Configuration aspects of tracking reference signal in new radio

Abstract

To provide methods, systems, and devices for wireless communications for configuration aspects of a tracking reference signal in New Radio.SOLUTION: In a wireless communication system, a base station 905 selects a first burst duration and a second burst duration for a tracking reference signal (TRS) burst, the second burst duration being different from the first burst duration, transmits configuration information indicating the first burst duration and the second burst duration to user equipment (UE), and transmits a first TRS burst having the first burst duration and a second TRS burst having the second burst duration. The UE 915 detects the first TRS burst having the first burst duration and the second TRS burst having the second burst duration based at least in part on the configuration information and performs resource tracking based at least in part on the detected first TRS burst and second TRS burst.SELECTED DRAWING: Figure 9

Description

cross reference

[0001]

[0001] This patent application claims priority to U.S. Provisional Patent Application No. 62 / 569,940 by Nam et al., entitled "Configuration Aspects of a Tracking Reference Signal in New Radio," filed October 9, 2017, and U.S. Patent Application No. 16 / 149,723 by Nam et al., entitled "Configuration Aspects of a Tracking Reference Signal in New Radio," filed October 2, 2018, each of which is assigned to the assignee of the present application. [Background technology]

[0002] The following relates generally to wireless communications, and more particularly to aspects of tracking reference signal configuration in new radios.

[0003] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasts. These systems may be capable of supporting 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) systems or LTE-Advanced (LTE-A) systems, and fifth-generation (5G) systems, sometimes referred to as New Radio (NR) systems. These systems may 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 spread OFDM (DFT-s-OFDM). A wireless multiple-access communication system may include several base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, sometimes known as user equipment (UE).

[0004]

[0004] Wireless communication systems attempt to maintain time and frequency synchronization to enable communication between communication devices, including base stations and UEs. In LTE, a base station transmits a cell-specific reference signal in every slot and resource block, and a UE within range of the base station can perform time tracking, frequency tracking, or both using the received cell-specific reference signal to maintain time and frequency synchronization with the base station. NR systems do not similarly transmit cell-specific reference signals in every slot and resource block. Instead, a base station in an NR system may transmit a tracking reference signal that a UE can use for time tracking, frequency tracking, or both. Conventional tracking reference signal transmission techniques cannot adequately balance the trade-off between time tracking and frequency tracking, resulting in degraded time and frequency synchronization, lower channel throughput due to increased tracking reference signal overhead, etc. Summary of the Invention

[0005] The described techniques relate to improved methods, systems, devices, or apparatuses that support tracking reference signal configuration aspects in new radio. Generally, the described techniques provide a tracking reference signal (TRS) configuration that enables a user equipment (UE) to maintain time and frequency synchronization with a base station while also reducing overhead resulting from the transmission of TRS bursts. A TRS is a multi-purpose reference signal that can be used for time tracking, frequency tracking, etc. The TRS configurations described herein can support multiple different usages to enable a UE to maintain time and frequency synchronization with a base station.

[0006] In some examples, the duration (e.g., length) of a TRS burst may be changed in a TRS configuration to improve resource tracking. For example, a base station may select a set of burst durations (or lengths) for a TRS burst, including a first burst duration and a second burst duration, where the first burst duration is different from the second burst duration. The base station may transmit configuration information indicating the set of burst durations to a UE. The base station may transmit a first TRS burst having the first burst duration and a second TRS burst having the second burst duration. The UE may detect the first TRS burst having the first burst duration and the second TRS burst having the second burst duration based at least in part on the configuration information, and the UE may perform resource tracking based at least in part on the detected first TRS burst and second TRS burst. In some cases, the resource tracking may be time tracking to maintain time synchronization, frequency tracking to maintain frequency synchronization, etc.

[0007] In some examples, the frequency offset of a TRS transmission may be changed in a TRS configuration to improve resource tracking. For example, a base station may select a frequency offset parameter. The frequency offset parameter may indicate an offset relative to a reference frequency and may be expressed as a number of resource elements, a frequency band, a frequency bandwidth portion, etc. In some cases, the offset may be indicated for a set of symbol indexes within a particular transmission time interval (e.g., within a slot), and the frequency offset parameter may specify an offset value for each symbol index in the set of symbol indexes. The base station may transmit configuration information indicating the frequency offset parameter to a UE, and the UE may receive the configuration information. The base station may transmit a TRS transmission having a frequency offset corresponding to the frequency offset parameter. The UE may detect a TRS transmission within the frequency band based at least in part on the frequency offset parameter and perform resource tracking based at least in part on the detected TRS transmission.

[0008] A method of wireless communication is described that may include receiving configuration information indicating a first burst duration and a second burst duration for a TRS burst, detecting the first TRS burst having the first burst duration and a second TRS burst having the second burst duration based at least in part on the configuration information, where the first burst duration differs from the second burst duration, and performing resource tracking based at least in part on the detected first TRS burst and second TRS burst.

[0009] An apparatus for wireless communications is described that may include means for receiving configuration information indicating a first burst duration and a second burst duration for a TRS burst, means for detecting a first TRS burst having the first burst duration and a second TRS burst having the second burst duration based at least in part on the configuration information, wherein the first burst duration differs from the second burst duration, and means for performing resource tracking based at least in part on the detected first TRS burst and second TRS burst.

[0010] Another apparatus for wireless communications is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to receive configuration information indicating a first burst duration and a second burst duration for a TRS burst, detect the first TRS burst having the first burst duration and the second TRS burst having the second burst duration based at least in part on the configuration information, where the first burst duration differs from the second burst duration, and perform resource tracking based at least in part on the detected first TRS burst and second TRS burst.

[0011] A non-transitory computer-readable medium for wireless communications is described, which may include instructions operable to cause a processor to receive configuration information indicating a first burst duration and a second burst duration for a TRS burst, detect the first TRS burst having the first burst duration and the second TRS burst having the second burst duration based at least in part on the configuration information, where the first burst duration differs from the second burst duration, and perform resource tracking based at least in part on the detected first TRS burst and second TRS burst.

[0012]

[0012] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for determining from the configuration information that the first burst duration corresponds to a first time interval and the second burst duration corresponds to a second time interval, the second time interval occurring after the first time interval.

[0013]

[0013] Some examples of the methods, devices, and non-transitory computer-readable media described above may further include a process, feature, means, or instruction for determining from the configuration information that transmission of TRS bursts may be scheduled to alternate between a first burst duration and a second burst duration in each time interval of a plurality of time intervals.

[0014]

[0014] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instruction for determining from the configuration information that a first resource and a second resource are allocated to the UE, wherein the first burst duration corresponds to the first resource and the second burst duration corresponds to the second resource.

[0015]

[0015] In some examples of the methods, devices, and non-transitory computer-readable media described above, determining the periodicity and time offset of the time interval from the configuration information, wherein detecting a first TRS burst having a first burst duration and a second TRS burst having a second burst duration includes monitoring, within each instance of the time interval, for a TRS burst having the first burst duration at a first location and a TRS burst having the second burst duration at a second location corresponding to the offset.

[0016]

[0016] Some examples of the methods, devices, and non-transitory computer-readable media described above may further include a process, feature, means, or instruction for determining that a first resource may be scheduled to conflict with a second resource during a transmission time interval (TTI).

[0017] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for determining a priority order of a first resource relative to a second resource based at least in part on configuration information or rules. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for monitoring for one of the first TRS burst or the second TRS burst within a TTI based at least in part on the priority order.

[0018]

[0018] Some examples of the methods, devices, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for determining at least one TRS parameter from the configuration information, wherein the at least one TRS parameter is one or more of a TRS burst duration parameter, a TRS burst periodicity parameter, a TRS tone aspect, a TRS symbol spacing parameter, a TRS number parameter, an offset parameter, and a TRS bandwidth parameter.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for: determining, from the configuration information, a plurality of burst durations and a corresponding time interval duration for each of the plurality of burst durations, wherein the plurality of burst durations comprises a first and a second burst duration. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for monitoring for a plurality of TRS bursts based at least in part on the plurality of burst durations and the corresponding time interval durations, wherein the plurality of TRS bursts comprises a first and a second TRS burst.

[0020] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for determining a frequency offset parameter from the configuration information. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for monitoring for a first TRS burst based at least in part on the frequency offset parameter.

[0021]

[0021] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for determining tone spacing from configuration information, wherein monitoring for the first TRS burst may be based at least in part on the tone spacing.

[0022] A method of wireless communication is described that may include selecting a first burst duration and a second burst duration for a TRS burst, transmitting configuration information indicating the first burst duration and the second burst duration, wherein the first burst duration differs from the second burst duration, and transmitting the first TRS burst having the first burst duration and the second TRS burst having the second burst duration.

[0023] An apparatus for wireless communications is described that may include means for selecting a first burst duration and a second burst duration for a TRS burst, means for transmitting configuration information indicating the first burst duration and the second burst duration, wherein the first burst duration differs from the second burst duration, and means for transmitting the first TRS burst having the first burst duration and the second TRS burst having the second burst duration.

[0024] Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to select a first burst duration and a second burst duration for a TRS burst, transmit configuration information indicating the first burst duration and the second burst duration, wherein the first burst duration is different from the second burst duration, and transmit the first TRS burst having the first burst duration and the second TRS burst having the second burst duration.

[0025] A non-transitory computer-readable medium for wireless communications is described, which may include instructions operable to cause a processor to select a first burst duration and a second burst duration for a TRS burst, transmit configuration information indicating the first burst duration and the second burst duration, wherein the first burst duration is different from the second burst duration, and transmit the first TRS burst having the first burst duration and the second TRS burst having the second burst duration.

[0026]

[0026] In some examples of the methods, devices, and non-transitory computer-readable media described above, transmitting the first TRS burst and the second TRS burst includes alternating between transmitting the first TRS burst and the second TRS burst in each time interval of a plurality of time intervals.

[0027]

[0027] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instruction for allocating a first resource and a second resource to a UE, wherein the configuration information indicates that each of the first resource and the second resource may be allocated to the UE.

[0028]

[0028] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for determining a time offset between a first resource and a second resource, wherein the configuration information indicates the time offset.

[0029]

[0029] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for determining a priority order of a first resource relative to a second resource, wherein the configuration information indicates the priority order.

[0030]

[0030] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for determining a plurality of burst durations and a corresponding time interval duration (e.g., a corresponding time interval length) for each of the plurality of burst durations, the plurality of burst durations including a first and a second burst duration, wherein the configuration information indicates the plurality of burst durations and the corresponding time interval durations.

[0031] A method of wireless communication is described that may include receiving configuration information indicating a frequency offset parameter, detecting a TRS transmission within a frequency band based at least in part on the frequency offset parameter, and performing resource tracking based at least in part on the detected TRS transmission.

[0032] An apparatus for wireless communications is described that may include means for receiving configuration information indicating a frequency offset parameter, means for detecting a TRS transmission within a frequency band based at least in part on the frequency offset parameter, and means for performing resource tracking based at least in part on the detected TRS transmission.

[0033] Another apparatus for wireless communications is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to receive configuration information indicating a frequency offset parameter, detect a TRS transmission within a frequency band based at least in part on the frequency offset parameter, and perform resource tracking based at least in part on the detected TRS transmission.

[0034] A non-transitory computer-readable medium for wireless communications is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to receive configuration information indicating a frequency offset parameter, detect a TRS transmission within a frequency band based at least in part on the frequency offset parameter, and perform resource tracking based at least in part on the detected TRS transmission.

[0035] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for determining tone spacing from configuration information. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for processing a frequency offset parameter and tone spacing to determine a location of at least one TRS tone of a TRS transmission within a frequency band relative to a reference frequency.

[0036] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for processing frequency offset parameters to determine a first offset value corresponding to the first TTI and a second offset value corresponding to the second TTI. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for monitoring for a TRS tone of a TRS transmission within the first TTI corresponding to the first offset value and a TRS tone of a TRS transmission within the second TTI corresponding to the second offset value.

[0037] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the frequency offset parameter indicates the offset in number of resource elements.

[0038] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the frequency offset parameter indicates a bandwidth portion of a plurality of different bandwidth portions within the system bandwidth.

[0039] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for determining a first burst duration and a second burst duration for a TRS transmission from the configuration information. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for monitoring for a TRS transmission having the first burst duration and a second TRS transmission having the second burst duration based at least in part on the configuration information.

[0040] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for determining offset values for a plurality of symbol indexes from a frequency offset parameter. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include a process, feature, means, or instructions for monitoring for a TRS tone of a TRS transmission in a plurality of respective symbol periods corresponding to the plurality of symbol indexes.

[0041] A method of wireless communication is described that may include selecting a frequency offset parameter, transmitting configuration information indicating the frequency offset parameter, and transmitting a TRS transmission having a frequency offset corresponding to the frequency offset parameter.

[0042] An apparatus for wireless communications is described that may include means for selecting a frequency offset parameter, means for transmitting configuration information indicative of the frequency offset parameter, and means for transmitting a TRS transmission having a frequency offset corresponding to the frequency offset parameter.

[0043] Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to select a frequency offset parameter, transmit configuration information indicating the frequency offset parameter, and transmit a TRS transmission having a frequency offset corresponding to the frequency offset parameter.

[0044] A non-transitory computer-readable medium for wireless communications is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to select a frequency offset parameter, transmit configuration information indicative of the frequency offset parameter, and transmit a TRS transmission having a frequency offset corresponding to the frequency offset parameter.

[0045]

[0045] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for determining tone spacing for TRS transmission, where the configuration information indicates the tone spacing.

[0046]

[0046] In some examples of the methods, devices, and non-transitory computer-readable media described above, determining a first offset value corresponding to a first TTI and a second offset value corresponding to a second TTI, wherein a frequency offset parameter indicates the first offset value and the second offset value, and transmitting a TRS transmission includes transmitting a TRS tone of the TRS transmission within the first TTI corresponding to the first offset value and transmitting a TRS tone of the TRS transmission within the second TTI corresponding to the second offset value.

