Patent Description:
3GPP Draft R2-<NUM> ("Measurement accuracy improvements") discusses the signaling impact to indicate power imbalance offset for neighbor cells in system information with focus on connected mode measurement accuracy, improved measurement accuracy during random access and power imbalance between serving and neighbor cells.

3GPP Draft R1-<NUM> ("Narrowband measurement accuracy improvements") relates to enhanced features for NB-IoT, supporting standalone, guard-band, and in-band operation modes. The discussion within the document refers to NPRACH reliability and range enhancements with special emphasis on CRS based measurements and NPBCH, NPDCCH and NPDSCH for improving connected mode measurements.

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. The sole purpose of this summary is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

Claim <NUM> defines a method of wireless communication, performed by a user equipment (UE), including receiving a plurality of master information blocks (MIBs) on a narrowband physical broadcast channel (NPBCH); determining an NPBCH signal power based at least in part on the plurality of MIBs; and estimating a narrowband reference signal received power (NRSRP) parameter based at least in part on the NPBCH signal power.

Claim <NUM> defines a UE for wireless communication comprising means for performing the method of claim <NUM>. Claim <NUM> defines a method of wireless communication, performed by a base station, including determining whether to enable or disable NPBCH-based estimates of an NRSRP parameter for a UE; and transmitting, to the UE, an indication of whether NPBCH-based estimates of the NRSRP parameter are enabled or disabled for the UE based at least in part on the determination.

Claim <NUM> defines a base station for wireless communication comprising means for performing the method of claim <NUM>.

Claims <NUM> and <NUM> define computer-programs comprising instructions for performing the methods of claims <NUM> and <NUM> respectively.

While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and/or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, and/or the like). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders/summers, etc.). It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.

In some aspects, a UE may be considered an Internet-of-Things (IoT) device, and/or may be implemented as a narrowband loT (NB-IoT) UE.

Controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with estimating an NRSRP parameter, as described in more detail elsewhere herein. For example, controller/processor <NUM> of base station <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, process <NUM> of <FIG>, process <NUM> of <FIG>, process <NUM> of <FIG>, and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively.

In some aspects, UE <NUM> includes means for receiving a plurality of master information blocks (MIBs) on a narrowband physical broadcast channel (NPBCH); means for determining an NPBCH signal power based at least in part on the plurality of MIBs; means for estimating a narrowband reference signal received power (NRSRP) parameter based at least in part on the NPBCH signal power; and/or the like. In some aspects, such means include one or more components of UE <NUM> described in connection with <FIG>.

In some aspects, base station <NUM> includes means for determining whether to enable or disable NPBCH-based estimates of an NRSRP parameter for a UE <NUM>; means for transmitting, to the UE <NUM>, an indication of whether NPBCH-based estimates of the NRSRP parameter are enabled or disabled for the UE <NUM> based at least in part on the determination; and/or the like. Additionally, or alternatively, base station <NUM> includes means for determining whether narrowband reference signals are present in all downlink subframes of a frame; means for transmitting an indication of whether the narrowband reference signals are present in all downlink subframes of the frame; and/or the like. In some aspects, such means include one or more components of base station <NUM> described in connection with <FIG>.

<FIG> shows an example frame structure <NUM> for FDD in a telecommunications system (e.g., NR). Each radio frame may have a predetermined duration and may be partitions into a set of Z (Z ≥ <NUM>) subframes (e.g., with indices of <NUM> through Z-<NUM>). Each subframe may include a set of slots (e.g., two slots per subframe are shown in <FIG>). For example, each slot may include seven symbol periods (e.g., as shown in <FIG>), fifteen symbol periods, and/or the like. In a case where the subframe includes two slots, the subframe may include <NUM> symbol periods, where the <NUM> symbol periods in each subframe may be assigned indices of <NUM> through <NUM>-<NUM>. In some aspects, a scheduling unit for the FDD may frame-based, subframe-based, slot-based, symbol-based, and/or the like.

Similarly, in some aspects, one or more SS blocks of the SS burst may be transmitted in consecutive radio resources (e.g., consecutive symbol periods) during one or more subframes.

The base station may transmit system information, such as system information blocks (SIBs) on a physical downlink shared channel (PDSCH) in certain subframes. The base station may transmit control information/data on a physical downlink control channel (PDCCH) in C symbol periods of a subframe, where B may be configurable for each subframe. The base station may transmit traffic data and/or other data on the PDSCH in the remaining symbol periods of each subframe.

<FIG> shows an example subframe format <NUM> with a normal cyclic prefix. In some aspects, subframe format <NUM> may be used for transmission of SS blocks that carry the PSS, the SSS, the PBCH, and/or the like, as described herein.

