Long-Term Evolution (LTE), mmWave systems, and the like. For example, one or more transceivers  220  can be configured to operate according to one or more of Rel-15, Rel-16, Rel-17, or other present/future 3GPP standards. 
     According to some aspects of this disclosure, processor  610 , alone or in combination with computer instructions stored within memory  650 , and/or one or more transceiver  620 , implements the methods and mechanisms discussed in this disclosure. For example, processor  610 , alone or in combination with computer instructions stored within memory  650 , and/or one or more transceiver  220 , implements mechanisms for configurations of resource elements to carry reference signals for a UE as shown in  FIG.  1   . According to some aspects of this disclosure, processor  610 , alone or in combination with computer instructions stored within memory  650 , and/or one or more transceiver  620 , can send, to the base station, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE. In addition, processor  610  can receive, using the transceiver and from the base station, a configuration of resource elements to carry reference signals for the UE; and further perform DMRS or CSI-RS reference signal processing based on the configuration of resource elements to carry reference signals for the UE. 
     Various aspects can be implemented, for example, using one or more computer systems, such as computer system  700  shown in  FIG.  7   . Computer system  700  can be any well-known computer capable of performing the functions described herein such as devices  101 ,  105  of  FIG.  1   , or  600  of  FIG.  6   . Computer system  700  includes one or more processors (also called central processing units, or CPUs), such as a processor  704 . Processor  704  is connected to a communication infrastructure  706  (e.g., a bus). Computer system  700  also includes user input/output device(s)  703 , such as monitors, keyboards, pointing devices, etc., that communicate with communication infrastructure  706  through user input/output interface(s)  702 . Computer system  700  also includes a main or primary memory  708 , such as random access memory (RAM). Main memory  708  may include one or more levels of cache. Main memory  708  has stored therein control logic (e.g., computer software) and/or data. 
     Computer system  700  may also include one or more secondary storage devices or memory  710 . Secondary memory  710  may include, for example, a hard disk drive  712  and/or a removable storage device or drive  714 . Removable storage drive  714  may be a floppy disk drive, a magnetic tape drive, a compact disk drive, an optical storage device, tape backup device, and/or any other storage device/drive. 
     Removable storage drive  714  may interact with a removable storage unit  718 . Removable storage unit  718  includes a computer usable or readable storage device having stored thereon computer software (control logic) and/or data. Removable storage unit  718  may be a floppy disk, magnetic tape, compact disk, DVD, optical storage disk, and/any other computer data storage device. Removable storage drive  714  reads from and/or writes to removable storage unit  718  in a well-known manner. 
     According to some aspects, secondary memory  710  may include other means, instrumentalities or other approaches for allowing computer programs and/or other instructions and/or data to be accessed by computer system  700 . Such means, instrumentalities or other approaches may include, for example, a removable storage unit  722  and an interface  720 . Examples of the removable storage unit  722  and the interface  720  may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and/or any other removable storage unit and associated interface. 
     In some examples, main memory  708 , the removable storage unit  718 , the removable storage unit  722  can store instructions that, when executed by processor  704 , cause processor  704  to perform operations for a UE, e.g., the UE  105 , or a base station, e.g., the base station  101 . In some examples, the operations include sending, to the base station, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE; receiving, from the base station, a configuration of resource elements to carry reference signals for the UE; and performing DMRS or CSI-RS reference signal processing based on the configuration of resource elements to carry reference signals for the UE. In addition, the operations include receiving, from the UE, a coherence bandwidth of the channel, a coherence time of the channel, a preference associated with CSI-RS, or a preference associated with DMRS for the UE; determining, based on the coherence bandwidth of the channel, the preference associated with CSI-RS, or the preference associated with DMRS, a configuration of resource elements to carry reference signals for the UE; and transmitting, to the UE, the configuration of resource elements to carry reference signals for the UE. 
     Computer system  700  may further include a communication or network interface  724 . Communication interface  724  enables computer system  700  to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referenced by reference number  728 ). For example, communication interface  724  may allow computer system  700  to communicate with remote devices  728  over communications path  726 , which may be wired and/or wireless, and which may include any combination of LANs, WANs, the Internet, etc. Control logic and/or data may be transmitted to and from computer system  700  via communication path  726 . 
     The operations in the preceding aspects can be implemented in a wide variety of configurations and architectures. Therefore, some or all of the operations in the preceding aspects may be performed in hardware, in software or both. In some aspects, a tangible, non-transitory apparatus or article of manufacture includes a tangible, non-transitory computer useable or readable medium having control logic (software) stored thereon is also referred to herein as a computer program product or program storage device. This includes, but is not limited to, computer system  700 , main memory  708 , secondary memory  710  and removable storage units  718  and  722 , as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system  700 ), causes such data processing devices to operate as described herein. 
     Based on the teachings contained in this disclosure, it will be apparent to persons skilled in the relevant art(s) how to make and use aspects of the disclosure using data processing devices, computer systems and/or computer architectures other than that shown in  FIG.  7   . In particular, aspects may operate with software, hardware, and/or operating system implementations other than those described herein. 
     It is to be appreciated 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 disclosure as contemplated by the inventor(s), and thus, are not intended to limit the disclosure or the appended claims in any way. 
     While the disclosure has been described herein with reference to exemplary aspects for exemplary fields and applications, it should be understood that the disclosure is not limited thereto. Other aspects and modifications thereto are possible, and are within the scope and spirit of the disclosure. For example, and without limiting the generality of this paragraph, aspects are not limited to the software, hardware, firmware, and/or entities illustrated in the figures and/or described herein. Further, aspects (whether or not explicitly described herein) have significant utility to fields and applications beyond the examples described herein. 
     Aspects have been described herein with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined as long as the specified functions and relationships (or equivalents thereof) are appropriately performed. In addition, alternative aspects may perform functional blocks, steps, operations, methods, etc. using orderings different from those described herein. 
     References herein to “one embodiment,” “an embodiment,” “an example embodiment,” or similar phrases, indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of persons skilled in the relevant art(s) to incorporate such feature, structure, or characteristic into other aspects whether or not explicitly mentioned or described herein. 
     The breadth and scope of the 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. 
     It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     For one or more embodiments or examples, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and/or methods as set forth in the example section below. For example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth below in the example section.

Metadata:
Filing Date: 20201016
Publication Date: 20240507
Grant Date: 20240507
Priority Date: 20201016
Inventors: YE, SIGEN
ZENG, WEI
ZHANG, DAWEI
OTERI, OGHENEKOME
SUN, HAITONG
ZHANG, YUSHU
YE, CHUNXUAN
Assignee: APPLE INC
CPC Classifications: [{"code": "H04L5/0051", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L5/0016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/0051", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L5/0051", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04J2011/0016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/0016", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 81208874