Methods for tracking reference signal resource overhead reduction

Abstract

Systems, methods, apparatuses, and computer program products for physical layer specification support for the reduction of reference signal resource overhead for time-and frequency tracking reference signal. For example, some example embodiments may include a method comprising receiving, by a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal; and determining, by the user equipment, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

Description

TITLEMETHODS FOR TRACKING REFERENCE SIGNAL RESOURCE OVERHEAD REDUCTIONTECHNICAL FIELD

[0001] Some example embodiments may generally relate to mobile or wireless telecommunication systems, such as 3rdGeneration Partnership Project (3GPP) Long Term Evolution (LTE), 5thgeneration (5G) radio access technology (RAT), new radio (NR) access technology, 6thgeneration (6G), and / or other communications systems. For example, certain example embodiments may relate to systems and / or methods for physical layer specification support to reduce reference signal resource overhead for time-and frequency tracking reference signals.BACKGROUND

[0002] Examples of mobile or wireless telecommunication systems may include radio frequency (RF) 5G RAT, the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), LTE Evolved UTRAN (E-UTRAN), LTE-Advanced (LTE-A), LTE-A Pro, NR access technology, and / or MulteFire Alliance. 5G wireless systems refer to the next generation (NG) of radio systems and network architecture. A 5G system is typically built on a 5G NR, but a 5G (or NG) network may also be built on E-UTRA radio. It is expected that NR can support service categories such as enhanced mobile broadband (eMBB), ultra-reliable low-latency- communication (URLLC), and massive machine-type communication (mMTC). NR is expected to deliver extreme broadband, ultra-robust, low-latency connectivity, and massive networking to support the Internet of Things (loT). The next generation radio access network (NG-RAN) represents the radio access network (RAN) for 5G, which may provide radio access for NR, LTE, and LTE-A. It is noted that the nodes in 5G providing radio access functionality to a user equipment (e.g., similar to the Node B in UTRAN or the Evolved Node B (eNB) in LTE) may be referred to as next-generation Node B (gNB) when built on NR radio, and may be referred to as next-generation eNB (NG-eNB) when built on E-UTRA radio.SUMMARY

[0003] In accordance with some example embodiments, a method may include receiving, by a user equipment (UE), from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal. The method may further include selecting, by the user equipment, a number of antenna port pairs according to at least one criterion associated with antenna port pairs. The method may further includedetermining, by the user equipment, at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0004] In accordance with certain example embodiments, an apparatus may include means for receiving, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal. The apparatus may further include means for selecting a number of antenna port pairs according to at least one criterion associated with antenna port pairs. The apparatus may further include means for determining at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0005] In accordance with various example embodiments, a non-transitory computer readable medium may include program instructions that, when executed by an apparatus, cause the apparatus to perform at least a method. The method may include receiving, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal. The method may further include selecting a number of antenna port pairs according to at least one criterion associated with antenna port pairs. The method may further include determining at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0006] In accordance with some example embodiments, a computer program product may perform a method. The method may include receiving, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal. The method may further include selecting a number of antenna port pairs according to at least one criterion associated with antenna port pairs. The method may further include determining at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0007] In accordance with certain example embodiments, an apparatus may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to receive, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal. The at least one memory and instructions, when executed by the at least one processor, may further cause the apparatus at least to select a number of antenna port pairs according to at least one criterion associated with antenna port pairs. The at least one memory and instructions, when executed bythe at least one processor, may further cause the apparatus at least to determine at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0008] In accordance with various example embodiments, an apparatus may include receiving circuitry configured to perform receiving, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal. The apparatus may further include selecting circuitry configured to perform selecting a number of antenna port pairs according to at least one criterion associated with antenna port pairs. The apparatus may further include determining circuitry configured to perform determining at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0009] In accordance with some example embodiments, a method may include receiving, by a user equipment, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal. The method may further include determining, by the user equipment, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0010] In accordance with certain example embodiments, an apparatus may include means for receiving, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal. The apparatus may further include means for determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0011] In accordance with various example embodiments, a non-transitory computer readable medium may include program instructions that, when executed by an apparatus, cause the apparatus to perform at least a method. The method may include receiving, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal. The method may further include determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0012] In accordance with some example embodiments, a computer program product may perform a method. The method may include receiving, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal. The method may further include determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0013] In accordance with certain example embodiments, an apparatus may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatusat least to receive, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal. The at least one memory and instructions, when executed by the at least one processor, may further cause the apparatus at least to determine, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0014] In accordance with various example embodiments, an apparatus may include receiving circuitry configured to perform receiving, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal. The apparatus may further include determining circuitry configured to perform determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0015] In accordance with some example embodiments, a method may include transmitting, by a network entity, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0016] In accordance with certain example embodiments, an apparatus may include means for transmitting, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0017] In accordance with various example embodiments, a non-transitory computer readable medium may include program instructions that, when executed by an apparatus, cause the apparatus to perform at least a method. The method may include transmitting, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0018] In accordance with some example embodiments, a computer program product may perform a method. The method may include transmitting, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0019] In accordance with certain example embodiments, an apparatus may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to transmit, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0020] In accordance with various example embodiments, an apparatus may include transmitting circuitry configured to perform transmitting, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0021] In accordance with some example embodiments, a method may include receiving, by a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal.The method may further include determining, by the user equipment, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0022] In accordance with certain example embodiments, an apparatus may include means for receiving at least one indication comprising at least one symbol configuration associated with at least one reference signal. The apparatus may further include means for determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0023] In accordance with various example embodiments, a non-transitory computer readable medium may include program instructions that, when executed by an apparatus, cause the apparatus to perform at least a method. The method may include receiving at least one indication comprising at least one symbol configuration associated with at least one reference signal. The method may further include determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0024] In accordance with some example embodiments, a computer program product may perform a method. The method may include receiving at least one indication comprising at least one symbol configuration associated with at least one reference signal. The method may further include determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0025] In accordance with certain example embodiments, an apparatus may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to receive at least one indication comprising at least one symbol configuration associated with at least one reference signal. The at least one memory and instructions, when executed by the at least one processor, may further cause the apparatus at least to determine, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0026] In accordance with various example embodiments, an apparatus may include receiving circuitry configured to perform receiving at least one indication comprising at least one symbol configuration associated with at least one reference signal. The apparatus may further include determining circuitry configured to perform determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0027] In accordance with some example embodiments, a method may include transmitting, by a network entity, to a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal.

