Patent Description:
Some aspects of 5GNR may be based on the <NUM> Long Term Evolution (LTE) standard.

Narrowband communications involve communicating with a limited frequency bandwidth as compared to the frequency bandwidth used for LTE communications. One example of narrowband communication is narrowband (NB) IoT (NB-IoT) communication, which may be limited to a single resource block (RB) of system bandwidth, e.g., <NUM>. Another example of narrowband communication is enhanced machine-type communication (eMTC), which may be limited to six RBs of system bandwidth, e.g., <NUM>. NB-IoT communication and/or eMTC may reduce device complexity, enable multi-year battery life, and provide deeper coverage to reach challenging locations such as deep inside buildings. However, supporting a six RB (e.g., <NUM>) communication bandwidth and/or a single RB (e.g., <NUM>) communication bandwidth operating in the unlicensed frequency spectrum may not always be possible.

Thus, there is a need for a mechanism that overcomes the bandwidth restrictions for narrowband communications using the unlicensed frequency spectrum.

United States Patent Application Publication No. <CIT> relates to raster design for narrowband operation for machine type communications.

Narrowband communications involve communicating with a limited frequency bandwidth as compared to the frequency bandwidth used for LTE communications. One example of narrowband communication is NB-IoT communication, which may be limited to a single RB of system bandwidth, e.g., <NUM>. Another example of narrowband communication is eMTC, which may be limited to six RBs of system bandwidth, e.g., <NUM>. NB-IoT communication and/or eMTC may reduce device complexity, enable multi-year battery life, and provide deeper coverage to reach challenging locations such as deep inside buildings.

In certain eMTC configurations, the channel bandwidth for narrowband communications may be six RBs with various repetition levels to support low complexity devices and high efficiency power amplifiers (PA). In certain NB-IoT configurations, the channel bandwidth for narrowband communications may be restricted to a single tone (e.g., <NUM>) to support low complexity devices and high efficiency PA.

However, supporting a six RB (e.g., <NUM>) communication bandwidth and/or a single tone (e.g., <NUM>, etc.) communication bandwidth may not be possible due to certain power spectral density (PSD) restrictions (e.g., transmission power restrictions) and bandwidth requirements for narrowband communications (e.g., eMTC and/or NB-IoT) that use the unlicensed frequency spectrum (e.g., <NUM> unlicensed frequency spectrum, the sub-<NUM> unlicensed frequency spectrum, or the sub-GHz unlicensed frequency spectrum, etc.).

For example, the PSD used for digital modulation (DTS) in the United States may be limited to a maximum of 8dBm / <NUM>. Hence, a UE may not be able to transmit a single tone transmission using full power in the unlicensed spectrum because the maximum PSD is limited to a bandwidth (e.g., <NUM>) that is smaller than a single tone (e.g., <NUM>). Further, the system bandwidth for narrowband communications using the unlicensed frequency spectrum in the United States may be restricted to, e.g., <NUM>. In other words, when using DTS mode, a base station may have to meet the minimum bandwidth requirement (e.g., <NUM>) and the PSD limit (e.g., <NUM> dBm/<NUM>) in order to be able to operate in the United States (and certain other countries).

Coverage enhancements, such as frequency hopping, for narrowband devices (e.g., UEs and/or base stations) may be employed to provide more reliable communications within a narrowband communication system, and to overcome the PSD restrictions and bandwidth requirements associated with DTS mode for narrowband communications using the unlicensed frequency spectrum.

For example, a UE and/or base station may perform frequency hopping in order to monitor, receive, and/or transmit signals by switching a carrier among different frequency channels (e.g., carrier aggregation) to exploit the frequency diversity of the unlicensed frequency spectrum.

In certain configurations, while operating in frequency hopping mode in the unlicensed frequency spectrum, a base station and/or UE may be constrained to a minimum number of frequency hopping channels (e.g., <NUM> channels) when the narrowband system bandwidth is less than a threshold criteria (e.g., less than <NUM>). However, a base station and/or UE operating in frequency hopping mode may not be constrained to the minimum bandwidth requirement and/or PSD limit associated with DTS mode.

In certain other configurations, a base station may operate in hybrid mode in which the PSD limit of the DTS mode is still applicable, but without the minimum bandwidth constraint associated with the DTS mode, but without being constrained to the minimum number of frequency hopping channels associated with frequency hopping mode.

There is a need for technique(s) that facilitate narrowband communication within the unlicensed frequency spectrum that meet the various constraints associated with DTS mode, frequency hopping mode, and hybrid mode.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. In one example, the apparatus may be a base station. In certain configurations, the apparatus may transmit information indicating a narrowband frequency hopping pattern to at least one user equipment (UE). In certain aspects, the narrowband frequency hopping pattern may correspond to a plurality of frames. In certain other aspects, the plurality of frames may include at least one non-anchor channel and being associated with a plurality of anchor channels. The apparatus may communicate with the at least one UE using the narrowband frequency hopping pattern. In certain aspects, communication on the plurality of anchor channels may occur during the same frames.