An interlace structure may be used for each of the downlink and uplink for FDD in certain telecommunications systems (e.g., NR). For example, Q interlaces with indices of <NUM> through Q - <NUM> may be defined, where Q may be equal to <NUM>, <NUM>, <NUM>, <NUM>, or some other value. Each interlace may include subframes that are spaced apart by Q frames. In particular, interlace q may include subframes q, q + Q, q + 2Q, etc., where q ∈ {<NUM>,. , Q-<NUM>}.

Received signal quality may be quantified by a signal-to-interference-plus-noise ratio (SINR), or a reference signal received quality (RSRQ), or some other metric.

New Radio (NR) may refer to radios configured to operate according to a new air interface (e.g., other than Orthogonal Frequency Divisional Multiple Access (OFDMA)-based air interfaces) or fixed transport layer (e.g., other than Internet Protocol (IP)).

Each radio frame may include <NUM> subframes with a length of <NUM>. Consequently, each subframe may have a length of <NUM>. Each subframe may indicate a link direction (e.g., DL or UL) for data transmission and the link direction for each subframe may be dynamically switched. Each subframe may include DL/UL data as well as DL/UL control data.

<FIG> is a diagram of an example NB-IoT resource block <NUM>, in accordance with various aspects of the present disclosure.

As shown, time and frequency resources may be partitioned into resource blocks. A resource block may cover a set of subcarriers (e.g., <NUM> subcarriers) in one transmission time interval (TTI) (e.g., a subframe, a slot, and/or the like), and may include a number of resource elements. A resource element may cover one subcarrier in one symbol period (e.g., in time) and may be used to send one modulation symbol, which may be a real or complex value. In some aspects, the TTI may be a subframe that includes two slots, and each slot may include <NUM> symbols. In this case, the TTI may have a duration of <NUM> symbols. In some aspects, in NB-IoT, each resource element may span <NUM> of bandwidth, and a resource block may span <NUM> of bandwidth. In this way, NB-IoT may be flexibly deployed using a small portion of existing radio frequency spectrum (e.g., by replacing a GSM carrier with an NB-IoT carrier, by deploying an NB-IoT carrier inside an LTE carrier, by deploying NB-IoT in the guard band of an LTE carrier, and/or the like).

In NB-IoT, a frame may include <NUM> subframes, labeled <NUM> through <NUM>. In some aspects, subframe <NUM> may be used for NPBCH communications in every NB-IoT frame, subframe <NUM> may be used for narrowband PSS (NPSS) communications in every NB-IoT frame, and subframes <NUM> through <NUM> and <NUM> through <NUM> may be used for NPDCCH and/or NPDSCH communications in every NB-IoT frame. In even-numbered NB-IoT frames, subframe <NUM> may be used for narrowband SSS (NSSS) communications, and in odd-numbered NB-IOT frames, subframe <NUM> may be used for NPDCCH and/or NPDSCH communications.

In NB-IoT, a UE <NUM> (e.g., an NB-IoT UE) may estimate power of a received signal using a narrowband reference signal received power (NRSRP) parameter, similar to an RSRP parameter in LTE, <NUM>, and/or the like. The UE <NUM> may use the NRSRP parameter to perform cell reselection, such as by performing a handover procedure from a serving cell to a neighbor cell associated with an NRSRP parameter that satisfies a threshold. In some aspects, the UE <NUM> may measure narrowband reference signals (NRSs) to estimate the NRSRP parameter. An NRS may be used to provide phase reference for demodulation of downlink channels, and may be multiplexed in time and frequency with information-bearing symbols in subframes carrying NPBCH signals, narrowband PDCCH (NPDCCH) signals, and/or narrowband PDSCH (NPDSCH) signals, using <NUM> resource elements per subframe per antenna port.

However, in some cases, NRSs may be transmitted and received relatively infrequently, and may be sparse in time. For example, as shown by reference number <NUM>, NRSs (e.g., shown as NB-RS0 and NB-RS1) may only be transmitted in symbols <NUM>, <NUM>, <NUM>, and <NUM> of a subframe. Furthermore, if the UE <NUM> has not received or decoded a system information block (SIB) (e.g., SIB1) for a cell, such as a neighbor cell, then the UE <NUM> may be configured to monitor for NRSs only on subframes <NUM>, <NUM>, and <NUM> of a frame (e.g., in <NUM> out of <NUM> subframes of the frame). Furthermore, the UE <NUM> may be configured to monitor for NRSs on subframe <NUM> only on odd-numbered frames, because subframe <NUM> may carry an NSSS in subframe <NUM> in even-numbered frames.