[0028] In accordance with certain example embodiments, an apparatus may include means for transmitting, to a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal.

[0029] In accordance with various example embodiments, a non-transitory computer readable medium may include program instructions that, when executed by an apparatus, cause the apparatus to perform at least a method. The method may include transmitting at least one indication comprising at least one symbol configuration associated with at least one reference signal.

[0030] In accordance with some example embodiments, a computer program product may perform a method. The method may include transmitting at least one indication comprising at least one symbol configuration associated with at least one reference signal.

[0031] In accordance with certain example embodiments, an apparatus may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to transmit at least one indication comprising at least one symbol configuration associated with at least one reference signal.

[0032] In accordance with various example embodiments, an apparatus may include transmitting circuitry configured to perform transmitting at least one indication comprising at least one symbol configuration associated with at least one reference signal.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] For a proper understanding of example embodiments, reference should be made to the accompanying drawings, wherein:

[0034] FIG. 1 illustrates an example of different tracking reference signal (TRS) configurations for frequency range (FR)1 and FR2 supported by NR;

[0035] FIG. 2 illustrates an example of resource configuration for non-zero power (NZP)-channel state information (CSI)-reference signal (RS) for time and frequency tracking where one NZP-CSI-RS resource is configured with ‘trs-info’ and four single antenna port NZP-CSI-RS resources with comb-4 resource element pattern;

[0036] FIG. 3 illustrates an example of a flow diagram of a method according to various example embodiments;

[0037] FIG. 4 illustrates an example of frequency offset tracking and compensation based on indicated demodulated reference signal (DMRS) antenna ports and symbols according to some example embodiments;

[0038] FIG. 5 illustrates an example of a flow diagram of a method according to certain example embodiments;

[0039] FIG. 6 illustrates an example of a flow diagram of a method according to some example embodiments;

[0040] FIG. 7 illustrates an example of a flow diagram of a method according to various example embodiments;

[0041] FIG. 8 illustrates an example of a flow diagram of a method according to certain example embodiments;

[0042] FIG. 9 illustrates an example of a flow diagram of a method according to some example embodiments;

[0043] FIG. 10 illustrates an example of various network devices according to some example embodiments; and

[0044] FIG. 11 illustrates an example of a 5G network and system architecture according to certain example embodiments.DETAILED DESCRIPTION

[0045] It will be readily understood that the components of certain example embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of some example embodiments of systems, methods, apparatuses, and computer program products for tracking reference signal resource overhead reduction is not intended to limit the scope of certain example embodiments, but is instead representative of selected example embodiments.

[0046] Currently, NR provides support to set channel estimator parameters properly to receive a DMRS of a physical dedicated control channel (PDCCH), DMRS of physical dedicated data channel (PDSCH), and NZP-CSI-RS by configuring the UE with periodic time, NZP-CSI-RS based time, and frequency TRS in NR. TRS may be a UE specific signal; mandatory periodic reference signals may be transmitted for each connected mode UE. The network may then share the same configuration to multiple UEs with a service area (e.g., a cell / sector).

[0047] TRS may enable the UE to optimize different parameters related to a channel estimator (e.g., for DMRS, the length of 2-D Wiener filter in a frequency and time). TRS may be configured by using one or two NZP-CSI-RS resource Set A with two or four one antenna port NZP-CSI-RS resources with various parameters. For example, for FR1 , TRS burst length may be two consecutive downlink slots valid, and for FR2, one or two consecutive valid downlink slots. Each TRS slot may have two TRS symbols. TRS symbols in the slot may have four symbol separation in time, and / or TRS burst periodicity may be 10 ms, 20 ms, 40 ms, 8 ms, etc.

[0048] FIG. 1 illustrates an example of different TRS configuration options for FR1 and FR2. Here, a notation of {4,8} may define a pair of TRS symbols located in the fourth and eighth symbol positions in a slot. The UE may be configured with multiple TRS configurations to receive TRS and keep tracking time and frequencydomain parameters for the channel estimators {e.g., from different transmission reception points (TRP) I TX beams). TRS may be periodical and / or UE specific ( / .a, TRS may be configured separately for each UE).

[0049] Any additional aperiodic TRS may be associated with periodical TRS. A UE configured with NZP- CSI-RS-ResourceSet(s) with higher layer parameter trs-lnfo may have the CSI-RS resources configured as periodic, with the CSI-RS resources in the NZP-CSI-RS-ResourceSet configured with same periodicity, bandwidth, and subcarrier location. The CSI-RS resources may be configured as a periodic CSI-RS resource in one set, and aperiodic CSI-RS resources in a second set, with the aperiodic CSI-RS and periodic CSI-RS resources having the same bandwidth ( / .a, with same RB location), and the aperiodic CSI-RS being configured with qcl-Type set to 'typeA' and 'typeD', where applicable, with the periodic CSI-RS resources.

[0050] FIG. 2 depicts an example of a NZP-CSI-RS based resource configuration for time- and frequency tracking. For example, one NZP-CSI-RS resource set may be configured with 'trs-lnfo' and four periodic NZP- CSI-RS resources with a single port associated with comb-4 type of resource element pattern, where time density associated with two resources may be four per slot. TRS may be configured for a UE specifically as periodic. Furthermore, TRS can also be configured as aperiodic, but with a restriction to be configured jointly as periodic. As a result, the number of TRS resources per cell may become large, leading to high reference signal resource overhead, especially when operating beam based operations {e.g., FR2, at frequency range 7-15 GHz, or at an upper 6 GHz frequency range).