In another example, the apparatus may be a UE. In certain configurations, the apparatus may receive information indicating a narrowband frequency hopping pattern within from a base station. In certain aspects, the narrowband frequency hopping pattern may correspond to a plurality of frames. In certain aspects, the plurality of frames may include at least one non-anchor channel and may be associated with a plurality of anchor channels. The apparatus may communicate with the base station using the narrowband frequency hopping pattern. In certain aspects, communication on the plurality of anchor channels may occur during the same frames.

A network that includes both small cell and macro cells may be known as a heterogeneous network. The base stations <NUM> / UEs <NUM> may use spectrum up to YMHz (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL).

The base station may also be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The base station <NUM> provides an access point to the EPC <NUM> for a UE <NUM>. Examples of UEs <NUM> include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a display, or any other similar functioning device.

Referring again to <FIG>, in certain aspects, the UE <NUM> and/ base station <NUM> may be configured to implement mechanisms that overcome the bandwidth restrictions for narrowband communications using the unlicensed frequency spectrum (<NUM>), e.g., as described below in connection with any of <FIG>.

<FIG> is a diagram <NUM> illustrating an example of an NB frame structure for in-band deployment inside an LTE carrier (even radio frame). <FIG> is a diagram <NUM> illustrating an example of an NB frame structure for in-band deployment inside an LTE carrier (odd radio frame). <FIG> is a diagram <NUM> illustrating an example of an NB frame structure for guard band / standalone deployment inside an LTE carrier (even radio frame). <FIG> is a diagram <NUM> illustrating an example of an NB frame structure for guard band / standalone deployment inside an LTE carrier (even radio frame). A radio frame (<NUM>) may be divided into <NUM> equally sized subframes (e.g., subframe <NUM> - subframe <NUM>). Each subframe may include two consecutive time slots (e.g., slot <NUM> and slot <NUM>). A resource grid may be used to represent the two time slots, each time slot including one or more time concurrent RBs (also referred to as physical RBs (PRBs)) of <NUM>. For a normal cyclic prefix, an RB may contain <NUM> consecutive subcarriers in the frequency domain and <NUM> consecutive symbols (for DL, orthogonal frequency-division multiplexing (OFDM) symbols; for UL, SC-FDMA symbols) in the time domain, for a total of <NUM> REs. For an extended cyclic prefix, an RB may contain <NUM> consecutive subcarriers in the frequency domain and <NUM> consecutive symbols in the time domain, for a total of <NUM> REs. The in-band deployment of NB-IoT may utilize RBs within an LTE carrier. The guard band deployment of NB-IoT may utilize the unused RBs within an LTE carrier's guard-band. The standalone deployment of NB-IoT may utilize RBs within the global system for mobile communications (GSM) carriers.

As illustrated in <FIG>, some of the REs in each of the subframes carry NB reference signals (NRS) that may be used for broadcast transmission(s) or dedicated DL transmission(s), regardless of whether data is actually transmitted. Depending on the transmission scheme, NRS may be transmitted on one antenna port or on two antenna ports (e.g., antenna port <NUM> and antenna port <NUM>). The values of the NRS may be similar to cell-specific reference signals (CRS) in LTE. NRS may indicate an NB cell identifier (NCellID), while LTE CRS may indicate a physical cell identifier (PCI). For the in-band deployment, the LTE CRS may also be transmitted in subframes which are not used for MBSFN, as illustrated in <FIG> and <FIG>. Although the structure of the NRS and the LTE CRS may not overlap, the CRS may be taken into account for rate matching and RE mapping purposes. DL transmissions may not use the REs allocated for NRS and/or LTE CRS.

For initial synchronization and in order to determine the NCellID, a narrowband primary synchronization signal (NPSS) may be transmitted in subframe <NUM> of even and odd radio frames, and a narrowband secondary synchronization signal (NSSS) may be transmitted in subframe <NUM> in even radio frames. Using in-band deployment, the first three OFDM symbols in each of subframe <NUM> and subframe <NUM> may carry the LTE physical downlink control channel (PDCCH), and hence, the first three OFDM symbols in subframes <NUM> and <NUM> may not carry NPSS and NSSS, as illustrated in <FIG> and <FIG>. NPSS and the NSSS may be punctured by LTE CRS in the in-band deployment. Using the guard band deployment and/or standalone deployment, the first three OFDM symbols in each of subframe <NUM> and subframe <NUM> may be unused, and hence, the first three OFDM symbols in subframes <NUM> and <NUM> may not carry the NPSS and NSSS, as illustrated in <FIG> and <FIG>.

