Patent Description:
More specifically, it discusses possible enhancements regarding the presence of NRS on non-anchor carriers in Rel-<NUM> considering both the desire to allow for more flexible network operation while minimizing any impact to the UE power consumption. It concludes that it may be sufficient if NRS are transmitted in subframes corresponding to the duration of the corresponding narrowband physical downlink control channel (NPDCCH) search spaces (irrespective of actual NPDCCH transmissions) and the associated actual NPDSCH transmissions. Further, the draft deems it beneficial in terms of facilitating cross-subframe channel estimation if NRS are transmitted a few narrowband-Internet of Things (NB-IoT) downlink (DL) subframes before and after the subframes corresponding to the NPDCCH search space and any associated NPDSCH transmissions.

<NPL>", mentions that without always-on NRS transmissions, a UE that monitors paging on one particular non-anchor carrier has to retune back to the corresponding anchor carrier for radio resource management (RRM) measurements and time frequency tracking, therefore increasing the UE power consumption. It therefore favors always-on NRS transmission to avoid UE power consumption caused by retuning. It observes that even if a narrowband reference signal received power measurement is based on a non-anchor carrier, a UE can still correctly select a neighbor cell with information on NRS-power offset in radio resource control (RRC) signaling.

Preferred embodiments of the invention are defined by the dependent claims. While several embodiments and/or examples are disclosed throughout this description, the subject matter for which protection is sought is limited to such examples and/or embodiments that are encompassed by the scope of the appended claims. Embodiments and/or examples described herein that do not fall under the scope of the appended claims are to be regarded as useful for understanding the invention.

In some aspects, a method of wireless communication, performed by a user equipment (UE), may include receiving a configuration for identifying narrowband reference signal (NRS) tones that are to be received in association with a scheduled paging occasion, wherein the NRS tones are configured to be received via a non-anchor carrier regardless of whether a page is to be received in connection with the scheduled paging occasion; and receiving the NRS tones via the non-anchor carrier based at least in part on the configuration.

In some aspects, a user equipment for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive a configuration for identifying NRS tones that are to be received in association with a scheduled paging occasion, wherein the NRS tones are configured to be received via a non-anchor carrier regardless of whether a page is to be received in connection with the scheduled paging occasion; and receive the NRS tones via the non-anchor carrier based at least in part on the configuration.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a user equipment, may cause the one or more processors to receive a configuration for identifying NRS tones that are to be received in association with a scheduled paging occasion, wherein the NRS tones are configured to be received via a non-anchor carrier regardless of whether a page is to be received in connection with the scheduled paging occasion; and receive the NRS tones via the non-anchor carrier based at least in part on the configuration.

In some aspects, an apparatus for wireless communication may include means for receiving a configuration for identifying NRS tones that are to be received in association with a scheduled paging occasion, wherein the NRS tones are configured to be received via a non-anchor carrier regardless of whether a page is to be received in connection with the scheduled paging occasion; and during the scheduled paging occasion, means for receiving the NRS tones via the non-anchor carrier based at least in part on the configuration.

In some aspects, a method of wireless communication, performed by a UE, may include determining that an NRS tone is to be received via a non-anchor carrier based at least in part on a characteristic of the non-anchor carrier; and activating from a low-power mode to determine a signal-to-noise ratio (SNR) of the non-anchor carrier based at least in part on the NRS tone.

In some aspects, a user equipment for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to determine that an NRS tone is to be received via a non-anchor carrier based at least in part on a characteristic of the non-anchor carrier; and activate from a low-power mode to determine an SNR of the non-anchor carrier based at least in part on the NRS tone.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a user equipment, may cause the one or more processors to determine that an NRS tone is to be received via a non-anchor carrier based at least in part on a characteristic of the non-anchor carrier; and activate from a low-power mode to determine an SNR of the non-anchor carrier based at least in part on the NRS tone.

In some aspects, an apparatus for wireless communication may include means for determining that an NRS tone is to be received via a non-anchor carrier based at least in part on a characteristic of the non-anchor carrier; and means for activating from a low-power mode to determine an SNR of the non-anchor carrier based at least in part on the NRS tone.

In some aspects, a method of wireless communication, performed by a base station (BS), may include determining a configuration for providing NRS tones in association with a scheduled paging occasion; and providing the NRS tones to at least one user equipment, via a non-anchor carrier, regardless of whether a page is to be provided in connection with the scheduled paging occasion, wherein at least one of the NRS tones permits a quality measurement, of the non-anchor carrier, to be made by the at least one user equipment.