[0047]

[0047] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the frequency offset parameter indicates the offset in terms of a number of resource elements.

[0048] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the frequency offset parameter indicates a bandwidth portion of a plurality of different bandwidth portions within the system bandwidth.

[0049]

[0049] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may further include processes, features, means, or instructions for determining offset values for multiple symbol indexes, wherein the configuration information indicates multiple symbol indexes. [Brief explanation of the drawings]

[0050] [Figure 1] FIG. 1 illustrates an example system for wireless communication supporting tracking reference signal configuration aspects in new radios, according to aspects of the present disclosure. [Figure 2] FIG. 1 illustrates an example wireless communication system that supports aspects of configuring a tracking reference signal in a new radio, in accordance with aspects of the present disclosure. [Figure 3] FIG. 10 illustrates an example of a TRS burst pattern configuration that supports tracking reference signal configuration aspects in a new radio, in accordance with aspects of the present disclosure. [Figure 4] FIG. 10 illustrates an example of a TRS burst pattern configuration that supports tracking reference signal configuration aspects in a new radio, in accordance with aspects of the present disclosure. [Figure 5] FIG. 10 illustrates an example of a TRS burst pattern configuration that supports tracking reference signal configuration aspects in a new radio, in accordance with aspects of the present disclosure. [Figure 6] FIG. 10 illustrates an example of a TRS burst pattern configuration that supports tracking reference signal configuration aspects in a new radio, in accordance with aspects of the present disclosure. [Figure 7] FIG. 10 illustrates an example of a TRS burst pattern configuration that supports tracking reference signal configuration aspects in a new radio, in accordance with aspects of the present disclosure. [Figure 8] FIG. 10 illustrates an example of a TRS burst pattern configuration that supports tracking reference signal configuration aspects in a new radio, in accordance with aspects of the present disclosure. [Figure 9] FIG. 10 illustrates an example process flow for supporting aspects of configuring a tracking reference signal in a new radio, in accordance with aspects of the present disclosure. [Figure 10] FIG. 10 illustrates an example process flow for supporting aspects of configuring a tracking reference signal in a new radio, in accordance with aspects of the present disclosure. [Figure 11] 1 is a block diagram of a device supporting aspects of tracking reference signal configuration in new radios, in accordance with aspects of the present disclosure. [Figure 12] 1 is a block diagram of a device supporting aspects of tracking reference signal configuration in new radios, in accordance with aspects of the present disclosure. [Figure 13] 1 is a block diagram of a device supporting aspects of tracking reference signal configuration in new radios, in accordance with aspects of the present disclosure. [Figure 14] 1 is a block diagram of a system including a UE that supports aspects of configuring a tracking reference signal in new radio, in accordance with aspects of the present disclosure. [Figure 15] 1 is a block diagram of a device supporting aspects of tracking reference signal configuration in new radios, in accordance with aspects of the present disclosure. [Figure 16] 1 is a block diagram of a device supporting aspects of tracking reference signal configuration in new radios, in accordance with aspects of the present disclosure. [Figure 17] 1 is a block diagram of a device supporting aspects of tracking reference signal configuration in new radios, in accordance with aspects of the present disclosure. [Figure 18] 1 is a block diagram of a system including a base station that supports aspects of tracking reference signal configuration in new radios, in accordance with aspects of the present disclosure. [Figure 19] 1 illustrates a method for configuration aspects of a tracking reference signal in a new radio, according to aspects of the present disclosure. [Figure 20] 1 illustrates a method for configuration aspects of a tracking reference signal in a new radio, according to aspects of the present disclosure. [Figure 21] 1 illustrates a method for configuration aspects of a tracking reference signal in a new radio, according to aspects of the present disclosure. [Figure 22] 1 illustrates a method for configuration aspects of a tracking reference signal in a new radio, according to aspects of the present disclosure. [Figure 23] 1 illustrates a method for configuration aspects of a tracking reference signal in a new radio, according to aspects of the present disclosure. [Figure 24] 1 illustrates a method for configuration aspects of a tracking reference signal in a new radio, according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0051]

[0059] The described techniques relate to an improved method, system, device, or apparatus that supports configuration aspects of tracking reference signals in new radio. A tracking reference signal (TRS) can be configured to enable a user equipment (UE) to maintain time and frequency synchronization with a base station while also reducing overhead resulting from transmitting TRS bursts. The TRS can be used for time tracking, frequency tracking, etc. The TRS configurations described herein can support multiple different usages to enable a UE to maintain time and frequency synchronization with a base station. In some cases, the TRS can be configured in higher layer signaling in a device-specific manner. In some receivers (e.g., advanced receivers), the UE can use the TRS for purposes in addition to time and / or frequency tracking, including estimating Doppler spread, delay spread, power delay profile, etc.

[0052]

[0060] In some examples, the duration (e.g., length) of a TRS burst may be changed in a TRS configuration to improve resource tracking. For example, a base station may select a set of burst durations (e.g., or a set of burst lengths) for a TRS burst including a first burst duration and a second burst duration, where the first burst duration is different from the second burst duration. The base station may transmit configuration information indicating the set of burst durations to a UE. The base station may transmit a first TRS burst having the first burst duration and a second TRS burst having the second burst duration. The UE may detect the first TRS burst having the first burst duration and the second TRS burst having the second burst duration based at least in part on the configuration information, and the UE may perform resource tracking based at least in part on the detected first TRS burst and second TRS burst. In some cases, the resource tracking may be time tracking to maintain time synchronization, frequency tracking to maintain frequency synchronization, etc.

[0053]

[0061] In some examples, the frequency offset of a TRS transmission may be changed in a TRS configuration to improve resource tracking. For example, a base station may select a frequency offset parameter. The frequency offset parameter may indicate an offset relative to a reference frequency and may be expressed as a number of resource elements, a frequency band, a frequency bandwidth portion, etc. In some cases, the offset may be indicated for a set of symbol indexes within a particular transmission time interval (e.g., within a slot), and the frequency offset parameter may specify an offset value for each symbol index in the set of symbol indexes. The base station may transmit configuration information indicating the frequency offset parameter to the UE, and the UE may receive the configuration information. The base station may transmit a TRS transmission with a frequency offset corresponding to the frequency offset parameter. The UE may detect a TRS transmission within the frequency band based at least in part on the frequency offset parameter and perform resource tracking based at least in part on the detected TRS transmission.

[0054]

[0062] Aspects of the present disclosure are first described in the context of a wireless communication system that may configure a TRS to improve a UE's ability to maintain time and frequency synchronization with a base station while also reducing overhead resulting from transmitting TRS bursts. Aspects of the present disclosure are illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts relating to configuration aspects of a tracking reference signal in a new radio environment.

[0055]

[0063] 1 illustrates an example of a wireless communication system 100 according to various aspects of the present disclosure. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, or a New Radio (NR) network. In some cases, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low-latency communications, or communications using low-cost and low-complexity devices.

[0056]

[0064] The base stations 105 may communicate wirelessly with the UEs 115 via one or more base station antennas. The base stations 105 described herein may include or be referred to by those skilled in the art as a base transceiver station, radio base station, access point, radio transceiver, Node B, eNode B (eNB), Next Generation Node B or Giga Node B (either of which may be referred to as gNB), Home Node B, Home eNode B, or some other suitable terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UEs 115 described herein may be capable of communicating with various types of base stations 105 and network equipment, including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.

[0057]

[0065] Each base station 105 may be associated with a particular geographic coverage area 110 in which communication with various UEs 115 may be supported. Each base station 105 may provide communication coverage to its respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include uplink transmissions from the UE 115 to the base station 105 or downlink transmissions from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, while uplink transmissions may also be referred to as reverse link transmissions.

[0058]

[0066] A geographic coverage area 110 for a base station 105 may be divided into sectors that make up only a portion of the geographic coverage area 110, and each sector may be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hotspot, or other type of cell, or various combinations thereof. In some examples, the base station 105 may be mobile and thus provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous LTE / LTE-A or NR network, in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0059]

[0067] The term "cell" refers to a logical communication entity used for communication with a base station 105 (e.g., via a carrier) and may be associated with an identifier (e.g., physical cell identifier (PCID), virtual cell identifier (VCID)) to distinguish adjacent cells operating over the same or different carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine-type communications (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB), etc.) that may provide access to different types of devices. In some cases, the term "cell" may refer to a portion (e.g., a sector) of a geographic coverage area 110 in which the logical entity operates.

[0060]

[0068] The UEs 115 may be dispersed throughout the wireless communication system 100, and each UE 115 may be fixed or mobile. The UEs 115 may also be referred to as mobile devices, wireless devices, remote devices, handheld devices, or subscriber devices, or some other suitable terminology, where a “device” may also be referred to as a unit, station, terminal, or client. The UEs 115 may also be personal electronic devices such as cellular phones, personal digital assistants (PDAs), tablet computers, laptop computers, or personal computers. In some examples, the UEs 115 may also refer to wireless local loop (WLL) stations, Internet of Things (IoT) devices, Internet of Everything (IoE) devices, MTC devices, etc., which may be implemented in various items such as appliances, vehicles, meters, etc.

[0061]

[0069] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automatic communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that enable devices to communicate with each other or with the base station 105 without human intervention. In some examples, M2M communication or MTC may include communication from devices that incorporate sensors or meters to measure or capture information and relay that information to a central server or application program that can utilize the information or present the information to a human interacting with the program or application. Some UEs 115 may be designed to gather information or enable automated machine behavior. Examples of 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 detection, physical access control, and transaction-based business billing.

[0062]

[0070] Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception rather than simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power conservation techniques for the UE 115 include entering a power-saving “deep sleep” mode when not engaged in active communication or operating over a limited bandwidth (e.g., pursuant to narrowband communication). In some cases, the UE 115 may be designed to support important functions (e.g., mission-critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communication for these functions.

[0063]

[0071] In some cases, the UE 115 may also be able to communicate directly with other UEs 115 (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more of a group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105 or otherwise unable to receive transmissions from the base station 105. In some cases, a group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE 115 transmits to every other UE 115 in the group. In some cases, the base station 105 facilitates scheduling of resources for D2D communication. In other cases, D2D communication occurs between UEs 115 without the involvement of the base station 105.

[0064]

[0072] The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interface with the core network 130 through backhaul links 132 (e.g., via an S1 or other interface). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130) via backhaul links 134 (e.g., via an X2 or other interface).

[0065]

[0073] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) that may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for the UEs 115 served by the base stations 105 associated with the EPC. User IP packets may be forwarded through the S-GW, which may itself be connected to a P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to network operator IP services. The operator IP services may include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or packet-switched (PS) streaming services.

[0066]

[0074] At least some of the network devices, such as the base stations 105, may include sub-components, such as access network entities, which may be an example of an access node controller (ANC). Each access network entity may communicate with the UE 115 through some other access network transmission entity, sometimes referred to as a radio head, a smart radio head, or a transmit / receive point (TRP). In some configurations, various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or integrated into a single network device (e.g., the base station 105).

[0067]

[0075] The wireless communication system 100 may generally operate using one or more frequency bands ranging from 300 MHz to 300 GHz. The 300 MHz to 3 GHz region is generally known as the ultra-high frequency (UHF) region or decimeter band because wavelengths range in length from approximately 1 decimeter to 1 meter. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may penetrate structures sufficiently for a macrocell to serve UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter distances (e.g., less than 100 km) compared to transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0068]

[0076] The wireless communication system 100 may also operate in the very high frequency (SHF) region using the frequency band from 3 GHz to 30 GHz, also known as the centimeter band. The SHF region includes bands such as the 5 GHz Industrial, Scientific, and Medical (ISM) band that may be used opportunistically by devices that can tolerate interference from other users.

[0069]

[0077] The wireless communication system 100 may also operate in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between the UE 115 and the base station 105, where the EHF antennas on each device may be even smaller and more closely spaced than the UHF antennas. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, propagation of EHF transmissions may experience greater atmospheric attenuation and shorter distances than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency regions, and the designated use of bands across these frequency regions may vary by country or regulatory body.

[0070]

[0078] In some cases, the wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ license-assisted access (LAA), LTE-unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band, such as the 5 GHz ISM band. When operating in an unlicensed radio frequency spectrum band, wireless devices such as the base station 105 and the UE 115 may employ a listen-before-talk (LBT) procedure to ensure that the frequency channel is clear before transmitting data. In some cases, operation in an unlicensed band may be based on a carrier aggregation (CA) configuration with a component carrier (CC) operating in a licensed band (e.g., LAA). Operation in the unlicensed spectrum may include downlink transmission, uplink transmission, peer-to-peer transmission, or a combination thereof. Duplexing in the unlicensed spectrum may be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both types of duplexing.

[0071]

[0079] In some examples, the base station 105 or the UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., the base station 105) and a receiving device (e.g., the UE 115), where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communications may employ multipath signal propagation to increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers, sometimes referred to as spatial multiplexing. Multiple signals may be transmitted by a transmitting device, for example, via different antennas or different combinations of antennas. Similarly, multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports used for channel measurements and reporting. MIMO techniques include single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0072]

[0080] Beamforming, sometimes referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting or receiving device (e.g., a base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming may be achieved by combining signals communicated through antenna elements of an antenna array such that signals propagating in a particular orientation relative to the antenna array experience constructive interference, while others experience destructive interference. Adjustment of signals communicated through antenna elements may include a transmitting or receiving device applying certain amplitude and phase offsets to signals carried through each of the antenna elements associated with the device. The adjustment associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., relative to the antenna array of the transmitting or receiving device, or to some other orientation).