The narrowband physical broadcasting channel (NPBCH) may carry the NB master information block (NB-MIB). After physical layer baseband processing, the resulting NB-MIB may be split into eight blocks. The first block may be transmitted in subframe <NUM> of each radio frame in a set of eight consecutive radio frames. The second block may be transmitted in subframe <NUM> of each radio frame in the subsequent set of eight consecutive radio frames. The process of NB-MIB block transmission may be continued until the entire NB-MIB is transmitted. By using subframe <NUM> for all NB-MIB block transmissions, collisions between the NPBCH and a potential LTE MBSFN transmission may be avoided when the in-band deployment of NB-IoT is used. As illustrated in <FIG> and <FIG>, NPBCH symbols may be mapped around the NRS and the LTE CRS for the in-band deployment. As illustrated in <FIG> and <FIG>, the NPBCH may occupy all of subframe <NUM> except for the first three symbols which are left unused for the guard band deployment and/or standalone deployment.

The principle of a control channel and a shared channel also applies to NB-IoT, defining the NB physical downlink control channel (NPDCCH) and the NB physical downlink shared channel (NPDSCH). Not all subframes may be used for the transmission of dedicated DL channels. In RRC signaling, a bitmap indicating the valid subframes for NPDCCH and/or NPDSCH may be signaled to the UE. When a subframe is not indicated as valid, an NPDCCH and/or NPDSCH may be postponed until the next valid subframe. The NPDCCH may indicate which UEs have data located in the NPDSCH, where to find the data, and how often the data is repeated. UL grants that indicate REs allocated to a UE for UL data transmission(s) may also be located in the NPDCCH. The NPDCCH may also carry paging and/or system information updates. NPDCCH symbols and NPDSCH symbols may be mapped around the NRS, and for the in-band deployment of NB-IoT, also around the LTE CRS.

For example, the PSD used for DTS in the United States may be limited to a maximum of 8dBm / <NUM>. Hence, a UE may not be able to transmit a single tone transmission using full power in the unlicensed spectrum because the maximum PSD is limited to a bandwidth (e.g., <NUM>) that is smaller than a single tone (e.g., <NUM>). Further, the system bandwidth for narrowband communications using the unlicensed frequency spectrum in the United States may be restricted to, e.g., <NUM>. In other words, when using DTS mode, a base station may have to meet the minimum bandwidth requirement (e.g., <NUM>) and the PSD limit (e.g., <NUM> dBm/<NUM>) in order to be able to operate in the United States (and certain other countries).

There is a need for technique(s) that facilitate narrowband communication within the unlicensed frequency spectrum that meet the various constraints associated with DTS mode (e.g., described below in connection with <FIG>), frequency hopping mode (e.g., described in connection with <FIG>), and hybrid mode (e.g., described below in connection with <FIG>).

<FIG> illustrates a frequency hopping pattern <NUM> that may be used for narrowband communications in the unlicensed frequency spectrum between a base station and a UE in accordance with certain aspects of the disclosure. The frequency hopping pattern <NUM> illustrated in <FIG> may be used for narrowband communications between a base station (e.g., base station <NUM>, <NUM>, <NUM>, <NUM>, eNB <NUM>, the apparatus <NUM>/<NUM>') operating in DTS mode and a UE (e.g., UE <NUM>, <NUM>, 504a, 504b, <NUM>, the apparatus <NUM>/<NUM>') operating in frequency hopping mode. Because the base station is operating in DTS mode in the unlicensed frequency spectrum, DL data sent from the base station may need to occupy at least a minimum bandwidth (e.g., <NUM>) at the expense of scheduling flexibility, and due to the PSD limit (e.g., <NUM> dBm/ <NUM>) associated with DTS mode, the DL data may be transmitted in at least 3RB in order to transmit at the maximum TX power of <NUM> dBm. Because the UE is operating in frequency hopping mode in the unlicensed frequency spectrum, the UE may send UL data to the base station in N ≥ x (e.g., x = <NUM>) hopping frequencies that each have at least a minimum bandwidth (e.g., <NUM>, <NUM>, etc.).

A base station operating in DTS mode may use the frequency hopping pattern <NUM> illustrated in <FIG> to monitor, receive, and/or transmit signals by switching among different frequency channels (e.g., anchor channels 404a, 404b, 404c and non-anchor channels 406a, 406b, 406c, 406d, 406e, 406f, <NUM>) to exploit the frequency diversity of the unlicensed frequency spectrum.

At the start of each hopping frame 430a, 430b, 430c, the base station may concurrently transmit a discovery reference signal (DRS) (e.g., NPSS, NSSS, NPBCH, and SIB-BR etc.) in each of the plurality of anchor channels 404a, 404b, 404c to at least one UE. The NPSS and NSSS may be used by a UE for initial synchronization, cell acquisition, timing estimation, and/or frequency estimation. In certain configurations, the base station may transmit NPSS and NSSS in the first anchor channel 404a, NPBCH in the second anchor channel 404b, and SIB-BR in the third anchor channel 404c. In certain other configurations, NPSS, NSSS, PBCH, and SIB-BR may be transmitted in each of the anchor channels 404a, 404b, 404c.