In some aspects, a base station for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to determine a configuration for providing NRS tones in association with a scheduled paging occasion; and provide the NRS tones to at least one user equipment, via a non-anchor carrier, regardless of whether a page is to be provided in connection with the scheduled paging occasion, wherein at least one of the NRS tones permits a quality measurement, of the non-anchor carrier, to be made by the at least one user equipment.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a base station, may cause the one or more processors to determine a configuration for providing NRS tones in association with a scheduled paging occasion; and provide the NRS tones to at least one user equipment, via a non-anchor carrier, regardless of whether a page is to be provided in connection with the scheduled paging occasion, wherein at least one of the NRS tones permits a quality measurement, of the non-anchor carrier, to be made by the at least one user equipment.

In some aspects, an apparatus for wireless communication may include means for determining a configuration for providing NRS tones in association with a scheduled paging occasion; and means for providing the NRS tones to at least one user equipment, via a non-anchor carrier, regardless of whether a page is to be provided in connection with the scheduled paging occasion, wherein at least one of the NRS tones permits a quality measurement, of the non-anchor carrier, to be made by the at least one user equipment.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and processing system as substantially described herein with reference to and as illustrated by the accompanying drawings and specification.

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 using narrowband reference signal (NRS) tones in a non-anchor carrier to determine quality of the non-anchor carrier, 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> may include means for receiving a configuration for identifying narrowband reference signal (NRS) tones that are to be received in association with a scheduled paging occasion, wherein the NRS tones are configured to be received via a non-anchor carrier regardless of whether a page is to be received in connection with the scheduled paging occasion; means for receiving the NRS tones via the non-anchor carrier based at least in part on the configuration; and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>.

In some aspects, UE <NUM> may include means for determining that an NRS tone is to be received via a non-anchor carrier based at least in part on a characteristic of the non-anchor carrier; means for activating from a low-power mode to determine a signal-to-noise ratio (SNR) of the non-anchor carrier based at least in part on the NRS tone; and/or the like. In some aspects, such means may include one or more components of UE <NUM> described in connection with <FIG>.

In some aspects, base station <NUM> may include means for determining a configuration for providing NRS tones in association with a scheduled paging occasion; means for providing the NRS tones to at least one user equipment, via a non-anchor carrier, regardless of whether a page is to be provided in connection with the scheduled paging occasion, wherein at least one of the NRS tones permits a quality measurement, of the non-anchor carrier, to be made by the at least one user equipment; and/or the like. In some aspects, such means may 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). The transmission time line for each of the downlink and uplink may be partitioned into units of radio frames. 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-noise-and-interference ratio (SNR), 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.

In some instances, a base station (e.g., BS <NUM>) and a user equipment (e.g., UE <NUM>) may communicate with one another via an anchor carrier and a non-anchor carrier pair. The anchor carrier may be used for synchronization between the BS and the UE, and the non-anchor carrier may be used for paging. According to some instances, quality measurements (e.g., radio resource management (RRM) measurements) of the anchor carrier are to be performed every discontinuous reception (DRX) cycle. Such quality measurements may be used to determine whether the UE is to reselect an anchor carrier/non-anchor carrier pair for communication with the BS.

However, due to the anchor carrier and non-anchor carrier being separated by a frequency (e.g., <NUM>), which may be preconfigured, and having different power characteristics, the anchor carrier and non-anchor carrier may be subject to different levels of interference. Therefore, the quality of the anchor carrier may not indicate, represent, or be the same as the quality of the non-anchor carrier. In some instances, interference on the non-anchor carrier may prevent the UE from receiving pages from the BS, despite the anchor carrier having strong quality. If a page is not received via the non-anchor carrier due to the interference, the UE may not be able to determine the quality of the non-anchor carrier (e.g., because NRS tones may be present only when the page is present or received). Furthermore, if the quality of the anchor carrier is strong (e.g., the signal-to-noise ratio (SNR) of the anchor carrier satisfies a threshold), the UE may not reselect a different anchor carrier/non-anchor carrier pair because the UE may not recognize the interference on the non-anchor carrier without receiving the page.