[0051] Certain example embodiments described herein may have various benefits and / or advantages to overcome the disadvantages described above. For example, to reduce reference signal overhead, different design options may be considered where RS resource overhead may be reduced. In order to enable reduced tracking reference signal overhead, and improve energy efficiency, in certain example embodiments, the problem of high tracking reference signal resource overhead in given deployment scenario may be addressed. Enabling specification / standard support for downlink (DL) DMRS PDSCH based frequency / phase offset tracking and compensation may significantly reduce resource overhead associated with NR time and- frequency reference signal, as well as save energy at both the network and UE. Furthermore, additional overhead may be unnecessary for frequency / phase offset tracking and compensation in other physical channels. Thus, certain example embodiments discussed below are directed to improvements in computer- related technology.

[0052] Some example embodiments may be applied at carrier frequency range 7-15 GHz or lower carrier frequency {e.g., upper 6 GHz) with different numerology options {e.g., 15 / 30 / 60 KHz s). Furthermore, the UE may be a high mobility UE {e.g., UE speed is more than 60 Km / h and / or the speed is high relative to the TRP). Alternatively, radio channel conditions in a radio network deployment may impose a need to enhancechannel estimation quality of PDSCH. As a result, the UE may be configured with at least two DMRS symbols for the demodulation of PDSCH. In this scenario, the UE may use TRS for residual frequency offset tracking and as a quasi co-location (QCL) source (e.g., type-A for DMRS of PDSCH). RS resource overhead associated with TRS and double DMRS symbol transmission may be increased.

[0053] In certain example embodiments, a UE may receive a dynamic indication via downlink control information (DCI) about DMRS antenna port ID(s) and / or DMRS symbols. The UE may determine corresponding channel estimates (including impact of an applied TX precoding, radio channel and receiver), from which the UE may determine residual frequency offset value as well as compensating the determined value from received PDSCH resources (as well as DMRS and / or phase-tracking reference signal (PTRS), if PTRS is configured). As an example, the dynamic indication may include various information elements, such as two separate codepoint fields configured for indicating (e.g., DMRS-TRS-Association, DMRS-TRS-Pos). The dynamic indication may also include a single codepoint configured for joint indications.

[0054] Some example embodiments may define the UE reception procedure for dynamic indication of DMRS antenna port ID(s) and / or DMRS symbols for frequency / phased offset determination compensation procedure.

[0055] In various example embodiments, the UE may assume that the TRS is associated with a certain antenna port (e.g., first DMRS port (port 1000)), and the network may implement this mapping.

[0056] In certain example embodiments, if the UE is not configured with dynamic indication of TRS-DMRS port association, the UE may assume that the first DMRS port (e.g., antenna port index 1000) across different DMRS symbols ( / .e., one or more pairs of the first DMRS antenna port across multiple DMRS symbols) within one or more slots may be configured to calculate channel estimates for a residual frequency / phase offset estimation and compensation. Here, an antenna port pair may be defined as a pair of antenna ports sharing the same antenna port index associated with at least two different DMRS symbols in time.

[0057] Some further example embodiments may define the UE capability signaling related to the usage of reference signal antenna ports and / or reference signal symbols based on which the UE may determine residual frequency offset / phase value. The UE may indicate to the network its capability of usage of DMRS antenna ports I D(s) and / or DMRS symbols for residual frequency / phase offset tracking. The UE may indicate its supported maximum number of reference signal antenna identifiers, such as supported maximum number of DMRS antenna IDs, which may indicate the hardware capability of the UE to jointly perform DMRS and TRS channel estimation and tracking based on the DMRS antenna ports. The UE may indicate its supported maximum length of reference signal in symbols for residual frequency / phase offset computation. The UEmay indicate at least one supported reference signal type, such as DMRS types of (type-1 , type-2, e-Type1 , e-Type2, 6G-Type1 , 6G-type2, etc.). Joint estimation may be performed the supported reference signal type.

[0058] In various example embodiments, the UE may be configured with the association of DMRS antenna port ID(s) (e.g., radio resource control (RRC)) and / or DMRS symbols based on which the UE may determine the corresponding channel estimates out of which residual frequency / phase offset value as well as compensating the determined value from received PDSCH resources. The configuration may include configuring one or more DMRS port ID / symbol pairs, which the UE may use for residual frequency / phase offset tracking. In some further example embodiments, having multiple pairs, the UE may select one or more pairs for residual frequency / phase offset tracking. Furthermore, the UE may receive an indication with PDSCH scheduled in two consecutive slots associated with multiple DMRS symbols, which may be configured for residual frequency offset / phase offset estimation and compensation.

[0059] FIG. 3 illustrates an example of a flow diagram of a method 300 for enabling a UE to determine residual frequency offset for PDSCH reception that may be performed by a UE, such as UE 1020 illustrated in FIG. 10, according to various example embodiments. For example, the UE may receive a dynamic indication about DMRS antenna port ID(s) and / or DMRS symbols. Based on indicated DMRS antenna ports and indicated / configured DMRS symbols, the UE may determine corresponding channel estimates out of which residual frequency offset value as well as compensating the determined value from received PDSCH resources. Indicated DMRS antenna ports for residual frequency offset computation and compensation may be associated with any configured DMRS type (e.g., type-1, type-2, e-Type1 , e-Type2, 6G-type1 , 6G-typ2, etc.).

[0060] More specifically, the UE may first determine antenna port pairs with antenna ports sharing the same DMRS antenna port index with different DMRS symbols in time. Then, the UE may compute two channel estimates for each antenna port pair by using various DMRS sequence(s) (e.g., where DMRS sequence type can be pseudo-random, Zadoff-Chu, or M-sequence). After this, the UE may compute relative phase difference (e.g., by computing correlation between channel estimates within a pair) between channel estimates of each antenna port pair. If multiple antenna port pairs exist, the relative phase differences of different antenna ports may be summed to obtain phase difference. By using computed phase difference value, the phase offset and related frequency offset value can then be computed and compensated.

[0061] Based on capability signaling, the UE may be configured (e.g., PDSCH config) with higher layer parameter 6G-DMRS-TRS-Association = 'ENABLED'. For example, two separate codepoint fields may be configured as an indication. First, DMRS-TRS-Association codepoint field with length of Ni-bits may be configured to indicate the DMRS antenna port IDs. Indicated DMRS antenna port IDs may be a subset ofactual indicated DMRS antenna ports when PDSCH is scheduled. Indicated DMRS antenna ports for residual frequency offset computation may be associated with one or more code-division multiplexing (CDM) groups as well as one or more codewords. For example, when DMRS-TRS-Association is 3-bits, 8 different DMRS antenna port IDs may be indicated. Another codepoint field may include a DMRS-TRS-Pos codepoint field with length of N2-bits configured to indicate time positions of DMRS symbols. For example, when DMRS- TRS-Pos is 2-bits, 4 different DMRS symbol locations may be indicated.