To accurately estimate an NRSRP parameter, an NB-IoT UE <NUM> may need to measure a large number of NRSs (e.g., across <NUM> subframes or more), particularly when the NB-IoT UE <NUM> is deployed in a deep coverage scenario, such as near a cell edge and/or in a location with poor cell coverage (e.g., less than <NUM> dB, less than -<NUM> dB, and/or the like). Because the NRSs are received infrequently, this may require the NB-IoT UE <NUM> to stay awake (e.g., in an ON duration of a discontinuous reception (DRX) cycle) for a long time period (e.g., <NUM> subframes, <NUM> subframes, <NUM> subframes, or more), to measure enough NRSs for an accurate estimation of the NRSRP parameter (e.g., using NRS averaging). This may cause a battery of the NB-IoT UE <NUM> to drain quickly, particularly when the NB-IoT UE <NUM> estimates NRSRP parameters for multiple neighbor cells. Some techniques and apparatuses described herein conserve battery power of NB-IoT UEs <NUM> by, for example, using an NPBCH signal power to estimate an NRSRP parameter, indicating presence or absence of NRSs in all subframes of a frame, and/or the like.

<FIG> is a diagram of an example master information block (MIB) structure <NUM>, in accordance with various aspects of the present disclosure.

As described in more detail elsewhere herein, a UE <NUM> (e.g., an NB-IoT UE) may determine an NPBCH signal power, and may use the NPBCH signal power to estimate an NRSRP parameter, which may conserve battery power of the UE <NUM>. For example, the NPBCH signal power, with which an NPBCH signal is transmitted and/or received, may be the same as an NRS power with which an NRS is transmitted and/or received. Alternatively, the NPBCH signal power and the NRS power may differ by an amount (e.g., according to a ratio) capable of being determined by the UE <NUM>.

In NB-IoT, the NPBCH may be transmitted in subframe <NUM> of every frame, may include <NUM> symbols per subframe, and may carry a master information block (MIB). As shown, the MIB may include a deterministic portion <NUM> that changes across MIBs according to a known pattern. For example, the deterministic portion <NUM> may indicate a system frame number (SFN), a hyper SFN (hSFN), and/or the like, which may, for example, be incremented by a value of <NUM> across successive MIBs. As further shown, the MIB may include a semi-static portion <NUM> that includes contents that are the same across multiple MIBs and change relatively infrequently (e.g., once per <NUM> minutes, once per hour, and/or the like). For example, the semi-static portion <NUM> may indicate scheduling information for a SIB (e.g., SIB1), a system information value tag, an operation mode, and/or the like, and/or may include reserved or spare bits. As further shown, the MIB may include a parity portion <NUM> that includes one or more parity bits used for a parity check (e.g., a cyclic redundancy check (CRC) and/or the like). The parity portion <NUM> may change deterministically with the changes to the deterministic portion <NUM>.

Because contents of the MIB change infrequently and/or change according to a predetermined pattern, the UE <NUM> may decode a MIB, and may use the decoded contents to generate (e.g., reconstruct) reference MIBs corresponding to later-received MIBs. Upon receiving a later MIB on the NPBCH, the UE <NUM> may compare a reference MIB to the received MIB to estimate an RSRP parameter for the NPBCH, and may use the estimated RSRP parameter for the NPBCH to estimate an NRSRP parameter for NRSs. In this way, the UE <NUM> may reduce a wake time (e.g., in a DRX cycle) by avoiding or supplementing NRS measurements to determine an NRSRP parameter, thereby conserving battery power of the UE <NUM>.

<FIG> is a diagram illustrating an example <NUM> of estimating an NRSRP parameter, in accordance with various aspects of the present disclosure.

As shown in <FIG>, a base station <NUM> and a UE <NUM> (e.g., an NB-IoT UE) may communicate with one another, such as via an NB-IoT carrier, described above in connection with <FIG>. As shown by reference number <NUM>, the base station <NUM> may transmit, and the UE <NUM> may receive, a plurality of MIBs on an NPBCH. For example, the base station <NUM> may transmit, and the UE <NUM> may receive, the MIBs in subframe <NUM> of every NB-IoT frame.

As shown by reference number <NUM>, the UE <NUM> may determine an NPBCH signal power based at least in part on the plurality of MIBs. In some aspects, the NPBCH signal power may be represented as an RSRP parameter for an NPBCH signal (e.g., a signal that includes a MIB), and may be calculated as a correlation between a reference MIB and a received MIB.