Because the bandwidth of each anchor channel 404a, 404b, 404c may be limited to the bandwidth capability of the UE's receiver (e.g., <NUM> RB, <NUM>, <NUM>, etc.), the bandwidth requirement (e.g., <NUM>) associated with DTS mode may be satisfied. Each of the non-anchor channels 406a, 406b, 406c, 406d, 406e, 406f, <NUM> may be used to communicate DL data and UL data. The UL data may be communicated by a UE operating in frequency hopping mode.

The anchor channels 404a, 404b, 404c may each be used to carry information that indicates the frequency hopping pattern <NUM> to the UE. For example, the information may indicate a duration of a hopping frame 430a, 430b, 430c (e.g., <NUM>, <NUM>, etc.), a duration of DRS transmissions (e.g., <NUM> radio frames, <NUM> radio frames, etc.) in each hopping frame 430a, 430b, 430c, an M number of non-anchor hopping channels per hopping frame (e.g., M = <NUM> in <FIG>), a duration on non-anchor hopping channels (e.g., <NUM> radio frames, <NUM> radio frames, etc.), a duration of DL data transmission(s) (e.g., <NUM> radio frames, <NUM> radio frames, etc.), a duration of UL data transmission(s) (e.g., <NUM> radio frames, <NUM> radio frames, etc.), a channel offset between each of the M non-anchor channels within each hopping frame 430a, 430b, 430c, a channel offset associated with M non-anchor channels located in adjacent hopping frames, a grouping of the M non-anchor channels into M carriers, a fixed offset associated with the non-anchor channels in each of the M carriers, etc.. Out of the maximum number of narrowband channels (e.g., <NUM> narrowband channels) within the wideband channel, the information may also indicate that communications between the base station and the UE may occur on a subset of the maximum number of narrowband channels (e.g., <NUM> out of <NUM> of the narrowband channels).

In the example illustrated in <FIG>, the frequency hopping pattern <NUM> may include a plurality of frames 430a, 430b, 430c that each include a plurality of anchor channels (e.g., three anchor channels) and a plurality of non-anchor channels (e.g., three anchor channels). The first hopping frame 430a may include the anchor channels 404a, 404b, 404c, the first non-anchor channel 406a, the second non-anchor channel 406b, and the third non-anchor channel 406c. The second hopping frame 430b may include the anchor channels 404a, 404b, 404c, the second non-anchor channel 406b, the third non-anchor channel 406c, and the fourth non-anchor channel 406d. The third hopping frame 430c may include the anchor channels 404a, 404b, 404c, the (N - <NUM>)th non-anchor channel 406e, the (N- <NUM>)th non-anchor channel 406f, and the Nth non-anchor channel <NUM>. In certain configurations, the non-anchor hopping channels located in a particular hopping frame may be contiguous non-anchor hopping channels within the wideband. In certain other configurations, the non-anchor hopping channels located in a particular hopping frame may be non-contiguous non-anchor hopping channels within the wideband. In certain other configurations, the anchor channels 404a, 404b, 404c may be contiguous channels within the wideband. In certain other configurations, the anchor channels 404a, 404b, 404c may be non-contiguous channels within the wideband.

In certain configurations, each of the M non-anchor channels across multiple hopping frames 430a, 430b, 430c may be grouped into M carriers. Each of the M carriers (e.g., carrier <NUM> (CA0), carrier <NUM> (CA1), and carrier <NUM> (CA2), where M = <NUM>) may occupy a set of non-anchor channels across the plurality of frames 430a, 430b, 430c. In the example illustrated in <FIG>, CA0 may occupy the first non-anchor channel 406a in the first hopping frame 430a, the second non-anchor channel 406b in the second hopping frame 430b, and the (N - <NUM>)th non-anchor channel 406e in the third hopping frame 430c. As also seen in the example illustrated in <FIG>, CA1 may occupy the second non-anchor channel 406b in the first hopping frame 430a, the third non-anchor channel 406c in the second hopping frame 430b, and the (N - <NUM>)th non-anchor channel 406f in the third hopping frame 430c. As also seen in the example illustrated in <FIG>, CA2 may occupy the third non-anchor channel 406c in the first hopping frame 430a, the fourth non-anchor channel 406d in the second hopping frame 430b, and the Nth non-anchor channel <NUM> in the third hopping frame 430c.

By way of example, when N = <NUM>, CA0 may be associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>], CA1 is associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>], and CA2 is associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>]. In other words, the non-anchor channel hopping sequence may be a pseudo-random hopping sequence with different fixed offsets between non-anchor channels in different hopping frames. For example, the fixed offset between the first non-anchor channel of a carrier in first hopping frame 430a and the second non-anchor channel of the same carrier in second hopping frame 430b is one non-anchor channel, and the fixed offset between the second non-anchor hopping channel of the same carrier in the second hopping frame 430b and the third non-anchor carrier of the same carrier in the third hopping frame 430c is four non-anchor hopping channels.