[0062] At step 301 , the method may include, upon detecting DCI with predefined codepoint fields (e.g, DMRS-TRS-Association and DMRS-TRS-Pos), determining channel estimates associated with indicated DMRS antenna ports IDs (e.g., DMRS-TRS-Association), as well as DMRS symbol positions (e.g., DMRS- TRS-Pos) across DMRS / PDSCH allocation.

[0063] At step 302, the method may further include using determined channel estimates to determine a phase / frequency offset difference between antenna port pairs associated with indicated DMRS antenna port IDs and symbol positions.

[0064] For example, an antenna port pair may define a pair of antenna ports sharing the same antenna port ID, where the antenna port ID is associated with the same resource element in consecutive / non-consecutive DMRS symbols, where symbol offsets may be regular or irregular. In particular, regular symbol offset may indicate that all indicated DMRS symbols have a same relative symbol offset among all indicated ones, while an irregular relative symbol offset between symbols among indicated ones may not be the same. The UE may determine the number of antenna ports pair based on the number of indicated DMRS symbols. For example, if 3 DMRS symbols are indicated via a DMRS-TRS-Pos codepoint field, the UE may determine 3 different antenna port pairs, which may be configured for the UE to determine phase / frequency offset differences.

[0065] At operation 303, the method may further include determining single phase / frequency offset value per antenna port pairs by averaging phase / frequency offset values over determined antenna port pairs across time as well as frequency allocation (e.g., antenna port pairs over indicated DMRS symbols in time and over DMRS allocation across all PRBs).

[0066] Based upon the single phase / frequency offset value determined at operation 303, the UE may determine a single phase / frequency offset value by averaging over all indicated DMRS antenna port IDs.

[0067] In various example embodiments, DMRS-TRS-Association and / or DMRS-TRS-Pos codepoint fields may be configured for the UE via RRC / medium access control (MAC), thereby enabling use of configured and / or dynamic grant operations.

[0068] As provided in example of Table 1 below, a DMRS-TRS-Association codepoint value may be configured to indicate DMRS antenna ports for residual frequency offset / phase computation and compensation by using four DMRS antenna ports. The number of indicated DMRS ports for frequency offset / phase offset compensation may be extended by increasing the bit-width of the DMRS-TRS-Association codepoint field. The indicated DMRS antenna port IDs may be a subset of actual indicated DMRS antenna ports when PDSCH is scheduled. For example, when DMRS-TRS-Association- 10', the UE may determine that three different DMRS antenna ports (e.g., po, pi, P2) are indicated for residual frequency offset determination and compensation. Indicated DMRS antenna ports for residual frequency offset computation may be associated with one or more CDM groups as well as one or more codewords. Additionally, a similar indication table may be derived during a standardization process (e.g., 6G) for any other dmrs-type and maximum length of DMRS symbols. maxLength may refer to the maximum number of DMRS symbols over which DMRS antenna ports can be multiplexed in time and / or frequency.Table 1 : DMRS-TRS-Association codepoint values (length of 2- bits), dmrs-Typel, maxLength=1

[0069] Table 2 below is an example of a DMRS-TRS-Pos codepoint value configured to indicate DMRS symbols configured for residual frequency offset computation and compensation. The indicated DMRS symbols may be a subset of actual indicated / configured DMRS symbols when PDSCH is scheduled. For example, when DMRS-TRS-Pos= ‘0T, pos2 may refer to three different DMRS symbol positions indices 3, 7, and 11, respectively. However, actual indicated value range of DMRS symbol positions may be any value.Table 2: DMRS-TRS-Pos codepoint values (length of 2-bits), dmrs-Typel, maxLength=1.

[0070] In various example embodiments, when a higher layer parameter (e.g., 6G-DMRS-TRS-Association =ENABLED’) and DMRS-TRS-Association codepoint field is not indicated, and DMRS-TRS-Pos is indicated via DCI, the UE may assume that the UE shall apply all DMRS symbols indicated by DMRS-TRS-Pos and corresponding DMRS antenna ports indicated for scheduling of PDSCH DMRS for residual frequency offset determination and compensation.

[0071] FIG. 4 depicts an example of frequency offset tracking and compensation for PDSCH based on indicated DMRS antenna ports and symbols. Upon detection of DCI with DMRS-TRS-Association and DMRS-TRS-Pos codepoint fields, the UE may determine phase / frequency offset values for each antenna port pair of received DMRS symbols. Based on the antenna port pair specific frequency / phase offset value, the UE may compute a single average frequency / phase offset value over all antenna port pairs. The UE may then compensate the computed frequency / phase offset from received PDSCH and DMRS symbols; thus, if the phase offset would not be compensated / corrected separately, the phase offset may remain in received symbols, leaving this to be performed by the UE.

[0072] In one embodiment, the UE may dynamically receive a joint indication with a single codepoint field via DCI about DMRS antenna port IDs / number of DMRS antenna ports and DMRS symbol positions for residual frequency / phase offset determination and compensation. For example, the UE may be configured with higher layer parameter 6G-DMRS-TRS-Association =’ENABLED’,' a single codepoint field (e.g. oint- DMRS-TRS) with the length of Ns-bits may be configured for the joint indication. Upon detection of DCI with joint-DMRS-TRS codepoint field, the UE may apply jointly indicated DMRS antenna port ID(s) and DMRS symbols for residual frequency / phase offset value determination and compensation.

[0073] Table 3 below provides an example of a joint indication of DMRS antenna ports and DMRS symbols with 2-bit joint-DRMS-TRS codepoint field. In various example embodiments, when the codepoint field of Joint-DMRS-TRS-Association has value 01, the UE may use the DMRS symbol indices 3 and 7 associated with DMRS antenna port indices 0,1, and 2 as well as corresponding antenna port pairs ( / .e., three pairs) for residual frequency / phase offset estimation and compensation.symbols with joint-DMRS-TRS with 2-bit codepoint field.