[0073]

[0081] In one example, the base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by the base station 105 multiple times in different directions, including signals being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used (e.g., by the base station 105 or a receiving device such as the UE 115) to identify a beam direction for subsequent transmission and / or reception by the base station 105. Some signals, such as data signals associated with a particular receiving device, may be transmitted by the base station 105 in a single beam direction (e.g., a direction associated with the receiving device such as the UE 115). In some examples, the beam direction associated with a transmission along a single beam direction may be determined based at least in part on signals transmitted in different beam directions. For example, the UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report an indication of the signal it received with the best or otherwise acceptable signal quality to the base station 105. Although these techniques are described with respect to signals transmitted by the base station 105 in one or more directions, the UE 115 may employ similar techniques to transmit a signal multiple times in different directions (e.g., to identify a beam direction for subsequent transmission or reception by the UE 115) or to transmit a signal in a single direction (e.g., to transmit data to a receiving device).

[0074]

[0082] A receiving device (e.g., a UE 115, which may be an example of a mmW receiving device) may attempt multiple receive beams when receiving various signals from the base station 105, such as a synchronization signal, a reference signal, a beam selection signal, or other control signals. For example, the receiving device may attempt 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 may be referred to as “listening” according to different receive beams or receive directions. In some examples, the receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). The single receive beam may be aligned to a beam direction determined at least in part based on listening according to different receive beam directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening according to multiple beam directions).

[0075]

[0083] In some cases, the antennas of the base station 105 or the UE 115 may be located in one or more antenna arrays that may support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located on an antenna assembly such as an antenna tower. In some cases, antennas or antenna arrays associated with the base station 105 may be located at various geographic locations. The base station 105 may have an antenna array with several rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

[0076]

[0084] In some cases, the wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. The Radio Link Control (RLC) layer may perform packet segmentation and reassembly in some cases to communicate on logical channels. The Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels onto transport channels. The MAC layer may also use Hybrid Automatic Repeat Request (HARQ) to perform retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may establish, configure, and maintain an RRC connection between the UE 115 and the base station 105 or core network 130, supporting radio bearers for user plane data. In the physical (PHY) layer, transport channels may be mapped to physical channels.

[0077]

[0085] In some cases, the UE 115 and the base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. HARQ feedback is one technique that increases the likelihood that data is correctly received over the communication link 125. HARQ may 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 may improve throughput at the MAC layer in poor radio conditions (e.g., poor signal-to-noise conditions). In some cases, a wireless device may support same-slot HARQ feedback, in which the device may provide HARQ feedback in a particular slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot or according to some other time interval.

[0078]

[0086] The time interval in LTE or NR is, for example, T s The time intervals of the communication resources may be organized according to radio frames, each having a duration of 10 milliseconds (ms), where the frame period is T f =307,200T s A radio frame may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into two slots, each having a duration of 0.5 ms, and each slot may include six or seven modulation symbol periods (e.g., depending on the length of a cyclic prefix prepended to each symbol period). Excluding the cyclic prefix, each symbol period may include 2048 sampling periods. In some cases, a subframe may be the smallest scheduling unit of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In other cases, the smallest scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in a burst of shortened TTI (sTTI) or in selected component carriers using sTTI).

[0079]

[0087] In some wireless communication systems, a slot may be further divided into multiple minislots containing one or more symbols. In some cases, a symbol or minislot may be the smallest unit of scheduling. For example, each symbol may vary in duration depending on the subcarrier spacing or frequency band of operation. Additionally, some wireless communication systems may implement slot aggregation, in which multiple slots or minislots are aggregated together and used for communication between the UE 115 and the base station 105.

[0080]

[0088] The term “carrier” refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over communication link 125. For example, a carrier of communication link 125 may include a portion of a radio frequency spectrum band operating according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a predefined frequency channel (e.g., an E-UTRA Absolute Radio Frequency Channel Number (EARFCN)) and may be arranged according to a channel raster for discovery by UE 115. A carrier may be downlink or uplink (e.g., in FDD mode) or may be configured to carry downlink and uplink communications (e.g., in TDD mode). In some examples, a signal waveform transmitted over a carrier may be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as OFDM or DFT-s-OFDM).

[0081]

[0089] The organizational structure of a carrier may vary for each radio access technology (e.g., LTE, LTE-A, NR, etc.). For example, communications over a carrier may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding the user data. A carrier may also include dedicated collection signaling (e.g., synchronization signals or system information, etc.) and control signaling that coordinates operation for the carrier. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have collection or control signaling that coordinates operation for other carriers.

[0082]

[0090] Physical channels may be multiplexed on carriers according to various techniques. Physical control channels and physical data channels may be multiplexed on downlink carriers using, for example, time division multiplexing (TDM), frequency division multiplexing (FDM), or hybrid TDM-FDM techniques. In some examples, control information transmitted in physical control channels may be distributed between different control regions in a cascaded manner (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

[0083]

[0091] A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as the carrier or the “system bandwidth” of the wireless communications system 100. For example, the carrier bandwidth may be one of several predetermined bandwidths for a particular radio access technology carrier (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE 115 may be configured to operate over a portion or all of the carrier bandwidth. In other examples, some UEs 115 may be configured for operation using a narrowband protocol type associated with a predefined portion or range (e.g., a set of subcarriers or RBs) within the carrier (e.g., “in-band” deployment of a narrowband protocol type).

[0084]

[0092] In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, where the symbol period and the subcarrier spacing have an inverse relationship. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the degree of modulation scheme). Thus, the more resource elements and the higher the degree of modulation scheme that the UE 115 receives, the higher the data rate of the UE 115 may be. In a MIMO system, wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers), and the use of multiple spatial layers may further increase the data rate for communications with the UE 115.

[0085]

[0093] A device (e.g., a base station 105 or a UE 115) of the wireless communication system 100 may have a hardware configuration that supports communication over a particular carrier bandwidth or may be configurable to support communication over one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 and / or UE that can support simultaneous communication over carriers associated with two or more different carrier bandwidths.

[0086]

[0094] The wireless communication system 100 may support communication with a UE 115 over multiple cells or carriers, a feature sometimes referred to as carrier aggregation or multi-carrier operation. The UE 115 may be configured with multiple downlink CCs and one or more uplink CCs according to a carrier aggregation configuration. Carrier aggregation may be used with both FDD and TDD component carriers.

[0087]

[0095] In some cases, the wireless communication system 100 may utilize an enhanced component carrier (eCC). An eCC may be characterized by one or more features including a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC may also be configured for use in unlicensed or shared spectrum (e.g., when two or more operators are authorized to use the spectrum). An eCC characterized by a wide carrier bandwidth may include one or more segments that can be utilized by UEs 115 that are not capable of monitoring the entire carrier bandwidth or that are possibly configured to use limited carrier bandwidth (e.g., to conserve power).

[0088]

[0096] In some cases, an eCC may utilize a different symbol duration than other CCs, which may include the use of a reduced symbol duration compared to the symbol duration of other CCs. The shorter symbol duration may be associated with increased spacing between adjacent subcarriers. A device, such as a UE 115 or a base station 105, utilizing an eCC may transmit a wideband signal (e.g., according to a frequency channel or carrier bandwidth of 20, 40, 60, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC may consist of one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in a TTI) may be variable.

[0089]

[0097] Wireless communication systems, such as NR systems, may utilize any combination of licensed, shared, and unlicensed spectrum bands, among others. Flexibility in eCC symbol duration and subcarrier spacing may enable the use of eCCs across multiple spectrum bands. In some examples, NR shared spectrum improves spectrum utilization and spectral efficiency, particularly through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

[0090]

[0098] The wireless communication system 100 may configure TRS to enable the UE 115 to maintain time and frequency synchronization with the base station while also reducing overhead resulting from transmitting TRS bursts. The base station 105 may specify a TRS burst pattern configuration to indicate which slots include TRS bursts and a set of resource elements in the TRS frequency band (e.g., one or more resource blocks) that include TRS tones. For example, the base station 105 may select a set of burst durations for the TRS bursts that includes a first burst duration and a second burst duration, where the first burst duration is different from the second burst duration. The base station 105 may transmit configuration information indicating the set of burst durations to the UE 115. The base station 105 may transmit a first TRS burst having the first burst duration and a second TRS burst having the second burst duration. The UE 115 may detect a first TRS burst having a first burst duration and a second TRS burst having a second burst duration based at least in part on the configuration information, and perform resource tracking based at least in part on the detected first and second TRS bursts. The resource tracking may be time tracking to maintain time synchronization, frequency tracking to maintain frequency synchronization, etc.

[0091]

[0099] In some examples, the base station 105 may select a frequency offset parameter for a TRS transmission. The frequency offset parameter may indicate an offset relative to a reference frequency and may be expressed in terms of a number of resource elements, a frequency band, a frequency bandwidth portion, etc. In some cases, the offset may be indicated for a set of symbol indexes within a particular transmission time interval (e.g., within a slot), and the frequency offset parameter may specify an offset value for each symbol index in the set of symbol indexes. The base station 105 may transmit configuration information indicating the frequency offset parameter to the UE 115, and the UE 115 may receive the configuration information. The base station 105 may transmit a TRS transmission with a frequency offset corresponding to the frequency offset parameter. The UE 115 may detect a TRS transmission within the frequency band based at least in part on the frequency offset parameter and perform resource tracking based at least in part on the detected TRS transmission.

[0092]

[0100] FIG. 2 illustrates an example of a wireless communication system 200 that supports configuration aspects of a tracking reference signal in new radio in accordance with various aspects of the present disclosure. In some examples, the system 200 may implement aspects of the system 100. Some examples of the system 200 may be mmW wireless communication systems. The system 200 may include a base station 205 and a UE 215, which may be examples of corresponding devices described with reference to FIG. 1. The system 200 may also operate in accordance with a new radio access technology (RAT), such as a 5G new radio RAT.

[0093]

[0101] In one example, the base station 205 may select a TRS burst pattern configuration to support time and / or frequency tracking in the UE 215. The TRS burst pattern configuration may include a set of TRS configuration parameters that indicate the pattern of TRS bursts and which resource elements in one or more resource blocks contain TRS tones. The TRS tones may be transmissions on subcarriers and within symbol periods with known characteristics (e.g., known amplitude and phase), and the UE 215 may use the known characteristics for frequency and / or time tracking. A TRS burst may be a transmission of a set of TRS tones in one or more transmission time intervals (TTIs) (e.g., several symbol periods, slots, subframes, frames, etc.). For example, a TRS burst may be communicated in a resource block including a set of resource elements, where each resource element corresponds to a subcarrier and symbol period. A TRS burst may be a transmission of a set of one or more TRS tones in a subset of the set of resource elements of a resource block. The configuration information may specify the TRS burst pattern by indicating in which resource blocks and slots the TRS bursts are transmitted and which resource elements of the resource blocks contain the TRS tones.

[0094]

[0102] To indicate the TRS burst pattern, the base station 205 may select values for one or more TRS configuration parameters and may generate configuration information to indicate the selected values of each of the one or more TRS configuration parameters. The base station 205 may send the configuration information to the UE 215 and transmit one or more TRS bursts in the pattern indicated in the configuration information. The UE 215 may receive and process the configuration information and monitor for the pattern of the TRS bursts according to the configuration information.

[0095]

[0103] In some examples, the configuration information may include one or more TRS parameters that indicate aspects of a TRS burst pattern. As described further below, a TRS burst pattern may correspond to a set of slots, and a TRS burst may be transmitted in (e.g., within) selected ones of the slots. Other slots may be used to communicate control and / or data information between the base station 205 and one or more UEs 215. Control and / or data information may also be transmitted in the same slot as the TRS burst using resource elements not occupied by TRS tones. In some examples, the TRS parameters may be specific to a single burst in the TRS pattern or may apply to multiple bursts in the TRS pattern.

[0096]

[0104] In one example, the TRS burst duration parameter X may indicate the duration of a TRS burst. The duration X may be a number of TTIs (e.g., a number of symbol periods, slots, subframes, frames, etc.). The TRS burst periodicity parameter Y may indicate the duration of the TRS burst pattern in a number of TTIs. The TRS burst pattern indicated by the configuration information may repeat every Y TTIs.

[0097]

[0105] Some of the TRS parameters may also specify aspects of the TRS tones in one or more TRS bursts. f The TRS symbol spacing parameter S may indicate how many resource elements are between each subcarrier (e.g., between each tone) during a particular symbol period of a TRS burst. tThe TRS number parameter N may indicate the spacing between TRS symbols within a TTI (e.g., within a slot). The TRS number parameter N may indicate the number of symbols (e.g., OFDM symbols) per TRS burst within a TTI (e.g., within a slot). The TRS bandwidth parameter B may indicate the bandwidth in number of resource blocks (RBs) of the TRS burst. A TRS burst may therefore be a transmission of a set of one or more TRS tones in selected resource elements of one or more resource blocks indicated by the configuration information.

[0098]

[0106] In some examples, the TRS parameters described above may be configured independently for any TRS burst or series of TRS bursts. For example, a TRS parameter may be configured or changed regardless of the value and presence of any other TRS parameter. In some cases, several of the TRS parameters may be configured together. In some examples, only some of the TRS parameters are used, while in other examples, other TRS parameters are used.

[0099]

[0107] 3 illustrates an example of a TRS burst pattern configuration 300 that supports configuration aspects of tracking reference signals in new radios in accordance with various aspects of the present disclosure. In some examples, the TRS burst pattern configuration 300 may implement aspects of the wireless communication systems 100 and 200.