Each of the M carriers may serve the same or different UEs. In certain configurations, CA0, CA1, and CA2 may each serve UE <NUM>. In certain other configurations, CA0 and CA1 may serve UE <NUM>, and CA2 may serve UE <NUM>. In certain other configurations, CA0 may serve UE <NUM>, CA1 may serve UE <NUM>, and CA <NUM> may serve UE <NUM>.

In certain aspects, each of the M carriers may have a same frame structure. For example, as illustrated in <FIG>, CA0 includes a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>. CA1 may include a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>. CA <NUM> may include a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>.

In certain configurations, the first portion <NUM>, <NUM>, <NUM> for CA0, CA1, and CA2 may be associated with DL data transmitted to UE <NUM>, UE <NUM>, and UE <NUM>, respectively. In other words, the DL data in the first portions <NUM>, <NUM>, <NUM> for UE <NUM>, UE <NUM>, and UE <NUM> may be transmitted concurrently in the time domain.

In certain other configurations, a first duration 440a of each of the first portions <NUM>, <NUM>, <NUM> may be reserved for DL data transmitted to UE <NUM>, a second duration 440b of each of the first portions <NUM>, <NUM>, <NUM> may be reserved for DL data transmitted to UE <NUM>, and a third duration 440c of each of the first portions <NUM>, <NUM>, <NUM> may be reserved for DL data transmitted to UE <NUM>. In other words, the DL data for UE <NUM>, UE <NUM>, and UE <NUM> may be time division multiplexed (TDM) in each of the M carriers.

In certain other configurations, a total bandwidth of each of the M carriers may meet a bandwidth threshold criteria (e.g., <NUM>, <NUM>, <NUM> RB, etc.). In other words, the base station may schedule DL data on each of the M carriers for one or more UEs concurrently to ensure the DL bandwidth is at least <NUM> (e.g., the minimum bandwidth requirement for DTS mode). When the base station has DL data to schedule for a single UE instead of multiple UEs and the single UE is not served by all of the M carriers, the DL data in the second portion <NUM> may be transmitted on a first carrier of the M carrier (e.g., CA0 in <FIG>), and a retransmission of the DL data in the second portion <NUM> may be transmitted on the remaining carriers of the M carriers (e.g., CA1 and CA2 in <FIG>) to ensure that the minimum DL bandwidth is at least <NUM>. In certain other configurations, when there is no DL data to be scheduled, the base station may send a reservation signal on each of the M carriers in order to meet the minimum DL bandwidth criteria. In the case of a single UE or no DL data to schedule, the power consumption at the base station may be increased in order to repeat DL data transmissions on multiple carriers, or to transmit reservation signals on multiple carriers.

Using the techniques described above in connection with <FIG>, a narrowband system of the present disclose may be able to meet the minimum bandwidth criteria and the PSD limit for DL data when the base station operates in DTS mode, and to meet the minimum number of hopping frequencies for UL data when the UE operates in frequency hopping mode.

<FIG> illustrates a frequency hopping pattern <NUM> that may be used for narrowband communications in the unlicensed frequency spectrum between a base station and a UE in accordance with certain aspects of the disclosure. The frequency hopping pattern <NUM> illustrated in <FIG> may be used for narrowband communications between a base station (e.g., base station <NUM>, <NUM>, <NUM>, <NUM>, eNB <NUM>, the apparatus <NUM>/<NUM>') operating in frequency hopping mode and a UE (e.g., UE <NUM>, <NUM>, 504a, 504b, <NUM>, the apparatus <NUM>/<NUM>') operating in frequency hopping mode. Because the base station is operating in frequency hopping mode in the unlicensed frequency spectrum, DL data may be sent to the UE in N ≥ x (e.g., x = <NUM>) hopping frequencies that each have at least a minimum bandwidth (e.g., <NUM>, <NUM>, etc.). Because the UE is operating in frequency hopping mode in the unlicensed frequency spectrum, the UE may send UL data to the base station in N ≥ x (e.g., x = <NUM>) hopping frequencies that each have at least a minimum bandwidth (e.g., <NUM>, <NUM>, etc.).

At the start of every K hopping frames (e.g., K is equal to four in <FIG>), the base station may transmit a DRS (e.g., NPSS, NSSS, NPBCH, and SIB-BR etc.) in the anchor channel <NUM> to at least one UE. The NPSS and NSSS may be used by a UE for initial synchronization, cell acquisition, timing estimation, and/or frequency estimation. In <FIG>, a DRS is transmitted at the start of the first hopping frame 430a and the fourth hopping frame 430d.

After performing DRS transmission on anchor channel <NUM> in the first hopping frame 430a, the base station may hop to the first non-anchor channel 406a, the second non-anchor channel 406b, and the third non-anchor channel 406c for DL data and/or UL data communications for the remainder of the K -<NUM> hopping frames (e.g., the portion of the first hopping frame 430a on first non-anchor channel 406a, the entirety of the second hopping frame 430b, and the entirety of the third hopping frame 430c) before revisiting anchor channel <NUM> for a DRS transmission during the fourth hopping frame 430d.