[0074] In some example embodiments, the UE may receive an indication via joint or separate codepoint field(s) about DMRS antenna port IDs and / or DMRS symbols based on which UE selects up to N antenna port pairs out of which residual frequency / phase offset values are computed and compensated from PDSCH reception. If no separate indication on number of antenna port pairs is indicated, the UE may assume that all antenna port pairs associated with all indicated antenna ports should be used for residual frequency / phase offset estimation and compensation.

[0075] In certain example embodiments, to enable the UE to determine residual frequency offset(s) for 6G- PDSCH reception, when higher layer parameter 6G-DMRS-TRS-Association =’ENABLED’ is configured, the UE may implicitly determine that residual frequency / phase offset value and compensation should be determined based on indicated about DMRS antenna port ID(s) and corresponding antenna port pairs as well as associated DMRS symbols (e.g., without any new codepoint fields described above). For example, the UE may determine autonomously which of the antenna ports with corresponding antenna port pairs are used for residual frequency / phase offset computation and compensation. Antenna port pairs may be defined as a pair of antenna ports sharing same antenna port index associated with at least two different DMRS symbols in time. In another example, when the UE is not configured with TRS, and DCI does not include one joint or two separate codepoint fields for frequency offset tracking, the UE may implicitly determine residual frequency / phase offset values based on indicated DMRS antenna ports and indicated / configured DMRS symbols. More specifically, the UE may first determine antenna port pairs with antenna ports sharing the same DMRS antenna port index with different DMRS symbols in time. Then, the UE may compute two channel estimates for each antenna port pair by using a DMRS sequence (e.g., where DMRS sequence type can be, pseudo-random, Zadoff-Chu, or M-Sequence). After this, the UE may compute phase difference (e.g., by computing correlation between channel estimates within a pair) between channel estimates of each antenna port pair. If multiple antenna port pairs exist, the phase differences of different antenna ports may be summed up to obtain phase difference. After this, by using computed phase difference value, the phase offset and related frequency offset value may be computed and compensated. As an example, an 6G- PDSCH-Config information element may be configured as 6G-DMRS-TRS-Assocation ENUMERATED {enabled}. The UE and network may have a mutual understanding that the UE shall use DMRS antenna ports and symbols associated with configured / scheduled PDSCH transmission for residual phase / frequency offset computation and compensation.;0076] In various example embodiments, upon receiving DCI with two separate or one joint indication codepoint field, the UE may select the best M e.g., 2 or more) according at least one criterion associated with antenna port pairs, where M may be indicated / configured by the network, or implemented by the UE. The criterion may be received power associated with received resource elements of reference signal antenna port(s). The UE may then rank antenna port pairs according to the criteria either in ascending or descending order and select the M-strongest antenna port pairs for residual frequency / phase offset computation and compensation. The criterion may be mean square error (MSE) between known constellation points associated antenna ports of reference signal sequence and detected constellation points associated with antenna ports of reference signal sequence, wherein the UE performs detection by utilizing reference signal channel estimation of antenna port(s) and received resource elements of reference signal antenna port(s). The UE may then rank antenna port pairs according to the criteria either in ascending or descending order, and select the M-smallest MSE antenna port pairs for residual frequency / phase offset computation and compensation.

[0077] FIG. 5 illustrates an example of a flow diagram of a method 500 that may be performed by a UE, such as UE 1020 illustrated in FIG. 10, according to various example embodiments.

[0078] At step 501 , the method may include receiving, from a network entity such as NE 1010 illustrated in FIG. 10, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal. The at least one indication may include a first codepoint including a reference signal association (RS- Association) field.

[0079] At step 502, the method may further include selecting a number of antenna port pairs according to at least one criterion associated with antenna port pairs. The at least one criterion may include at least one of received power associated with received resource elements of reference signal antenna port(s), or meansquare error (MSE) between known constellation points associated antenna ports of reference signal sequence and detected constellation points associated with antenna ports of reference signal sequence. The UE performs detection by utilizing reference signal channel estimation of antenna port(s) and received resource elements of reference signal antenna port(s).

[0080] At step 503, the method may further include determining at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0081] In various example embodiments, the method may further include ranking antenna port pairs according to received reference signal power (RSRP) either in ascending or descending order, and selecting a number of strongest antenna port pairs for residual frequency / phase offset computation and compensation.

[0082] In certain example embodiments, the method may further include ranking antenna port pairs according to mean square error either in ascending or descending order, and selecting a number of antenna port pairs having smallest mean square error for residual frequency / phase offset computation and compensation.

[0083] In various example embodiments, the number of antenna port pairs may be indicated / configured by network or determined by the user equipment.

[0084] In certain example embodiments, the at least one indication is received via at least one of DCI, MAC CE, or RRC message.

[0085] In some example embodiments, the method may further include transmitting UE capability information related to utilizing at least one of reference signal antenna ports or reference signal symbol configurations for frequency offset tracking and / or phase offset tracking.

[0086] In various example embodiments, the at least one antenna port identifier may include at least one of a reference signal port identity of, for example, 1000, or a hardcoded reference signal port identity.

[0087] FIG. 6 illustrates an example of a flow diagram of a method 600 that may be performed by a UE, such as UE 1020 illustrated in FIG. 10, according to various example embodiments.

[0088] At step 601 , the method may further include transmitting, to a network entity such as NE 1010 illustrated in FIG. 10, UE capability information related to utilizing at least one of reference signal antenna ports or reference signal symbol configurations for frequency offset tracking and / or phase offset tracking.

[0089] At step 602, the method may further include transmitting, to the network entity, at least one of a UE supported maximum number of reference signal antenna port identifiers, or at least one UE supported reference signal type.

[0090] At step 603, the method may further include receiving a configuration indicating reference signal association enabled.

[0091] At step 604, the method may include receiving, from the network entity, at least one indication including at least one antenna port identifier associated with at least one reference signal. The at least one indication may include a first codepoint including a reference signal association (RS-Association) field. The at least one antenna port identifier may include at least one pair of reference signal antenna port identities.

