Enhanced tracking reference signal pattern

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) can transmit, to a base station, a UE capability for receiving a first portion of a tracking reference signal (TRS) and a second portion of the TRS, the first portion and the second portion associated with a TRS pattern. The UE can receive, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern. The UE can receive one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

Description

[0001] Cross-references

[0002] This patent application claims the benefits of U.S. Provisional Patent Application No. 63 / 025,130, entitled “Enhanced Tracking Reference SIGNAL PATTERNS”, filed May 14, 2020, and U.S. Patent Application No. 17 / 318,985, entitled “Enhanced Tracking Reference SIGNAL PATTERNS”, filed May 12, 2021, with each of these patent applications assigned to the assignee of this application. Technical Field

[0003] The following content generally relates to wireless communication, specifically to the management of Tracking Reference Signal (TRS) mode. Background Technology

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasting. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth-generation (4G) systems such as Long Term Evolution (LTE), LTE-A Advanced (LTE-A), or LTE-A Pro systems, and fifth-generation (5G) systems, also known as New Radio (NR) systems. These systems can employ technologies such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each supporting communication from multiple communication devices simultaneously, where the communication devices may also be referred to as User Equipment (UE). Summary of the Invention

[0005] A method for wireless communication at a UE is described. The method can include transmitting, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of the TRSs, the first portion and the second portion being associated with a TRS pattern, receiving, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern, where the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs, and receiving one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0006] An apparatus for wireless communication at a UE is described. The apparatus can include a processor and memory coupled to the processor, the memory and processor configured to transmit, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of the TRSs, the first portion and the second portion being associated with a TRS pattern, receive, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern, where the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs, and receive one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0007] Another apparatus for wireless communication at a UE is described. The apparatus can include means for transmitting, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of the TRSs, the first portion and the second portion being associated with a TRS pattern, means for receiving, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern, where the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs, and means for receiving one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0008] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code can include instructions executable by a processor to transmit, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of the TRSs, the first portion and the second portion associated with a TRS pattern, receive, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern, where the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs, and receive one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0009] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for transmitting, to the base station, a request for the second portion of the TRS pattern.

[0010] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for detecting that the UE can be moving at a speed that satisfies a speed threshold, where the request can be transmitted based on the detection.

[0011] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for selecting the TRS pattern from a pattern table based on the indication of the TRS pattern.

[0012] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for receiving, from the base station, a medium access control (MAC) control element (CE) indicating the pattern table from a set of multiple pattern tables.

[0013] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication of the TRS pattern corresponds to an index of the pattern table.

[0014] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for receiving, from the base station, radio resource control (RRC) signaling for configuring the pattern table.

[0015] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the indication of the TRS pattern can be received via downlink control information (DCI).

[0016] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, receiving the indication of the TRS pattern can include operations, features, means, or instructions for receiving DCI allocating aperiodic resources for a set of multiple TRSs.

[0017] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for receiving, from the base station, an indication of a triggering state via DCI or a MAC-CE, where the TRS pattern can be based on the triggering state.

[0018] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the second portion of the TRS pattern can be between, before, or after the first portion of TRSs.

[0019] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the TRS pattern spans a slot or a set of multiple slots.

[0020] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the first portion of the TRS pattern spans a TRS bandwidth, and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0021] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for performing time and frequency synchronization based on receiving the one or more TRSs.

[0022] A method for wireless communications at a base station is described. The method can include receiving, from a UE, an indication of a UE capability, transmitting, to the UE, an indication of a TRS pattern including a first portion and a second portion for a set of multiple TRSs based on the received indication of the UE capability, where the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion of the TRS pattern and the second portion include a second symbol gap between at least two TRSs, and transmitting the set of multiple TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0023] An apparatus for wireless communication at a base station is described. The apparatus can include a processor and memory coupled to the processor, the memory and processor configured to: receive, from a UE, an indication of a UE capability; transmit, to the UE, an indication of a TRS pattern including a first portion and a second portion for a set of multiple TRSs based on the received indication of the UE capability, wherein the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs; and transmit the set of multiple TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0024] Another apparatus for wireless communication at a base station is described. The apparatus can include means for receiving, from a UE, an indication of a UE capability; means for transmitting, to the UE, an indication of a TRS pattern including a first portion and a second portion for a set of multiple TRSs based on the received indication of the UE capability, wherein the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs; and means for transmitting the set of multiple TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0025] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code can include instructions executable by a processor to: receive, from a UE, an indication of a UE capability; transmit, to the UE, an indication of a TRS pattern including a first portion and a second portion for a set of multiple TRSs based on the received indication of the UE capability, wherein the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs; and transmit the set of multiple TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0026] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for receiving, from the UE, a request for the second portion of the TRS pattern based on a high speed of the UE.

[0027] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the indication of the TRS pattern corresponds to an index of a pattern table configured at the UE.

[0028] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for transmitting, to the UE, a MAC-CE indicating the pattern table from a set of multiple pattern tables.

[0029] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for transmitting, to the UE, RRC signaling configuring the pattern table.

[0030] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the indication of the TRS pattern can be transmitted via DCI.

[0031] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, transmitting the indication of the TRS pattern can include operations, features, means, or instructions for transmitting DCI allocating aperiodic resources for the set of multiple TRSs.

[0032] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for transmitting, from the base station, an indication of a trigger state via DCI or a MAC-CE, where the TRS pattern can be based on the trigger state.

[0033] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the second portion of the TRS pattern can be between, before, or after the first portion of TRSs.

[0034] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the first portion of the TRS pattern spans a TRS bandwidth, and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0035] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for transmitting, to a second UE that can not be able to receive the second portion of the TRS pattern, the indication of the TRS pattern and scheduling downlink shared channel resources for the second UE, where the downlink shared channel resources at least partially overlap in time, frequency, antenna ports, or any combination thereof with the second portion of the TRS based on a modulation and coding scheme of the second UE being lower order.

[0036] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for scheduling a second UE for a downlink shared channel during a slot that includes the set of TRSs, where the second UE can not be able to receive the second portion of the TRS pattern and transmitting, to the second UE, the indication of the TRS pattern, where the indication is for configuring the second UE for a zero-power channel state information reference signal during the second portion of the TRS pattern.

[0037] A method for wireless communications at a UE is described. The method can include transmitting, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of the TRSs, the first portion and the second portion being associated with a TRS pattern, receiving, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern, and monitoring a set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0038] An apparatus for wireless communications at a UE is described. The apparatus can include a processor and a memory coupled to the processor. The processor and the memory can be configured to transmit, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of the TRSs, the first portion and the second portion being associated with a TRS pattern. The processor and the memory can also be configured to receive, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern. In addition, the processor and the memory can be configured to monitor a set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0039] Another apparatus for wireless communication at a UE is described. The apparatus can include means for transmitting, to a base station, a UE capability for receiving a first portion of TRS and a second portion of the TRS, the first portion and the second portion being associated with a TRS pattern; means for receiving, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern; and means for monitoring a set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0040] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code can include instructions executable by a processor to transmit, to a base station, a UE capability for receiving a first portion of TRS and a second portion of the TRS, the first portion and the second portion being associated with a TRS pattern; receive, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern; and monitor a set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0041] Some examples of the method, apparatus, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for transmitting, to the base station, a request for the second portion of the TRS pattern.

[0042] Some examples of the method, apparatus, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for detecting that the UE can be moving at a speed that satisfies a speed threshold, where the request can be transmitted based on the detection.

[0043] Some examples of the method, apparatus, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for selecting the TRS pattern from a pattern table based on the indication of the TRS pattern.

[0044] Some examples of the method, apparatus, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for receiving, from the base station, a MAC-CE indicating the pattern table from a set of multiple pattern tables.

[0045] In some examples of the method, apparatus, and non-transitory computer-readable medium described herein, the indication of the TRS pattern corresponds to an index of the pattern table.

[0046] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for receiving, from the base station, RRC signaling configuring the pattern table.

[0047] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the indication of the TRS pattern can be received via DCI.

[0048] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, receiving the indication of the TRS pattern can include operations, features, means, or instructions for receiving DCI allocating aperiodic resources for a set of TRSs.

[0049] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for receiving, from the base station, an indication of a trigger state via DCI or a MAC-CE, where the TRS pattern can be based on the trigger state.

[0050] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the first portion of the TRS pattern includes a four symbol gap between TRSs, and the first portion of the TRS pattern and the second portion of the TRS pattern include a smaller symbol gap (e.g., fewer symbols than a four symbol gap) between at least two TRSs.

[0051] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the second portion of the TRS pattern can be between, before, or after the TRSs of the first portion.

[0052] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the TRS pattern spans a slot or a set of slots.

[0053] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the first portion of the TRS pattern spans a TRS bandwidth, and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0054] A method for wireless communication at a base station is described. The method can include receiving, from a UE, a UE capability for receiving a first portion of TRS and a second portion of TRS, the first portion and the second portion being associated with a TRS pattern; selecting, based on receiving the UE capability, the TRS pattern that includes the first portion and the first portion for a set of TRS; transmitting, to the UE, an indication of the TRS pattern; and transmitting the set of TRS in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0055] An apparatus for wireless communication at a base station is described. The apparatus can include a processor and a memory coupled to the processor. The processor and the memory can be configured to receive, from a UE, a UE capability for receiving a first portion of TRS and a second portion of TRS. The first portion and the second portion can be associated with a TRS pattern. The processor and the memory can also be configured to select, based on receiving the UE capability, the TRS pattern that includes the first portion and the first portion for a set of TRS. In addition, the processor and the memory can be configured to transmit the set of TRS in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0056] Another apparatus for wireless communication at a base station is described. The apparatus can include means for receiving, from a UE, a UE capability for receiving a first portion of TRS and a second portion of TRS, the first portion and the second portion being associated with a TRS pattern; means for selecting, based on receiving the UE capability, the TRS pattern that includes the first portion and the first portion for a set of TRS; means for transmitting, to the UE, an indication of the TRS pattern; and means for transmitting the set of TRS in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0057] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code can include instructions executable by a processor to receive, from a UE, a UE capability for receiving a first portion of TRS and a second portion of TRS, the first portion and the second portion being associated with a TRS pattern; select, based on receiving the UE capability, the TRS pattern that includes the first portion and the first portion for a set of TRS; transmit, to the UE, an indication of the TRS pattern; and transmit the set of TRS in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0058] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for receiving, from the UE, a request for the second portion of the TRS pattern based on a high speed of the UE.

[0059] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication of the TRS pattern corresponds to an index of a pattern table configured at the UE.

[0060] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for transmitting, to the UE, a MAC-CE indicating the pattern table from a set of multiple pattern tables.

[0061] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for transmitting, to the UE, RRC signaling to configure the pattern table.

[0062] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication of the TRS pattern can be transmitted via DCI.

[0063] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the indication of the TRS pattern can include operations, features, means, or instructions for transmitting DCI to allocate aperiodic resources for the set of TRSs.

[0064] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for transmitting, from the base station, an indication of a trigger state via DCI or a MAC-CE, where the TRS pattern can be based on the trigger state.

[0065] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first portion of the TRS pattern includes a four symbol gap between TRSs, and the first portion of the TRS pattern and the second portion of the TRS pattern include a two symbol gap between at least two TRSs.

[0066] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the second portion of the TRS pattern can be between, before, or after the first portion of the TRS pattern.

[0067] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the TRS pattern spans a slot or a group of multiple slots.

[0068] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the first portion of the TRS pattern spans a TRS bandwidth and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0069] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for transmitting, to a second UE that can not be able to receive the second portion of the TRS pattern, the indication of the TRS pattern and scheduling downlink shared channel resources for the second UE, where the downlink shared channel resources at least partially overlap with the second portion of the TRS in time, frequency, antenna ports, or any combination thereof based on a modulation and coding scheme of the second UE being lower order.

[0070] Some examples of the method, apparatuses, and non-transitory computer- readable medium described herein can further include operations, features, means, or instructions for scheduling a second UE for a downlink shared channel during a slot that includes the group of multiple TRSs, where the second UE can not be able to receive the second portion of the TRS pattern and transmitting, to the second UE, the indication of the TRS pattern, where the indication is used to configure the second UE for a zero-power channel state information reference signal during the second portion of the TRS pattern. BRIEF DESCRIPTION OF DRAWINGS

[0071] Figure 1 An example of a system for wireless communication that supports enhanced TRS patterns is shown in accordance with aspects of the present disclosure.

[0072] Figure 2 An example of a system for wireless communication that supports enhanced TRS patterns is shown in accordance with aspects of the present disclosure.

[0073] Figure 3 An example of a system for wireless communication that supports enhanced TRS patterns is shown in accordance with aspects of the present disclosure.

[0074] Figure 4 An example of a system for wireless communication that supports enhanced TRS patterns is shown in accordance with aspects of the present disclosure.

[0075] Figure 5 And 6 A block diagram of a device that supports enhanced TRS patterns is shown in accordance with aspects of the present disclosure.

[0076] Figure 7 A block diagram illustrating a communications manager that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown.

[0077] Figure 8 A diagram illustrating a system including a device that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown.

[0078] Figure 9 and 10 A block diagram of a device that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown.

[0079] Figure 11 A block diagram illustrating a communications manager that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown.

[0080] Figure 12 A diagram illustrating a system including a device that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown.