In order to increase the probability of successful communication of DL data and/or UL data, a particular duration (e.g., dwell period) of each of the non-anchor channels 406a, 406b, 406c, 406d may be used to accommodate a minimum number of DL control repetitions, DL data repetitions, UL control repetitions, and/or UL data repetitions. To ensure equal channel occupancy for each of the hopping frequencies (e.g., the anchor channel <NUM>, first non-anchor channel 406a, second non-anchor channel 406b, third non-anchor channel 406c, fourth non-anchor channel 406d, etc.), the frequency hopping system may perform multiple non-anchor hops (e.g., non-anchor channels 406a, 406b, 406c) within a K - <NUM> hopping frame period before returning to anchor channel <NUM>. In certain aspects, the average time of occupancy on any channel may not be greater than <NUM> seconds within a period of <NUM> seconds multiplied by the number of hopping channels employed.

Although three non-anchor channels 406a, 406b, 406c are depicted in K - <NUM> hopping frames in <FIG>, more or fewer than three non-anchor hopping channels may be included in K - <NUM> hopping frames without departing from the scope of the present disclosure.

After L number of hops between non-anchor hopping channels (e.g., where L is equal to <NUM> in the example illustrated in <FIG>), the UE may return to the anchor channel <NUM> to monitor for DRS in order to reduce synchronization delay. In other words, at the end of each K - <NUM> hopping frames, the base station and the UE may return to the anchor channel <NUM> for the communication of DRS in the anchor channel <NUM>. Consider an example not illustrated in <FIG> in which K - <NUM> hopping frames (e.g., hopping frames 430a, 430b, 430c) include <NUM> non-anchor channels that each include <NUM> radio frames. Here, a total duration on the non-anchor hopping channels may be <NUM>, and the duration on the anchor channel <NUM> may be <NUM>. Consequently, the UE may attempt cell acquisition, synchronization, timing estimation, and/or frequency estimation every <NUM>.

When the duration of DRS transmission(s) on the anchor channel <NUM> is reduced as compared to DL data / UL data transmission(s) on a non-anchor channel 406a, 406b, 406c, 406d, the UE may return to the anchor channel <NUM> more often (as compared to using a longer DRS duration) to allow for faster acquisition. As the minimum number of hopping frequencies (e.g., the anchor channel and non-anchor channels) may be <NUM> channels, how often the anchor channel is visited may determine the acquisition delay. For a hopping frame with a duration of <NUM>, when the DRS transmission(s) on the anchor channel <NUM> is <NUM>, K may be equal to four, and the delay between adjacent hops to the anchor channel (adjacent DRS transmissions) may be <NUM>. For a hopping frame with a duration of <NUM>, when the DRS transmission(s) on the anchor channel <NUM> is <NUM>, K may be equal to seven, and the delay between adjacent hops to the anchor channel (adjacent DRS transmissions) may be <NUM>. In other words, the delay between DRS transmissions on adjacent hops to the anchor channel <NUM> may not scale with the duration of the hopping frame.

Using the techniques described above in connection with <FIG>, a narrowband system of the present disclose may be able to meet the minimum channel requirement when the base station and the UE are operating in frequency hopping mode. However, the acquisition time for the UE may be undesirably long when both the base station and the UE operate in frequency hopping mode, and thus, the base station may use hybrid mode, e.g., described below in connection with <FIG>.

<FIG> illustrates a frequency hopping pattern <NUM> that may be used for narrowband communications in the unlicensed frequency spectrum between a base station and a UE in accordance with certain aspects of the disclosure. The frequency hopping pattern <NUM> illustrated in <FIG> may be used for narrowband communications between a base station (e.g., base station <NUM>, <NUM>, <NUM>, <NUM>, eNB <NUM>, the apparatus <NUM>/<NUM>') operating in hybrid mode and a UE (e.g., UE <NUM>, <NUM>, 504a, 504b, <NUM>, the apparatus <NUM>/<NUM>') operating in frequency hopping mode. Because the base station is operating in hybrid mode in the unlicensed frequency spectrum, DRS sent from the base station may occupy at least a minimum bandwidth (e.g., <NUM>), and DL data may be sent to the UE in N ≥ x (e.g., x = <NUM>) hopping frequencies that each have at least a minimum bandwidth (e.g., <NUM>, <NUM>, etc.). Because the UE is operating in frequency hopping mode in the unlicensed frequency spectrum, the UE may send UL data to the base station in N ≥ x (e.g., x = <NUM>) hopping frequencies that each have at least a minimum bandwidth (e.g., <NUM>, <NUM>, etc.).

A base station operating in hybrid mode may use the frequency hopping pattern <NUM> illustrated in <FIG> to monitor, receive, and/or transmit signals by switching among different frequency channels (e.g., anchor channels 404a, 404b, 404c and non-anchor channels 406a, 406b, 406c, 406d) to exploit the frequency diversity of the unlicensed frequency spectrum.