For example, as shown by reference number <NUM>, the UE <NUM> may decode a first MIB (e.g., received earlier in time than a second MIB). As shown by reference number <NUM>, the UE <NUM> may generate a reference MIB using the first MIB. For example, the UE <NUM> may generate a deterministic portion <NUM> of the reference MIB using the first MIB and a predetermined pattern (e.g., by incrementing a bit counter that represents an SFN, an hSFN, and/or the like), may generate a semi-static portion <NUM> of the reference MIB to be the same as the semi-static portion <NUM> of the first MIB, may generate a parity portion <NUM> of the reference MIB such that the deterministic portion <NUM> and the semi-static portion <NUM> of the reference MIB pass a CRC, and/or the like. As shown by reference number <NUM>, the UE <NUM> may compare the reference MIB and a second MIB (e.g., received later in time than the first MIB).

As shown by reference number <NUM>, the UE <NUM> may estimate an NRSRP parameter based at least in part on the NPBCH signal power. In some aspects, the UE <NUM> may determine a correlation value based at least in part on comparing the reference MIB and the second MIB, and may estimate the NRSRP parameter using the correlation value. In some aspects, the UE <NUM> may non-coherently accumulate multiple correlation values determined across multiple frames (e.g., by generating multiple reference MIBs and comparing the reference MIBs to corresponding received MIBs). In some aspects, the UE <NUM> may estimate the NRSRP parameter using an accumulated correlation value if the accumulated correlation value (e.g., a correlation peak) satisfies a threshold, indicating that the accumulated correlation value has converged. In some aspects, the number of MIBs used to determine the NRSRP parameter (e.g., the number of MIBs required for convergence of the accumulated correlation value) may depend on a SINR for the PBCH. For example, a greater number of MIBs may be used for a lower SINR value, and a lesser number of MIBs may be used for a higher SINR value.

In some aspects, the UE <NUM> may set the NRSRP parameter to be equal to the accumulated correlation value and/or may map the accumulated correlation value to the NRSRP parameter, such as when the NPBCH signal power, with which an NPBCH signal is transmitted and/or received, is the same as an NRS power with which an NRS is transmitted and/or received. In some aspects, the NPBCH signal power and the NRS power may differ by an amount (e.g., according to a ratio) capable of being determined by the UE <NUM>. In this case, the UE <NUM> may estimate the NRSRP parameter using the NPBCH signal power and a ratio between the NPBCH signal power and a signal power associated with the set of narrowband reference signals (NRS). For example, the UE <NUM> may determine the ratio by comparing a converged PBCH signal power and a converged NRS signal power, and may calculate the NRSRP parameter by applying the ratio to the determined NPBCH signal power.

In some aspects, the UE <NUM> may estimate the NRSRP parameter for a serving cell using NPBCH signal power of the serving cell. Additionally, or alternatively, the UE <NUM> may estimate the NRSRP parameter for a neighbor cell using NPBCH signal power of the neighbor cell. Additionally, or alternatively, the UE <NUM> may estimate a plurality of NRSRP parameters, for a corresponding plurality of neighbor cells, based at least in part on a plurality of NPBCH signal powers corresponding to the plurality of neighbor cells. In this way, the UE <NUM> may conserve battery power associated with performing NRSRP measurements on multiple neighbor cells.

In some aspects, the UE <NUM> may estimate the NRSRP parameter using the NPBCH signal power based at least in part on determining that semi-static content of the MIB (e.g., in a semi-static portion <NUM> of the MIB) has not changed (e.g., from one MIB to the next MIB). In some aspects, the UE <NUM> may estimate the NRSRP parameter using the set of NRS (e.g., and not using the NPBCH signal power) based at least in part on determining that semi-static content of the MIB has changed (e.g., from one MIB to the next MIB). In this case, the UE <NUM> may use the set of NRS to estimate the NRSRP parameter until a new correlation value, associated with the plurality of MIBs, converges. For example, the UE <NUM> may obtain and decode a MIB with the changed contents, may generate a reference MIB from the MIB with the changed contents, may compare the reference MIB to a later MIB, and/or the like, in a similar manner as described above in connection with reference numbers <NUM>-<NUM>.

As shown by reference number <NUM>, in some aspects, the UE <NUM> may disable NRS measurements based at least in part on determining that the accumulated correlation value has converged and thus NPBCH signal power can be used to estimate the NRSRP parameter. In this case, the UE <NUM> may determine the NRSRP parameter using only the NPBCH signal power and not a signal power determined for the set of NRS. In this way, using the NPBCH signal power to estimate the NRSRP parameter may reduce a DRX cycle wake time and/or an NRSRP measurement period for the UE as compared to estimating the NRSRP parameter using only the set of NRS. Furthermore, battery power of the UE <NUM> may be conserved (e.g., due to the shorter DRX cycle wake time and/or fewer NRS measurements) by disabling NRS measurements.