[0100]

[0108] FIG. 3 illustrates a set of TTIs shown as slots 330, a TRS burst pattern having a single TRS burst with a single slot duration 335, and the periodicity 340 of the TRS burst pattern. In this example, the configuration information may indicate that the TRS duration parameter X is one slot (e.g., X=1), and the periodicity parameter Y is five slots (e.g., Y=5). As shown, a TRS burst with a single slot duration is transmitted in slots 0, 5, and 10, and this pattern may repeat every five slots until a base station, such as base station 205, changes the configuration information. Base station 205 may transmit configuration information to a UE, such as UE 215, indicating that base station 205 may transmit a TRS burst with a one slot duration once every five slots. In some examples, the configuration information may be a bit sequence having a first set of bits indicating the duration X and a second set of bits indicating the periodicity parameter Y. The configuration information may also include a TRS subcarrier spacing parameter S f , the TRS symbol spacing parameter S t , a TRS number parameter N, a TRS bandwidth parameter B, etc., or any combination thereof. The UE 215 may receive and process the configuration information and monitor for TRS bursts according to the configuration information. Other TRS configurations may also be used.

[0101]

[0109] 4 illustrates an example of a TRS burst pattern configuration 400 that supports configuration aspects of tracking reference signals in new radios in accordance with various aspects of the present disclosure. In some examples, the TRS burst pattern configuration 400 may implement aspects of the wireless communication systems 100 and 200.

[0102]

[0110] FIG. 4 illustrates a set of TTIs shown as slots 330-a and a TRS burst pattern and periodicity 340-a having TRS bursts with a single slot duration 335-a. In this example, the configuration information may indicate that the TRS duration parameter X is two slots (e.g., X=2) and the TRS burst periodicity parameter Y is ten slots (e.g., Y=10). As shown, TRS bursts with a two-slot duration are transmitted in slots 0-1, 10-11, and this TRS burst pattern may repeat every ten slots until the base station 205 changes the configuration information. The base station 205 may transmit configuration information to the UE 215 indicating that the base station 205 may transmit a TRS burst with a two-slot duration once every ten slots. The configuration information may be a bit sequence having a first set of bits indicating the duration X and a second set of bits indicating the periodicity parameter Y. The configuration information also includes a TRS subcarrier spacing parameter S f , the TRS symbol spacing parameter S t , a TRS number parameter N, a TRS bandwidth parameter B, etc., or any combination thereof. The UE 215 may receive and process the configuration information and monitor for TRS bursts according to the configuration information. Other TRS configurations may also be used.

[0103]

[0111] In some examples, different TRS burst pattern configurations may provide better performance for different use cases. The TRS burst pattern in the example of FIG. 3, where {X=1, Y=5}, may be suitable for time tracking, such as determining delays for use in maintaining time synchronization, power delay profile (PDP) estimation, etc. The TRS burst pattern in the example of FIG. 4, where {X=2, Y=10}, may be suitable for frequency tracking, such as Doppler estimation for maintaining frequency synchronization. The suitability of a particular TRS burst pattern configuration for time or frequency tracking may be a function of the measurement technique applied to the tracking. In some types of measurements, correlation techniques may be applied to samples of the received signal in the frequency domain, and thus the TRS burst pattern configuration in FIG. 3 may be more suitable for time tracking. Other correlation techniques may be applied to samples of the received signal in the time domain, and thus the TRS burst pattern configuration in FIG. 4 may be more suitable for frequency tracking.

[0104]

[0112] One solution to support both time and frequency tracking may be to select a larger value for the TRS parameter X and a smaller value for the TRS parameter Y. However, the TRS overhead increases correspondingly with such a solution. For example, a TRS burst pattern configuration, where {X=2, Y=5}, may be used, but the overhead may be unacceptably high in some cases.

[0105]

[0113] According to the techniques described herein, the configuration information may indicate a TRS burst pattern, where each TRS burst in the TRS burst pattern has a different duration to support both time tracking and frequency tracking while also maintaining reasonable TRS overhead. FIG. 5 illustrates an example TRS burst pattern configuration 500 that supports configuration aspects of a tracking reference signal in a new radio in accordance with various aspects of the present disclosure. In some examples, the TRS burst pattern configuration 500 may implement aspects of wireless communication systems 100 and 200.

[0106]

[0114] FIG. 5 illustrates a TRS burst pattern configuration 500 including a set of TTIs, shown as slots 530, and TRS bursts 535-a, 535-b, each having a different duration. In this example, the configuration information may include different parameter combinations for different TRS bursts in the TRS burst pattern. Instead of the configuration information indicating a single value of duration X for all TRS bursts in the TRS burst pattern, the configuration information may specify different values of duration X for each TRS burst in the set of TRS bursts. In the illustrated example, the configuration information may specify that a first TRS burst has a duration 535-a of one slot (e.g., one TTI) and that a second TRS burst has a duration 535-b of two slots. In other examples, the configuration information may specify any desired duration for each TRS burst in the TRS burst pattern.

[0107]

[0115] As shown, a TRS burst having a duration of one slot is transmitted in slot 0, and a TRS burst having a duration of two slots is transmitted in slots 5-6. This TRS burst pattern may repeat every 10 slots until the base station 205 changes the configuration information. The base station 205 may transmit configuration information to the UE 215 indicating that the base station 205 may transmit a TRS burst having a duration of two slots once every 10 slots. The configuration information may be a bit sequence having a first set of bits indicating a duration X=1 for the first TRS burst and a second set of bits indicating a duration X=2 for the second TRS burst. Thus, the duration of the TRS bursts may vary for each TRS burst in the TRS burst pattern, and transmission of the TRS bursts may alternate with different durations in a set of time intervals corresponding to the periodicity of the TRS burst pattern. This illustrated and described example may apply to a TRS burst pattern having a set of TRS bursts including any number of TRS bursts, and the configuration information may indicate a different value of duration X for each TRS burst in the set of TRS bursts. In some cases, multiple TRS bursts in the set may have the same duration, or each TRS burst may have a different duration.

[0108]

[0116] In some examples, the configuration information may indicate TRS parameters that vary for each TRS burst in the TRS burst pattern and may be unique to each TRS burst in the TRS burst pattern. For example, for the first TRS burst in the TRS burst pattern, the configuration information may indicate a first TRS subcarrier spacing parameter S f , the first TRS symbol spacing parameter S t , a first TRS number parameter N, a first TRS bandwidth parameter B, etc., or any combination thereof. For a second TRS burst in the TRS burst pattern, the configuration information may indicate a second TRS subcarrier spacing parameter S f , the second TRS symbol spacing parameter S t, a second TRS number parameter N, a second TRS bandwidth parameter B, etc., or any combination thereof. In some cases, multiple TRS bursts in a TRS burst pattern may have the same values for one or more of the TRS parameters.

[0109]

[0117] In some examples, multiple different TRS resources may be allocated per base station-UE pair (e.g., per transmit / receive point (TRP)-UE pair). FIG. 6 illustrates an example of a TRS burst pattern configuration 600 that supports configuration aspects of a tracking reference signal in new radios in accordance with various aspects of the present disclosure. In some examples, the TRS burst pattern configuration 600 may implement aspects of wireless communication systems 100 and 200.

[0110]

[0118] In this example, the configuration information may be specific to a particular TRS resource, and multiple TRS resources may be allocated to the UE 215. Each TRS resource may define a TRS burst pattern that specifies values for one or more TRS parameters. The UE 215 may apply first configuration information corresponding to a first TRS resource, apply second configuration information corresponding to a second TRS resource, and so on. Some or all instances of the configuration information may include an additional configuration parameter Z that specifies an offset. The UE 215 may process the offset to determine which TTI to monitor for each TRS resource and the configuration of the TRS burst pattern to expect within one or more TTIs.

[0111]

[0119] 6 illustrates a set of TTIs, shown as slots 630, and TRS bursts having different durations 635-a, 635-b corresponding to different TRS resources. The TRS burst for a first TRS resource 1 is shown using a first type of shading, and the TRS burst for a second TRS resource 2 is shown using a second type of shading. In the illustrated example, the first configuration information for TRS resource 1 may specify that the TRS burst has a duration 635-a of one slot (e.g., X=1), a periodicity of 10 slots (e.g., Y=10), and an offset of zero (e.g., Z=0). The second configuration information for TRS resource 2 may specify that the TRS burst has a duration 635-a of two slots (e.g., X=2), a periodicity of 10 slots (e.g., Y=10), and an offset of five slots (e.g., Z=5). In this example, the TRS burst for TRS resource 1 occurs in slot 0, repeats in slot 10, and every 10 slots thereafter until base station 205 changes the first configuration information. The TRS burst for TRS resource 2 occurs in slots 5-6, repeats in slots 15-16, and every 10 slots thereafter until base station 205 changes the second configuration information. Note that the techniques described herein can be extended to more than two TRS resources.

[0112]

[0120] In some cases, multiple TRS resources may collide. A collision may refer to an instance when multiple TRS resources are scheduled in at least one overlapping TTI (e.g., in the same slot). In such a situation, a priority among the TRS resources may be determined. In one example, the configuration information may explicitly specify a priority order among different TRS resources, and when the UE 215 determines that there is a collision, it monitors for a TRS burst corresponding to the configuration information of the TRS resource with the highest priority in the priority order of the conflicting TRS resources. For example, if there are three TRS resources, with TRS resource 1 having the highest priority, TRS resource 2 having the next highest priority, and TRS resource 3 having the lowest priority, the UE 215 applies the configuration information for TRS resource 1 when there is a collision with any other TRS resource, and applies the configuration information for TRS resource 2 when there is a collision with TRS resource 3. The base station 205 may similarly determine which TRS resource priority order to use to transmit a TRS burst when multiple TRS bursts collide. The base station 205 or the UE 215 may assign a priority order to the bursts. In one example, bursts with longer durations may be given higher priority. In another example, bursts with shorter durations may be given higher priority. Other examples assign priority to bursts based on other characteristics described herein.

[0113]

[0121] In another example, the UE 215 may apply one or more rules to implicitly determine a priority order among the TRS resources. For example, the priority order may be based on the values of the TRS parameters. The UE 215 may determine the value of the TRS parameter for each TRS resource and determine a priority order based on the determined values. For example, if TRS resources having durations X=1 and X=2 respectively collide, the TRS resource with X=2 may be determined to have a higher priority according to a rule indicating that a TRS parameter with a larger value is prioritized. In another example, a TRS parameter with a smaller value may be determined to have a higher priority. If there is a tie, the values of different TRS parameters may similarly be used to determine the relative priority among the TRS resources. The base station 205 may determine what TRS resources to use when transmitting a TRS burst based on the priority order, and the UE 215 may determine what TRS resources to expect when receiving a TRS burst based on the priority order.

[0114]

[0122] In some examples, a single TRS resource may be defined, and the configuration information may indicate a sequence of values for the TRS parameter in a TRS burst pattern instead of defining a single value for the TRS parameter. In one example, the configuration information may define a sequence of values for each TRS parameter, and a TRS burst may be communicated in the TRS burst pattern according to the sequence. For example, the TRS burst pattern shown in FIG. 6 may be defined by indicating a sequence of values duration X={1, 2} and time interval Y={5, 5} in the configuration information. Thus, in the first five time slots, the duration of the TRS burst is one slot, and in the second five time slots, the duration of the TRS burst is two slots. The TRS burst pattern may then repeat.

[0115]

[0123] In some examples, the configuration information may indicate a sequence of values of TRS parameters of any desired duration to define any type of TRS burst pattern. For example, more complex sequences for TRS burst patterns may be defined (e.g., X={1, 2, 1, 1, 2}, Y={5, 5, 10, 10, 5}). The TRS burst pattern may repeat according to the indicated sequence of values of each TRS parameter until the base station 205 changes the configuration information. In some examples, a maximum duration sequence of values of one or more TRS parameters may be defined. Thus, each burst duration X may be associated with a corresponding time interval duration Y, and the base station 205 may transmit, and the UE 215 may receive, a TRS burst having the respective duration during each time interval of duration Y.

[0116]

[0124] The techniques described herein may also support frequency hopping. FIG. 7 illustrates an example of a TRS burst pattern configuration 700 that supports configuration aspects of a tracking reference signal in a new radio in accordance with various aspects of the present disclosure. In some examples, the TRS burst pattern configuration 700 may implement aspects of the wireless communication systems 100 and 200. In TRS hopping, the frequency of one or more tones of a TRS transmission may vary over time, and the configuration information may include a TRS parameter that indicates the hopping pattern. In one example, the hopping pattern may be a tone hopping pattern. In one example, the configuration information may include a TRS frequency shift parameter O, alone or in combination with any of the TRS parameters described herein. f The TRS tone spacing parameter S f The configuration information may indicate the TRS tone locations within the TRS band within a particular TRS symbol, along with the TRS frequency shift parameter O f may be defined as a sequence of values that defines a frequency hopping pattern of TRS tones within one or more transmission time intervals (e.g., within a single slot).

[0117]

[0125] FIG. 7 illustrates resource grids 705-a and 705-b, with frequency on the y-axis and time on the x-axis. Each box in the resource grid 705 may represent a resource element corresponding to a single subcarrier (e.g., tone) and a single TTI (e.g., symbol period, OFDM symbol period, etc.). The bandwidth for communicating the TRS burst may correspond to a particular TRS frequency band, which may include one or more resource blocks. In this example, the TRS frequency band for each of the resource grids 705 may correspond to a single resource block including 12 subcarriers (e.g., subcarriers 0 through 11). A slot may be defined to include 14 symbol periods, and the resource grid 705 may represent one slot (e.g., symbol periods 0 through 13).