[0081] Figures 13 to 18 A flow diagram illustrating a method that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0082] Some wireless communications systems support TRS for fine time and frequency tracking by UEs. For example, a UE can receive one or more TRSs transmitted by a base station, and the UE can track frequency and time variations with high resolution when communicating with the base station based on the received TRSs. TRSs can be configured on a channel state information reference signal (CSI-RS) resource set. In some examples, TRSs can be configured on a UE-specific basis. In some examples, multiple UEs can be configured to share TRSs. In some examples, TRSs can be transmitted according to a pattern. For example, in some wireless communications systems, a set of TRSs can be transmitted in a slot with a four symbol gap between TRSs according to a TRS pattern. For example, some other wireless communications TRS patterns can use a TRS pattern with two TRSs, where a first TRS is transmitted in symbol period 4 and a second TRS is transmitted in symbol period 8. A UE can search for a TRS within a pull-in signal range, where the UE can detect a signal as long as the signal is within the pull-in signal range of the originally allocated frequency. The pull-in signal range can be a distance from a transmitting device where a receiving device within the distance of the pull-in signal range is able to coherently decode a signal from the transmitting device. The pull-in signal range can compensate for effects such as Doppler shift, which can affect the frequency of transmissions related to movement of the UE. If the UE detects a TRS, the UE can use the TRS to perform time and frequency tracking, such as performing a center frequency offset estimation.

[0083] Some wireless communications using TRSs can also support wireless communications with high speed devices. For example, a wireless communications network can provide service for UEs on high speed trains. When a UE is in a high speed scenario, the maximum Doppler shift can be close to or exceed the pull-in range for carrier frequency offset estimation. The maximum pull-in range for carrier frequency offset estimation for TRSs can be based on the spacing between TRS symbols. For example, for a TRS pattern used by some systems, the maximum pull-in range can be very close to the maximum Doppler shift for a UE on a high speed train. This can result in some cases where a UE on a high speed train is unable to acquire a TRS to perform carrier frequency offset estimation, and the UE and serving cell are unable to reliably perform fine time / frequency tracking.

[0084] The UEs and base stations described herein can implement techniques to configure a UE with an enhanced TRS pattern, where more TRSs are transmitted within a given time period. With the enhanced TRS pattern, for example, there can be only one symbol period between TRS transmissions, which can provide a larger capture range. For example, instead of a TRS symbol interval with four symbols, additional TRSs can be transmitted so that the TRS symbol interval is reduced to two symbols. This can roughly double the capture range for the UE, preventing the Doppler shift from exceeding the maximum capture range and enabling the UE to reliably acquire the TRS and perform fine time and frequency tracking. The enhanced TRS pattern can be backward compatible with other systems. For example, the enhanced TRS pattern can include a first portion of TRSs and a second portion of TRSs. The first portion of TRSs can be the TRS pattern of other systems, and the second portion can include additional TRSs to provide a smaller symbol interval between transmissions of each TRS. This can enable both capable UEs and non-capable user equipment to still use the same TRS, as UEs on the same train can be provided the same TRS. The UE can indicate its capability to support the second portion of the TRS pattern, and the base station can configure the UE for the TRS pattern with the first portion and the second portion based on the UE capability. These techniques can enable a UE to perform time and frequency synchronization using one or more TRSs in high speed scenarios. These techniques can provide a higher quality communication link between a UE and a serving cell in high speed scenarios (e.g., on a high speed train).

[0085] Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to enhanced TRS patterns.

[0086] Figure 1 An example of a wireless communications system 100 that supports enhanced TRS patterns is shown in accordance with aspects of the present disclosure. The wireless communications system 100 includes one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 can be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some cases, wireless communications system 100 can support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or combinations thereof.

[0087] The base stations 105 can be dispersed throughout the geographic area 100 and can be geographic distributed, or associated with different

[0088] The UEs 115 can be dispersed throughout the coverage areas 110 of wireless communications system 100, and each UE 115 can be stationary, or mobile, or both at different times. The UEs 115 can be devices in different forms or having different capabilities. Figure 1 Some example UEs 115 are illustrated. As shown, UEs 115 described herein can communicate with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, transit devices, integrated access and backhaul (IAB) nodes, or other network equipment). Figure 1 As shown, UEs 115 described herein can communicate with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, transit devices, integrated access and backhaul (IAB) nodes, or other network equipment).

[0089] The base stations 105 can communicate with the core network 130, or with one another, or both. For example, base stations 105 can interface with the core network 130 through one or more backhaul links 120 (e.g., via an SI, N2, N3, or other interface). The base stations 105 can communicate with one another over backhaul links 120 (e.g., via an X2, Xn, or other interface) either directly (e.g., direct point-to-point), indirectly (e.g., via core network 130), or both, in some examples, the backhaul links 120 can be or include one or more wireless links.

[0090] One or more of the base stations 105 described herein can include or can be referred to by a person of skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or giga-nodeB (either of which can be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology.

[0091] A UE 115 can include or can be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” can also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 can also include or can be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 can also include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which can be implemented in various objects such as devices, vehicles, meters, or the like.

[0092] The UEs 115 described herein can be able to communicate with various types of devices, such as other UEs 115, a base station 105, or an Internet Protocol (IP) device, as shown. Figure 1 As shown, various types of devices, such as other UEs 115, a base station 105, or a network device including a macro eNB or gNB, a small cell eNB or gNB, or a relay base station, among other examples, can sometimes act as a relay for other UEs 115. In some cases, a UE 115 can communicate with a core network 130 through the communication link 155.

[0093] The UEs 115 and the base stations 105 can wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” can refer to a set of radio frequency spectrum resources with a defined physical layer structure

[0094] In some examples (e.g., in carrier aggregation configurations), a carrier can also have acquisition signaling or control signaling that coordinates operations of other carriers. A carrier can be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and can be positioned according to a channel raster for discovery by the UEs 115. Carriers can be operated in a standalone mode where initial acquisition and connection can be achieved via the carriers, or can be operated in a non- standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology).

[0095] The communication links 125 shown in wireless communication system 100 can include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions from a base station 105 to a UE 115. Carriers can carry downlink or uplink communications (e.g., in an FDD mode), or can be configured to carry downlink and uplink communications (e.g., in a TDD mode).

[0096] A carrier can be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth can be referred to as a “system bandwidth” of the carrier or wireless communications system 100. For example, the carrier bandwidth can be one of a set of defined bandwidths for wireless communications (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)). Devices of wireless communications system 100 (e.g., base stations 105, UEs 115, or both) can have hardware configurations that support communications over a particular carrier bandwidth, or can be configurable to support communications over a set of carrier bandwidths. In some examples, wireless communications system 100 can include base stations 105 or UEs 115 that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 can be configured to operate over portions (e.g., sub-bands, BWPs) or all of a carrier bandwidth.

[0097] Signal waveforms transmitted over a carrier can be composed of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element can consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element can depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rates can be for the UE 115. A wireless communications resource can refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams), and the use of multiple spatial layers can further increase the data rate for communications with a UE 115.

[0098] One or more numerologies can be supported for a carrier, where a numerology can include a subcarrier spacing (Af) and a cyclic prefix. A carrier can be partitioned into one or more BWPs with the same or different numerologies. In some examples, a UE 115 can be configured with multiple BWPs. In some examples, a single BWP for a carrier can be active at a given time and communications by the UE 115 can be limited to one or more active BWPs.

[0099] Time intervals for the base stations 105 or the UEs 115 can be expressed in multiples of a basic time unit, which may, for example, be a T s = 1 / (Af max · N f ) seconds, where Af max may represent the maximum supported subcarrier spacing, and N f may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource can be organized as radio frames, each

[0100] Each frame can include a plurality of subframes or slots, each subframe or slot can have the same time duration, and each subframe or slot can be further divided into mini-slots, each having a duration of, for example, one or more symbol periods. In some examples, a frame can be divided into subframes, and each subframe can be divided into slots. In other examples, a frame can be divided into slots, and each slot can be divided into mini-slots. In some examples, a frame can be divided into 10 subframes, each subframe having a duration of 1 millisecond. In the example of slot-based frame structures, each subframe can be divided into 2 slots of 0.5 milliseconds each. In the example of mini-slot-based frame structures, each subframe can be divided into 4 mini-slots of 0.25 milliseconds each. In the example of slot-based frame structures, each slot can include a varying number of symbol periods depending on the length of the cyclic prefix (CP). In the example of mini-slot-based frame structures, each mini-slot can include an integer number of symbol periods. f The duration of a symbol period can depend on the subcarrier spacing or the operating band, for example.

[0101] A subframe, a slot, a mini-slot, or a symbol can be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and can be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system 100 can be dynamically selected (e.g., in bursts of short TTIs (sTTIs)).

[0102] Physical channels can be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel can be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel can be defined by a number of symbol periods and can extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) can be configured for a set of UEs 115. For example, one or more of the UEs 115 can monitor or search control regions for control information according to one or more search space sets, and each search space set can include one or more control channel candidates arranged in a cascaded manner with one or more aggregation levels. An aggregation level for a control channel candidate can refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets can include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets configured for sending control information to a specific UE 115.

[0103] Each base station 105 can provide communication coverage for a respective geographic coverage area 110 via one or more cells (e.g., a macro cell, a small cell, a hot spot, or other types of cells or various combinations thereof). The term "cell" can refer to a logical communication entity used for communication with a base station 105 (e.g., through a carrier) and can be associated with a identifier, such as a physical cell identifier (PCID), a virtual cell identifier (VCID), etc. In some examples, a cell can also refer to a geographic coverage area of a logical communication entity operating on the geographic coverage area 110 or a portion (e.g., a sector) of the geographic coverage area 110. Such a cell can vary in size depending on a variety of factors including capacity requirements, coverage requirements, and the like. For example, a cell can be or include a structure, a subset of a structure, an outdoor space between structures or overlapping with structures, and the like.

[0104] A macro cell can cover a relatively large geographic area (e.g., several kilometers in radius) and can allow unrestricted access by UEs 115 with service subscriptions with the network provider supporting the macro cell. A small cell can be associated with a lower- powered base station 105 and can be used to cover a relatively small geographic area, such as a home, office, or vehicle. A small cell can support restricted access by UEs 115, allowing only UE 115 subscriptions with an associated network provider to access the small cell. A base station 105 can support one or multiple cells, and can also support communication with UEs 115 using one or multiple component carriers.

[0105] In some examples, a carrier can support multiple cells, and different cells of the carrier can be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that can provide access for different types of devices.

[0106] In some examples, base stations 105 can be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, but the different geographic coverage areas 110 can be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communications system 100 can include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0107] The wireless communications system 100 can support synchronous or asynchronous operation. For synchronous operation, the base stations 105 can have similar frame timings, and transmissions from different base stations 105 can be approximately aligned in time. For asynchronous operation, the base stations 105 can have different frame timings, and transmissions from different base stations 105 can not be aligned in time. The techniques described herein can be used for either synchronous or asynchronous operations.

[0108] Some UEs 115, such as MTC or IoT devices, can be low cost or low complexity devices and can provide for automated communication between machines or machines and humans (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with one another or a base station 105 without the need for human intervention. In some examples, M2M communication or MTC can include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of that information or present that information to humans in human-machine interface displays. Some UEs 115 can be designed to collect information or enable automated behavior of machines or other devices. Applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

[0109] Some UEs 115 can be configured to employ operating modes that reduce power consumption, such as a half-duplex communications mode that supports only reception or transmission, but not both simultaneously (e.g., a mode that supports either transmission or reception, but not both). In some examples, half-duplex communications can be performed at a reduced peak rate. Other power conservation techniques for UEs 115 include entering a power saving “deep sleep” mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs 115 can be configured for operation using a narrowband protocol type associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs)) within a carrier, within a guardband of a carrier, or outside of a carrier.

[0110] The wireless communications system 100 can be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 can be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. UEs 115 can be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions), such as in a mission critical services. Ultra-reliable communications can include private communications or group communications and can be supported by one or more mission critical services, such as mission critical push-to-talk (MCPTT), mission critical video (MCVideo), or mission critical data (MCData). Support for mission critical functions can include prioritization of services, and the mission critical services can be used for public safety or general commercial application. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low- latency can be used interchangeably herein.

[0111] In some examples, UEs 115 can also be able to communicate directly with each other using device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communications can be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group can be outside the geographic coverage area 110 of a base station 105, or be otherwise unable to receive transmissions from a base station 105. In some examples, groups of UEs 115 communicating via D2D communications can utilize a one-to-many (1 :M) system in which each UE 115 transmits to every other UE 115 in the group. In some examples, a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between UEs 115 without the involvement of a base station 105.

[0112] In some systems, the D2D communication link 135 can be an example of a communication channel, such as a sidelink communication channel between vehicles (e.g., UEs 115). In some examples, vehicles can communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle can transmit information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system can communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations 105) using vehicle-to-network (V2N) communications, or both.

[0113] The core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 can be an evolved packet core (EPC) or 5G core (5GC), which can include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), a user plane function (UPF)). The control plane entity can manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the core network 130. User IP packets can be transferred through the user plane entity, which can provide IP address allocation as well as other functions. The user plane entity can be connected to the network operators IP services 150. The operators IP services 150 can include access to the Internet, Intranet, IP Multimedia Subsystem (IMS), or Packet-Switched (PS) streaming services.

[0114] At least some of the network devices, such as a base station 105, can include subcomponents such as an access network entity 140, which can be an example of an access node controller (ANC). Each access network entity 140 can communicate with the UEs 115 through a number of other access network transmission entities 145, which can be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). Each access network transmission entity 145 can include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 can be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105).