Alternatively, the UE <NUM> may keep NRS measurements enabled, and may use the NPBCH signal power to supplement an NRS-based estimation of NRSRP. In this case, the UE <NUM> may determine the NRSRP parameter using both the NPBCH signal power and a signal power determined for the set of NRS. In some aspects, presence or absence of the set of NRS in one or more subframes of a frame (e.g., in all subframes of a frame) may be indicated to the UE <NUM> by the base station <NUM>. This may reduce a number of NRS measurements needed to determine NRSRP, thereby conserving battery power of the UE <NUM>. Additionally, or alternatively, supplementing NRS-based estimation of NRSRP with an NPBCH-based estimation of NRSRP may increase an accuracy of the determined NRSRP parameter.

As shown by reference number <NUM>, in some aspects, the base station <NUM> may transmit, and the UE <NUM> may receive, an indication of whether NPBCH-based NRSRP estimates are to be enabled or disabled (e.g., whether the UE <NUM> is to use the NPBCH signal power to estimate the NRSRP parameter). If the base station <NUM> indicates that NPBCH-based NRSRP estimates are enabled for the UE <NUM>, then the UE <NUM> may estimate the NRSRP parameter using the NPBCH signal power. If the base station <NUM> indicates NPBCH-based NRSRP estimates are disabled for the UE <NUM>, then the UE <NUM> may estimate the NRSRP parameter using the set of NRS.

In some aspects, the indication may be included in a MIB of the plurality of MIBs transmitted and/or received via the NPBCH. In some aspects, the indication may be included in a system information block (SIB) associated with a cell. In some aspects, the cell may be a serving cell. In some aspects, the cell may be a neighbor cell. The indication may indicate, for example, whether NPBCH-based NRSRP estimates are enabled or disabled for the cell, whether NPBCH-based NRSRP estimates are enabled or disabled for one or more neighbor cells of the cell, whether NPBCH-based NRSRP estimates are enabled or disabled for all intra-band cells, whether NPBCH-based NRSRP estimates are enabled or disabled for all cells, and/or the like.

In some aspects, the base station <NUM> may determine whether to enable or disable NPBCH-based estimates of the NRSRP parameter for a UE <NUM>, and may transmit the indication based at least in part on the determination. In some aspects, the determination may be based at least in part on a relative power between NPBCH transmissions and NRS transmissions. For example, if the relative power (e.g., a ratio or a difference) between NPBCH transmissions and NRS transmissions is greater than or equal to a threshold, then the base station <NUM> may determine to disable NPBCH-based estimates of the NRSRP parameter. In this way, the base station <NUM> may assist the UE <NUM> in avoiding inaccurate NRSRP estimates. Otherwise, the base station <NUM> may enable NPBCH-based estimates.

Additionally, or alternatively, the determination may be based at least in part on a frequency with which content (e.g., semi-static content) of a MIB changes. For example, if MIB content changes frequently (e.g., with a frequency or at a rate that is greater than or equal to a threshold), then the base station <NUM> may determine to disable NPBCH-based estimates because UE power savings associated with NPBCH-based estimates may be reduced or eliminated if the MIB content changes often. Otherwise, the base station <NUM> may enable NPBCH-based estimates.

<FIG> is a diagram illustrating another example <NUM> of estimating an NRSRP parameter, in accordance with various aspects of the present disclosure. Example <NUM> shows example operations that may be performed by a UE <NUM> in association with estimating an NRSRP parameter.

As shown by reference number <NUM>, the UE <NUM> may set an estimation flag (e.g., shown as continueEstimation) to True, and may perform one or more processes to estimate an NRSRP parameter (e.g., using averaging over a time window) when the estimation flag is set to True. In some aspects, the UE <NUM> may perform parallel processes (e.g., simultaneously and/or concurrently) associated with NPBCH-based estimation of the NRSRP parameter (e.g., shown by reference numbers <NUM>-<NUM>) and NRS-based estimation of the NRSRP parameter (e.g., shown by reference numbers <NUM>-<NUM>).

As shown by reference number <NUM>, the UE <NUM> may receive and decode a first MIB, and may set a MIB known flag (e.g., shown as MIBKnownFlag) to True based at least in part on decoding the first MIB (e.g., once the contents of the MIB are determined by the UE <NUM>). The UE <NUM> may then receive another MIB in a later frame (e.g., in subframe <NUM> of the late frame). If the contents of the MIB are not known or the current subframe is not subframe <NUM>, then the UE <NUM> may wait until the contents of the MIB are known and the current subframe is subframe <NUM> before proceeding with NPBCH-based estimation of the NRSRP parameter.