[0118]

[0126] TRS frequency shift parameter f may define an offset relative to a reference frequency (e.g., an offset relative to a subcarrier of a particular reference element). The reference frequency may be the frequency of a subcarrier within resource grid 705 (e.g., subcarrier 11). In the illustrated example for resource grid 705-a, the configuration information includes a TRS frequency shift parameter O f has a value of 1 (e.g., O f = 1) and the TRS tone spacing parameter S f has a value of 4 (for example, S f = 4) and the TRS symbol spacing parameter S t has a value of 7 (for example, S t In some cases, the TRS symbol spacing parameter S tmay indicate the distance between two TRS symbols in the same slot, and the location of the starting symbol index may be specified or indicated in the configuration information. In some cases, the configuration information may specify an offset value for each symbol index in the set of symbol indexes. In the illustrated example in resource grid 705-a, the starting symbol index may indicate symbol 3. Thus, the configuration information may indicate that a TRS tone is communicated in subcarrier 1 in symbol period 3 in resource grid 705-a, and an additional TRS tone is communicated in symbol period 3 spaced apart by four subcarriers in resource grid 705-a. Thus, a TRS tone is also located in resource elements in symbol period 3 on subcarriers 5 and 9. In this example, the TRS symbol spacing parameter S t has a value of 7, and therefore the TRS tone is communicated in subcarriers 1, 5, and 9 of symbol period 10.

[0119]

[0127] In some examples, the configuration information may include, for a TRS burst pattern, a TRS frequency shift parameter O to support frequency hopping of the TRS tones. f In resource grid 705-b, the TRS frequency shift parameter O f may vary from slot to slot or from TRS symbol index to TRS symbol index within a slot. In the illustrated example, the TRS frequency shift parameter O f may have a value of 3 during the first TRS symbol period of a slot (e.g., at symbol index 3) and a value of 1 during the second TRS symbol period of the same slot. Thus, a TRS tone is communicated in subcarriers 3, 6, and 11 of symbol period 3 of a slot in grid 705-b, and a TRS tone is communicated in subcarriers 1, 5, and 9 of symbol period 10 of a slot in grid 705-b. Beneficially, multiple TRS tones with different frequency offsets (e.g., different frequency shifts) may be communicated in the same slot to achieve increased pull-in range in delay spread estimation, PDP estimation, etc. S fResource grid 705-b has a subcarrier spacing of S = 4 and uses frequency hopping of 2 resource elements. f = 2. Thus, the same estimation range can be obtained while using half the number of TRS tones, thereby significantly reducing the TRS tone overhead while maintaining comparable performance.

[0120]

[0128] Some of the benefits of frequency hopping may also be obtained on a larger bandwidth scale. FIG. 8 illustrates an example of a TRS burst pattern configuration 800 that supports configuration aspects of a tracking reference signal in new radios according to various aspects of the present disclosure. In some examples, the TRS burst pattern configuration 800 may implement aspects of the wireless communication systems 100 and 200. TRS subband hopping may be applied when a small bandwidth TRS resource can be configured with subband hopping to cover a wider bandwidth. For example, the bandwidth of a TRS resource may be defined to include several or more sets of resource blocks that make up a portion of a bandwidth portion or an entire bandwidth portion. The system bandwidth may include a set of distinct bandwidth portions.

[0121]

[0129] The configuration information may include configuration parameters indicating the frequency offset and / or hopping pattern being used. For example, a bandwidth portion may be divided into a set of available TRS bandwidths, and the configuration information may specify a hopping pattern for TRS bursts. The TRS bursts may hop from the available TRS bandwidth to a bandwidth according to the hopping pattern. The configuration information may identify one or more slots and one or more available bandwidths for TRS transmission. A TRS transmission may include one or more TRS bursts. In the illustrated example, three available TRS bandwidths may be defined (e.g., TRS BW0, 1, and 2). The configuration information may specify that TRS transmissions are communicated in TRS BW2 in slot 0, in TRS BW1 in slot 5, and in TRS BW0 in slot 10. The hopping pattern for TRS transmissions may repeat every 15 slots until the base station changes the configuration information. The configuration information may define other hopping patterns. In another example, the system bandwidth may be divided into a set of available bandwidth portions, and the configuration information may specify a hopping pattern for TRS bursts. The TRS burst may hop from bandwidth portion to bandwidth portion according to a hopping pattern. The TRS parameters described herein may also vary from slot to slot.

[0122]

[0130] 9 illustrates an example process flow 900 that supports aspects of configuring a tracking reference signal in a new radio in accordance with various aspects of the present disclosure. In some examples, the process flow 900 may implement aspects of the wireless communication systems 100 and 200. The base station 905 is an example of a base station 105, 205, and the UE 915 is an example of a UE 115, 215.

[0123]

[0131] At 920, the base station 905 may select a set of burst durations for the TRS burst including a first burst duration and a second burst duration, where the first burst duration is different from the second burst duration. In other examples, three or more burst durations may be selected.

[0124]

[0132] At 925, the base station 905 may transmit configuration information to the UE 915 indicating a set of burst durations including a first burst duration and a second burst duration. In some cases, the base station 905 may allocate a set of TRS resources including a first TRS resource and a second TRS resource to the UE 915, where the configuration information indicates each of the set of resources allocated to the UE 915. In some cases, the base station 905 may determine a time offset between the first resource and the second resource, where the configuration information indicates the time offset. In some cases, the base station 905 may determine a priority order of the first resource relative to the second resource, where the configuration information indicates the priority order.

[0125]

[0133] At 930, the UE 915 may receive and process the configuration information. In some examples, the UE 915 may determine from the configuration information that the first burst duration corresponds to a first time interval and the second burst duration corresponds to a second time interval, the second time interval occurring after the first time interval. In some examples, the UE 915 may determine from the configuration information that transmission of TRS bursts is scheduled to alternate between the first burst duration and the second burst duration in each time interval of the set of time intervals. In some cases, the UE 915 may determine from the configuration information that the first burst duration corresponds to a first resource and the second burst duration corresponds to a second resource.

[0126]

[0134] At 935, the base station 905 may transmit a first TRS burst having a first burst duration according to the configuration information. At 940, the UE 915 may monitor and detect for the first TRS burst having the first burst duration according to the configuration information.

[0127]

[0135] At 945, the base station 905 may transmit a second TRS burst having a second burst duration in accordance with the configuration information. In some cases, the base station 905 may alternate between transmitting the first TRS burst and the second TRS burst in each time interval of the set of time intervals. At 950, the UE 915 may monitor and detect for a second TRS burst having a second burst duration in accordance with the configuration information.

[0128]

[0136] At 955, the UE 915 may perform resource tracking based at least in part on the detected first and second TRS bursts. The resource tracking may be time tracking to maintain time synchronization, frequency tracking to maintain frequency synchronization, etc. The UE 915 may also process the received TRS tones for one or more of a Doppler spread estimation, a power delay profile (PDP) estimation, a delay estimation, etc.

[0129]

[0137] 10 illustrates an example process flow 1000 that supports aspects of configuring a tracking reference signal in a new radio in accordance with various aspects of the present disclosure. In some examples, the process flow 1000 may implement aspects of the wireless communication systems 100 and 200. The base station 1005 is an example of a base station 105, 205, 905, and the UE 1015 is an example of a UE 115, 215, 1015.

[0130]

[0138] At 1020, the base station 1005 may select a frequency offset parameter. The frequency offset parameter may indicate an offset relative to a reference frequency (e.g., subcarriers of a particular reference element) and may be expressed in terms of a number of resource elements, a frequency band, a frequency bandwidth portion, etc. In some cases, the base station 1005 may determine a first offset value (e.g., an offset value for a first symbol period of a slot) and a second offset value (e.g., an offset value for a second, different symbol period of the slot), where the frequency offset parameter indicates the first offset value and the second offset value. In some cases, the offset may be indicated for a set of symbol indexes within a particular transmission time interval (e.g., within a slot), and the frequency offset parameter may specify an offset value for each symbol index in the set of symbol indexes.

[0131]

[0139] At 1025, the base station 1005 may transmit configuration information indicating the frequency offset parameter to the UE 1015, and the UE 1015 may receive the configuration information. In some cases, the base station 1005 may determine tone spacing for TRS transmission, and the configuration information may indicate the tone spacing.

[0132]

[0140] At 1030, the UE 1015 may receive and process the configuration information. At 1035, the base station 1005 may transmit a TRS transmission having a frequency offset corresponding to the frequency offset parameter. At 1040, the UE 1015 may monitor and detect for a TRS transmission within the frequency band based at least in part on the frequency offset parameter. At 1045, the UE 1015 may perform resource tracking based at least in part on the detected TRS transmission.

[0133]

[0141] Beneficially, the techniques described herein provide a TRS burst pattern configuration that enables a UE to perform resource tracking while managing TRS overhead.

[0134]

[0142] 11 illustrates a block diagram 1100 of a wireless device 1105 that supports aspects of configuring a tracking reference signal in new radios in accordance with aspects of the present disclosure. The wireless device 1105 may be an example of aspects of a user equipment (UE) 115 described herein. The wireless device 1105 may include a receiver 1110, a UE communications manager 1115, and a transmitter 1120. The wireless device 1105 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0135]

[0143] The receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., information related to configuration aspects of the control channel, data channel, and tracking reference signal in the radio). The information may be passed to other components of the device. The receiver 1110 may be an example of an aspect of the transceiver 1435 described with reference to FIG. 14. The receiver 1110 may utilize a single antenna or a set of antennas.

[0136]

[0144] The UE communications manager 1115 may be an example of an aspect of the UE communications manager 1415 described with reference to FIG.

[0137]

[0145] The UE communications manager 1115 and / or at least some of its various subcomponents may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the UE communications manager 1115 and / or at least some of its various subcomponents may be performed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in this disclosure. The UE communications manager 1115 and / or at least some of its various subcomponents may be physically located in various locations, including being distributed such that portions of the functionality are implemented by one or more physical devices at different physical locations. In some examples, the UE communications manager 1115 and / or at least some of its various subcomponents may be separate and distinct components according to various aspects of the present disclosure. In other examples, the UE communications manager 1115 and / or at least some of its various subcomponents may be combined with one or more other hardware components, including, but not limited to, an I / O component, a transceiver, a network server, another computing device, one or more other components described in this disclosure, or combinations thereof, in accordance with various aspects of the present disclosure.

[0138]

[0146] The UE communications manager 1115 may receive configuration information indicating a first burst duration and a second burst duration for a TRS burst, detect the first TRS burst having the first burst duration and the second TRS burst having the second burst duration based on the configuration information, where the first burst duration is different from the second burst duration, and perform resource tracking based on the detected first TRS burst and second TRS burst. The UE communications manager 1115 may also receive configuration information indicating a frequency offset parameter, detect a TRS transmission in the frequency band based on the frequency offset parameter, and perform resource tracking based on the detected TRS transmission.

[0139]

[0147] The transmitter 1120 may transmit signals generated by other components of the device. In some examples, the transmitter 1120 may be co-located with the receiver 1110 in a transceiver module. For example, the transmitter 1120 may be an example of an aspect of the transceiver 1435 described with reference to FIG. 14. The transmitter 1120 may utilize a single antenna or a set of antennas.

[0140]

[0148] 12 illustrates a block diagram 1200 of a wireless device 1205 that supports aspects of configuring a tracking reference signal in new radio in accordance with aspects of the present disclosure. The wireless device 1205 may be an example of aspects of the wireless device 1105 or the UE 115 described with reference to FIG. 11. The wireless device 1205 may include a receiver 1210, a UE communications manager 1215, and a transmitter 1220. The wireless device 1205 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0141]

[0149] The receiver 1210 may receive information such as packets, user data, or control information associated with various information channels (e.g., information related to configuration aspects of the control channel, data channel, and tracking reference signal in the radio). The information may be passed to other components of the device. The receiver 1210 may be an example of an aspect of the transceiver 1435 described with reference to FIG. 14. The receiver 1210 may utilize a single antenna or a set of antennas.

[0142]

[0150] The UE communications manager 1215 may be an example of an aspect of the UE communications manager 1415 described with reference to FIG. 14. The UE communications manager 1215 may also include a configuration component 1225, a detection component 1230, and a tracking component 1235.

[0143]

[0151] The configuration component 1225 may receive configuration information indicating a first burst duration and a second burst duration for the TRS burst, where the first burst duration differs from the second burst duration, and may determine from the configuration information the first burst duration and the second burst duration for the TRS transmission. The configuration component 1225 may determine from the configuration information that transmission of the TRS burst is scheduled to alternate between the first burst duration and the second burst duration in each time interval of a set of time intervals, and may determine from the configuration information a set of burst durations and a corresponding time interval duration for each of the set of burst durations, where the set of burst durations includes the first and second burst durations.

[0144]

[0152] The configuration component 1225 may determine one or both of a frequency offset parameter and a tone spacing from the configuration information. In some cases, monitoring for the first TRS burst is based on the tone spacing. The configuration component 1225 may determine from the configuration information that the first burst duration corresponds to a first time interval and the second burst duration corresponds to a second time interval, the second time interval occurring after the first time interval, and may process the frequency offset parameter and the tone spacing to determine a location of at least one TRS tone of the TRS transmission within the frequency band relative to a reference frequency.

[0145]

[0153] The configuration component 1225 may process the frequency offset parameters to determine a first offset value corresponding to the first TTI and a second offset value corresponding to the second TTI, and may receive configuration information indicating the frequency offset parameters. The configuration component 1225 may determine offset values for multiple symbol indexes from the frequency offset parameters. The configuration component 1225 may monitor for a TRS tone of the TRS transmission in multiple respective symbol periods corresponding to the multiple symbol indexes.

[0146]

[0154] Possibly determining a periodicity and a time offset of the time intervals from the configuration information. The frequency offset parameter may indicate an offset in number of resource elements. Possibly, the frequency offset parameter indicates a bandwidth portion of a set of different bandwidth portions within the system bandwidth.