[0115] The wireless communications system 100 can operate using one or more frequency bands, such as in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Often, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves can be blocked or redirected by buildings and environmental features, but the waves can penetrate structures sufficiently for a macro cell to provide service to UEs 115 located indoors. Transmission of UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

[0116] The wireless communications system 100 can also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as centimeter band. In some examples, the wireless communications system 100 can support millimeter wave (mmW) communications between the UEs 115 and the base stations 105, and EHF antennas of the respective devices can be even smaller and more closely spaced than UHF antennas. In some examples, this can facilitate use of antenna arrays within a device. However, the propagation of EHF transmissions can be subject to even greater atmospheric attenuation and shorter range than SHF transmissions or UHF transmissions. The techniques disclosed herein can be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions can differ by country or regulating body.

[0117] The electromagnetic spectrum is often subdivided based on frequency / wavelength into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz - 7.125 GHz) and FR2 (24.25 GHz - 52.6 GHz). It should be understood that although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with respect to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) which is also referred to as a “millimeter wave” band by the International Telecommunications Union (ITU).

[0118] The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified operating bands for these mid-band frequencies as frequency range designation FR3 (7.125 GHz - 24.25 GHz). Bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, and thus can effectively extend the characteristics of FR1 and / or FR2 to mid-band frequencies. Moreover, even higher bands are currently under exploration to extend 5G NR operations beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz - 71 GHz), FR4 (52.6 GHz - 114.25 GHz), and FR5 (114.25 GHz - 300 GHz). Each of these higher bands falls within the EHF band.

[0119] With the above in mind, unless specifically stated otherwise, it should be appreciated that the term “sub-6 GHz” or the like, if used herein, can broadly represent frequencies that can be less than 6 GHz, can be within FR1, or can include mid-band frequencies. Further, unless specifically stated otherwise, it should be appreciated that the term “millimeter wave” or the like, if used herein, can broadly represent frequencies that can include mid-band frequencies, can be within FR2, FR4, FR4-a or FR4-1, and / or FR5, or can be within the EHF frequency band.

[0120] Wireless communications system 100 can utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system 100 can employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed frequency band such as the 5 GHz industrial, scientific and medical (ISM) band. When operating in unlicensed frequency

[0121] Base stations 105 or UEs 115 can be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station 105 or a UE 115 can be located in one or more antenna arrays or antenna panels, which can support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays can be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station 105 can be located in different geographic locations. A base station 105 can have antenna arrays with a number of rows and columns of antenna ports that the base station 105 can use to support beamforming of communications to UEs 115. Similarly, a UE 115 can have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, antenna panels can support radio frequency beamforming of signals transmitted via antenna ports.

[0122] The base stations 105 or the UEs 115 can use MIMO communications through the transmission or reception of multiple signals over different spatial layers. Such techniques can be referred to as spatial multiplexing. For example, multiple signals can be transmitted by a transmitting device via different antennas or different combinations of antennas. Similarly, multiple signals can be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals can be referred to as a separate spatial stream, and can carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers can be associated with different antenna ports used for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices.

[0123] Beamforming, which can also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer a beam of energy in a specific direction, for example, to optimize or otherwise enhance communication between a transmitting device and a receiving device. Beamforming can be achieved by combining the signals transmitted or received by antennas of a base station 105 or a UE 115, for example, by adjusting the amplitude and phase of signals transmitted or received by the individual antennas. In one example, a base station 105 can use beamforming to focus the energy of the signals transmitted by the base station 105 in a specific direction. Similarly, a UE 115 can use beamforming to focus the energy of the signals transmitted by the UE 115 in a specific direction. The direction of the energy can be adjusted or steered by the base station 105 or the UE 115 by adjusting the amplitude and phase of the signals transmitted or received by the antennas. For example, signals transmitted by a base station 105 can be adjusted to have a first amplitude and phase to focus the energy of the signals transmitted by the base station 105 in a first direction, and the signals transmitted by the base station 105 can be adjusted to have a second amplitude and phase to focus the energy of the signals transmitted by the base station 105 in a second direction.

[0124] The base stations 105 or the UEs 115 can use beam sweeping techniques as part of beamforming operations. For example, a base station 105 can use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE 115. Signals can be transmitted by a base station 105 multiple times in different directions. For example, the base station 105 can transmit a signal according to different beamforming weight sets associated with different transmission directions. Transmissions in different beam directions can be used to identify (e.g., by a transmitting device such as a base station 105, or by a receiving device such as a UE 115) a beam direction for subsequent transmissions or receptions by the base station 105.

[0125] Some signals, such as data signals associated with particular receiving devices, can be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with a receiving device, such as a UE 115). In some examples, signals transmitted in a single beam direction can be associated with a particular geographical region over which the base station 105 has a line of sight or other suitable wireless signal propagation relationship. For example, signals transmitted by a base station 105 can be received by a UE 115 that is located in a geographical region associated with the signal transmission. In some examples, the geographical region can be associated with an area of possible beam coverage for the base station 105. In some examples, a geographical region associated with a signal transmission can be broken up into a number of areas or zones that can each be associated with a respective beam direction for the base station 105.

[0126] In some examples, transmissions by a device (e.g., by a base station 105 or a UE 115) can be performed using multiple beam directions, and the device can use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmissions (e.g., from a base station 105 to a UE 115). A UE 115 can report feedback that indicates precoding weights for one or more beam directions, and the feedback can correspond to a configured number of beams across a system bandwidth or one or more sub-bands. A base station 105 can transmit reference signals (e.g., cell-specific reference signals (CRS), CSI-RS) that can be precoded or unprecoded. A UE 115 can provide feedback for beam selection, which can be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 can employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device).

[0127] A receiving device (e.g., a UE 115) can try multiple receive configurations (e.g., directional detection) when receiving various signals from base stations 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device can try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which can be referred to as“detecting” according to different receive configurations or receive directions. In some examples, a receiving device can use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration can be aligned in a beam direction determined based on detecting according to different receive configuration directions.

[0128] Wireless communications system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer can be IP -based. A Radio Link Control (RLC) layer can perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer can perform priority handling and multiplexing of logical channels into transport channels. The MAC layer can also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer can provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or core network 130 supporting radio bearers for user plane data. At the physical layer, transport channels can be mapped to physical channels.

[0129] The UEs 115 and the base stations 105 can support retransmissions of data to increase the likelihood that data is received successfully. HARQ feedback is one technique used to increase the likelihood that data is received correctly over a communication link 125. HARQ can include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions). In some examples, a device can support same-slot HARQ feedback, where the device can provide HARQ feedback in a specific time slot for data received in a previous time slot. In other cases, the device can provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0130] The wireless communications system 100 can support TRS for fine time and frequency tracking for UEs 115. Some wireless communications systems can not support CRS. In some cases, TRS can be transmitted in regular bursts over a wide bandwidth. Parameters of the burst structure can include a TRS burst length expressed in number of slots and a TRS burst periodicity expressed in number of slots.

[0131] A TRS can be configured on a CSI-RS resource set. For example, some common values of non-zero power CSI-RS in a CSI-RS resource set can be configured for TRS to reduce signaling overhead. While TRS can be UE specifically managed and configured on a UE specific basis, multiple UEs 115 can be configured to share TRS. From the perspective of a UE 115, a demodulation reference signal (DMRS) and a TRS can be time division multiplexed. TRS can be configured on a carrier or active bandwidth part when there is no synchronization signal block. TRS can be quasi co-located with a downlink shared channel DMRS at least in terms of delay spread, average delay, Doppler shift, and Doppler spread. TRS sequences can be based on a pseudo-random noise generator, which can be similar to CSI-RS. For connected mode UEs 115, a UE 115 can be expected to receive UE specific configuration of TRS for sub-6 GHz communications and above-6 GHz communications.

[0132] In some examples, TRS can be transmitted according to a pattern. For example, in some wireless communications systems, a set of TRS can be transmitted in a slot with four symbol gaps between TRS according to a TRS pattern.

[0133] A UE 115 can search for TRSs within a capture signal range. If the UE 115 detects a TRS, the UE 115 can use the TRS to perform fine time and frequency tracking. In some examples, a maximum pull-in range |f| can be determined based on a gap between TRS symbols according to N*Ts*pi*|f| < pi, where N is a gap between symbol periods and Ts is a symbol duration. For a TRS pattern with a four symbol period gap between TRSs, a capture range for 120 kHz subcarrier spacing can be 14 kHz.

[0134] Some wireless communications using TRSs can also support wireless communications with high speed devices. For example, a wireless communications network can provide service for UEs 115 on high speed trains, vehicles, etc. When a UE 115 is in a high speed scenario, a maximum Doppler shift can approach or exceed a capture range for carrier frequency offset estimation. A Doppler shift for a UE 115 on a high speed train can be as high as, for example, 13.9 kHz. Thus, for TRS patterns used by some systems, a maximum capture range can be very close to the maximum Doppler shift for a UE 115 on a high speed train. This can result in some cases where a UE 115 on a high speed train is unable to acquire a TRS to perform carrier frequency offset estimation, and the UE 115 and serving cell are unable to reliably perform fine time / frequency tracking. Furthermore, communicating at high carrier frequencies can increase Doppler shift. For example, open loop frequency synchronization in some radio frequency components can be difficult to achieve at high frequencies.

[0135] The UEs 115 described herein can be configured with an enhanced TRS pattern in which more TRSs are transmitted in a given time period. With the enhanced TRS pattern, there can be smaller spacing between TRS transmissions, which can provide a larger capture range or a capture range with a larger distance. For example, instead of having a TRS symbol spacing of four symbols, additional TRSs can be transmitted such that the TRS symbol spacing is reduced to two symbols. This can double the capture range of the UE 115, preventing the Doppler shift from exceeding the maximum capture range, and enabling the UE 115 to reliably acquire the TRSs and perform fine time and frequency tracking. The enhanced TRS pattern can be backward compatible with other systems. For example, the enhanced TRS pattern can include a first portion of TRSs and a second portion of TRSs. The first portion of TRSs can be the TRS pattern of other systems, and the second portion can include additional TRSs to provide a smaller symbol spacing between the transmission of each TRS. This can enable both capable and non-capable UEs 115 to still use the same TRSs, as UEs 115 on the same train can be provided the same TRSs. The UE 115 can indicate its capability to support the second portion of the TRS pattern, and the base station can configure the UE 115 for the TRS pattern with the first portion and the second portion based on the UE capability.

[0136] In various examples, the communication manager 101 can be included in a device to support an enhanced TRS pattern with higher TRS density in a TRS pattern. For example, a UE 115 can include a communication manager 101-a, or a base station can include a communication manager 110-b.

[0137] In some examples, the communication manager 101 can transmit, to a base station 105, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion associated with a TRS pattern. The communication manager 101 can receive, from the base station 105, an indication of the TRS pattern. In some cases, the TRS pattern can include a first portion of the TRS pattern and a second portion of the TRS pattern. The communication manager 101 can monitor for a set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0138] In some examples, the communication manager 101 can receive, from a UE 115, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion associated with a TRS pattern. The communication manager 101 can select, based on the received UE capability, a TRS pattern that includes the first portion and the second portion for a set of TRSs. The communication manager 101 can transmit, to the UE 115, an indication of the TRS pattern. The communication manager 101 can transmit the set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0139] In some examples, the communications manager 101 can transmit, to a base station 105, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern. The communications manager 101 can receive, from the base station 105, an indication of the TRS pattern. In some cases, the TRS pattern can include a first portion of the TRS pattern and a second portion of the TRS pattern. In some cases, the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap (e.g., of at least one symbol) between at least two TRSs. The communications manager 101 can receive the one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0140] In some examples, the communications manager 101 can receive, from a UE 115, an indication of a UE capability. The communications manager 101 can transmit, to the UE, an indication of a TRS pattern including a first portion and a second portion for a set of one or more TRSs based on the received indication of the UE capability. In some cases, the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs. The communications manager 101 can transmit the set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0141] Figure 2 An example of a wireless communications system 200 that supports enhanced TRS patterns is shown in accordance with aspects of the present disclosure. In some examples, the wireless communications system 200 can implement aspects of the wireless communications system 100.

[0142] The wireless communications system 200 can include a device 205 (e.g., a TRS transmitter) and a device 210 (e.g., a TRS receiver), which can be examples of the various types of devices described with reference to FIG. 1. For example, when the described reference signals are associated with downlink transmissions, the device 205 can be a base station 105 and the second device 210 can be a UE 115. For example, the device 205 is an example of the base station 105 described with reference to FIG. 1, and the device 210 is an example of the UE 115 described with reference to FIG. 1. Figure 1 The wireless communications system 200 can include a device 205 (e.g., a TRS transmitter) and a device 210 (e.g., a TRS receiver), which can be examples of the various types of devices described with reference to FIG. 1. For example, when the described reference signals are associated with downlink transmissions, the device 205 can be a base station 105 and the second device 210 can be a UE 115. For example, the device 205 is an example of the base station 105 described with reference to FIG. 1, and the device 210 is an example of the UE 115 described with reference to FIG. 1. Figure 1 The wireless communications system 200 can include a device 205 (e.g., a TRS transmitter) and a device 210 (e.g., a TRS receiver), which can be examples of the various types of devices described with reference to FIG. 1. For example, when the described reference signals are associated with downlink transmissions, the device 205 can be a base station 105 and the second device 210 can be a UE 115. For example, the device 205 is an example of the base station 105 described with reference to FIG. 1, and the device 210 is an example of the UE 115 described with reference to FIG. 1.