[0092] At step 605, the method may further include receiving at least another indication including at least one symbol configuration associated with the at least one reference signal. The at least another indication may include a second codepoint including a reference signal position (RS-Pos) field. The second codepoint may include a different codepoint from the first codepoint for separate indication. The second codepoint may include a same codepoint as the first codepoint for joint indication.

[0093] At step 606, the method may further include performing channel estimates, for example, by determining, by the user equipment, at least one corresponding channel estimate associated with each of the indicated antenna port identifiers; determining, by the user equipment, one or more antenna port pairs, wherein the antenna ports in a same antenna port pair share same antenna port identifier; based upon the at least one corresponding channel estimate, determining, by the user equipment, at least one phase / frequency offset difference between the one or more antenna port pairs; determining, by the user equipment, a single phase / frequency offset value per antenna port pair by averaging phase / frequency offset values over the antenna port pair across time as well as frequency allocation; and determining, by the user equipment, a single phase / frequency offset value by averaging over all antenna port pairs.

[0094] At step 607, the method may further include determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0095] In certain example embodiments, the at least one antenna port identifier my include at least one of a reference signal port identity of 1000, or a hardcoded reference signal port identity.

[0096] In some example embodiments, the at least one indication may be received via at least one of DCI, MAC CE, or RRC message.

[0097] FIG. 7 illustrates an example of a flow diagram of a method 700 that may be performed by a NE, such as NE 1010 illustrated in FIG. 10, according to various example embodiments.

[0098] At step 701, the method may further include receiving, from a user equipment such as UE 1020 illustrated in FIG. 10, UE capability information related to utilizing at least one of reference signal antenna ports or reference signal symbol configurations for frequency offset tracking and / or phase offset tracking.

[0099] At step 702, the method may include transmitting, to the user equipment, at least one indication including at least one antenna port identifier associated with at least one reference signal. The at least one indication may be transmitted via at least one of DCI, MAC CE, and / or RRC message.

[0100] FIG. 8 illustrates an example of a flow diagram of a method 800 that may be performed by a UE, such as UE 1020 illustrated in FIG. 10, according to various example embodiments.

[0101] At step 801 , the method may include transmitting, to a network entity such as UE 1020 illustrated in FIG. 10, UE capability information related to utilizing at least one of reference signal antenna ports or reference signal symbol configurations for frequency offset tracking and / or phase offset tracking.

[0102] At step 802, the method may further include transmitting, to the network entity, at least one of a UE supported maximum length of reference signal symbols, or at least one UE supported reference signal type.

[0103] At step 803, the method may further include receiving a configuration indicating reference signal symbol configuration enabled.

[0104] At step 804, the method may include receiving at least one indication including at least one symbol configuration associated with at least one reference signal. The at least one indication may include a codepoint field including a reference signal position (RS-Pos) field. The at least one indication may be received via at least one of DCI, MAC CE, or RRC message.

[0105] At step 805, the method may further include performing channel estimates, for example, by computing channel estimates based on symbol configurations associated with reference signals. For example, the performing of channel estimates may be based on symbol positions of PDSCH DMRS.

[0106] At step 806, the method may further include determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal. For example, the determining may further include determining, by the user equipment, at least one corresponding channel estimate associated with the indicated at least one symbol configuration; determining, by the user equipment, one or more antenna port pairs based on the symbol configuration; based upon the at least one corresponding channel estimate, determining, by the user equipment, at least one phase / frequency offset difference between the one or more antenna port pairs; determining, by the user equipment, single phase / frequency offset value per antenna port pair by averaging phase / frequency offset values over the antenna port pair across time as well as frequency allocation; and determining, by the user equipment, single phase / frequency offset value by averaging over all antenna port pairs.

[0107] FIG. 9 illustrates an example of a flow diagram of a method 900 that may be performed by a NE, such as NE 1010 illustrated in FIG. 10, according to various example embodiments.

[0108] At step 901 , the method may further include receiving, from a user equipment such as UE 1020 illustrated in FIG. 10, UE capability information related to utilizing at least one of reference signal antenna ports or reference signal symbol configurations for frequency offset tracking and / or phase offset tracking.

[0109] At step 902, the method may include transmitting, to a user equipment, at least one indication including at least one symbol configuration associated with at least one reference signal. The at least one indication may include a codepoint field including a RS-Pos field. The at least one indication may be transmitted via at least one of DCI, MAC CE, or RRC message.

[0110] FIG. 10 illustrates an example of a system according to certain example embodiments. In one example embodiment, a system may include multiple devices, such as, for example, NE 1010 and / or UE 1020.

[0111] NE 1010 may be one or more of a base station (e.g, 3G UMTS NodeB, 4G LTE Evolved NodeB, or 5G NR Next Generation NodeB), a serving gateway, a server, and / or any other access node or combination thereof.

[0112] NE 1010 may further include at least one gNB-centralized unit (CU), which may be associated with at least one gNB-distributed unit (DU). The at least one gNB-CU and the at least one gNB-DU may be in communication via at least one F1 interface, at least one Xn-C interface, and / or at least one NG interface via a 5thgeneration core (5GC).

[0113] UE 1020 may include one or more of a mobile device, such as a mobile phone, smart phone, personal digital assistant (PDA), tablet, or portable media player, digital camera, pocket video camera, video game console, navigation unit, such as a global positioning system (GPS) device, desktop or laptop computer, singlelocation device, such as a sensor or smart meter, or any combination thereof. Furthermore, NE 1010 and / or UE 1020 may be one or more of a citizens broadband radio service device (CBSD).

[0114] NE 1010 and / or UE 1020 may include at least one processor, respectively indicated as 1011 and 1021. Processors 1011 and 1021 may be embodied by any computational or data processing device, such as a central processing unit (CPU), application specific integrated circuit (ASIC), or comparable device. The processors may be implemented as a single controller, or a plurality of controllers or processors.