Some aspects, described herein, permit a UE to detect interference on the non-anchor carrier and determine whether a reselection of an anchor carrier/non-anchor carrier pair should be made by making a quality measurement of the non-anchor carrier even when a page is not received. For example, NRS tones (pilot signals) may be made available to the UE during a paging occasion regardless of whether a page is present or received via the non-anchor carrier. In some aspects, a BS may be configured to transmit the NRS tones during a scheduled paging occasion (e.g., during every paging occasion, once every Mth DRX cycle, and/or the like), and a UE may be configured to receive the NRS tones during the scheduled paging occasion. Therefore, the UE may determine the quality of the non-anchor carrier based at least in part on the NRS tones to determine whether a reselection of the anchor carrier/non-anchor carrier pair is to be made for communication with the BS. In some aspects, the UE may monitor the non-anchor carrier to determine whether NRS tones are to be present on the non-anchor carrier based at least in part on a characteristic of the non-anchor carrier. For example, the UE may determine that the non-anchor carrier is to be used during a random access channel (RACH) procedure, which may involve receiving NRS tones from the BS. The UE may detect the NRS tones associated with the RACH procedure and determine the quality of the non-anchor carrier based at least in part on the NRS tones associated with the RACH procedure.

Accordingly, examples herein enable a UE to make a quality measurement of a non-anchor carrier using NRS tones within the non-anchor carrier. As a result, the UE may conserve power resources and/or processing resources by performing an early termination of page monitoring and not wasting the power resources and/or processing resources to monitor for pages when there is a strong non-anchor carrier connection (because the NRS tones indicate the strong connection). Furthermore, some aspects described herein may prevent a UE from missing one or more pages by performing a reselection of the anchor carrier/non-anchor carrier pair when the measure of quality of the non-anchor carrier does not satisfy a threshold, thus conserving power resources and/or processing resources that may otherwise be consumed due to missing the pages. Still further, some aspects described herein may enable a UE to maintain synchronization with the BS based at least in part on the quality measurements of the non-anchor carrier, thus conserving power resources and/or processing resources associated with the UE searching for anchor carrier/non-anchor carrier pairs to keep synchronization with BS.

<FIG> is a diagram illustrating an example <NUM> of using NRS tones in a non-anchor carrier to determine a measure of quality of the non-anchor carrier, in accordance with various aspects of the present disclosure. As shown in <FIG>, example <NUM> includes a BS <NUM> and a UE <NUM>. In example <NUM> of <FIG>, UE <NUM> uses NRS tones to assess the quality of the non-anchor carrier used during a communication session with BS <NUM>.

As shown in <FIG>, and by reference number <NUM>, BS <NUM> determines a configuration for providing NRS tones, via a non-anchor carrier, in association with a paging occasion. The NRS tones may be used by the UE <NUM> to determine a quality measurement of the non-anchor carrier. The paging occasion may be a scheduled paging occasion. In some aspects, paging occasions may be scheduled or configured such that UE <NUM> is to monitor for pages at or during a time period associated with the paging occasions, during particular locations of subframes, and/or the like. According to some aspects described herein, the configuration indicates that the NRS tones are to be provided regardless of whether a page is transmitted to UE <NUM> in association with the paging occasion.

In some aspects, the configuration may identify a spreading factor (SF) (e.g., a minimum SF) of the NRS tones relative to a timing of the paging occasion. For example, the SF may indicate a number of subframes that are to include NRS tones before, after, or during the paging occasion. In some aspects, the configuration may indicate that zero NRS tones are to be received when NRS tones, in the non-anchor carrier, are not to be used to determine a quality measurement. In some aspects, the configuration identifies locations of the NRS tones relative to the scheduled paging occasion. For example, the configuration may indicate within which subframes, relative to the paging occasion, the NRS tones are to be included. More specifically, as described herein, the configuration may indicate one or more sets of subframes that are to include the NRS tones relative to which subframe is associated with the paging occasion (e.g., at which subframe the paging occasion is to occur). In some aspects, the configuration may be preconfigured according to a specification of a network associated with BS <NUM> and UE <NUM>. For example, a number of the NRS tones that are to be provided to UE <NUM> may be preconfigured based at least in part on the specification of the network.

In some aspects, the configuration may indicate when NRS tones are to be provided according to DRX cycles. For example, the configuration may indicate the NRS tones are to be provided once every Mth DRX cycle, where M is a threshold number of DRX cycles. Accordingly, on the Mth DRX cycle, UE <NUM> may be configured to monitor for and/or receive the NRS tones. Accordingly, during the remaining M-<NUM> DRX cycles between the Mth DRX cycles, UE <NUM> may enter into a low-power mode. For example, UE <NUM> may enter into a sleep mode during the remaining M-<NUM> DRX cycles between the Mth DRX cycles. In sleep mode, UE <NUM> may perform (in some instances, only perform) wake up signal (WUS) detection or narrowband physical downlink control channel (NPDCCH) detection if the UE <NUM> does not have WUS detection capabilities. Accordingly, UE <NUM> may wake up to determine a measure of quality of the non-anchor carrier if regularly received NRS tones and a paging occasion do not overlap. In some aspects, the configuration may identify at least one of a periodicity, a timing, an offset, or a number of subframes associated with the NRS tones regardless of the DRX cycle. For example, the configuration may identify that BS <NUM> is configured to provide (and UE <NUM> is to be configured to receive) the NRS tones every threshold period of time (e.g., every <NUM>, every <NUM>, and/or the like) or every X number of subframes (e.g., every 15th subframe, every 30th subframe, and/or the like).