[0143] Wireless communications system 200 can support a TRS scheme for fine time and frequency tracking for devices such as device 210. TRSs can be configured on a CSI-RS resource set and can be configured on a device-specific basis, but multiple devices 210 can be configured to share a TRS. In some examples, TRSs can be transmitted according to a pattern. For example, in some wireless communications systems, device 205 can transmit a set of one or more TRSs according to a TRS pattern with a four-symbol gap between TRSs in a slot. Device 210 can search for TRSs within a capture range. If device 210 detects a TRS, device 210 can use the TRS to perform time and frequency tracking.

[0144] Wireless communications system 200 can support wireless communications with high speed devices. For example, device 210 can be on a high speed train and device 205 can provide service for device 210. In some cases, a maximum capture range for carrier frequency offset estimation for TRSs can be based on a spacing between TRS symbols. When device 210 is in a high speed scenario, a maximum Doppler shift can approach or exceed the capture range for carrier frequency offset estimation. For example, for a TRS pattern used by some other systems, the maximum capture range can be very close to the maximum Doppler shift for a wireless device on a high speed train. This can result in some cases in which a wireless device on a high speed train is unable to acquire a TRS to perform carrier frequency offset estimation and the wireless device and serving cell are unable to reliably perform fine time and frequency tracking.

[0145] Devices such as device 210 described herein can be configured with an enhanced TRS pattern in which more TRSs are transmitted within a given time period. With the enhanced TRS pattern, there can be a smaller spacing between TRS transmissions, which can provide a larger capture range. For example, instead of a TRS symbol spacing of four symbols, additional TRSs can be transmitted such that the TRS symbol spacing is reduced to two symbols. This can approximately double the capture range of device 210, preventing the Doppler shift from exceeding the maximum capture range and enabling device 210 to reliably acquire a TRS and perform fine time and frequency tracking.

[0146] The enhanced TRS pattern can be backward compatible with other system's TRS pattern. For example, the enhanced TRS pattern can include a first portion of the TRS pattern 215 and a second portion of the TRS pattern 220. The first portion of the TRS pattern 215 can correspond to other system's TRS pattern, while the second portion of the TRS pattern 220 can include additional TRS to provide smaller symbol spacing between transmissions of each TRS. This can enable capable devices and incapable devices to still use the same TRS, as devices on the same train can be provided the same TRS. Techniques described herein, such as the enhanced TRS pattern, can be applied to devices in high speed scenarios, applied to devices with high mobility, applied to UEs 11 operating on high frequency carriers, or any combination thereof.

[0147] The device 210 can indicate a capability 230 to the device 205 that indicates support for the second portion of the TRS pattern 220. The device 205 can transmit an indication 225 of a TRS configuration to the device 210 based on receiving the capability 230 to indicate a TRS pattern with the first portion of the TRS pattern 215 and the second portion of the TRS pattern 220. The device 205 can indicate the mode selection via RRC signaling or a MAC control element (CE). For example, the device 210 can have two tables of modes, corresponding to a TRS pattern without the second portion and a TRS pattern with the second portion. Based on the MAC-CE, the device 210 can select the table to use. The device 205 can transmit a DCI to indicate an index of the selected table corresponding to the TRS pattern.

[0148] The TRS pattern with the first portion and the second portion can have a shorter time spacing between TRS transmissions compared to just the first portion of the TRS pattern 215. In some cases, the second portion of the TRS pattern 220 can span the same time slot as the first portion of the TRS pattern (e.g., time slot 235), or the second portion of the TRS pattern 220 can span multiple time slots. For example, there can be a first symbol gap 240 between TRSs transmitted according to the first portion of the TRS pattern 215. For example, there can be three symbols between a first TRS transmitted according to the first pattern and a second TRS transmitted according to the first pattern. For example, when only using the first portion of the TRS pattern 215, TRSs can be transmitted in symbol periods 3 and 7. The second portion of the TRS pattern 220 together with the first portion of the TRS pattern 215 can reduce the size of the symbol gap between TRSs. For example, there can be a second symbol gap 245 between TRSs when using both the first portion of the TRS pattern 215 and the second portion of the TRS pattern 220. For example, TRSs can be transmitted in symbols 3, 5, and 7 with both portions of the TRS pattern, where the second symbol gap 245 can be one symbol.

[0149] In some examples, the device 210 can transmit a request for the second portion of the TRS pattern 220. For example, the device 210 can detect a high speed, and the device 210 can transmit the request or recommendation based on detecting the high speed. In some cases, a table configured for the device 210 can be reselected (e.g., via a MAC-CE) based on the speed of the device 210.

[0150] In some examples, the device 210 can be configured for aperiodic TRS. For aperiodic TRS, a triggering DCI can indicate a TRS pattern. A TRS resource set of the TRS pattern can be configured in an aperiodic triggering state. The DCI, a MAC-CE, or both can indicate a triggering state from a list of triggering states that corresponds to the TRS pattern. A field in the DCI can indicate whether an enhanced TRS pattern is selected for the aperiodic TRS. In some cases, the field can be an example of a new field of a previous type of DCI, or the field can be an example of an unused field from a previous type of DCI.

[0151] By implementing these techniques, the device 210 can reliably acquire the TRS and perform time and frequency tracking. Even in high speed cases, a capture range for the TRS transmitted according to the TRS pattern with the second portion can be higher than a Doppler spread of the TRS, and the TRS can be acquired by the device 210.

[0152] Figure 3 An example of a TRS pattern configuration 300 that supports an enhanced TRS pattern is shown, in accordance with aspects of the present disclosure. In some examples, the TRS pattern configuration 300 can implement aspects of the wireless communications system 100.

[0153] The base station 105 can transmit a TRS to the UE 115 according to a TRS pattern. The UE 115 can acquire the TRS and perform time and frequency tracking based on the TRS. The techniques described herein support an enhanced TRS pattern with a higher density of TRS, which can increase a capture range for the TRS. By increasing the capture range, even though a high speed scenario increases a Doppler spread of the TRS, the UE 115 traveling at the high speed can reliably acquire the TRS.

[0154] The enhanced TRS pattern can include a first portion of TRS 305 and a second portion of TRS 310. The first portion of TRS 305 can correspond to a TRS pattern used in other systems. By also transmitting the second portion of TRS 310, the base station 105 can transmit the TRS at a higher density for a period of time. The first portion of TRS 305 can span a slot 320. The second portion 310 can span the slot 320 or multiple slots.

[0155] TRSs can be shared by multiple UEs 115. In some cases, sharing TRSs is transparent to the UEs 115. TRSs can be configured per UE 115, and the configuration can not explicitly indicate that the TRSs are shared with other UEs 115. For example, if multiple UEs 115 are in the same train, the UEs 115 can be configured to use the same TRS. Configuring multiple UEs 115 for the same TRS can reduce system overhead compared to transmitting separate TRSs for the UEs 115.

[0156] In some examples, a base station 105 can configure at least two UEs 115 to share a TRS, where a first UE 115 is capable of supporting an enhanced TRS mode and a second UE 115 is not capable of supporting the enhanced TRS mode. In some examples, the base station 105 can transmit a TRS pattern with a first portion 305 of the TRS and a second portion 310 of the TRS to increase a capture range of the first UE 115. The second UE 115 can be scheduled for downlink shared channel resources 315 in a slot that includes the TRS. However, the second UE 115 can not be able to receive the second portion 310 of the TRS. The base station 105 can implement techniques to avoid introducing errors for the second UE 115 when transmitting the TRS according to the enhanced TRS mode.

[0157] In some cases, the base station 105 can schedule a CSI-RS for the second UE 115 at resources corresponding to the second portion 310 of the TRS. In some cases, the base station 105 can schedule the second UE for a zero-power CSI-RS. The second UE 115 can then rate match around the resources with the second portion 310 of the TRS.

[0158] In some cases, the base station 105 can configure the second portion 310 of the TRS to be transmitted on a subset of the TRS bandwidth. In some cases, the TRS can be transmitted on up to 50 resource blocks. The first portion 305 of the TRS can be transmitted on a first bandwidth of frequencies 325 (e.g., all 50 resource blocks), and the second portion 310 of the TRS can be transmitted on a subset of the first bandwidth. Based on transmitting the second portion 310 of the TRS on a smaller bandwidth, the downlink shared channel resources 315 for the second UE 115 can be scheduled to not overlap with the first portion 310 of the TRS.

[0159] In some cases, the base station 105 can determine that a downlink shared channel modulation and coding scheme (MCS) for the second UE 115 is very low order. If the MCS for the second UE 115 is lower order, the base station 105 can not adjust scheduling or the enhanced TRS pattern to the second UE 115. For example, if the MCS is lower order, the second UE 115 can still be able to successfully decode a physical downlink shared channel (PDSCH). In some examples, the base station 105 can avoid scheduling the enhanced TRS pattern and downlink shared channel resources 315 for UEs 115 that do not support the enhanced TRS pattern in the same slot and port.

[0160] Figure 4 An example of a process flow 400 that supports enhanced TRS patterns is shown in accordance with aspects of the present disclosure. In some examples, process flow 400 can implement aspects of wireless communications system 100.

[0161] Process flow 400 can be implemented by a UE 115 or a base station 105, or both. For example, process flow 400 can be implemented by a base station 405, a UE 410, or both, which can be respective examples of a base station 105 and a UE 115.

[0162] UE 410 can be an example of a capable device for receiving an enhanced TRS pattern. The enhanced TRS pattern can have additional TRS and shorter symbol period spacing between TRS transmissions. At 415, UE 410 can transmit, to a base station 405, a UE capability for receiving a first portion of TRS and a second portion of the TRS. The first portion and the second portion can be associated with a TRS pattern such as the enhanced TRS pattern described herein.

[0163] At 420, base station 405 can select a TRS pattern that includes a first portion and a second portion for a set of TRS based on receiving the UE capability. Base station 405 can transmit, to UE 410 at 420, an indication of the TRS pattern. In some cases, the indication is transmitted via DCI. For example, UE 410 can be configured with a TRS pattern or a table of TRS patterns via RRC signaling or a MAC-CE, and the DCI can indicate a TRS pattern corresponding to an index of one of the tables.

[0164] At 425, UE 410 can monitor for the set of TRS according to the first portion of the TRS pattern and the second portion of the TRS pattern. At 430, base station 405 can transmit the set of TRS according to the first portion of the TRS pattern and the second portion of the TRS pattern. UE 410 can receive the TRS of the first portion and the second portion and perform, for example, carrier frequency offset estimation for time and frequency tracking.

[0165] Figure 5 A block diagram 500 of a device 505 supporting enhanced TRS mode according to various aspects of this disclosure is shown. Device 505 may be an example of various aspects of UE 115 as described herein. Device 505 may include a receiver 510, a communications manager 515, and a transmitter 520. Device 505 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0166] Receiver 510 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channel information, data channel information, and information related to enhanced TRS mode). This information can be transmitted to other components of device 505. Receiver 510 can be a reference... Figure 8 Examples of various aspects of the transceiver 820 are described. The receiver 510 can utilize a single antenna or a set of antennas.

[0167] Communication manager 515 can send to the base station the UE's capability to receive a first part and a second part of a TRS, the first and second parts being associated with a TRS mode, and receive from the base station an indication of the TRS mode, wherein the TRS mode includes the first part and the second part of the TRS mode. The first part of the TRS mode may include a first symbol gap between one or more symbols between TRSs, and the first and second parts of the TRS mode may include a second symbol gap between at least two TRSs. In some cases, communication manager 515 can monitor one or more TRSs based on the first part and the second part of the TRS mode. Communication manager 515 can receive one or more TRSs based on the first part and the second part of the TRS mode. Communication manager 515 may be an example of various aspects of communication manager 810 described herein.

[0168] The communication manager 515 or its sub-components may be implemented in hardware, processor-executable code (e.g., software or firmware), or any combination thereof. If implemented in processor-executable code, the functionality of the communication manager 515 or its sub-components may be performed by a general-purpose processor, DSP, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described in this disclosure.

[0169] The communications manager 515, or its sub-components, can be physically located in various places in the apparatus including but not limited to being distributed as sub-components to one or more physical devices. In some examples, the communications manager 515, or its sub-components, can be in different physical locations and be implemented as sub-components of one or more physical devices. In some examples, according to various aspects of the disclosure, the communications manager 515, or its sub-components, can be a separate and distinct component in accordance with various aspects of the disclosure. In some examples, the communications manager 515, or its sub-components, can be combined with one or more other hardware components, including but not limited to an input / output (I / O) component, a transceiver, a network server, another computing device, one or more other components described in the disclosure, or a combination thereof.

[0170] The actions performed by the UE communications manager 515 as described herein can be implemented to enable the UE 115 to reliably acquire TRSs to perform time and frequency tracking. For example, if the UE 115 is traveling at a high speed, the UE 115 can implement these techniques for an enhanced TRS pattern to increase the acquisition range for TRSs despite the higher Doppler spread based on the high speed.

[0171] The communications manager 515 can be an example of means for performing various aspects of managing an intelligent repeater as described herein. The communications manager 515, or its sub-components, can be implemented in hardware, e.g., in communications management circuitry. The circuitry can comprise a processor, Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the disclosure.

[0172] In another implementation, the communications manager 515, or its sub-components, can be implemented in code (e.g., as communications management software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 515, or its sub-components, can be executed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device.