[0115] At least one memory may be provided in one or more of the devices, as indicated at 1012 and 1022. The memory may be fixed or removable. The memory may include computer program instructions or computer code contained therein. Memories 1012 and 1022 may independently be any suitable storage device, such as a non-transitory computer-readable medium. The term "non-transitory,” as used herein, may correspond to a limitation of the medium itself ( / .e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., random access memory (RAM) vs. read-only memory (ROM)). A hard disk drive (HDD), random access memory (RAM), flash memory, or other suitable memory may be used. The memories may be combined on a single integrated circuit as the processor, or may be separate from the one or more processors. Furthermore, the computer program instructions stored in the memory, and which may be processed by the processors, may be any suitable form of computer program code, for example, a compiled or interpreted computer program written in any suitable programming language.

[0116] Processors 1011 and 1021 , memories 1012 and 1022, and any subset thereof, may be configured to provide means corresponding to the various blocks of FIGs. 3-9. Although not shown, the devices may also include positioning hardware, such as GPS or micro electrical mechanical system (MEMS) hardware, which may be used to determine a location of the device. Other sensors are also permitted, and may be configured to determine location, elevation, velocity, orientation, and so forth, such as barometers, compasses, and the like.

[0117] As shown in FIG. 10, transceivers 1013 and 1023 may be provided, and one or more devices may also include at least one antenna, respectively illustrated as 1014 and 1024. The device may have many antennas, such as an array of antennas configured for multiple input multiple output (Ml MO) communications, or multiple antennas for multiple RATs. Other configurations of these devices, for example, may be provided. Transceivers 1013 and 1023 may be a transmitter, a receiver, both a transmitter and a receiver, or a unit or device that may be configured both for transmission and reception.

[0118] The memory and the computer program instructions may be configured, with the processor for the particular device, to cause a hardware apparatus, such as UE, to perform any of the processes described above ( / .e., FIGs. 3-9). Therefore, in certain example embodiments, a non-transitory computer-readable medium may be encoded with computer instructions that, when executed in hardware, perform a process such as one of the processes described herein. Alternatively, certain example embodiments may be performed entirely in hardware.

[0119] In certain example embodiments, an apparatus may include circuitry configured to perform any of the processes or functions illustrated in FIGs. 3-9. As used in this application, the term "circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry), (b) combinations of hardware circuits and software, such as (as applicable): (I) a combination of analog and / or digital hardware circuit(s) with software / fi rmware and (II) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions), and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processorintegrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0120] FIG. 11 illustrates an example of a 5G network and system architecture according to certain example embodiments. Shown are multiple network functions that may be implemented as software operating as part of a network device or dedicated hardware, as a network device itself or dedicated hardware, or as a virtual function operating as a network device or dedicated hardware. The NE and UE illustrated in FIG. 11 may be similar to NE 1010 and UE 1020, respectively. The user plane function (UPF) may provide services such as intra-RAT and inter-RAT mobility, routing and forwarding of data packets, inspection of packets, user plane quality of service (QoS) processing, buffering of downlink packets, and / or triggering of downlink data notifications. The application function (AF) may primarily interface with the core network to facilitate application usage of traffic routing and interact with the policy framework.

[0121] According to certain example embodiments, processors 1011 and 1021 , and memories 1012 and 1022, may be included in or may form a part of processing circuitry or control circuitry. In addition, in some example embodiments, transceivers 1013 and 1023 may be included in or may form a part of transceiving circuitry.

[0122] In some example embodiments, an apparatus (e.g., NE 1010 and / or UE 1020) may include means for performing a method, a process, or any of the variants discussed herein. Examples of the means may include one or more processors, memory, controllers, transmitters, receivers, and / or computer program code for causing the performance of the operations.

[0123] In various example embodiments, apparatus 1020 may be controlled by memory 1022 and processor 1021 to receive, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal; select a number of antenna port pairs according to at least one criterion associated with antenna port pairs; and determine at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0124] Certain example embodiments may be directed to an apparatus that includes means for performing any of the methods described herein including, for example, means for receiving, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal; means for selecting a number of antenna port pairs according to at least one criterion associated with antenna port pairs; and means for determining at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0125] In various example embodiments, apparatus 1020 may be controlled by memory 1022 and processor 1021 to receive, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal; select a number of antenna port pairs according to at least one criterion associated with antenna port pairs; and determine at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0126] Certain example embodiments may be directed to an apparatus that includes means for performing any of the methods described herein including, for example, means for receiving, from a network entity, at least one indication comprising one or more of at least one antenna port identifier associated with at least one reference signal or at least one symbol configuration associated with at least one reference signal; means for selecting a number of antenna port pairs according to at least one criterion associated with antenna port pairs; and means for determining at least one residual frequency / phase offset based on the at least one reference signal via the number of antenna port pairs.

[0127] In various example embodiments, apparatus 1020 may be controlled by memory 1022 and processor 1021 to receive, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal; and determine, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0128] Certain example embodiments may be directed to an apparatus that includes means for performing any of the methods described herein including, for example, means for receiving, from a network entity, at least one indication comprising at least one antenna port identifier associated with at least one reference signal; and means for determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0129] In various example embodiments, apparatus 1010 may be controlled by memory 1012 and processor 1011 to transmit, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0130] Certain example embodiments may be directed to an apparatus that includes means for performing any of the methods described herein including, for example, means for transmitting, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0131] In various example embodiments, apparatus 1020 may be controlled by memory 1022 and processor 1021 to receive at least one indication comprising at least one symbol configuration associated with at least onereference signal; and determine, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0132] Certain example embodiments may be directed to an apparatus that includes means for performing any of the methods described herein including, for example, means for receiving at least one indication comprising at least one symbol configuration associated with at least one reference signal; and determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

[0133] In various example embodiments, apparatus 1010 may be controlled by memory 1012 and processor 1011 to transmit, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0134] Certain example embodiments may be directed to an apparatus that includes means for performing any of the methods described herein including, for example, means for transmitting, to a user equipment, at least one indication comprising at least one antenna port identifier associated with at least one reference signal.

[0135] The features, structures, or characteristics of example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, the usage of the phrases "various embodiments,” "certain embodiments,” "some embodiments,” or other similar language throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with an example embodiment may be included in at least one example embodiment. Thus, appearances of the phrases "in various embodiments,” "in certain embodiments,” "in some embodiments,” or other similar language throughout this specification does not necessarily all refer to the same group of example embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments.