As shown by reference number <NUM>, the UE <NUM> may generate a reference MIB, using the current SFN and hSFN, from the first MIB, and may correlate the reference MIB (e.g., shown as reconstructed NPBCH) with a MIB received after the first MIB (e.g., shown as over-the-air (OTA) NPBCH). The UE <NUM> may non-coherently accumulate correlated MIBs (e.g., reference MIBs and received MIBs) for multiple frames.

As shown by reference number <NUM>, the UE <NUM> may determine whether a correlation peak (e.g., a peak correlation energy), associated with the non-coherently accumulated MIBs, satisfies a threshold. If the correlation peak does not satisfy the threshold, then the UE <NUM> may continue to receive MIBs and non-coherently accumulate the MIBs.

As shown by reference number <NUM>, if the correlation peak satisfies the threshold, then the UE <NUM> may map the correlation peak to an estimate of the NRSRP parameter, such as by adjusting the correlation peak, using a previously determined ratio, to estimate the NRSRP parameter. As shown by reference number <NUM>, the UE <NUM> may update the ratio between NPBCH signal power and NRS signal power. As shown by reference number <NUM>, the UE <NUM> may set the estimation flag to False, and may return the NRSRP parameter estimated using the correlation peak (e.g., using NPBCH-based estimation). For example, the UE <NUM> may store the NRSRP parameter in association with a cell, may use the NRSRP parameter to determine whether to request and/or perform a handover, and/or the like.

As shown by reference number <NUM>, the UE <NUM> may determine whether the current subframe is subframe <NUM>, subframe <NUM>, or subframe <NUM> in an odd-numbered frame. If the current subframe is not subframe <NUM>, subframe <NUM>, or subframe <NUM> in an odd-numbered frame, then the UE <NUM> may wait until the current subframe is subframe <NUM>, subframe <NUM>, or subframe <NUM> in an odd-numbered frame before proceeding with legacy NRSRP estimation (e.g., NRS-based estimation of the NRSRP parameter).

As shown by reference number <NUM>, if the current subframe is subframe <NUM>, subframe <NUM>, or subframe <NUM> in an odd-numbered frame, then the UE <NUM> may perform legacy NRSRP estimation. For example, the UE <NUM> may combine the measured NRS in the current subframe with previous NRS measurements (e.g., using accumulation), and may perform NRS averaging to estimate the NRSRP parameter. As shown by reference number <NUM>, the UE <NUM> may update the estimate of the NRSRP parameter using the NRS received in the current subframe.

As shown by reference number <NUM>, the UE <NUM> may determine whether the legacy NRSRP estimate has converged. If the legacy NRSRP estimate has not converged, then the UE <NUM> may continue to receive NRS and perform NRS averaging (e.g., concurrently with performing NPBCH-based estimation) until the legacy NRSRP estimate converges. In some aspects, the NPBCH-based estimate may converge before the legacy NRSRP estimate (e.g., when the correlation peak satisfies the threshold). In this case, the UE <NUM> may disable NRS measurements in some aspects (e.g., may stop performing the process described in connection with reference numbers <NUM>-<NUM>), as described elsewhere herein.

As shown by reference number <NUM>, if the legacy NRSRP estimate has converged, then the UE <NUM> may set the estimation flag to False, and may return the NRSRP parameter estimated using legacy NRSRP estimation (e.g., using NRS-based estimation). For example, the UE <NUM> may store the NRSRP parameter in association with a cell, may use the NRSRP parameter to determine whether to request and/or perform a handover, and/or the like. Additionally, or alternatively, the UE <NUM> may set the MIB known flag to False. For example, because the NRS-based estimation converged before the PBCH-based estimation, this may indicate that content of the MIB has changed. In this case, the UE <NUM> may obtain and decode a MIB with the changed content, and may use that MIB to perform NPBCH-based estimation, as described elsewhere herein. In this way, the UE <NUM> may fall back to legacy NRSRP estimation when NPBCH-based estimation fails or takes a long time to converge due to a change in MIB content. After accounting for the changed MIB content, the UE <NUM> may resume NPBCH-based estimation to conserve battery power.

<FIG> is a diagram illustrating another example <NUM> of estimating an NRSRP parameter, in accordance with various aspects of the present disclosure.