[0147]

[0155] The detection component 1230 may detect a first TRS burst having a first burst duration and a second TRS burst having a second burst duration based on the configuration information, and may monitor within each instance of the time interval for a TRS burst having the first burst duration at a first location and a TRS burst having the second burst duration at a second location corresponding to the offset. The detection component 1230 may monitor for one of the first TRS burst or the second TRS burst within the TTI based on a priority order, and may monitor for a set of TRS bursts based on a set of burst durations and corresponding time interval durations, the set of TRS bursts including the first and second TRS bursts. The detection component 1230 may monitor for a first TRS burst based on the frequency offset parameter and may monitor for a TRS tone of the TRS transmission within a first TTI corresponding to the first offset value and a TRS tone of the TRS transmission within a second TTI corresponding to the second offset value. The detection component 1230 may detect a TRS transmission within the frequency band based on the frequency offset parameter and may monitor for a TRS transmission having a first burst duration and a second TRS transmission having a second burst duration based on the configuration information.

[0148]

[0156] The tracking component 1235 may perform resource tracking based on the detected first and second TRS bursts and may perform resource tracking based on the detected TRS transmission.

[0149]

[0157] The transmitter 1220 may transmit signals generated by other components of the device. In some examples, the transmitter 1220 may be co-located with the receiver 1210 in a transceiver module. For example, the transmitter 1220 may be an example of an aspect of the transceiver 1435 described with reference to FIG. 14. The transmitter 1220 may utilize a single antenna or a set of antennas.

[0150]

[0158] 13 illustrates a block diagram 1300 of a UE communications manager 1315 that supports configuration aspects of a tracking reference signal in new radio in accordance with aspects of the present disclosure. The UE communications manager 1315 may be an example of aspects of the UE communications manager 1115, the UE communications manager 1215, or the UE communications manager 1415 described with reference to FIGS. 11, 12, and 14. The UE communications manager 1315 may include a configuration component 1320, a detection component 1325, a tracking component 1330, a resource allocator 1335, a collision detector 1340, and a priority component 1345. Each of these modules may communicate with one another directly or indirectly (e.g., via one or more buses).

[0151]

[0159] The configuration component 1320 may receive configuration information indicating a first burst duration and a second burst duration for a TRS burst, where the first burst duration is different from the second burst duration. The configuration component 1320 may determine from the configuration information the first burst duration and the second burst duration for the TRS transmission and may determine from the configuration information that transmission of the TRS bursts is scheduled to alternate between the first burst duration and the second burst duration in each time interval of a set of time intervals. The configuration component 1320 may determine from the configuration information a set of burst durations and a corresponding time interval duration for each of the set of burst durations, where the set of burst durations includes the first and second burst durations.

[0152]

[0160] The configuration component 1320 may determine a frequency offset parameter and a tone spacing from the configuration information. In some cases, monitoring for a first TRS burst is based on the tone spacing. The configuration component 1320 may determine from the configuration information that the first burst duration corresponds to a first time interval and the second burst duration corresponds to a second time interval, the second time interval occurring after the first time interval. The configuration component 1320 may process the frequency offset parameter and the tone spacing to determine a location of at least one TRS tone of the TRS transmission within the frequency band relative to a reference frequency. In some cases, the configuration component 1320 may process the frequency offset parameter to determine a first offset value corresponding to the first TTI and a second offset value corresponding to the second TTI and receive configuration information indicating the frequency offset parameter. In some cases, determine a periodicity and a time offset of the time intervals from the configuration information. In some cases, the frequency offset parameter indicates an offset by some resource elements. In some cases, the frequency offset parameter indicates a bandwidth portion of a set of different bandwidth portions within the system bandwidth.

[0153]

[0161] The detection component 1325 may detect a first TRS burst having a first burst duration and a second TRS burst having a second burst duration based on the configuration information, and may monitor within each instance of the time interval for a TRS burst having the first burst duration at a first location and a TRS burst having the second burst duration at a second location corresponding to the offset. The detection component 1325 may monitor for one of the first TRS burst or the second TRS burst within the TTI based on a priority order, and may monitor for a set of TRS bursts based on a set of burst durations and corresponding time interval durations, the set of TRS bursts including the first and second TRS bursts. The detection component 1325 may monitor for a first TRS burst based on the frequency offset parameter and may monitor for a TRS tone of the TRS transmission within a first TTI corresponding to the first offset value and a TRS tone of the TRS transmission within a second TTI corresponding to the second offset value. The detection component 1325 may detect a TRS transmission within the frequency band based on the frequency offset parameter and may monitor for a TRS transmission having a first burst duration and a second TRS transmission having a second burst duration based on the configuration information.

[0154]

[0162] The tracking component 1330 may perform resource tracking based on the detected first and second TRS bursts and may perform resource tracking based on the detected TRS transmission.

[0155]

[0163] The resource allocator 1335 may determine from the configuration information that a first resource and a second resource are allocated to the UE, where the first burst duration corresponds to the first resource and the second burst duration corresponds to the second resource.

[0156]

[0164] The collision detector 1340 may determine that a first resource is scheduled to collide with a second resource during the TTI.

[0157]

[0165] The priority component 1345 may determine a priority order of the first resource relative to the second resource from the configuration information and may determine a priority order of the first resource relative to the second resource based on one or more rules.

[0158]

[0166] 14 illustrates a diagram of a system 1400 including a device 1405 supporting aspects of configuring a tracking reference signal over new radios in accordance with aspects of the present disclosure. The device 1405 may be, or may include, an example of components of the wireless device 1105, the wireless device 1205, or the UE 115 described above with reference to FIGS. 11 and 12, for example. The device 1405 may include components for two-way voice and data communication, including components for transmitting and receiving communications, including a UE communications manager 1415, a processor 1420, a memory 1425, software 1430, a transceiver 1435, an antenna 1440, and an I / O controller 1445. These components may be in electronic communication via one or more buses (e.g., bus 1410). The device 1405 may communicate wirelessly with one or more base stations 105.

[0159]

[0167] The processor 1420 may 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, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 1420 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be incorporated into the processor 1420. The processor 1420 may be configured to execute computer-readable instructions stored in memory to perform various functions (e.g., functions or tasks supporting configuration aspects of tracking reference signals in new radios).

[0160]

[0168] The memory 1425 may include random access memory (RAM) and read-only memory (ROM). The memory 1425 may store computer-readable, computer-executable software 1430 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1425 may include a basic input / output system (BIOS), which may control basic hardware or software operations such as interaction with peripheral components or devices, among other things.

[0161]

[0169] The software 1430 may include code for implementing aspects of the present disclosure, including code for supporting configuration aspects of tracking reference signals in new radios. The software 1430 may be stored in a non-transitory computer-readable medium, such as system memory or other memory. In some cases, the software 1430 may not be directly executable by a processor, but may (e.g., when compiled and executed) cause a computer to perform functions described herein.

[0162]

[0170] The transceiver 1435 may communicate bidirectionally via one or more antennas, wired links, or wireless links, as described above. For example, the transceiver 1435 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1435 may also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and for demodulating packets received from the antenna.

[0163]

[0171] In some cases, a wireless device may include a single antenna 1440. However, in some cases, the device may have two or more antennas 1440 that may be capable of simultaneously transmitting or receiving multiple wireless transmissions.

[0164]

[0172] The I / O controller 1445 may manage input and output signals for the device 1405. The I / O controller 1445 may also manage peripherals not built into the device 1405. In some cases, the I / O controller 1445 may represent a physical connection or port to an external peripheral. In some cases, the I / O controller 1445 may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS / 2®, UNIX®, LINUX®, or another known operating system. In other cases, the I / O controller 1445 may represent or interact with a modem, keyboard, mouse, touchscreen, or similar device. The I / O controller 1445 may be implemented as part of a processor. In some examples, a user may interact with the device 1405 through the I / O controller 1445 or through hardware components controlled by the I / O controller 1445.

[0165]

[0173] 15 illustrates a block diagram 1500 of a wireless device 1505 that supports aspects of configuring a tracking reference signal over new radios in accordance with aspects of the present disclosure. The wireless device 1505 may be an example of aspects of a base station 105 described herein. The wireless device 1505 may include a receiver 1510, a base station communications manager 1515, and a transmitter 1520. The wireless device 1505 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0166]

[0174] The receiver 1510 may receive information such as packets, user data, or control information associated with various information channels (e.g., information related to configuration aspects of the control channel, data channel, and tracking reference signal in the radio). The information may be passed on to other components of the device. The receiver 1510 may be an example of an aspect of the transceiver 1835 described with reference to FIG. 18. The receiver 1510 may utilize a single antenna or a set of antennas.

[0167]

[0175] The base station communications manager 1515 may be an example of an aspect of the base station communications manager 1815 described with reference to FIG.

[0168]

[0176] The base station communications manager 1515 and / or at least some of its various subcomponents may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the base station communications manager 1515 and / or at least some of its various subcomponents may be performed by a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, individual hardware components, or any combination thereof designed to perform the functions described in this disclosure. The base station communications manager 1515 and / or at least some of its various subcomponents may be physically located in various locations, including being distributed such that portions of the functionality are implemented by one or more physical devices at different physical locations. In some examples, the base station communications manager 1515 and / or at least some of its various subcomponents may be separate and distinct components according to various aspects of the present disclosure. In other examples, the base station communications manager 1515 and / or at least some of its various subcomponents may be combined with one or more other hardware components, including, but not limited to, an I / O component, a transceiver, a network server, another computing device, one or more other components described in this disclosure, or combinations thereof, in accordance with various aspects of the disclosure.

[0169]

[0177] The base station communications manager 1515 may select a first burst duration and a second burst duration for the TRS burst, transmit configuration information indicating the first burst duration and the second burst duration, where the first burst duration is different from the second burst duration, and transmit the first TRS burst having the first burst duration and the second TRS burst having the second burst duration. The base station communications manager 1515 may also select a frequency offset parameter, transmit configuration information indicating the frequency offset parameter, and transmit a TRS transmission with a frequency offset corresponding to the frequency offset parameter.

[0170]

[0178] The transmitter 1520 may transmit signals generated by other components of the device. In some examples, the transmitter 1520 may be co-located with the receiver 1510 in a transceiver module. For example, the transmitter 1520 may be an example of an aspect of the transceiver 1835 described with reference to FIG. 18. The transmitter 1520 may utilize a single antenna or a set of antennas.

[0171]

[0179] 16 illustrates a block diagram 1600 of a wireless device 1605 that supports aspects of configuring a tracking reference signal over new radios in accordance with aspects of the present disclosure. The wireless device 1605 may be an example of aspects of the wireless device 1505 or base station 105 described with reference to FIG. 15. The wireless device 1605 may include a receiver 1610, a base station communications manager 1615, and a transmitter 1620. The wireless device 1605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0172]

[0180] The receiver 1610 may receive information such as packets, user data, or control information associated with various information channels (e.g., information related to configuration aspects of the control channel, data channel, and tracking reference signal in the radio). The information may be passed on to other components of the device. The receiver 1610 may be an example of an aspect of the transceiver 1835 described with reference to FIG. 18. The receiver 1610 may utilize a single antenna or a set of antennas.

[0173]

[0181] The base station communications manager 1615 may be an example of an aspect of the base station communications manager 1815 described with reference to Figure 18. The base station communications manager 1615 may also include a selector component 1625, a configuration component 1630, a burst component 1635, and a TRS communicator 1640.

[0174]

[0182] The selector component 1625 may select a first burst duration and a second burst duration for the TRS burst, the first burst duration being different from the second burst duration, select a frequency offset parameter, and determine a tone spacing for the TRS transmission, where the configuration information indicates the tone spacing. The selector component 1625 may determine an offset value for a set of symbol indexes, where the configuration information indicates a plurality of symbol indexes. In some cases, determining a first offset value corresponding to a first TTI and a second offset value corresponding to a second TTI, where the frequency offset parameter indicates the first offset value and the second offset value, where transmitting the TRS transmission includes transmitting a TRS tone of the TRS transmission within the first TTI corresponding to the first offset value and transmitting a TRS tone of the TRS transmission within the second TTI corresponding to the second offset value. In some cases, the frequency offset parameter indicates an offset by several resource elements. In some cases, the frequency offset parameter indicates a bandwidth portion of a set of different bandwidth portions within the system bandwidth.

[0175]

[0183] The configuration component 1630 may transmit configuration information indicating the first burst duration and the second burst duration, and may transmit configuration information indicating a frequency offset parameter.

[0176]

[0184] The burst component 1635 may transmit a first TRS burst having a first burst duration and a second TRS burst having a second burst duration. In some cases, transmitting the first TRS burst and the second TRS burst includes alternating transmission of the first TRS burst and the second TRS burst in each time interval of the set of time intervals.

[0177]

[0185] The TRS communicator 1640 may transmit a TRS transmission having a frequency offset corresponding to the frequency offset parameter.

[0178]

[0186] The transmitter 1620 may transmit signals generated by other components of the device. In some examples, the transmitter 1620 may be co-located with the receiver 1610 in a transceiver module. For example, the transmitter 1620 may be an example of an aspect of the transceiver 1835 described with reference to FIG. 18. The transmitter 1620 may utilize a single antenna or a set of antennas.

[0179]

[0187] 17 illustrates a block diagram 1700 of a base station communications manager 1715 that supports configuration aspects of tracking reference signals in new radios in accordance with aspects of the present disclosure. The base station communications manager 1715 may be an example of an aspect of the base station communications manager 1815 described with reference to FIGS. 15, 16, and 18. The base station communications manager 1715 may include a selector component 1720, a configuration component 1725, a burst component 1730, a TRS communicator 1735, an allocation component 1740, an offset component 1745, and a priority determiner 1750. Each of these modules may communicate with one another directly or indirectly (e.g., via one or more buses).