As further shown in <FIG>, and by reference number <NUM>, BS <NUM> may transmit the configuration for identifying the NRS tones to UE <NUM> and provide the NRS tones in association with paging occasions. In some aspects, BS <NUM> may transmit the configuration within a communication that includes system information (SI). For example, BS <NUM> may broadcast the configuration within the SI to enable UE <NUM> to successfully connect to a network associated with BS <NUM>. Accordingly, UE <NUM> may receive the configuration via a broadcast from BS <NUM> once UE <NUM> is within communication range of BS <NUM>.

In some aspects, BS <NUM> provides the NRS tones for every paging occasion that is scheduled for UE <NUM>, regardless of whether a page is transmitted from BS <NUM> in association with the paging occasions. In some aspects, the NRS tones are provided once every threshold number of DRX cycles. Accordingly, in order to enable UE <NUM> to enter a low-power mode (e.g., a sleep mode), UE <NUM> may be configured to monitor for and/or analyze NRS tones only during every Mth DRX cycle, as described above.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> receives the configuration, and during scheduled paging occasions, determines the measure of quality of the non-anchor carrier based at least in part on the configuration and the NRS tones. For example, UE <NUM> may make an RRM measurement and/or an SNR measurement of the non-anchor carrier. Accordingly, regardless of whether a page is received during a particular paging occasion, UE <NUM> may make a quality measurement of the non-anchor carrier using the NRS tones received in association with the paging occasion. In some aspects, UE <NUM> may make an RRM measurement and/or an SNR measurement of the anchor carrier based at least in part on the configuration and/or based at least in part on determining a measurement associated with the non-anchor carrier.

According to some aspects, UE <NUM> is configured to monitor for the NRS tones according to the configuration. For example, UE <NUM> may be configured to monitor for the NRS tones every Mth DRX cycle. Accordingly, UE <NUM> may be configured to perform RRM measurements, resynchronization, SNR estimation, and/or the like based at least in part on the timing of receiving the NRS tones every Mth DRX cycle. In some aspects, UE <NUM> may make RRM measurements based at least in part on NRS tones in the anchor carrier, and SNR measurements based at least in part on NRS tones in the non-anchor carrier. Accordingly, UE <NUM> may enter into a low-power mode according to the configuration and wake up during the Mth DRX cycle and/or paging occasions to detect the NRS tones and assess the quality of the non-anchor channel. Accordingly, in some aspects, during a first DRX cycle, UE <NUM> may determine a quality measurement based at least in part on an NRS tone received via an anchor carrier associated with the non-anchor carrier and determine, during a second DRX cycle, an SNR based at least in part on one of the NRS tones received via the non-anchor carrier. Additionally, or alternatively, UE <NUM> may identify NRS tones during a first DRX cycle and perform a WUS detection or an NPDCCH detection during a second DRX cycle (that is different from the first DRX cycle). Accordingly, UE <NUM> may determine when to monitor for NRS tones based at least in part on the DRX cycles.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> may maintain the same anchor carrier/non-anchor carrier pair or reselect an anchor carrier/non-anchor carrier pair based at least in part on the quality of the non-anchor carrier. For example, during scheduled paging occasions, UE <NUM> may determine a quality measurement (e.g., RRM measurement, SNR measurement, and/or the like) of the non-anchor carrier based at least in part on one or more of the NRS tones received according to the configuration. In some aspects, UE <NUM> may reselect a carrier (e.g., the anchor carrier and/or non-anchor carrier) based at least in part on the quality measurement. For example, UE <NUM> may determine, from the quality measurement, that the non-anchor carrier is not suitable to receive a page within a threshold number of attempts to receive the page or within a threshold number of retransmissions of the page from BS <NUM>. In such cases, the threshold number of attempts may correspond to a reliability metric of a network associated with BS <NUM>.

In some aspects, UE <NUM> may maintain the same anchor carrier/non-anchor carrier pair based at least in part on the quality measurement. For example, UE <NUM> may maintain at least one of a time tracking loop (TTL) or frequency tracking loop (FTL) associated with BS <NUM> based at least in part on the quality measurement. For example, the quality measurement may indicate that the quality of the non-anchor carrier is suitable to receive a page within the threshold number of attempts to receive the page or within the threshold number of retransmissions from BS <NUM>. In some aspects, UE <NUM> may avoid tuning to an anchor carrier for resynchronization when the SNR of the non-anchor carrier satisfies a threshold SNR.