As shown in <FIG>, a base station <NUM> and a UE <NUM> (e.g., an NB-IoT UE) may communicate with one another, such as via an NB-IoT carrier, described above in connection with <FIG>. As shown by reference number <NUM>, the base station <NUM> may determine whether narrowband reference signals (NRS) are present in all downlink subframes of a frame. For example, in some cases, NRS may be present in all downlink subframes of a frame, such as any subframe that includes PBCH, PDCCH, and/or PDSCH (e.g., subframes <NUM>-<NUM> in every frame, subframes <NUM>-<NUM> in every frame, and subframe <NUM> in odd-numbered frames). In some aspects, the downlink subframes may exclude subframes that carry synchronization signals, such as an NPSS (e.g., in subframe <NUM> in every frame), NSSS (e.g., in subframe <NUM> in even-numbered frames), and/or the like. In some aspects, NRS may be present in all subframes (e.g., including subframes that carry synchronization signals).

As shown by reference number <NUM>, the base station <NUM> may transmit, and the UE <NUM> may receive, an indication of whether the narrowband reference signals are present in all downlink subframes of the frame. In some aspects, the indication may be a one bit indication, which indicates that either NRS is present in all downlink subframes, or that NRS is not present in all downlink subframes. Additionally, or alternatively, the UE <NUM> may monitor for and/or detect presence or absence of the narrowband reference signals in all downlink subframes (e.g., in addition to or instead of receiving the indication). In this way, the UE <NUM> may determine presence or absence of NRS in all downlink subframes without an explicit indication from the base station <NUM>, thereby conserving network resources.

As shown by reference number <NUM>, the UE <NUM> may estimate an NRSRP parameter based at least in part on the indication. For example, if NRS is present in all downlink subframes, then the UE <NUM> may measure NRS in all downlink subframes, and may use the measurements to determine the NRSRP parameter, thereby reducing a wake time of the UE in a DRX cycle and/or reducing a measurement period as compared to using sparse NRS measurements to determine the NRSRP parameter. In some aspects, if NRS is present in all downlink subframes, then the UE <NUM> may disable NPBCH-based estimates of the NRSRP parameter, and may enable NRS-based estimates of the NRSRP parameter. Alternatively, the UE <NUM> may use NPBCH-based estimates to improve the accuracy of NRS-based estimates.

In some aspects, if NRS is not present in all downlink subframes, then the UE <NUM> may enable NPBCH-based estimates, and may disable NRS-based estimates (e.g., after the NPBCH-based estimate converges and/or as long as the MIB contents remain unchanged). In this way, the UE <NUM> may conserve battery power used to estimate the NRSRP parameter.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a UE (e.g., UE <NUM> and/or the like) performs operations associated with NRSRP parameter estimation.

As shown in <FIG>, in some aspects, process <NUM> includes receiving a plurality of master information blocks (MIBs) on a narrowband physical broadcast channel (NPBCH) (block <NUM>). For example, the UE receives (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) a plurality of MIBs on an NPBCH, as described above in connection with <FIG> and <FIG>.

As further shown in <FIG>, in some aspects, process <NUM> includes determining an NPBCH signal power based at least in part on the plurality of MIBs (block <NUM>). For example, the UE determines (e.g., using controller/processor <NUM> and/or the like) an NPBCH signal power based at least in part on the plurality of MIBs, as described above in connection with <FIG> and <FIG>.

As further shown in <FIG>, in some aspects, process <NUM> includes estimating a narrowband reference signal received power (NRSRP) parameter based at least in part on the NPBCH signal power (block <NUM>). For example, the UE estimates (e.g., using controller/processor <NUM> and/or the like) an NRSRP parameter based at least in part on the NPBCH signal power, as described above in connection with <FIG> and <FIG>. In some aspects, the UE estimates the NRSRP parameter for a set of narrowband reference signals.

Process <NUM> may include additional aspects, such as any single aspect or any combination of aspects described below.

In some aspects, using the NPBCH signal power reduces at least one of a discontinuous reception (DRX) cycle wake time or an NRSRP measurement period for the UE as compared to estimating the NRSRP parameter using only the set of NRS. In some aspects, determining the NPBCH signal power comprises: decoding a first MIB of the plurality of MIBs; generating a reference MIB using the decoded first MIB; and comparing the reference MIB and a second MIB of the plurality of MIBs.

In some aspects, the NRSRP parameter is estimated using the NPBCH signal power and a ratio between the NPBCH signal power and a signal power associated with the set of NRS. In some aspects, the NRSRP parameter is estimated using the NPBCH signal power based at least in part on a determination that semi-static content, included in the plurality of MIBs, has not changed. In some aspects, the UE may estimate the NRSRP parameter using the set of NRS based at least in part on a determination that semi-static content, included in the plurality of MIBs, has changed.