[0173] In some examples, the communications manager 515 can be configured to perform various operations (e.g., receiving, determining, transmitting) using or otherwise in cooperation with the receiver 510, the transmitter 520, or both.

[0174] The transmitter 520 can transmit signals generated by other components of the device 505. In some examples, the transmitter 520 can be collocated with a receiver 510 in a transceiver module. For example, the transmitter 520 can be an example of aspects of the transmitter 820 described with reference to FIG. 8. The transmitter 520 can utilize a single antenna or a set of antennas. Figure 8 The transmitter 520 can transmit signals generated by other components of the device 505. In some examples, the transmitter 520 can be collocated with a receiver 510 in a transceiver module. For example, the transmitter 520 can be an example of aspects of the transmitter 820 described with reference to FIG. 8. The transmitter 520 can utilize a single antenna or a set of antennas.

[0175] Figure 6 A block diagram 600 of a device 605 that supports enhanced TRS patterns is shown, in accordance with aspects of the present disclosure. The device 605 can be an example of aspects of a device 505 or a UE 105 as described herein. The device 605 can include a receiver 610, a communications manager 615, and a transmitter 635. The device 605 can also include a processor. Each of these components can be in communication with one another (e.g., via one or more buses).

[0176] The receiver 610 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to enhanced TRS patterns, etc.). Information can be passed on to other components of the device 605. The receiver 610 can be an example of aspects of the transceiver 820 described with reference to FIG. 8. The receiver 610 can utilize a single antenna or a set of antennas. Figure 8

[0177] The communications manager 615, as described herein, can be an example of aspects of the communications manager 515. The communications manager 615 can include a UE capability component 620, a TRS pattern indication component 625, and a TRS reception component 630. The communications manager 615 can be an example of aspects of the communications manager 810 described herein.

[0178] The UE capability component 620 can transmit, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion associated with a TRS pattern.

[0179] The TRS pattern indication component 625 can receive, from a base station, an indication of a TRS pattern, where the TRS pattern includes a first portion of the TRS pattern and a second portion of the TRS pattern. The first portion of the TRS pattern can include a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern can include a second symbol gap between at least two TRSs.

[0180] In some cases, the TRS reception component 630 can monitor for a plurality of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern. The TRS reception component 630 can receive one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0181] The transmitter 635 can transmit signals generated by other components of the device 605. In some examples, the transmitter 635 can be collocated with the receiver 610 in a transceiver module. The transmitter 635 can be an example of aspects of the transmitter 830 described with reference to FIG. 8. The transmitter 635 can utilize a single antenna or a set of antennas. Figure 8 ​Examples of aspects of the described transceiver 820 are shown. The transmitter 635 can use a single antenna or a set of antennas.

[0182] Figure 7 A block diagram 700 showing a communications manager 705 that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown. The communications manager 705 can be an example of aspects of the communications manager 515, the communications manager 615, or the communications manager 810 described herein. The communications manager 705 can include a UE capability component 710, a TRS pattern indication component 715, a TRS reception component 720, a TRS pattern request component 725, a TRS pattern selection component 730, and an aperiodic TRS component 735. Each of these modules can communicate, directly or indirectly, with one another (e.g., via one or more buses).

[0183] The UE capability component 710 can transmit, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern.

[0184] The TRS pattern indication component 715 can receive, from a base station, an indication of a TRS pattern, where the TRS pattern includes a first portion of the TRS pattern and a second portion of the TRS pattern. The first portion of the TRS pattern can include a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern can include a second symbol gap between at least two TRSs. In some cases, the indication of the TRS pattern is received via DCI. In some cases, the first portion of the TRS pattern includes a four symbol gap between TRSs, and the first portion and the second portion of the TRS pattern include a smaller symbol gap between at least two TRSs. In some cases, the second portion of the TRS pattern is before, after, or between the TRSs of the first portion.

[0185] The TRS reception component 720 can receive one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern. In some cases, the TRS pattern spans one slot or a set of slots. In some cases, the first portion of the TRS pattern spans a TRS bandwidth, and the second portion of the TRS pattern spans a subset of the TRS bandwidth. In some cases, the TRS reception component 720 can perform time and frequency synchronization based on receiving the one or more tracking reference signals.

[0186] The TRS pattern request component 725 can transmit, to the base station, a request for a second portion of a TRS pattern. In some examples, the TRS pattern request component 725 can detect that the UE is moving at a speed that satisfies a speed threshold, where the request is transmitted based on the detection. The TRS pattern selection component 730 can select the TRS pattern from a pattern table based on the indication of the TRS pattern.

[0187] In some examples, the TRS pattern selection component 730 can receive, from the base station, a MAC-CE to indicate a pattern table from a set of pattern tables. In some examples, the TRS pattern selection component 730 can receive, from the base station, RRC signaling to configure a pattern table. In some cases, the indication of the TRS pattern corresponds to an index of the pattern table. The aperiodic TRS component 735 can receive DCI to allocate aperiodic resources for the set of TRSs. In some examples, the aperiodic TRS component 735 can receive, from the base station, an indication of a triggering state via the DCI or the MAC-CE, where the TRS pattern is based on the triggering state.

[0188] Figure 8 FIG. 8 shows a diagram of a system 800 including a device 805 that supports enhanced TRS patterns in accordance with aspects of the present disclosure. The device 805 can be an example of or include the components of device 505, device 605, or a UE 115 as described herein. The device 805 can include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 810, an I / O controller 815, a transceiver 820, an antenna 825, memory 830, and a processor 840. These components can be in electronic communication via one or more buses (e.g., bus 845).

[0189] The communications manager 810 can transmit, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion associated with a TRS pattern, receive, from the base station, an indication of the TRS pattern, where the TRS pattern includes a first portion of the TRS pattern and a second portion of the TRS pattern. The first portion of the TRS pattern can include a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern can include a second symbol gap between at least two TRSs. In some cases, the communications manager 810 can monitor for one or more TRSs in accordance with the first portion. The communications manager 810 can receive the one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0190] The I / O controller 815 can manage input and output signals for the device 805. The I / O controller 815 can also manage peripherals not integrated into the device 1305. In some cases, the I / O controller 815 can represent a physical connection or port to the external peripherals. In some cases, the I / O controller 815 can utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS / 2®, LINUX®, or another known operating system. In other cases, the I / O controller 815 can represent or interact with a modem, a keyboard, a mouse, a touchscreen, or similar devices. In some cases, the I / O controller 815 can be implemented as part of a processor. In some cases, a user can interact with the device 805 via the I / O controller 815 or via hardware components controlled by the I / O controller 815. The I / O controller 815 can manage input and output signals for the device 805. The I / O controller 815 can also manage peripherals not integrated into the device 1305. In some cases, the I / O controller 815 can represent a physical connection or port to the external peripherals. In some cases, the I / O controller 815 can utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS / 2®, LINUX®, or another known operating system. In other cases, the I / O controller 815 can represent or interact with a modem, a keyboard, a mouse, a touchscreen, or similar devices. In some cases, the I / O controller 815 can be implemented as part of a processor. In some cases, a user can interact with the device 805 via the I / O controller 815 or via hardware components controlled by the I / O controller 815.

[0191] The transceiver 820 can communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 820 can represent a wireless transceiver and can communicate bi-directionally with another wireless transceiver. The transceiver 820 can also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

[0192] In some cases, the wireless device can include a single antenna 825. However, in some cases the device can have more than one antenna 825, which can be capable of concurrently transmitting or receiving multiple wireless transmissions.

[0193] The memory 830 can include random access memory (RAM) and read-only memory (ROM). The memory 830 can store computer-readable, computer-executable software 835 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 830 can contain, among other computer-readable software, a basic input / output system (BIOS), which can control basic hardware or software operation such as the interaction with peripheral components or devices.

[0194] The processor 840 can include an intelligent hardware device, (e.g., a general- purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 840 can be configured to operate a memory array using a memory controller. In other cases, a memory controller can be integrated into the processor 840. The processor 840 can be configured to execute computer-readable instructions stored in a memory (e.g., the memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks supporting enhanced TRS mode).

[0195] The code 835 can include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 835 can be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 835 can not be directly executable by the processor 840 but can cause a computer (e.g., when compiled and executed) to perform functions described herein.

[0196] Figure 9 FIG. 9 shows a block diagram of a device 905 that supports enhanced TRS patterns in accordance with aspects of the present disclosure. The device 905 can be an example of aspects of a base station 105 as described herein. The device 905 can include a receiver 910, a communications manager 915, and a transmitter 920. The device 905 can also include a processor. Each of these components can be in communication with one another (e.g., via one or more buses).

[0197] The receiver 910 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to enhanced TRS patterns, etc.). Information can be passed on to other components of the device 905. The receiver 910 can be an example of aspects of the transceiver 1220 described with reference to FIG. 11. The receiver 910 can utilize a single antenna or a set of antennas. Figure 12 The transmitter 920 can transmit signals generated by other components of the device 905. For example, the transmitter 920 can transmit information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to enhanced TRS patterns, etc.). The

[0198] The communications manager 915 can receive, from a UE, an indication of a UE capability. In some cases, the communications manager 915 can receive, from a UE, an indication of a UE capability for receiving a first portion and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern. The communications manager 915 can transmit, to the UE, an indication of the TRS pattern. Based on the received indication of the UE capability, the TRS pattern can include a first portion and a second portion for a plurality of TRSs, where the first portion of the TRS pattern can include a first symbol gap of one or more symbols between the TRSs, and the first portion and the second portion of the TRS pattern can include a second symbol gap between at least two of the TRSs. In some cases, the communications manager 915 selects the TRS pattern including the first portion and the second portion for a plurality of TRSs based on receiving the UE capability. The communications manager 915 can transmit the set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern. The communications manager 915 can be an example of aspects of the communications manager 1210 described herein.

[0199] The communications manager 915, or its sub-components, can be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 915, or its sub-components can be executed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

[0200] The communications manager 915, or its sub-components, can be physically located in various places in the apparatus including but not limited to centralized in a single location, completely distributed among multiple locations, or combinations thereof. In some examples, the communications manager 915, or its sub-components, can be in different physical locations.

[0201] The communications manager 915 can be an example of means for performing various aspects of managing an intelligent repeater as described herein. The communications manager 915, or its sub-components, can be implemented in hardware (e.g., in communications management circuitry). The circuitry can comprise a processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

[0202] In another implementation, the communications manager 915, or its sub-components, can be implemented in code (e.g., as communications management software or firmware) executed by a processor or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 915, or its sub-components can be executed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device.

[0203] In some examples, the communications manager 915 can be configured to perform various operations (e.g., receiving, determining, transmitting) using or otherwise in cooperation with the receiver 910, the transmitter 920, or both.

[0204] The transmitter 920 can transmit signals generated by other components of the device 905. In some examples, the transmitter 920 can be collocated with a receiver 910 in a transceiver module. For example, the transmitter 920 can be an example of a means for transmitting. Figure 12Examples of aspects of the described transceiver 1220. The transmitter 920 can utilize a single antenna or a set of antennas.

[0205] Figure 10 FIG. 10 shows a block diagram 1000 of a device 1005 that supports enhanced TRS patterns in accordance with aspects of the present disclosure. The device 1005 can be an example of aspects of a device 905 or a base station 105 as described herein. The device 1005 can include a receiver 1010, a communications manager 1015, and a transmitter 1040. The device 1005 can also include a processor. Each of these components can be in communication with one another (e.g., via one or more buses).

[0206] The receiver 1010 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to enhanced TRS patterns, etc.). Information can be passed on to other components of the device 1005. The receiver 1010 can be a receiver as described with reference to FIG. 9. The receiver 1010 can utilize a single antenna or a set of antennas. Figure 12 Examples of aspects of the described transceiver 1220. The receiver 1010 can utilize a single antenna or a set of antennas.

[0207] The communications manager 1015, as described herein, can be an example of aspects of the communications manager 915. The communications manager 1015 can include a UE capability component 1020, a TRS pattern selection component 1025, a TRS pattern indication component 1030, and a TRS transmission component 1035. The communications manager 1015 can be an example of aspects of the communications manager 1210 described herein.

[0208] The UE capability component 1020 can receive, from a UE, an indication of a UE capability. In some cases, the UE capability component 1020 can receive, from a UE, an indication of a capability for receiving a first portion and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern. The TRS pattern indication component 1030 can transmit, to the UE, an indication of a TRS pattern including a first portion and a second portion for a plurality of TRSs based on the received indication of the UE capability. The first portion of the TRS pattern can include a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern can include a second symbol gap between at least two TRSs. In some examples, the first symbol gap in time between a plurality of TRS symbols can not be short enough to track a frequency offset or adjust a communication link for a Doppler effect, such as in a high mobility scenario. Thus, based on the UE capability, the device 1005 (e.g., a gNB) can include the second portion of the TRS pattern and can select the second symbol gap such that the gap between two TRS symbols is short enough for frequency tracking, adjusting a communication link for a Doppler effect, and / or the like. In some cases, the TRS pattern selection component 1025 can select a TRS pattern including a first portion and a second portion for a set of TRSs based on receiving the UE capability. The TRS transmitting component 1035 can transmit the set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0209] The transmitter 1040 can transmit signals generated by other components of the device 1005. In some examples, the transmitter 1040 can be collocated with the receiver 1010 in a transceiver module. The transmitter 1040 can be an example of aspects of the transmitter 1220 described with reference to FIG. 1. The transmitter 1040 can utilize a single antenna or a set of antennas. Figure 12

[0210] Figure 11 A block diagram 1100 illustrating the communication manager 1105 in accordance with aspects of the present disclosure that supports enhanced TRS patterns is shown. The communication manager 1105 can be an example of aspects of a communication manager 915, a communication manager 1015, or a communication manager 1210 described herein. The communication manager 1105 can include a UE capability component 1110, a TRS pattern selection component 1115, a TRS pattern indication component 1120, a TRS transmitting component 1125, a TRS pattern request component 1130, and a shared TRS configuration component 1135. Each of these modules can communicate, directly or indirectly, with one another (e.g., via one or more buses).