Accordingly, UE <NUM> may be able to assess the quality of the non-anchor carrier based at least in part on the NRS tones received according to the configuration received from BS <NUM>. When the NRS tones indicate that the quality of the non-anchor carrier is relatively high (e.g., when the SNR of the non-anchor carrier satisfies a high-quality threshold), UE <NUM> may terminate page monitoring and/or avoid searches to keep synchronization with BS <NUM> to conserve power and/or processing resources. Furthermore, when the NRS tones indicate that the quality of the non-anchor carrier is relatively low (e.g., when the SNR of the non-anchor carrier satisfies a low-quality threshold), UE <NUM> may conserve power and/or processing resources associated with attempting to receive pages by reselecting an anchor carrier/non-anchor carrier pair that has better quality.

<FIG> is a diagram illustrating an example <NUM> of using NRS tones in a non-anchor carrier to determine a measure of quality of the non-anchor carrier, in accordance with various aspects of the present disclosure. As shown in <FIG>, example <NUM> includes a BS <NUM> and a UE <NUM>. UE <NUM>, in example <NUM>, may be configured to monitor paging in a non-anchor carrier of BS <NUM>. In example <NUM> of <FIG>, UE <NUM> uses NRS tones associated with one or more communications from BS <NUM> to assess the quality of the non-anchor carrier.

As shown in <FIG>, and by reference number <NUM>, BS <NUM> transmits NRS tones via a non-anchor carrier in association with a communication. Over the course of a communication session between BS <NUM> and UE <NUM>, some communications may transmit or include NRS tones within the non-anchor carrier of the communication session. For example, a communication associated with a RACH procedure, a single cell point to multipoint (SC-PTM) transmission, and/or the like may send or include NRS tones, as such communications involve or are associated with BS <NUM> sending NRS tones. Accordingly, BS <NUM> may send one or more communications to UE <NUM> that are configured to include or be associated with NRS tones.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> is to detect the presence of NRS tones based at least in part on the type of communication and use the NRS tones to measure quality of the non-anchor carrier. For example, UE <NUM> may be configured to determine that an NRS tone is to be received via the non-anchor carrier based at least in part on a characteristic of the non-anchor carrier that indicates that an NRS tone is to be present during the communication. For example, UE <NUM> may determine which subframes of the non-anchor carrier are to include the NRS tone based at least in part on narrowband physical random access channel (NPRACH) resources (e.g., a location, a periodicity, a length, and/or the like of the NPRACH) or an NPDCCH search space periodicity (e.g., an offset, a length, and/or the like of the NPDCCH). In some aspects, UE <NUM> may activate from a low-power mode (or "wake up") to determine the SNR of the non-anchor carrier based at least in part on the NRS tone.

As further shown in <FIG>, and by reference number <NUM>, UE <NUM> may maintain the anchor carrier/non-anchor carrier pair or reselect the anchor carrier based at least in part on the measure of quality of the non-anchor carrier. UE <NUM> may use any suitable means to determine the quality of the non-anchor carrier using the NRS tone to maintain or reselect the anchor carrier/non-anchor carrier pair, as described herein.

Accordingly, UE <NUM> may take advantage of NRS tones that are provided during ordinary communications between BS <NUM> and UE <NUM>. Therefore, by monitoring for NRS tones within the non-anchor carrier based at least in part on types of communications between BS <NUM> and UE <NUM>, power resources and processing resources associated with monitoring for paging and/or reselecting an anchor carrier/non-anchor carrier pair can be conserved.

<FIG> is a diagram illustrating an example <NUM> of using NRS tones in a non-anchor carrier to determine a measure of quality of the non-anchor carrier, in accordance with various aspects of the present disclosure. As shown in <FIG>, NRS tones may be provided within subframes of a non-anchor carrier in association with a scheduled paging occasion that is to occur at subframe N. In some aspects, each one of the subframes that is to include NRS tones includes a single, respective NRS tone. Example <NUM> illustrates how a configuration may identify a location of the NRS tones relative to a scheduled paging occasion.

As shown in <FIG>, and by reference number <NUM>, eight subframes (N-<NUM> to N-<NUM>) (SF = <NUM>) are included within a set of subframes of the non-anchor carrier before the scheduled paging occasion. Accordingly, UE <NUM> may identify, based at least in part on the configuration, that eight subframes preceding the scheduled paging occasion (i.e., subframes N-<NUM> to N-<NUM>) are to be monitored for NRS tones.