In some aspects, the UE may disable NRS measurements based at least in part on a determination that a correlation value associated with the plurality of MIBs satisfies a threshold. In some aspects, the NRSRP parameter is estimated using only the NPBCH signal power and not a signal power determined for the set of NRS. In some aspects, the NRSRP parameter is estimated using the NPBCH signal power and a signal power determined for the set of NRS. In some aspects, presence or absence of the set of NRS in all downlink subframes of a frame is indicated to the UE by a base station.

In some aspects, the UE may estimate the NRSRP parameter using the set of NRS based at least in part on an indication, from a base station, that NPBCH-based NRSRP estimates are disabled for the UE. In some aspects, the NRSRP parameter is estimated using the NPBCH signal power based at least in part on an indication, from a base station, that NPBCH-based NRSRP estimates are enabled for the UE. In some aspects, the UE may receive an indication, from a base station, of whether NPBCH-based NRSRP estimates are enabled or disabled for the UE. In some aspects, the indication is received in a MIB of the plurality of MIBs. In some aspects, the indication is received in a system information block (SIB) associated with a cell. In some aspects, the indication indicates at least one of: whether NPBCH-based NRSRP estimates are enabled or disabled for the cell, whether NPBCH-based NRSRP estimates are enabled or disabled for one or more neighbor cells of the cell, whether NPBCH-based NRSRP estimates are enabled or disabled for all intra-band cells, whether NPBCH-based NRSRP estimates are enabled or disabled for all cells, or some combination thereof.

In some aspects, the NRSRP parameter is estimated for a serving cell. In some aspects, the NRSRP parameter is estimated for a neighbor cell. In some aspects, a plurality of NRSRP parameters are estimated, for a corresponding plurality of neighbor cells, based at least in part on a plurality of NPBCH signal powers corresponding to the plurality of neighbor cells. In some aspects, the plurality of MIBs includes a different quantity of MIBs for different SINR values determined for the NPBCH.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a base station, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a base station (e.g., base station <NUM> and/or the like) performs operations associated with NRSRP parameter estimation.

As shown in <FIG>, in some aspects, process <NUM> includes determining whether to enable or disable narrowband physical broadcast channel (NPBCH)-based estimates of a narrowband reference signal received power (NRSRP) parameter for a user equipment (UE) (block <NUM>). For example, the base station determines (e.g., using controller/processor <NUM> and/or the like) whether to enable or disable NPBCH-based estimates of an NRSRP parameter for a UE, as described above in connection with <FIG> and <FIG>.

As further shown in <FIG>, process <NUM> includes transmitting, to the UE, an indication of whether NPBCH-based estimates of the NRSRP parameter are enabled or disabled for the UE based at least in part on the determination (block <NUM>). For example, the base station transmits (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like), to the UE, an indication of whether NPBCH-based estimates of the NRSRP parameter are enabled or disabled for the UE based at least in part on the determination, as described above in connection with <FIG> and <FIG>.

In some aspects, the determination is based at least in part on a relative power between NPBCH transmissions and narrowband reference signal (NRS) transmissions. In some aspects, the determination is based at least in part on a frequency with which content of a master information block (MIB) changes.

As shown in <FIG>, in some aspects, process <NUM> may include determining whether narrowband reference signals are present in all downlink subframes of a frame (block <NUM>). For example, the base station may determine (e.g., using controller/processor <NUM> and/or the like) whether narrowband reference signals are present in all downlink subframes of a frame, as described above in connection with <FIG>.

As further shown in <FIG>, in some aspects, process <NUM> may include transmitting an indication of whether the narrowband reference signals are present in all downlink subframes of the frame (block <NUM>). For example, the base station may transmit (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) an indication of whether the narrowband reference signals are present in all downlink subframes of the frame, as described above in connection with <FIG>. In some aspects, the indication is a one bit indication.

Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the The intended limitations are defined by the claims.

As used herein, a "processor" is implemented in hardware, firmware, or a combination of hardware and software.

The intended limitations are defined by the claims.

Claim 1:
A method of wireless communication (<NUM>) performed by a user equipment, UE, comprising:
Receiving (<NUM>) a plurality of master information blocks, MIBs, on a narrowband physical broadcast channel, NPBCH;
Determining (<NUM>) an NPBCH signal power based at least in part on the plurality of MIBs; and
Estimating (<NUM>) a narrowband reference signal received power, NRSRP, parameter based at least in part on the NPBCH signal power.