[0136] As used herein, "at least one of the following: ” and "at least one of ” and similar wording, where the list of two or more elements are joined by "and” or "or,” mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0137] Additionally, if desired, the different functions or procedures discussed above may be performed in a different order and / or concurrently with each other. Furthermore, if desired, one or more of the described functions or procedures may be optional or may be combined. As such, the description above should be considered as illustrative of the principles and teachings of certain example embodiments, and not in limitation thereof.

[0138] One having ordinary skill in the art will readily understand that the example embodiments discussed above may be practiced with procedures in a different order, and / or with hardware elements in configurations which are different than those which are disclosed. Therefore, although some embodiments have been described based upon these example embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the example embodiments.

[0139] Partial Glossary

[0140] 3GPP 3rdGeneration Partnership Project

[0141] 5G 5thGeneration

[0142] 5GC 5thGeneration Core

[0143] 6G 6thGeneration

[0144] AF Application Function

[0145] ASIC Application Specific Integrated Circuit

[0146] CBSD Citizens Broadband Radio Service Device

[0147] CDM Code Division Multiplexing

[0148] CPU Central Processing Unit

[0149] CSI Channel State Information

[0150] CU Centralized Unit

[0151] DCI Downlink Control Information

[0152] DL Downlink

[0153] DMRS Demodulation Reference Signal

[0154] DU Distributed Unit

[0155] eMBB Enhanced Mobile Broadband

[0156] FR Frequency Range

[0157] eNB Evolved Node B

[0158] gNB Next Generation Node B

[0159] GPS Global Positioning System

[0160] HDD Hard Disk Drive

[0161] loT Internet of Things

[0162] LTE Long-Term Evolution

[0163] LTE-A Long-Term Evolution Advanced

[0164] MAC Medium Access Control

[0165] MCS Modulation and Coding Scheme

[0166] MEMS Micro Electrical Mechanical System

[0167] MIMO Multiple Input Multiple Output

[0168] mMTC Massive Machine Type Communication

[0169] MSE Mean Square Error

[0170] NE Network Entity

[0171] NG Next Generation

[0172] NG-eNB Next Generation Evolved Node B

[0173] NG-RAN Next Generation Radio Access Network

[0174] NR New Radio

[0175] NZP-CSI-RS Non-Zero Channel State Information Reference Signal

[0176] PBCH Physical Broadcast Channel

[0177] PDA Personal Digital Assistance

[0178] PDCCH Physical Downlink Control Channel

[0179] PDSCH Physical Downlink Shared Channel

[0180] PTRS Phase-Tracking Reference Signal

[0181] PUSCH Physical Uplink Shared Channel

[0182] QCL Quasi co-location

[0183] QoS Quality of Service

[0184] RAM Random Access Memory

[0185] RAN Radio Access Network

[0186] RAT Radio Access Technology

[0187] RF Radio Frequency

[0188] ROM Read-Only Memory

[0189] RRC Radio Resource Control

[0190] RS Reference Signal

[0191] SSB Synchronization Signal Block

[0192] TCI Transmission Configuration Indicator

[0193] TRP Transmission Reception Point

[0194] TRS Tracking Reference Signal

[0195] UE User Equipment

[0196] UMTS Universal Mobile Telecommunications System

[0197] UPF User Plane Function

[0198] URLLC Ultra-Reliable and Low-Latency Communication

[0199] UTRAN Universal Mobile Telecommunications System Terrestrial Radio AccessNetwork

[0200] WLAN Wireless Local Area Network

Claims

WE CLAIM:1 . An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive at least one indication comprising at least one symbol configuration associated with at least one reference signal; and determine, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

2. The apparatus of claim 1 , wherein the at least one indication comprises a codepoint field comprising a reference signal position (RS-Pos) field.

3. The apparatus of claim 1 or 2, wherein the at least one memory and the instructions, when executed by the at least one processor, further cause the apparatus at least to: determine at least one corresponding channel estimate associated with the indicated at least one symbol configuration; determine one or more antenna port pairs based on the symbol configuration; based upon the at least one corresponding channel estimate, determining, by the user equipment, at least one phase / frequency offset difference between the one or more antenna port pairs; determine single phase / frequency offset value per antenna port pair by averaging phase / frequency offset values over the antenna port pair across time as well as frequency allocation; and determine single phase / frequency offset value by averaging over all antenna port pairs.

4. The apparatus of any of claims 1-3, wherein the at least one indication is received via at least one of: downlink control information (DCI); medium access control control element; or radio resource control message.

5. The apparatus of any of claims 1-4, wherein the at least one memory and the instructions, whenexecuted by the at least one processor, further cause the apparatus at least to: transmit, to the network entity, at least one of the following: a UE supported maximum length of reference signal symbols; or at least one UE supported reference signal type.

6. The apparatus of any of claims 1-5, wherein the at least one memory and the instructions, when executed by the at least one processor, further cause the apparatus at least to: receive a configuration indicating reference signal symbol configuration enabled.

7. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal.

8. The apparatus of claim 7, wherein the at least one indication comprises a codepoint field comprising a reference signal position (RS-Pos) field.

9. The apparatus of claim 7 or 8, wherein the at least one indication is transmitted via at least one of: downlink control information (DCI); medium access control control element; or radio resource control message.

10. The apparatus of any of claims 7-9, wherein the at least one memory and the instructions, when executed by the at least one processor, further cause the apparatus at least to: receive, from the user equipment, UE capability information related to utilizing at least one of reference signal antenna ports or reference signal symbol configurations for frequency offset tracking and / or phase offset tracking.

11. A method comprising:receiving, by a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal; and determining, by the user equipment, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

12. A method comprising: transmitting, by a network entity, to a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal.

13. An apparatus comprising: means for receiving at least one indication comprising at least one symbol configuration associated with at least one reference signal; and means for determining, based on the received indication, at least one of residual frequency offset or residual phase offset based on the at least one reference signal.

14. An apparatus comprising: means for transmitting, to a user equipment, at least one indication comprising at least one symbol configuration associated with at least one reference signal.

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