As shown in <FIG>, and by reference number <NUM>, eight subframes (N+<NUM> to N-<NUM>) (SF = <NUM>) are included within a set of subframes of the non-anchor carrier during the scheduled paging occasion. Accordingly, a first set of subframes (N-<NUM> to N-<NUM>) are to be received before the scheduled paging occasion and a second set of subframes (N to N+<NUM>) are to be received after the scheduled paging occasion. The first set of subframes may include the same number of subframes as the second set of subframes (as shown), or the first set of subframes may include a different number of subframes than the second set of subframes. Accordingly, UE <NUM> may identify, based at least in part on the configuration, that four subframes preceding the scheduled paging occasion (i.e., subframes N-<NUM> to N-<NUM>) and four subframes succeeding the scheduled paging occasion (i.e., subframes N to N+<NUM>) are to be monitored for NRS tones.

Accordingly, a set of subframes (which may be defined by the SF indicated in the configuration of the system information) may include NRS tones that are to be received and/or detected by UE <NUM>. As explained above, one or more subframes, of the set of subframes, may occur before and/or after the scheduled paging occasion.

<FIG> and <FIG> are diagrams illustrating examples associated with using NRS tones in a non-anchor carrier to determine a measure of quality of the non-anchor carrier, in accordance with various aspects of the present disclosure. <FIG> and <FIG> include graphs <NUM>, <NUM>, respectively, that illustrate example power savings using NRS tones to determine a measure of quality of a non-anchor carrier in accordance with various aspects of the present disclosure. Graph <NUM> shows an example of power savings of using NRS tones provided and/or received in association with a paging occasion, regardless of the presence of a page on the non-anchor carrier, for a static channel, and Graph <NUM> shows an example of the same for a fading channel. As shown by reference number <NUM> in <FIG>, with a maximum coupling loss (MCL) of between <NUM> and at least <NUM> dB, power savings are achieved in a static channel for retransmissions (Rmax) of up to <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. Further, as shown by reference number <NUM> in <FIG>, with an MCL between <NUM> and at least <NUM> dB, power savings are achieved in a fading channel for retransmissions (Rmax) of up to <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

Other examples may differ from what is described with respect to <FIG> and <FIG>.

<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>) uses NRS tones received in association with a paging occasion, regardless of whether a page is received, to assess a quality of a non-anchor carrier.

As shown in <FIG>, in some aspects, process <NUM> may include receiving a configuration for identifying NRS tones that are to be received in association with a scheduled paging occasion, wherein the NRS tones are configured to be received via a non-anchor carrier regardless of whether a page is to be received in connection with the scheduled paging occasion (block <NUM>). For example, UE <NUM> (e.g., using antenna <NUM>, demodulator <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may receive the configuration from BS <NUM> to determine a measure of quality of the non-anchor carrier. In some aspects, UE <NUM> may receive the configuration based at least in part on being in communication with BS <NUM>, based at least in part on being within a communication range of BS <NUM>, and/or the like.

As shown in <FIG>, in some aspects, process <NUM> may include receiving the NRS tones via the non-anchor carrier based at least in part on the configuration (block <NUM>). For example, UE <NUM> (e.g., using receive processor <NUM>, controller/processor <NUM>, and/or the like) may receive the NRS tones via the non-anchor carrier based at least in part on the configuration, as described above.

In a first aspect, process <NUM> includes determining, during the scheduled paging occasion, a quality measurement of the non-anchor carrier based at least in part on one or more of the NRS tones.

In a second aspect, alone or in combination with the first aspect, the quality measurement comprises a radio resource management (RRM) measurement.

In a third aspect, alone or in combination with one or more of the first and second aspects, the UE is configured to determine a signal-to-noise ratio (SNR), of the non-anchor carrier, from at least one of the NRS tones.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the UE is configured to reselect a carrier based at least in part on a quality measurement, wherein the quality measurement indicates that a quality of the non-anchor carrier is not suitable to receive a page within a threshold number of attempts to receive the page.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the UE is configured to maintain at least one of a time tracking loop or a frequency tracking loop based at least in part on a quality measurement, wherein the quality measurement indicates that a quality of the non-anchor carrier is suitable to receive a page within a threshold number of attempts to receive the page.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the configuration identifies a minimum spreading factor of the NRS tones relative to a timing of the scheduled paging occasion.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the configuration identifies a minimum number of subframes with presence of NRS tones relative to a timing of the scheduled paging occasion.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the configuration identifies that zero NRS tones are to be received when the UE is not to use NRS tones in the non-anchor carrier to determine a quality measurement.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the configuration is received within system information (SI) provided to the UE by a network.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the configuration identifies locations of the NRS tones relative to the scheduled paging occasion.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the configuration identifies that the NRS tones are to be located within a set of subframes of the non-anchor carrier to be received before the scheduled paging occasion.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the configuration identifies that a first set of the NRS tones are to be located within a first set of subframes to be received before the scheduled paging occasion and a second set of the NRS tones are to be located within a second set of subframes to be received after the scheduled paging occasion.