At the start of each hopping frame 430a, 430b, the base station may concurrently transmit a DRS (e.g., NPSS, NSSS, NPBCH, and SIB-BR etc.) in each of the plurality of anchor channels 404a, 404b, 404c to at least one UE. The NPSS and NSSS may be used by a UE for initial synchronization, cell acquisition, timing estimation, and/or frequency estimation. In certain configurations, the base station may transmit NPSS and NSSS in the first anchor channel 404a, NPBCH in the second anchor channel 404b, and SIB-BR in the third anchor channel 404c. In certain configurations, NPSS, NSSS, PBCH, and SIB-BR may be transmitted in each of the anchor channels 404a, 404b, 404c.

Because the bandwidth of each anchor channel 404a, 404b, 404c may be limited to the bandwidth capability of the UE's receiver (e.g., <NUM> RB, <NUM>, <NUM>, etc.), the bandwidth requirement (e.g., <NUM>) associated with hybrid mode for transmitting DRS may be satisfied. Each of the non-anchor channels 406a, 406b, 406c, 406d may be used to communicate DL data and UL data. The UL data may be communicated by a UE operating in frequency hopping mode. Although each hopping frame 430a, 430b is illustrated as including two non-anchor channels, a single non-anchor hopping channel may be included in each hopping frame 430a, 430b without departing from the scope of the present disclosure.

In certain configurations, the DRS transmission may not be subject to minimum DL bandwidth, and hence, the base station may transmit the DRS on a single anchor channel (e.g., as in <FIG>). In certain other configurations, the UE and/or base station may return to the anchor channel after every hop to the non-anchor channel (not illustrated in <FIG>).

Using the techniques described above in connection with <FIG>, the base station may use DTS mode for DRS transmission to avoid the bandwidth requirement in which transmitting on a single anchor channel may require communication with a <NUM> RB UE receiver or complex multi-UE scheduling, and the long acquisition time associated with frequency hopping mode (e.g., single anchor channel) for DRS transmission.

<FIG> illustrates a data flow <NUM> that may be used by a base station <NUM> and a plurality of UEs 504a, 504b for narrowband communication using the unlicensed frequency spectrum in accordance with certain aspects of the disclosure. Base station <NUM> may correspond to, e.g., base station <NUM>, <NUM>, <NUM>, eNB <NUM>, apparatus <NUM>/<NUM>'. First UE 504a may correspond to, e.g., UE <NUM>, <NUM>, <NUM>, the apparatus <NUM>/<NUM>'. Second UE 504b may correspond to, e.g., UE <NUM>, <NUM>, <NUM>, the apparatus <NUM>/<NUM>'. In addition, the base station <NUM> and the UEs 504a, 504b may be configured to communicate using a frequency hopping pattern in the unlicensed frequency spectrum. For example, the base station <NUM> and UEs 504a, 504b may be NB-IoT devices and/or eMTC devices. In <FIG>, optional operations are indicated with dashed lines.

In certain configurations, the base station <NUM> may transmit (at <NUM>) information indicating a narrowband frequency hopping pattern (e.g., frequency hopping patterns <NUM>, <NUM>, <NUM> in <FIG>, <FIG>, and <FIG>, respectively). The information may be transmitted in an MIB/SIB, a broadcast communication, or a unicast communication. In certain aspects, the narrowband frequency hopping pattern may include a plurality of frames (e.g., hopping frames 430a, 430b, 430c in <FIG>; hopping frames 430a, 430b, 430c, 430d in <FIG>, and hopping frames 430a, 430b in <FIG>). In certain aspects, each of the plurality of frames may include a plurality of anchor channels (e.g., anchor channels 404a, 404b, 404c in <FIG> and <FIG>) and at least one non-anchor channel (e.g., non-anchor channels 406a, 406b, 406c in the first hopping frame 430a in <FIG>; non-anchor channels 406b, 406c, 406d in the second hopping frame in <FIG>; non-anchor channels 406e, 406f, <NUM> in the third hopping frame in <FIG>; non-anchor channels 406a, 406b in the first hopping frame 430a in <FIG>; and non-anchor channels 406c, 406d in the second hopping frame 430b in <FIG>).

In certain aspects, the at least one non-anchor channel in each of the plurality of frames may include M non-anchor channels within a wideband. For example, referring to <FIG>, the frequency hopping pattern <NUM> includes M non-anchor channels in each of the hopping frames 430a, 430b, 430c.

In certain other aspects, the M non-anchor channels may be grouped into M carriers across a plurality of frames. For example, referring to <FIG>, the M non-anchor channels are grouped across each of the hopping frames 430a, 430b, 430c in to carriers CA0, CA1, and CA2.

In certain other aspects, each of the M carriers may occupy a set of adjacent non-anchor channels in each of the plurality of frames. For example, referring to <FIG>, each of the M carriers are located in adjacent non-anchor channels (e.g., non-anchor channels 406a, 406b, 406c in hopping frame 430a) within each of the hopping frames.

In certain other configurations, the base station <NUM> may communicate (at 503a, 503b) with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern (e.g., frequency hopping patterns <NUM>, <NUM>, <NUM> in <FIG>, <FIG>, and <FIG>, respectively).