[0211] ​The UE capability component 1110 can receive, from a UE, an indication of a UE capability. In some cases, the UE capability component 1110 can receive, from the UE, an indication of a UE capability for receiving a first portion and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern. In some cases, the TRS pattern selection component 1115 can select, based on receiving the UE capability, a TRS pattern that includes a first portion and a second portion for a set of TRSs. In some cases, the first portion of the TRS pattern includes a four symbol gap between TRSs, and the first portion and the second portion of the TRS pattern include a two symbol gap between at least two TRSs. In some cases, the second portion of the TRS pattern is before, after, or between the TRSs of the first portion.

[0212] The TRS pattern indication component 1120 can transmit, to a UE, an indication of a TRS pattern. The TRS pattern can include, based on the received indication of the UE capability, a first portion and a second portion for a plurality of TRSs. The first portion of the TRS pattern can include a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern can include a second symbol gap between at least two TRSs. In some examples, the TRS pattern indication component 1120 can transmit, to the UE, a MAC-CE indicating a pattern table from a set of pattern tables. In some examples, the TRS pattern indication component 1120 can transmit, to the UE, RRC signaling to configure the pattern table.

[0213] In some examples, the TRS pattern indication component 1120 can transmit, to the UE, a DCI for allocating aperiodic resources for the set of TRSs. In some examples, the TRS pattern indication component 1120 can transmit, from the base station, an indication of a trigger state via the DCI or the MAC-CE, where the TRS pattern is based on the trigger state. In some cases, the indication of the TRS pattern corresponds to an index of a pattern table configured at the UE. In some cases, the indication of the TRS pattern is transmitted via the DCI.

[0214] The TRS transmitting component 1125 can transmit the set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern. In some cases, the TRS pattern spans a slot or a set of slots. In some cases, the first portion of the TRS pattern spans a TRS bandwidth, and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0215] The TRS pattern request component 1130 can receive a request from a UE for a second portion of a TRS pattern based on a high speed of the UE. The shared TRS configuration component 1135 can transmit an indication of the TRS pattern to a second UE that is unable to receive the second portion of the TRS pattern. In some examples, the shared TRS configuration component 1135 can schedule downlink shared channel resources for the second UE, where a modulation and coding scheme of the second UE is lower order, downlink common channel resources overlap at least in part with the second portion of the TRS in time, frequency, antenna ports, or any combination thereof.

[0216] In some examples, the shared TRS configuration component 1135 can schedule the second UE for a downlink shared channel during a slot that includes the set of TRSs, where the second UE is unable to receive the second portion of the TRS pattern. In some examples, the shared TRS configuration component 1135 can transmit an indication of the TRS pattern to the second UE, where the indication is to configure the second UE for a zero-power channel state information reference signal during the second portion of the TRS pattern.

[0217] Figure 12 A diagram illustrating a system 1200 including a device 1205 that supports enhanced TRS patterns is shown, in accordance with aspects of the present disclosure. The device 1205 can be an example of or include the components of device 905, device 1005, or a base station 105. The device 1205 can include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1210, a network communications manager 1215, a transceiver 1220, an antenna 1225, memory 1230, a processor 1240, and an inter-station communications manager 1245. These components can be in electronic communication via one or more buses (e.g., bus 1250).

[0218] The communications manager 1210 can receive, from a UE, an indication of a UE capability. In some cases, the communications manager 1210 can receive an indication of a UE capability for receiving a first portion and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern. In some cases, the communications manager 1210 can select a TRS pattern including a first portion and a second portion for a set of TRSs based on receiving the UE capability. The communications manager 1210 can transmit, to the UE, an indication of a TRS pattern including a first portion and a second portion for a plurality of TRSs based on the received indication of the UE capability. The first portion of the TRS pattern can include a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern can include a second symbol gap between at least two TRSs. The communications manager 1210 can transmit the set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0219] The network communications manager 1215 can manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager 1215 can manage the transfer of data communications for client devices, such as one or more UEs 115.

[0220] As described above, the transceiver 1220 can communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1220 can represent a wireless transceiver and can communicate bi-directionally with another wireless transceiver. The transceiver 1220 can also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

[0221] In some cases, the wireless device can include a single antenna 1225. However, in some cases the device can have more than one antenna 1225, which can be capable of concurrently transmitting or receiving multiple wireless transmissions.

[0222] The memory 1230 can include RAM, ROM, or a combination thereof. The memory 1230 can store computer-readable code 1235 including instructions that, when executed by a processor (e.g., the processor 1240), cause the device to perform various functions described herein. In some cases, the memory 1230 can also include a BIOS, which can control basic hardware or software operation such as the interaction with peripheral components or devices.

[0223] The processor 1240 can include an intelligent hardware device, (e.g., a general- purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 1240 can be configured to operate a memory array using a memory controller. In some cases, a memory controller can be integrated into the processor 1240. The processor 1240 can be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1230) to cause the device 1205 to perform various functions (e.g., functions or tasks supporting enhanced TRS patterns).

[0224] The inter-station communications manager 1245 can manage communications with other base station 105 and can include a controller or scheduler for controlling

[0225] The code 1235 can include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1235 can be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1235 can not be directly executable by the processor 1240 but can cause a computer (e.g., when compiled and executed) to perform functions described herein.

[0226] Figure 13 A method 1300 that supports enhanced TRS patterns is shown. The operations of method 1300 can be implemented by a UE 115 or its components as described herein. For example, the operations of method 1300 can be performed by a communications manager as described with reference to Figures 5 to 8 In some examples, a UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware.

[0227] At 1305, the UE can transmit, to a base station, a UE capability for receiving a first portion of TRS and a second portion of TRS, the first portion and the second portion being associated with a TRS pattern. The operations of 1305 can be performed according to the methods described herein. In some examples, aspects of the operations of 1305 can be performed by a UE capability component as described with reference to Figures 5 to 8 FIG. 13, described supra. Additionally or alternatively, the UE capability component can be configured to perform one or more of the operations described herein. FIG. 13, described supra. Additionally or alternatively, the UE capability component can be configured to perform one or more of the operations described herein.

[0228] At 1310, the UE can receive, from the base station, an indication of a TRS pattern, where the TRS pattern includes a first portion of the TRS pattern and a second portion of the TRS pattern. The operations of 1310 can be performed according to the methods described herein. In some examples, aspects of the operations of 1310 can be performed by a TRS pattern indication component as described with reference to Figures 5 to 8 FIG. 15.

[0229] At 1315, the UE can monitor for a set of TRSs according to the first portion of the TRS pattern and the second portion of the TRS pattern. The operations of 1315 can be performed according to the methods described herein. In some examples, aspects of the operations of 1315 can be performed by a TRS reception component as described with reference to Figures 5 to 8 FIG. 15.

[0230] Figure 14 Methods 1400 can support wireless communications. For example, the operations of method 1400 can be performed to support enhanced TRS patterns as described herein. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware. Figures 5 to 8 FIG. 15.

[0231] At 1405, the UE can transmit, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern. The operations of 1405 can be performed according to the methods described herein. In some examples, aspects of the operations of 1405 can be performed by a UE capability component as described with reference to Figures 5 to 8 FIG. 15.

[0232] At 1410, the UE can transmit, to the base station, a request for the second portion of the TRS pattern. The operations of 1410 can be performed according to the methods described herein. In some examples, aspects of the operations of 1410 can be performed by a TRS pattern request component as described with reference to Figures 5 to 8 FIG. 15.

[0233] At 1415, the UE can receive, from the base station, an indication of a TRS pattern, where the TRS pattern includes a first portion of the TRS pattern and a second portion of the TRS pattern. The operations of 1415 can be performed according to the methods described herein. In some examples, aspects of the operations of 1415 can be performed by a TRS pattern indication component as described with reference to Figures 5 to 8 FIG. 15.

[0234] At 1420, the UE can monitor a set of TRSs according to the first portion of the TRS pattern and the second portion of the TRS pattern. The operations of 1420 can be performed according to the methods described herein. In some examples, aspects of the operations of 1420 can be performed by a TRS reception component as described with reference to Figures 5 to 8 FIG. 15 as described herein. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware.

[0235] Figure 15 A method 1500 that supports enhanced TRS patterns is shown in FIG. 15. The operations of method 1500 can be implemented by a UE 115 or its components as described herein. For example, the operations of method 1500 can be performed by a communications manager as described with reference to Figures 5 to 8 FIG. 15 as described herein. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware.

[0236] At 1505, the UE can transmit, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion associated with a TRS pattern. The operations of 1505 can be performed according to the methods described herein. In some examples, aspects of the operations of 1505 can be performed by a UE capability component as described with reference to Figures 5 to 8 FIG. 15 as described herein. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware.

[0237] At 1510, the UE can receive, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern. The operations of 1510 can be performed according to the methods described herein. In some examples, aspects of the operations of 1510 can be performed by a TRS pattern indication component as described with reference to Figures 5 to 8 FIG. 15 as described herein. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware.

[0238] At 1515, the UE can select the TRS pattern from a pattern table based on the indication of the TRS pattern. The operations of 1515 can be performed according to the methods described herein. In some examples, aspects of the operations of 1515 can be performed by a TRS pattern selection component as described with reference to Figures 5 to 8 FIG. 15 as described herein. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware.

[0239] At 1520, the UE can monitor a set of TRSs according to the first portion of the TRS pattern and the second portion of the TRS pattern. The operations of 1520 can be performed according to the methods described herein. In some examples, aspects of the operations of 1520 can be performed by a TRS reception component as described with reference to Figures 5 to 8 FIG. 15 as described herein. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware.

[0240] Figure 16A flow diagram illustrating a method 1600 that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown. The operations of method 1600 can be implemented by a base station 105 or its components as described herein. For example, the operations of method 1600 can be performed by a communications manager as described with reference to Figures 9 to 12 The described communications manager performs. In some examples, a base station can execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station can perform aspects of the functions described below using special-purpose hardware.

[0241] At 1605, the base station can receive, from a UE, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern. The operations of 1605 can be performed according to the methods described herein. In some examples, aspects of the operations of 1605 can be performed by a UE capability component as described with reference to Figures 9 to 12 FIG. 14.

[0242] At 1610, the base station can select, based on receiving the UE capability, a TRS pattern including a first portion and a second portion for a set of TRSs. The operations of 1610 can be performed according to the methods described herein. In some examples, aspects of the operations of 1610 can be performed by a TRS pattern selection component as described with reference to Figures 9 to 12 FIG. 14.

[0243] At 1615, the base station can transmit, to the UE, an indication of the TRS pattern. The operations of 1615 can be performed according to the methods described herein. In some examples, aspects of the operations of 1615 can be performed by a TRS pattern indication component as described with reference to Figures 9 to 12 FIG. 14.

[0244] At 1620, the base station can transmit the set of TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern. The operations of 1620 can be performed according to the methods described herein. In some examples, aspects of the operations of 1620 can be performed by a TRS transmitting component as described with reference to Figures 9 to 12 FIG. 14.

[0245] Figure 17 A flow diagram illustrating a method 1700 that supports enhanced TRS patterns in accordance with aspects of the present disclosure is shown. The operations of method 1700 can be implemented by a UE 115 or its components as described herein. For example, the operations of method 1700 can be performed by a communications manager as described with reference to Figures 5 to 8 The described communications manager performs. In some examples, a UE can execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE can perform aspects of the functions described below using special-purpose hardware.

[0246] At 1705, the method can include transmitting, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern. The operations of 1705 can be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1705 can be performed by a UE capability component as described with reference to Figures 5 to 8 FIG. 16.

[0247] At 1710, the method can include receiving, from the base station, an indication of the TRS pattern, where the TRS pattern includes the first portion of the TRS pattern and the second portion of the TRS pattern, and where the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs. The operations of 1710 can be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1710 can be performed by a TRS pattern indication component as described with reference to Figures 5 to 8 FIG. 16.

[0248] At 1715, the method can include receiving the one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern. The operations of 1715 can be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1715 can be performed by a TRS reception component as described with reference to Figures 5 to 8 FIG. 16.

[0249] Figure 18 A method 1800 that supports enhanced TRS patterns is illustrated in FIG. 16. The operations of method 1800 can be implemented by a base station 105 or its components as described herein. For example, the operations of method 1800 can be performed by a communications manager as described with reference to Figures 9 to 12 FIG. 15. In some examples, a base station can execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station can perform aspects of the functions described below using special-purpose hardware.

[0250] At 1805, the method can include receiving, from a UE, an indication of a UE capability. The operations of 1805 can be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1805 can be performed by a UE capability component as described with reference to Figures 9 to 12 FIG. 16.

[0251] At 1810, the method can include transmitting, to the UE based on the received indication of the UE capability, an indication of a TRS pattern including a first portion and a second portion for a set of multiple TRSs, where the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs. The operations of 1810 can be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1810 can be performed by a TRS pattern indication component as described with reference to Figures 9 to 12 The described TRS pattern indication component.