In a thirteenth aspect, alone or in combination with the twelfth aspect, a number of subframes in the first set of subframes matches a number of subframes in the second set of subframes.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the configuration identifies at least one of: that the NRS tones are to be received in a subset of discontinuous reception cycles associated with the non-anchor carrier; at least one of a periodicity, a timing, an offset, or a number of subframes associated with the NRS tones regardless of a discontinuous reception cycle associated with the non-anchor carrier, or a combination thereof.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, a number of the NRS tones to be received is preconfigured based at least in part on a specification of a network of the non-anchor carrier.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, the UE is configured to avoid tuning to an anchor carrier for resynchronization when a signal-to-noise ratio (SNR) determined in association with a quality measurement satisfies a threshold SNR, wherein the anchor carrier is associated with the non-anchor carrier.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the configuration identifies that the NRS tones are to be received once every threshold number of discontinuous reception cycles associated with the non-anchor carrier.

In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, the configuration identifies at least one of a periodicity, a timing, an offset, or a number of subframes associated with the NRS tones regardless of a discontinuous reception cycle associated with the non-anchor carrier.

In a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, the UE is configured to identify the NRS tones once every threshold number of discontinuous reception cycles associated with the non-anchor carrier.

In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, the UE is configured to determine, during a first discontinuous reception cycle, a quality measurement based at least in part on an NRS tone received via an anchor carrier associated with the non-anchor carrier and determine, during a second discontinuous reception cycle, a signal-to-noise ratio based at least in part on one of the NRS tones received via the non-anchor carrier.

In a twenty-first aspect, alone or in combination with one or more of the first through twentieth aspects, the UE is configured to identify the NRS tones during a first discontinuous reception cycle and perform a wake up signal detection or a narrowband physical downlink control channel (NPDCCH) detection during a second discontinuous reception cycle that is different from the first discontinuous reception cycle. In some aspects, each of the NRS tones is received within a respective subframe of the non-anchor carrier.

<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>) performs detection of NRS tones within communications from a BS (e.g., BS <NUM>) over a non-anchor carrier and uses the NRS tones to determine a measure of quality of the non-anchor carrier.

As shown in <FIG>, in some aspects, process <NUM> may include determining that an NRS tone is to be received via a non-anchor carrier based at least in part on a characteristic of the non-anchor carrier (block <NUM>). For example, UE <NUM> (e.g., using receive processor <NUM>, controller/processor <NUM>, and/or the like) may determine that the NRS tone is to be received from BS <NUM>. In some aspects, UE <NUM> may determine that the NRS tone is to be received from BS <NUM> based at least in part on receiving system information from BS <NUM>, based at least in part on being in communication with BS <NUM>, based at least in part on being in communication range of BS <NUM>, and/or the like.

As shown in <FIG>, in some aspects, process <NUM> may include activating from a low-power mode to determine an SNR of the non-anchor carrier based at least in part on the NRS tone (block <NUM>). For example, UE <NUM> (e.g., using receive processor <NUM>, controller/processor <NUM>, and/or the like) may activate from low-power mode to determine the SNR of the non-anchor carrier. In some aspects, UE <NUM> may activate from the low-power mode based at least in part on determining that the NRS tone is to be received via the non-anchor carrier.

In a first aspect, the UE is configured to monitor paging in the non-anchor carrier.

In a second aspect, alone or in combination with the first aspect, the characteristic comprises the non-anchor carrier being configured for a random access channel procedure.

In a third aspect, alone or in combination with one or more of the first and second aspects, the UE is configured to determine which subframes of the non-anchor carrier are to include the NRS tone based at least in part on at least one of narrowband physical random access channel (NPRACH) resources or narrowband physical downlink control channel (NPDCCH) search space periodicity.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the UE is configured to activate from the low-power mode for a paging occasion in addition to activating from the low-power mode to determine the SNR based at least in part on the NRS tone.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the characteristic comprises the non-anchor carrier including a single cell point to multipoint (SC-PTM) transmission.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the characteristic comprises at least one of: the non-anchor carrier being configured for a random access channel procedure, the non-anchor carrier including a single cell point to multipoint (SC-PTM) transmission, or a combination thereof.