[0180]

[0188] The selector component 1720 may select a first burst duration and a second burst duration for the TRS burst, the first burst duration being different from the second burst duration, select a frequency offset parameter, and determine a tone spacing for the TRS transmission, where the configuration information indicates the tone spacing. In some cases, determining a first offset value corresponding to the first TTI and a second offset value corresponding to the second TTI, where the frequency offset parameter indicates the first offset value and the second offset value, where transmitting the TRS transmission includes transmitting a TRS tone of the TRS transmission within the first TTI corresponding to the first offset value and transmitting a TRS tone of the TRS transmission within the second TTI corresponding to the second offset value. In some cases, the frequency offset parameter indicates an offset by a number of resource elements. In some cases, the frequency offset parameter indicates a bandwidth portion of a set of different bandwidth portions within the system bandwidth.

[0181]

[0189] The configuration component 1725 may transmit configuration information indicating a first burst duration and a second burst duration, and may transmit configuration information indicating a frequency offset parameter. The configuration component 1725 may determine a plurality of burst durations and a corresponding time interval duration for each of the plurality of burst durations, the plurality of burst durations including the first and second burst durations, where the configuration information indicates the plurality of burst durations and the corresponding time interval durations.

[0182]

[0190] The burst component 1730 may transmit a first TRS burst having a first burst duration and a second TRS burst having a second burst duration. In some cases, transmitting the first TRS burst and the second TRS burst includes alternating transmission of the first TRS burst and the second TRS burst in each time interval of the set of time intervals.

[0183]

[0191] The TRS communicator 1735 may transmit a TRS transmission having a frequency offset corresponding to the frequency offset parameter.

[0184]

[0192] The allocation component 1740 may allocate a first resource and a second resource to the UE, where the configuration information indicates that each of the first resource and the second resource is allocated to the UE.

[0185]

[0193] The offset component 1745 may determine a time offset between the first resource and the second resource, where the configuration information indicates the time offset.

[0186]

[0194] The priority determiner 1750 may determine a priority order of the first resource relative to the second resource, where the configuration information indicates the priority order.

[0187]

[0195] 18 illustrates a diagram of a system 1800 including a device 1805 supporting aspects of configuring a tracking reference signal over new radios in accordance with aspects of the present disclosure. The device 1805 may be, or include, an example of, the components of the base station 105 described above with reference to FIG. 1, for example. The device 1805 may include components for two-way voice and data communication, including components for transmitting and receiving communications, including a base station communications manager 1815, a processor 1820, a memory 1825, software 1830, a transceiver 1835, an antenna 1840, a network communications manager 1845, and an inter-station communications manager 1850. These components may be in electronic communication via one or more buses (e.g., bus 1810). The device 1805 may be in wireless communication with one or more UEs 115.

[0188]

[0196] The processor 1820 may 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, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 1820 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be incorporated into the processor 1820. The processor 1820 may be configured to execute computer-readable instructions stored in memory to perform various functions (e.g., functions or tasks supporting configuration aspects of tracking reference signals in new radios).

[0189]

[0197] The memory 1825 may include RAM and ROM. The memory 1825 may store computer-readable, computer-executable software 1830 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1825 may include a BIOS, which may control basic hardware or software operations such as interaction with peripheral components or devices, among other things.

[0190]

[0198] The software 1830 may include code for implementing aspects of the present disclosure, including code for supporting configuration aspects of tracking reference signals in new radios. The software 1830 may be stored in a non-transitory computer-readable medium, such as system memory or other memory. In some cases, the software 1830 may not be directly executable by a processor, but may (e.g., when compiled and executed) cause a computer to perform functions described herein.

[0191]

[0199] The transceiver 1835 may communicate bidirectionally via one or more antennas, wired links, or wireless links, as described above. For example, the transceiver 1835 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1835 may also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and for demodulating packets received from the antenna.

[0192]

[0200] In some cases, a wireless device may include a single antenna 1840. However, in some cases, a device may have two or more antennas 1840 that may be capable of simultaneously transmitting or receiving multiple wireless transmissions.

[0193]

[0201] The network communications manager 1845 may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager 1845 may manage the forwarding of data communications for client devices, such as one or more UEs 115.

[0194]

[0202] The inter-station communications manager 1850 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with the UE 115 in cooperation with the other base stations 105. For example, the inter-station communications manager 1850 may coordinate scheduling for transmissions to the UE 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-station communications manager 1850 may provide an X2 interface within the LTE / LTE-A wireless communications network technology for communicating between the base stations 105.

[0195]

[0203] FIG. 19 illustrates a flowchart illustrating a method 1900 for configuration aspects of a tracking reference signal in new radios according to aspects of the present disclosure. The operations of method 1900 may be implemented by the UE 115 or components thereof described herein. For example, the operations of method 1900 may be performed by the UE communications manager described with reference to FIGS. 11-14. In some examples, the UE 115 may execute a set of code for controlling functional elements of the device to perform functions described below. Additionally or alternatively, the UE 115 may perform aspects of the functions described below using dedicated hardware.

[0196]

[0204] At 1905, the UE 115 may receive configuration information indicating a first burst duration and a second burst duration for a TRS burst, where the first burst duration is different from the second burst duration. The operations of 1905 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 1905 may be performed by configuration components described with reference to FIGS. 11-14.

[0197]

[0205] At 1910, the UE 115 may detect a first TRS burst having a first burst duration and a second TRS burst having a second burst duration based at least in part on the configuration information. The operations of 1910 may be performed according to methods described herein. In some examples, aspects of the operations of 1910 may be performed by the detection components described with reference to FIGS. 11-14.

[0198]

[0206] At 1915, the UE 115 may perform resource tracking based at least in part on the detected first and second TRS bursts. The operations of 1915 may be performed according to methods described herein. In some examples, aspects of the operations of 1915 may be performed by a tracking component described with reference to FIGS. 11-14.

[0199]

[0207] FIG. 20 illustrates a flowchart illustrating a method 2000 for configuration aspects of a tracking reference signal in new radios according to aspects of the present disclosure. The operations of method 2000 may be implemented by the UE 115 or components thereof described herein. For example, the operations of method 2000 may be performed by the UE communications manager described with reference to FIGS. 11-14. In some examples, the UE 115 may execute a set of code for controlling functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may perform aspects of the functions described below using dedicated hardware.

[0200]

[0208] At 2005, the UE 115 may receive configuration information indicating a first burst duration and a second burst duration for a TRS burst, where the first burst duration is different from the second burst duration. For example, the first burst duration may be longer or shorter than the second burst duration. The operations of 2005 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2005 may be performed by configuration components described with reference to FIGS. 11-14.

[0201]

[0209] At 2010, the UE 115 may determine from the configuration information that a first resource and a second resource are allocated to the UE, where the first burst duration corresponds to the first resource and the second burst duration corresponds to the second resource. The operations of 2010 may be performed according to methods described herein. In some examples, aspects of the operations of 2010 may be performed by configuration components described with reference to FIGS. 11-14.

[0202]

[0210] In 2015, the UE 115 may determine that a first resource is scheduled to collide with a second resource during the TTI. The operations of 2015 may be performed according to methods described herein. In some examples, aspects of the operations of 2015 may be performed by a collision detector described with reference to FIGS. 11-14.

[0203]

[0211] At 2020, the UE 115 may determine, from the configuration information, a priority order of the first resource relative to the second resource. The operations of 2020 may be performed according to methods described herein. In some examples, aspects of the operations of 2020 may be performed by the priority component described with reference to FIGS. 11-14.

[0204]

[0212] At 2025, the UE 115 may monitor for one of the first TRS burst or the second TRS burst within the TTI based at least in part on the priority order. The operations of 2025 may be performed according to methods described herein. In some examples, aspects of the operations of 2025 may be performed by a detection component described with reference to FIGS. 11-14.

[0205]

[0213] At 2030, the UE 115 may detect one of the first TRS burst or the second TRS burst. The operations of 2030 may be performed according to methods described herein. In some examples, aspects of the operations of 2030 may be performed by the detection components described with reference to FIGS. 11-14.

[0206]

[0214] At 2035, the UE 115 may perform resource tracking based at least in part on the detected TRS burst. The operations of 2035 may be performed according to methods described herein. In some examples, aspects of the operations of 2035 may be performed by the tracking components described with reference to FIGS. 11-14.

[0207]

[0215] FIG. 21 illustrates a flowchart illustrating a method 2100 for configuration aspects of a tracking reference signal in a new radio, according to aspects of the present disclosure. The operations of method 2100 may be implemented by a base station 105 or components thereof, as described herein. For example, the operations of method 2100 may be performed by a base station communications manager, as described with reference to FIGS. 15-18. In some examples, the base station 105 may execute a set of code for controlling functional elements of a device to perform functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0208]

[0216] In 2105, the base station 105 may select a first burst duration and a second burst duration for the TRS burst, where the first burst duration is different from the second burst duration. The operations of 2105 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2105 may be performed by a selector component described with reference to Figures 15-18.

[0209]

[0217] In 2110, the base station 105 may transmit configuration information indicating the first burst duration and the second burst duration. The operations of 2110 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2110 may be performed by configuration components described with reference to Figures 15-18.

[0210]

[0218] In 2115, the base station 105 may transmit a first TRS burst having a first burst duration and a second TRS burst having a second burst duration. The operations of 2115 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2115 may be performed by burst components described with reference to FIGS. 15-18.

[0211]

[0219] FIG. 22 illustrates a flowchart illustrating a method 2200 for configuration aspects of a tracking reference signal in new radios according to aspects of the present disclosure. The operations of method 2200 may be implemented by the UE 115 or components thereof, as described herein. For example, the operations of method 2200 may be performed by the UE communications manager described with reference to FIGS. 11-14. In some examples, the UE 115 may execute a set of code to control functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may perform aspects of the functions described below using dedicated hardware.

[0212]

[0220] At 2205, the UE 115 may receive configuration information indicating the frequency offset parameter. The operations of 2205 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2205 may be performed by configuration components described with reference to FIGS. 11-14.

[0213]

[0221] At 2210, the UE 115 may detect for a TRS transmission within the frequency band based at least in part on the frequency offset parameter. The operations of 2210 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2210 may be performed by a detection component described with reference to FIGS. 11-14.

[0214]

[0222] At 2215, the UE 115 may perform resource tracking based at least in part on the detected TRS transmission. The operations of 2215 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2215 may be performed by the tracking components described with reference to FIGS. 11-14.

[0215]

[0223] FIG. 23 illustrates a flowchart illustrating a method 2300 for configuration of a tracking reference signal in a new radio in accordance with an aspect of the present disclosure. The operations of method 2300 may be implemented by the UE 115 or components thereof, as described herein. For example, the operations of method 2300 may be performed by the UE communications manager described with reference to FIGS. 11-14. In some examples, the UE 115 may execute a set of code to control functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may perform aspects of the functions described below using dedicated hardware.

[0216]

[0224] At 2305, the UE 115 may receive configuration information indicating the frequency offset parameter. The operations of 2305 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2305 may be performed by configuration components described with reference to FIGS. 11-14.

[0217]

[0225] At 2310, the UE 115 may process the frequency offset parameters to determine a first offset value corresponding to the first TTI and a second offset value corresponding to the second TTI. The operations of 2310 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2310 may be performed by components described with reference to FIGS. 11-14.

[0218]

[0226] At 2315, the UE 115 may monitor for a TRS tone of a TRS transmission within a first TTI corresponding to the first offset value and a TRS tone of a TRS transmission within a second TTI corresponding to the second offset value. The operations of 2315 may be performed according to methods described herein. In some examples, aspects of the operations of 2315 may be performed by a detection component described with reference to FIGS. 11-14.

[0219]

[0227] At 2320, the UE 115 may detect for a TRS transmission within the frequency band based at least in part on the frequency offset parameter. The operations of 2320 may be performed according to methods described herein. In some examples, aspects of the operations of 2320 may be performed by a detection component described with reference to FIGS. 11-14.

[0220]

[0228] At 2325, the UE 115 may perform resource tracking based at least in part on the detected TRS transmission. The operations of 2325 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2325 may be performed by the tracking components described with reference to FIGS. 11-14.

[0221]

[0229] FIG. 24 illustrates a flowchart illustrating a method 2400 for configuration aspects of a tracking reference signal in a new radio, according to aspects of the present disclosure. The operations of method 2400 may be implemented by a base station 105 or components thereof, as described herein. For example, the operations of method 2400 may be performed by a base station communications manager, as described with reference to FIGS. 15-18. In some examples, the base station 105 may execute a set of code for controlling functional elements of a device to perform functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0222]

[0230] At 2405, the base station 105 may select a frequency offset parameter. The operations of 2405 may be performed according to methods described herein. In some examples, aspects of the operations of 2405 may be performed by a selector component described with reference to Figures 15-18.

[0223]

[0231] At 2410, the base station 105 may transmit configuration information indicating the frequency offset parameter. The operations of 2410 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2410 may be performed by configuration components described with reference to Figures 15-18.

[0224]

[0232] At 2415, the base station 105 may transmit a TRS transmission having a frequency offset corresponding to the frequency offset parameter. The operations of 2415 may be performed in accordance with methods described herein. In some examples, aspects of the operations of 2415 may be performed by a TRS communicator described with reference to FIGS. 15-18.

[0225]

[0233] It should be noted that the methods described above represent possible implementations, and that the operations and steps may be rearranged or otherwise modified, and that other implementations are possible. Furthermore, aspects from two or more of the methods may be combined.

[0226]

[0234] The techniques described herein may be used for various wireless communication systems such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-Carrier Frequency Division Multiple Access (SC-FDMA), and other systems. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 releases are sometimes commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM).