[0252] At 1815, the method can include transmitting the set of multiple TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern. The operations of 1815 can be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1815 can be performed by a TRS transmitting component as described with reference to Figures 9 to 12 The described TRS transmitting component.

[0253] implementations, and that the operations and / or steps can be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods can be combined.

[0254] The following provides an overview of aspects of the disclosure:

[0255] Aspect 1 : A method for wireless communication at a UE, comprising: transmitting, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern; receiving, from the base station, an indication of the TRS pattern, wherein the TRS pattern includes a first portion of the TRS pattern and a second portion of the TRS pattern, wherein the first portion of the TRS pattern includes a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern include a second symbol gap between at least two TRSs; and receiving one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0256] Aspect 2: The method of aspect 1, further comprising: transmitting, to the base station, a request for the second portion of the TRS pattern.

[0257] Aspect 3: The method of aspect 2, further comprising: detecting that the UE is moving at a speed that satisfies a speed threshold, wherein the request is transmitted based on the detection.

[0258] Aspect 4: The method of any of aspects 1-3, further comprising: selecting the TRS pattern from a pattern table based on the indication of the TRS pattern.

[0259] Aspect 5: The method of aspect 4, further comprising: receiving, from the base station, a MAC CE indicating a pattern table from the one or more pattern tables.

[0260] Aspect 6: The method of any of aspects 4-5, wherein the indication of the TRS pattern corresponds to an index of the pattern table.

[0261] Aspect 7: The method of any of aspects 4-6, further comprising: receiving, from the base station, RRC signaling to configure the pattern table.

[0262] Aspect 8: The method of any of aspects 1-7, wherein the indication of the TRS pattern is received via DCI.

[0263] Aspect 9: The method of any of aspects 1-8, wherein receiving the indication of the TRS pattern comprises: receiving DCI allocating aperiodic resources for one or more TRSs.

[0264] Aspect 10: The method of aspect 9, further comprising: receiving, from the base station, an indication of a trigger state via DCI or a MAC CE, wherein the TRS pattern is based on the trigger state.

[0265] Aspect 11: The method of any of aspects 1-10, wherein the TRSs of the second portion of the TRS pattern are between, before, or after the TRSs of the first portion.

[0266] Aspect 12: The method of any of aspects 1-11, wherein the TRS pattern spans a slot or one or more slots.

[0267] Aspect 13: The method of any of aspects 1-12, wherein the first portion of the TRS pattern spans a TRS bandwidth and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0268] Aspect 14: The method of any of aspects 1-13, further comprising: performing time and frequency synchronization based on receiving the one or more TRSs.

[0269] Aspect 15: A method for wireless communication at a base station, comprising: receiving, from a UE, an indication of a UE capability; transmitting, to the UE based on the received indication of the UE capability, an indication of a TRS pattern comprising a first portion and a second portion for one or more TRSs, wherein the first portion of the TRS pattern comprises a first symbol gap of one or more symbols between TRSs, and the first portion and the second portion of the TRS pattern comprise a second symbol gap between at least two TRSs; and transmitting the one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0270] Aspect 16: The method of aspect 15, further comprising: receiving a request from the UE for the second portion of the TRS pattern based on a high speed of the UE.

[0271] Aspect 17: The method of any of aspects 15-16, wherein the indication of the TRS pattern corresponds to an index of a pattern table configured at the UE.

[0272] Aspect 18: The method of aspect 17, further comprising: transmitting, to the UE, a MAC CE indicating a pattern table from one or more pattern tables.

[0273] Aspect 19: The method of any of aspects 17-18, further comprising: transmitting, to the UE, RRC signaling to configure the pattern table.

[0274] Aspect 20: The method of any of aspects 15-19, wherein the indication of the TRS pattern is transmitted via DCI.

[0275] Aspect 21: The method of any of aspects 15-20, wherein transmitting the indication of the TRS pattern comprises: transmitting DCI to allocate aperiodic resources for the one or more TRSs.

[0276] Aspect 22: The method of aspect 21, further comprising: transmitting, from the base station, an indication of a trigger state via DCI or a MAC CE, wherein the TRS pattern is based on the trigger state.

[0277] Aspect 23: The method of aspect 22, wherein the TRSs of the second portion of the TRS pattern are between, before, or after the TRSs of the first portion.

[0278] Aspect 24: The method of any of aspects 15-23, wherein the first portion of the TRS pattern spans a TRS bandwidth, and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0279] Aspect 25: The method of any of aspects 15 through 24, wherein the UE is a first UE, further comprising: transmitting, to a second UE that is unable to receive the second portion of the TRS pattern, an indication of the TRS pattern; and scheduling downlink shared channel resources for the second UE, wherein the downlink shared channel resources at least partially overlap in time, frequency, antenna port, or any combination thereof, with the second portion of the TRS based on a modulation and coding scheme of the second UE being lower order.

[0280] Aspect 26: The method of any of aspects 15 through 25, wherein the UE is a first UE, further comprising: scheduling a second UE for a downlink shared channel during a slot that includes one or more TRSs, wherein the second UE is unable to receive a second portion of the TRS pattern; and transmitting, to the second UE, an indication of the TRS pattern, wherein the indication is to configure the second UE for a zero-power channel state information reference signal during the second portion of the TRS pattern.

[0281] Aspect 27: An apparatus for wireless communication at a UE, comprising a processor; and a memory coupled to the processor, the processor and the memory configured to perform the method of any of aspects 1 through 14.

[0282] Aspect 28: An apparatus for wireless communication at a UE, comprising at least one means for performing the method of any of aspects 1 through 14.

[0283] Aspect 29: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code comprising instructions executable by a processor to perform the method of any of aspects 1 through 14.

[0284] Aspect 30: An apparatus for wireless communication at a base station, comprising a processor; and a memory coupled to the processor, the processor and the memory configured to perform the method of any of aspects 15 through 26.

[0285] Aspect 31 : An apparatus for wireless communication at a base station, comprising at least one means for performing the method of any of aspects 15 through 26.

[0286] Aspect 32: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform the method of any of aspects 15 through 2.

[0287] Aspect 33: A method for wireless communication at a user equipment (UE), comprising: transmitting, to a base station, a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion being associated with a TRS pattern; receiving, from the base station, an indication of the TRS pattern, wherein the TRS pattern comprises a first portion of the TRS pattern and a second portion of the TRS pattern; and monitoring one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0288] Aspect 34: The method of aspect 33, further comprising: transmitting, to the base station, a request for the second portion of the TRS pattern.

[0289] Aspect 35: The method of any of aspects 33 or 34, further comprising: detecting that the UE is moving at a speed that satisfies a speed threshold, wherein the request is transmitted based on the detection.

[0290] Aspect 36: The method of any of aspects 33-35, further comprising: selecting the TRS pattern from a pattern table based on the indication of the TRS pattern.

[0291] Aspect 37: The method of any of aspects 33-36, further comprising: receiving, from the base station, a MAC-CE indicating a pattern table from one or more pattern tables.

[0292] Aspect 38: The method of any of aspects 33-37, wherein the indication of the TRS pattern corresponds to an index of the pattern table.

[0293] Aspect 39: The method of any of aspects 33-38, further comprising: receiving, from the base station, RRC signaling configuring the pattern table.

[0294] Aspect 40: The method of any of aspects 33-39, wherein the indication of the TRS pattern is received via DCI.

[0295] Aspect 41: The method of any of aspects 33-40, wherein receiving the indication of the TRS pattern comprises: receiving DCI configuring aperiodic resources for one or more TRSs.

[0296] Aspect 42: The method of any of aspects 33-41, further comprising: receiving, from the base station, an indication of a triggering state via DCI or a MAC-CE, wherein the TRS pattern is based on the triggering state.

[0297] Aspect 43: The method of any of aspects 33 through 42, wherein the first portion of the TRS pattern comprises four symbol gaps between TRSs, and the first portion and the second portion of the TRS pattern comprise smaller symbol gaps between at least two TRSs.

[0298] Aspect 44: The method of any of aspects 33 through 43, wherein the TRSs of the second portion of the TRS pattern are before, after, or between the TRSs of the first portion.

[0299] Aspect 45: The method of any of aspects 33 through 44, wherein the TRS pattern spans a slot or one or more slots.

[0300] Aspect 46: The method of any of aspects 33 through 45, wherein the first portion of the TRS pattern spans a TRS bandwidth, and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0301] Aspect 47: A method for wireless communications at a base station, comprising: receiving, from a user equipment (UE), a UE capability for receiving a first portion of TRSs and a second portion of TRSs, the first portion and the second portion associated with a TRS pattern; selecting, based on receiving the UE capability, a TRS pattern comprising the first portion for one or more TRSs and the first portion; transmitting, to the UE, an indication of the TRS pattern; and transmitting the one or more TRSs in accordance with the first portion of the TRS pattern and the second portion of the TRS pattern.

[0302] Aspect 48: The method of aspect 47, further comprising: receiving a request from the UE for the second portion of the TRS pattern based on a high speed of the UE.

[0303] Aspect 49: The method of aspect 47 or 48, wherein the indication of the TRS pattern corresponds to an index of a pattern table configured at the UE.

[0304] Aspect 50: The method of any of aspects 47 through 49, further comprising: transmitting, to the UE, a MAC CE to indicate a pattern table from one or more pattern tables.

[0305] Aspect 51: The method of any of aspects 47 through 50, further comprising: transmitting, to the UE, RRC signaling to configure the pattern table.

[0306] Aspect 52: The method of any of aspects 47 through 51, wherein the indication of the TRS pattern is transmitted via DCI.

[0307] Aspect 53: The method of any of aspects 47-52, wherein transmitting the indication of the TRS pattern comprises transmitting DCI allocating aperiodic resources for one or more TRSs.

[0308] Aspect 54: The method of any of aspects 47-53, further comprising transmitting, from the base station, an indication of a triggering state via DCI or a MAC CE, wherein the TRS pattern is based on the triggering state.

[0309] Aspect 55: The method of any of aspects 47-54, wherein the first portion of the TRS pattern comprises four-symbol gaps between TRSs, and the first portion and the second portion of the TRS pattern comprise two-symbol gaps between at least two TRSs.

[0310] Aspect 56: The method of any of aspects 47-55, wherein the second portion of the TRS pattern is between, before, or after the TRSs of the first portion.

[0311] Aspect 57: The method of any of aspects 47-56, wherein the TRS pattern spans a slot or one or more slots.

[0312] Aspect 58: The method of any of aspects 47-57, wherein the first portion of the TRS pattern spans a TRS bandwidth, and the second portion of the TRS pattern spans a subset of the TRS bandwidth.

[0313] Aspect 59: The method of any of aspects 47-58, wherein the UE is a first UE, further comprising transmitting the indication of the TRS pattern to a second UE that is unable to receive the second portion of the TRS pattern, and scheduling downlink shared channel resources for the second UE, wherein the downlink shared channel resources at least partially overlap in time, frequency, antenna ports, or any combination thereof with the second portion of the TRS based on a modulation and coding scheme of the second UE being lower order.

[0314] Aspect 60: The method of any of aspects 47-59, wherein the UE is a first UE, further comprising scheduling a second UE for a downlink shared channel during a slot comprising one or more TRSs, wherein the second UE is unable to receive a second portion of the TRS pattern, and transmitting the indication of the TRS pattern to the second UE, wherein the indication is to configure the second UE for a zero-power channel state information reference signal during the second portion of the TRS pattern.

[0315] Aspect 61: An apparatus for wireless communication, comprising at least one means for performing a method of any of aspects 33-46.

[0316] Aspect 62: An apparatus for wireless communication, comprising a processor; and a memory coupled to the processor, the processor and the memory configured to perform the method of any of aspects 33 through 46.

[0317] Aspect 63: A non-transitory computer-readable medium storing code for wireless communication, comprising a processor, a memory in electronic communication with the processor, and instructions stored in the memory and executable by the processor to cause an apparatus to perform the method of any of aspects 47 through 60.

[0318] Aspect 64: An apparatus for wireless communication, comprising at least one means for performing the method of any of aspects 47 through 60.

[0319] Aspect 65: An apparatus for wireless communication, comprising a processor; and a memory coupled to the processor, the processor and the memory configured to perform the method of any of aspects 33 through 46.

[0320] Aspect 66: A non-transitory computer-readable medium storing code for wireless communication, comprising a processor, a memory in electronic communication with the processor, and instructions stored in the memory and executable by the processor to cause an apparatus to perform the method of any of aspects 47 through 60.

[0321] Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system can be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology can be used in much of the description, aspects of the described techniques can be applicable to LTE, LTE-A, LTE-A Pro, or NR applications beyond the examples described. For example, the described techniques can be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and others, among others.

[0322] Information and signals described herein can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0323] The various illustrative blocks and modules described in connection with the present disclosure can be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0324] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions can also be physically located at various positions, including being distributed as discrete components or

[0325] Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium can be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media can comprise random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0326] As used herein, including in the claims “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of’ or “one or more of’) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an exemplary step that is described as “based on condition A” can be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.”

[0327] In the drawings, like reference numerals can be used to denote similar components throughout the several views. Moreover, various components of the same type can be distinguished by following the convention of numbering them with the first two digits representing the hundreds place (i.e., the most significant digit) and the last two digits representing the least significant digit (i.e., the ones place). When reference is made to a range including two endpoints, the endpoints are inclusive of that value.