<FIG> is a diagram illustrating an example process <NUM> performed, for example, by a BS, in accordance with various aspects of the present disclosure. Example process <NUM> is an example where a BS (e.g., BS <NUM>) determines a configuration for providing NRS tones, via a non-anchor carrier, in association with scheduled paging occasions to permit a UE (e.g., UE <NUM>) to determine a measure of quality of the non-anchor carrier.

As shown in <FIG>, in some aspects, process <NUM> may include determining a configuration for providing NRS tones in association with a scheduled paging occasion (block <NUM>). For example, BS <NUM> (e.g., using controller/processor <NUM>, scheduler <NUM>, and/or the like) may determine the configuration for providing the NRS tones to UE <NUM>. In some aspects, BS <NUM> may determine the configuration based at least in part on being in communication with UE <NUM>, based at least in part on UE <NUM> being within communication range of BS <NUM>, and/or the like.

As shown in <FIG>, in some aspects, process <NUM> may include providing the NRS tones to at least one user equipment, via a non-anchor carrier, regardless of whether a page is to be provided in connection with the scheduled paging occasion, wherein at least one of the NRS tones permits a quality measurement, of the non-anchor carrier, to be made by the at least one user equipment (block <NUM>). For example, BS <NUM> (e.g., using transmit processor <NUM>, TX MIMO processor <NUM>, modulator <NUM>, antenna <NUM>, controller/processor <NUM>, and/or the like) may provide the NRS tones to at least one UE <NUM>. In some aspects, BS <NUM> may provide the NRS tones based at least in part on determining the configuration for providing the NRS tones.

In a first aspect, the quality measurement comprises a radio resource management (RRM) measurement.

In a second aspect, alone or in combination with the first aspect, at least one of the NRS tones permits an SNR, of the non-anchor carrier, to be determined by the at least one user equipment.

In a third aspect, alone or in combination with one or more of the first and second aspects, the configuration identifies a minimum spreading factor of the NRS tones relative to a timing of the scheduled paging occasion.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the configuration identifies a minimum number of subframes with presence of NRS tones relative to a timing of the scheduled paging occasion.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the configuration identifies that zero NRS tones are to be received when NRS tones, in the non-anchor carrier, are not to be used to determine a quality measurement.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the configuration is provided within system information (SI) provided to the at least one user equipment.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the configuration identifies locations of the NRS tones relative to the scheduled paging occasion.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the configuration identifies that the NRS tones are to be located within a set of subframes of the non-anchor carrier provided before the scheduled paging occasion.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the configuration identifies that a first set of the NRS tones are to be located within a first set of subframes provided before the scheduled paging occasion, and a second set of the NRS tones are to be located within a second set of subframes provided after the scheduled paging occasion.

In a tenth aspect, alone or in combination with the ninth aspect, a number of subframes in the first set of subframes matches a number of subframes in the second set of subframes.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the configuration identifies at least one of: that the NRS tones are to be located within a set of subframes of the non-anchor carrier provided before the scheduled paging occasion, that a first set of the NRS tones are to be located within a first set of subframes provided before the scheduled paging occasion and a second set of the NRS tones are to be located within a second set of subframes provided after the scheduled paging occasion, or a combination thereof.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, a number of the NRS tones provided to the at least one user equipment is preconfigured based at least in part on a specification of a network of the non-anchor carrier.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the NRS tones are to be provided, via the non-anchor carrier, once every threshold number of discontinuous reception cycles associated with the non-anchor carrier.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the NRS tones are to be provided, via the non-anchor carrier, in a subset of discontinuous reception cycles associated with the non-anchor carrier.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the configuration identifies at least one of a periodicity, a timing, an offset, or a number of subframes associated with the NRS tones regardless of a discontinuous reception cycle associated with the non-anchor carrier.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, each of the NRS tones is provided within a respective subframe of the non-anchor carrier.

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

Claim 1:
A method of wireless communication performed by a user equipment, UE, comprising:
receiving (<NUM>) a configuration for identifying narrowband reference signal, NRS, tones that are to be received during a scheduled paging occasion, wherein the NRS tones are configured to be received via a non-anchor carrier regardless of whether a page is to be received in connection with the scheduled paging occasion; and
receiving (<NUM>) the NRS tones via the non-anchor carrier based at least in part on the configuration;
characterized in that
the configuration identifies that the NRS tones are to be received in a subset of discontinuous reception cycles.