[0227]

[0235] An OFDMA system may implement radio technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are parts of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, NR, and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP®). CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. Although aspects of LTE or NR systems may be described as examples and LTE or NR terminology may be used throughout much of the description, the techniques described herein are applicable beyond LTE or NR applications.

[0228]

[0236] A macrocell generally covers a relatively large geographic area (e.g., a few kilometers in radius) and may allow unrestricted access by UEs 115 with a service subscription with the network provider. Small cells may be associated with lower power base stations 105 compared to macrocells, and small cells may operate in the same or different frequency bands (e.g., licensed, unlicensed, etc.) as macrocells. Small cells may include picocells, femtocells, and microcells, according to various examples. A picocell, for example, may cover a small geographic area and allow unrestricted access by UEs 115 with a service subscription with the network provider. A femtocell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs 115 with an association with the femtocell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 for users in the home, etc.). An eNB for a macrocell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, pico eNB, femto eNB, or home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells and may support communication using one or more component carriers.

[0229]

[0237] The wireless communications system 100 or any system described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timing, and transmissions from different base stations 105 may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operation.

[0230]

[0238] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0231]

[0239] The various example blocks and modules described in connection with the disclosure herein may be implemented or performed using a general-purpose processor, a DSP, an ASIC, an FPGA or other PLD, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional or future processor, controller, microcontroller, or state machine. A processor may 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).

[0232]

[0240] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features implementing the functions may also be physically located in various locations, including being distributed so that portions of the functions are implemented in different physical locations.

[0233]

[0241] 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. Non-transitory storage media may 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 may comprise RAM, ROM, Electrically Erasable Programmable Read-Only Memory (EEPROM), Flash memory, Compact Disc (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. Also, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of medium. As used herein, disk and disc include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0234]

[0242] As used herein, including in the claims, "or" used within a list of items (e.g., a list of items ending with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, such as, 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, the phrase "based on" as used herein should not be construed as a reference to a closed set of conditions. For example, an example step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted similarly to the phrase "based at least in part on."

[0235]

[0243] In the accompanying figures, similar components or features may have the same reference label. Furthermore, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes among the similar components. If only a first reference label is used herein, the description is applicable to any of the similar components having the same first reference label, regardless of a second reference label or other subsequent reference label.

[0236]

[0244] The description set forth herein with reference to the accompanying drawings describes exemplary configurations and does not necessarily represent every example that may be implemented or that falls within the scope of the claims. As used herein, the term "exemplary" means "serving as an example, instance, or illustration," and does not mean "preferred" or "advantageous over other examples." The detailed description includes specific details for the purpose of providing an understanding of the described techniques. However, these techniques may 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.

[0237]

[0245] The description herein is provided 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 general principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. 1. A method for wireless communication by a user equipment (UE), comprising: receiving configuration information indicating a first burst duration and a second burst duration for a tracking reference signal (TRS) burst, the first burst duration being different from the second burst duration; detecting a first TRS burst having the first burst duration and a second TRS burst having the second burst duration based at least in part on the configuration information; performing resource tracking based at least in part on the detected first TRS burst and the second TRS burst; and A method comprising:

2. determining from the configuration information that the first burst duration corresponds to a first time interval and the second burst duration corresponds to a second time interval, the second time interval occurring after the first time interval. The method of claim 1.

3. determining from the configuration information that transmission of TRS bursts is scheduled to alternate between the first burst duration and the second burst duration in each time interval of a plurality of time intervals. The method of claim 1.

4. determining from the configuration information that a first resource and a second resource are allocated to the UE, wherein the first burst duration corresponds to the first resource and the second burst duration corresponds to the second resource. The method of claim 1.

5. determining a periodicity and a time offset of a time interval from the configuration information, wherein detecting the first TRS burst having the first burst duration and the second TRS burst having the second burst duration includes: monitoring within each instance of the time interval for a TRS burst having the first burst duration at a first location and a TRS burst having the second burst duration at a second location corresponding to the offset. The method of claim 4.

6. determining that the first resource is scheduled to conflict with the second resource during a transmission time interval (TTI). The method of claim 4.

7. determining a priority order of the first resource relative to the second resource based at least in part on the configuration information or rules; monitoring for one of the first TRS burst or the second TRS burst within the TTI based at least in part on the priority order; The method of claim 6 further comprising:

8. determining at least one TRS parameter from the configuration information, wherein the at least one TRS parameter is one or more of a TRS burst duration parameter, a TRS burst periodicity parameter, a TRS tone aspect, a TRS symbol spacing parameter, a TRS number parameter, an offset parameter, and a TRS bandwidth parameter. The method of claim 1.

9. determining a plurality of burst durations and a corresponding time interval duration for each of the plurality of burst durations from the configuration information, the plurality of burst durations including the first and second burst durations; monitoring for a plurality of TRS bursts based at least in part on the plurality of burst durations and the corresponding time interval durations, the plurality of TRS bursts including the first and second TRS bursts; The method of claim 1 further comprising:

10. determining a frequency offset parameter from the configuration information; monitoring for the first TRS burst based at least in part on the frequency offset parameter; The method of claim 1 further comprising:

11. determining a tone spacing from the configuration information, wherein monitoring for the first TRS burst is based at least in part on the tone spacing. The method of claim 10.

12. 1. A method for wireless communication by a base station, comprising: selecting a first burst duration and a second burst duration for a tracking reference signal (TRS) burst, the first burst duration being different from the second burst duration; transmitting configuration information indicating the first burst duration and the second burst duration; transmitting a first TRS burst having the first burst duration and a second TRS burst having the second burst duration; A method comprising:

13. Transmitting the first TRS burst and the second TRS burst includes: alternating transmission of the first TRS burst and the second TRS burst in each time interval of a plurality of time intervals. The method of claim 12.

14. allocating a first resource and a second resource to a user equipment (UE), wherein the configuration information indicates that each of the first resource and the second resource is allocated to the UE. The method of claim 12.

15. determining a time offset between the first resource and the second resource, wherein the configuration information indicates the time offset.

15. The method of claim 14.

16. determining a priority order of the first resource relative to the second resource, wherein the configuration information indicates the priority order.

15. The method of claim 14.

17. determining a plurality of burst durations and a corresponding time interval duration for each of the plurality of burst durations, the plurality of burst durations including the first and second burst durations, and the configuration information indicating the plurality of burst durations and the corresponding time interval durations.

15. The method of claim 14.

18. 1. A method for wireless communication by a user equipment (UE), comprising: receiving configuration information indicating a frequency offset parameter; Detecting a tracking reference signal (TRS) transmission within a frequency band based at least in part on the frequency offset parameter; performing resource tracking based at least in part on the detected TRS transmissions; and A method comprising:

19. determining tone spacing from said configuration information; processing the frequency offset parameter and the tone spacing to determine a location of at least one TRS tone of the TRS transmission within the frequency band relative to a reference frequency; 20. The method of claim 18, further comprising:

20. processing the frequency offset parameters to determine a first offset value corresponding to a first transmission time interval (TTI) and a second offset value corresponding to a second TTI; monitoring for a TRS tone of the TRS transmission within the first TTI corresponding to the first offset value and a TRS tone of the TRS transmission within the second TTI corresponding to the second offset value; 20. The method of claim 18, further comprising:

21. the frequency offset parameter indicates an offset in number of resource elements.

20. The method of claim 18.

22. the frequency offset parameter indicates a bandwidth portion of a plurality of different bandwidth portions within a system bandwidth; 20. The method of claim 18.

23. determining a first burst duration and a second burst duration for the TRS transmission from the configuration information; monitoring for the TRS transmission having the first burst duration and a second TRS transmission having the second burst duration based at least in part on the configuration information; 20. The method of claim 18, further comprising:

24. determining offset values for a plurality of symbol indices from the frequency offset parameter; monitoring for a TRS tone of the TRS transmission during a plurality of respective symbol periods corresponding to the plurality of symbol indexes; 20. The method of claim 18, further comprising:

25. 1. A method for wireless communication by a base station, comprising: selecting a frequency offset parameter; transmitting configuration information indicating the frequency offset parameter; transmitting a tracking reference signal (TRS) transmission having a frequency offset corresponding to the frequency offset parameter; A method comprising:

26. determining a tone spacing for the TRS transmission, wherein the configuration information indicates the tone spacing.

26. The method of claim 25.

27. determining a first offset value corresponding to a first transmission time interval (TTI) and a second offset value corresponding to a second TTI, wherein the frequency offset parameter indicates the first offset value and the second offset value; and transmitting the TRS transmission includes: transmitting a TRS tone of the TRS transmission within the first TTI corresponding to the first offset value, and transmitting a TRS tone of the TRS transmission within the second TTI corresponding to the second offset value.

26. The method of claim 25.

28. the frequency offset parameter indicates an offset in number of resource elements.

28. The method of claim 27.

29. the frequency offset parameter indicates a bandwidth portion of a plurality of different bandwidth portions within a system bandwidth; 28. The method of claim 27.

30. determining offset values for a plurality of symbol indexes, wherein the configuration information indicates the plurality of symbol indexes.

28. The method of claim 27.

31. 1. An apparatus for wireless communication, comprising: means for receiving configuration information indicating a first burst duration and a second burst duration for a tracking reference signal (TRS) burst, the first burst duration being different from the second burst duration; means for detecting a first TRS burst having the first burst duration and a second TRS burst having the second burst duration based at least in part on the configuration information; means for performing resource tracking based at least in part on the detected first TRS burst and the second TRS burst; An apparatus comprising:

32. means for determining from the configuration information that the first burst duration corresponds to a first time interval and the second burst duration corresponds to a second time interval, the second time interval occurring after the first time interval.

32. The apparatus of claim 31.

33. means for determining from the configuration information that transmission of TRS bursts is scheduled to alternate between the first burst duration and the second burst duration in each time interval of a plurality of time intervals.

32. The apparatus of claim 31.

34. and means for determining from the configuration information that a first resource and a second resource are allocated to a user equipment (UE), wherein the first burst duration corresponds to the first resource and the second burst duration corresponds to the second resource.

32. The apparatus of claim 31.

35. The method further includes means for determining a periodicity and a time offset of a time interval from the configuration information, wherein the means for detecting the first TRS burst having the first burst duration and the second TRS burst having the second burst duration comprises: means for monitoring within each instance of the time interval for a TRS burst having the first burst duration at a first location and a TRS burst having the second burst duration at a second location corresponding to the offset.

35. The apparatus of claim 34.

36. means for determining that the first resource is scheduled to conflict with the second resource during a transmission time interval (TTI).

35. The apparatus of claim 34.

37. means for determining a priority order of the first resource relative to the second resource based at least in part on the configuration information or rules; means for monitoring for one of the first TRS burst or the second TRS burst within the TTI based at least in part on the priority order; 37. The apparatus of claim 36, further comprising:

38. and means for determining from the configuration information at least one TRS parameter, the at least one TRS parameter being one or more of a TRS burst duration, a TRS burst periodicity parameter, a TRS tone aspect, a TRS symbol spacing parameter, a TRS number parameter, an offset parameter, and a TRS bandwidth parameter.

37. The apparatus of claim 36.

39. 1. An apparatus for wireless communication, comprising: means for selecting a first burst duration and a second burst duration for a tracking reference signal (TRS) burst, the first burst duration being different from the second burst duration; means for transmitting configuration information indicating the first burst duration and the second burst duration; means for transmitting a first TRS burst having the first burst duration and a second TRS burst having the second burst duration; An apparatus comprising:

40. The means for transmitting the first TRS burst and the second TRS burst comprises: means for alternating transmission of the first TRS burst and the second TRS burst in each time interval of a plurality of time intervals.

40. The apparatus of claim 39.

41. and means for allocating a first resource and a second resource to a user equipment (UE), wherein the configuration information indicates that each of the first resource and the second resource is allocated to the UE.

40. The apparatus of claim 39.

42. and means for determining a time offset between the first resource and the second resource, the configuration information indicating the time offset.

42. The apparatus of claim 41.

43. and means for determining a priority order of the first resource relative to the second resource, wherein the configuration information indicates the priority order.

42. The apparatus of claim 41.

44. 1. An apparatus for wireless communication, comprising: means for receiving configuration information indicative of a frequency offset parameter; means for detecting a tracking reference signal (TRS) transmission within a frequency band based at least in part on the frequency offset parameter; means for performing resource tracking based at least in part on the detected TRS transmissions; An apparatus comprising:

45. means for determining tone spacing from said configuration information; means for processing the frequency offset parameter and the tone spacing to determine a location of at least one TRS tone of the TRS transmission within the frequency band relative to a reference frequency; 45. The apparatus of claim 44, further comprising:

46. means for processing the frequency offset parameters to determine a first offset value corresponding to a first transmission time interval (TTI) and a second offset value corresponding to a second TTI; means for monitoring a TRS tone of the TRS transmission within the first TTI corresponding to the first offset value and a TRS tone of the TRS transmission within the second TTI corresponding to the second offset value; 45. The apparatus of claim 44, further comprising:

47. 1. An apparatus for wireless communication, comprising: means for selecting a frequency offset parameter; means for transmitting configuration information indicative of said frequency offset parameter; means for transmitting a tracking reference signal (TRS) transmission having a frequency offset corresponding to said frequency offset parameter; An apparatus comprising:

48. and means for determining a tone spacing for the TRS transmission, the configuration information indicating the tone spacing.

48. The apparatus of claim 47.

49. The method further comprises: determining a first offset value corresponding to a first transmission time interval (TTI) and a second offset value corresponding to a second TTI, wherein the frequency offset parameter indicates the first offset value and the second offset value; and wherein the means for transmitting the TRS transmission comprises: means for transmitting a TRS tone of the TRS transmission within the first TTI corresponding to the first offset value and for transmitting a TRS tone of the TRS transmission within the second TTI corresponding to the second offset value.

48. The apparatus of claim 47.

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