[0328] The description set forth herein describes example configurations and does not represent all possible examples consistent with the claims. The term “exemplary” is used herein to mean “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing a thorough understanding of the described techniques. These techniques, however, can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0329] The description herein is presented to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: Sends to the access network entity the UE capability to receive a first portion and a second portion of the tracking reference signal, the first portion and the second portion being associated with a tracking reference signal mode; Based on the detection that the UE is moving at a speed that meets a threshold, a request for the second part of the tracking reference signal mode is sent to the access network entity; Receive an indication of the tracking reference signal pattern from the access network entity, wherein the tracking reference signal pattern includes a first portion and a second portion of the tracking reference signal pattern, and wherein the first portion of the tracking reference signal pattern includes a first symbol gap having one or more symbols between tracking reference signals, and the first portion and the second portion of the tracking reference signal pattern include a second symbol gap between at least two tracking reference signals; and One or more tracking reference signals are received according to the first part of the tracking reference signal pattern and the second part of the tracking reference signal pattern.

2. The method according to claim 1, further comprising: The tracking reference signal mode is selected from the mode table based at least in part on the indication of the tracking reference signal mode.

3. The method according to claim 2, further comprising: The access network entity receives a Media Access Control (MAC) control element (CE) for indicating the pattern tables from multiple pattern tables.

4. The method according to claim 2, wherein, The indication of the tracking reference signal mode corresponds to the index of the mode table.

5. The method according to claim 2, further comprising: Receive radio resource control signaling from the access network entity for configuring the mode table.

6. The method according to claim 1, wherein, The indication of the tracking reference signal mode is received via downlink control information.

7. The method according to claim 1, wherein, Receiving the indication of the tracking reference signal mode includes: Receive downlink control information for allocating aperiodic resources for the one or more tracking reference signals.

8. The method according to claim 7, further comprising: The trigger state is received from the access network entity via downlink control information or a media access control (MAC) control element (CE), wherein the tracking reference signal mode is at least partially based on the trigger state.

9. The method according to claim 1, wherein, The tracking reference signal of the second part of the tracking reference signal mode is between, before, or after the tracking reference signal of the first part.

10. The method according to claim 1, wherein, The tracking reference signal pattern spans one or more time slots.

11. The method according to claim 1, wherein, The first portion of the tracking reference signal mode spans the tracking reference signal bandwidth, and the second portion of the tracking reference signal mode spans a subset of the tracking reference signal bandwidth.

12. The method according to claim 1, further comprising: Time and frequency synchronization is performed, at least in part, based on receiving the one or more tracking reference signals.

13. A method for wireless communication at an access network entity, comprising: Receive an indication of the capability associated with a first portion and a second portion for a plurality of tracking reference signals, the first portion and the second portion being associated with a tracking reference signal mode; Receive requests for the second part of the tracking reference signal pattern, at least in part based on the high speed of the user equipment (UE); The indication of a tracking reference signal pattern, comprising a first portion and a second portion for the plurality of tracking reference signals, is transmitted at least in part based on the received indication of the capability, wherein the first portion of the tracking reference signal pattern includes a first symbol gap having one or more symbols between the tracking reference signals, and the first portion and the second portion of the tracking reference signal pattern include a second symbol gap between at least two tracking reference signals. as well as The plurality of tracking reference signals are transmitted according to the first part of the tracking reference signal pattern and the second part of the tracking reference signal pattern.

14. The method according to claim 13, wherein, The indication of the tracking reference signal mode corresponds to an index in the mode table.

15. The method of claim 14, further comprising: Send a Media Access Control (MAC) Control Element (CE) for instructing the multiple schema tables.

16. The method of claim 14, further comprising: Send radio resource control signaling for configuring the mode table.

17. The method according to claim 13, wherein, The indication of the tracking reference signal mode is transmitted via downlink control information.

18. The method according to claim 13, wherein, Sending the indication for the tracking reference signal mode includes: Send downlink control information for allocating aperiodic resources for the plurality of tracking reference signals.

19. The method of claim 18, further comprising: Indications of the trigger state are sent via downlink control information or a media access control (MAC) control element (CE), wherein the tracking reference signal mode is at least partially based on the trigger state.

20. The method according to claim 19, wherein, The tracking reference signal of the second part of the tracking reference signal mode is between, before, or after the tracking reference signal of the first part.

21. The method according to claim 13, wherein, The first portion of the tracking reference signal mode spans the tracking reference signal bandwidth, and the second portion of the tracking reference signal mode spans a subset of the tracking reference signal bandwidth.

22. The method of claim 13, further comprising: Scheduling downlink shared channel resources, wherein at least in part based on the modulation and coding scheme associated with the downlink shared channel resources being of lower order, the downlink shared channel resources overlapping at least in part with the second portion of the tracking reference signal mode in terms of time, frequency, antenna port, or any combination thereof.

23. The method of claim 13, further comprising: Schedule the downlink shared channel during time slots that include the plurality of tracking reference signals; as well as Send the indication for the tracking reference signal mode, the indication being used to configure a zero-power channel state information reference signal during the second part of the tracking reference signal mode.

24. An apparatus for wireless communication at a user equipment (UE), comprising: One or more memory units; as well as One or more processors coupled to the one or more memories, the one or more processors being configured such that the UE: Output to the access network entity the UE capability to receive a first portion and a second portion of the tracking reference signal, the first portion and the second portion being associated with a tracking reference signal mode; Based on the detection that the UE is moving at a speed that meets a threshold, a request for the second part of the tracking reference signal mode is output to the access network entity; An indication of the tracking reference signal pattern is obtained from the access network entity, wherein the tracking reference signal pattern includes a first portion and a second portion of the tracking reference signal pattern, wherein the first portion of the tracking reference signal pattern includes a first symbol gap of one or more symbols between tracking reference signals, and the first portion and the second portion of the tracking reference signal pattern include a second symbol gap between at least two tracking reference signals; and One or more tracking reference signals are obtained based on the first part of the tracking reference signal pattern and the second part of the tracking reference signal pattern.

25. The apparatus according to claim 24, wherein, The one or more processors are further configured such that the UE: The tracking reference signal mode is selected from the mode table based at least in part on the indication of the tracking reference signal mode.

26. The apparatus according to claim 25, wherein, The one or more processors are further configured such that the UE: The access network entity receives a Media Access Control (MAC) control element (CE) for indicating the pattern tables from multiple pattern tables.

27. The apparatus according to claim 24, wherein, The device further includes: One or more antennas, wherein the one or more processors are further configured to cause the UE to: The tracking reference signal mode is selected from the mode table based at least in part on the indication of the tracking reference signal mode.

28. The apparatus according to claim 25, wherein, The indication of the tracking reference signal mode corresponds to the index of the mode table.

29. The apparatus according to claim 25, wherein, The one or more processors are further configured such that the UE: Radio resource control signaling for configuring the mode table is obtained from the access network entity.

30. The apparatus according to claim 24, wherein, The indication of the tracking reference signal mode is obtained via downlink control information.

31. An apparatus for wireless communication at an access network entity, comprising: One or more memory units; as well as One or more processors coupled to the one or more memories, the one or more processors being configured to cause the access network entity to: Obtain an indication of the capability associated with a first portion and a second portion for multiple tracking reference signals, the first portion and the second portion being associated with a tracking reference signal pattern; To obtain, at least in part, a request for the second portion of the tracking reference signal pattern based on high speed of the user equipment (UE); Based at least in part on the obtained indication of the capability, an indication of a tracking reference signal pattern including a first portion and a second portion for the plurality of tracking reference signals is output, wherein the first portion of the tracking reference signal pattern includes a first symbol gap including a plurality of symbols between the tracking reference signals, and the first portion and the second portion of the tracking reference signal pattern include a second symbol gap including a plurality of symbols between at least two tracking reference signals; as well as The plurality of tracking reference signals are output according to the first part of the tracking reference signal pattern and the second part of the tracking reference signal pattern.

32. The apparatus according to claim 31, wherein, The one or more processors are further configured to cause the access network entity to: Send a Media Access Control (MAC) control element (CE) for indicating a pattern table including the tracking reference signal pattern.

33. The apparatus according to claim 31, wherein, The indication of the tracking reference signal mode is output via downlink control information.

34. The apparatus according to claim 31, wherein, The device further includes: One or more antennas, wherein the one or more processors are further configured to cause the access network entity to: Scheduling downlink shared channel resources, wherein at least in part based on the modulation and coding scheme associated with the downlink shared channel resources being of lower order, the downlink shared channel resources overlapping at least in part with the second portion of the tracking reference signal mode in terms of time, frequency, antenna port, or any combination thereof.

35. The apparatus according to claim 31, wherein, The one or more processors are further configured to cause the access network entity to: Schedule the downlink shared channel during time slots that include the plurality of tracking reference signals; as well as Send the indication for the tracking reference signal mode, the indication being used to configure a zero-power channel state information reference signal during the second part of the tracking reference signal mode.

36. A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by one or more processors to cause the UE to perform the following operations: Sends to the access network entity the UE capability to receive a first portion and a second portion of the tracking reference signal, the first portion and the second portion being associated with a tracking reference signal mode; Based on the detection that the UE is moving at a speed that meets a threshold, a request for the second part of the tracking reference signal mode is sent to the access network entity; Receive an indication of the tracking reference signal pattern from the access network entity, wherein the tracking reference signal pattern includes a first portion and a second portion of the tracking reference signal pattern, and wherein the first portion of the tracking reference signal pattern includes a first symbol gap having one or more symbols between tracking reference signals, and the first portion and the second portion of the tracking reference signal pattern include a second symbol gap between at least two tracking reference signals; and One or more tracking reference signals are received according to the first part of the tracking reference signal pattern and the second part of the tracking reference signal pattern.

37. The non-transitory computer-readable medium according to claim 36, wherein, The instructions are executable by the one or more processors to cause the UE to perform the following operations: The tracking reference signal mode is selected from the mode table based at least in part on the indication of the tracking reference signal mode.

38. The non-transitory computer-readable medium according to claim 37, wherein, The instructions are executable by the one or more processors to cause the UE to perform the following operations: The access network entity receives a Media Access Control (MAC) control element (CE) for indicating the pattern tables from multiple pattern tables.

39. A non-transitory computer-readable medium storing code for wireless communication at an access network entity, the code comprising instructions executable by one or more processors to cause the access network entity to perform the following operations: Receive an indication of the capability associated with a first portion and a second portion for a plurality of tracking reference signals, the first portion and the second portion being associated with a tracking reference signal mode; Receive requests for the second part of the tracking reference signal pattern, at least in part based on the high speed of the user equipment (UE); The indication of a tracking reference signal pattern, comprising a first portion and a second portion for the plurality of tracking reference signals, is transmitted at least in part based on the received indication of the capability, wherein the first portion of the tracking reference signal pattern includes a first symbol gap comprising a plurality of symbols between the tracking reference signals, and the first portion and the second portion of the tracking reference signal pattern include a second symbol gap comprising a plurality of symbols between at least two tracking reference signals. as well as The plurality of tracking reference signals are transmitted according to the first part of the tracking reference signal pattern and the second part of the tracking reference signal pattern.

40. The non-transitory computer-readable medium according to claim 39, wherein, The instructions are executable by the one or more processors to cause the access network entity to perform the following operations: Send a Media Access Control (MAC) control element (CE) for indicating a pattern table including the tracking reference signal pattern.

41. An apparatus for wireless communication at a user equipment (UE), comprising: A unit for transmitting to an access network entity the UE's capability to receive a first portion and a second portion of a tracking reference signal, the first portion and the second portion being associated with a tracking reference signal mode; A unit for sending a request for the second part of the tracking reference signal pattern to the access network entity based on detecting that the UE is moving at a speed that meets a threshold; A unit for receiving an indication of the tracking reference signal pattern from the access network entity, wherein the tracking reference signal pattern includes a first portion and a second portion of the tracking reference signal pattern, and wherein the first portion of the tracking reference signal pattern includes a first symbol gap having one or more symbols between tracking reference signals, and the first portion and the second portion of the tracking reference signal pattern include a second symbol gap between at least two tracking reference signals; and A unit for receiving one or more tracking reference signals according to the first part of the tracking reference signal pattern and the second part of the tracking reference signal pattern.

42. The apparatus of claim 41, comprising: A unit for selecting the tracking reference signal mode from the mode table based at least in part on the indication of the tracking reference signal mode.

43. The apparatus of claim 42, comprising: A unit for receiving from the access network entity a Media Access Control (MAC) Control Element (CE) for indicating the pattern tables from a plurality of pattern tables.

44. An apparatus for wireless communication at an access network entity, comprising: A unit for receiving an indication of the capability associated with a first portion and a second portion of a plurality of tracking reference signals, the first portion and the second portion being associated with a tracking reference signal pattern; A unit for receiving requests for the second part of the tracking reference signal pattern, at least in part based on the high speed of the user equipment (UE); A unit for transmitting an indication of a tracking reference signal pattern comprising a first portion and a second portion for the plurality of tracking reference signals, based at least in part on a received indication of the capability, wherein the first portion of the tracking reference signal pattern comprises a first symbol gap having one or more symbols between the tracking reference signals, and the first portion and the second portion of the tracking reference signal pattern comprise a second symbol gap between at least two tracking reference signals. as well as A unit for transmitting the plurality of tracking reference signals according to the first part of the tracking reference signal pattern and the second part of the tracking reference signal pattern.

45. The apparatus of claim 44, comprising: A unit for transmitting a media access control (MAC) control element (CE) for indicating a pattern table including the tracking reference signal pattern.

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