In certain configurations, the base station <NUM> may communicate with the first UE 504a and the second UE 504b by transmitting (at <NUM>) a plurality of downlink transmissions (e.g., DL data in the first portions <NUM>, <NUM>, <NUM> in <FIG>) to the first UE 504a and the second UE 504b concurrently in each of the M carriers (e.g., CA0, CA1, CA2 in <FIG>) in each hopping frame (e.g., hopping frames 430a, 430b, 430c in <FIG>).

In certain other configurations, the base station <NUM> may communicate with the first UE 504a and the second UE 504b by receiving (at 507a, 507b) a plurality of uplink transmissions (e.g., UL data in the second portions <NUM>, <NUM>, <NUM> in <FIG>) from the first UE 504a and the second UE 504b concurrently in the M carriers (e.g., CA0, CA1, and CA2 in <FIG>) in each hopping frame (e.g., hopping frames 430a, 430b, 430c in <FIG>).

In certain aspects, a first portion of each of the M carriers may be allocated for downlink transmissions and a second portion of each of the M carriers may be allocated for uplink transmissions. In certain other aspects, the second portion may be located subsequent to the first portion in a time domain. For example, referring to <FIG>, first portions <NUM>, <NUM>, <NUM> may be allocated for DL data for UE <NUM>, UE <NUM>, and UE <NUM> on CA <NUM>, CA <NUM>, and CA <NUM>, respectively, and second portions <NUM>, <NUM>, <NUM> may be allocated for UL data from UE <NUM>, UE <NUM>, and UE <NUM> on CA <NUM>, CA <NUM>, and CA <NUM>, respectively.

In certain other aspects, each of the M carriers may be associated with a respective hopping sequence across a plurality of frames. For example, referring to <FIG>, when N = <NUM>, CA0 may be associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>], CA1 is associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>], and CA2 is associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>].

In certain other aspects, the respective hopping sequence may include a fixed offset between contiguous non-anchor hopping channels in the M carrier. For example, referring to <FIG>, the fixed offset between the first non-anchor channel of a carrier in first hopping frame 430a and the second non-anchor channel of the same carrier in second hopping frame 430b is one non-anchor channel, and the fixed offset between the second non-anchor hopping channel of the same carrier in the second hopping frame 430b and the third non-anchor carrier of the same carrier in the third hopping frame 430c is four non-anchor hopping channels.

In certain other configurations, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the frequency hopping pattern by concurrently transmitting (at <NUM>) a DRS in each of the plurality of anchor channels (e.g., anchor channels 404a, 404b, 404c in <FIG>) at a start of each hopping frame (e.g., hopping frames 430a, 430b, 430c in <FIG>).

In certain aspects, each of the M carriers may comprise a same frame structure. For example, as illustrated in <FIG>, CA0 includes a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>. CA1 may include a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>. CA <NUM> may include a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>.

In certain other aspects, a total bandwidth of each of the M carriers meets a bandwidth threshold criteria. For example, referring to <FIG>, each of the M carriers (CA0, CA1, CA2 in each hopping frame 430a, 430b, 430c) may have a bandwidth of at least, e.g., <NUM> RB, <NUM>, <NUM>, etc..

In certain configurations, the base station <NUM> may communicate with the first UE 504a and not the second UE 504b. Here, the plurality of downlink transmissions transmitted (at <NUM>) may include an initial downlink transmission transmitted on one of the M carriers and downlink retransmissions transmitted on a subset of the M carriers. For example, referring to <FIG>, when the base station has DL data to schedule for a single UE instead of multiple UEs and the single UE is not served by all of the M carriers, the DL data in the second portion <NUM> may be transmitted on a first carrier of the M carrier, and a retransmission of the DL data in the second portion <NUM> may be transmitted on the remaining carriers of the M carriers to ensure that the minimum DL bandwidth is at least <NUM>.

In certain other configurations, when the base station <NUM> does not have any DL data to schedule for either the first UE 504a or the second UE 504b, the base station <NUM> may transmit a reservation signal in the downlink data portion of each of the M carriers (e.g., <NUM> on CA0, <NUM> on 4CA1, and <NUM> on CA2 in <FIG>).

In certain other configurations, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern by concurrently transmitting (at 511a) a first downlink transmission to the first UE 504a in a first portion (e.g., second duration 440b in <FIG>) of each of theM carriers (e.g., CA0, CA1, CA2 in <FIG>).

In certain other configurations, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern by concurrently transmitting (at 511b) a second downlink transmission to the second UE 504a in a second portion (e.g., third duration 440c in <FIG>) of each of the M carriers (e.g., CA0, CA1, CA2 in <FIG>). In certain aspects, the second portion (e.g., third duration 440c in <FIG>) may be subsequent to the first portion (e.g., second duration 440b in <FIG>) in a time domain.

In certain other configurations, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern by receiving (at 513a) a first uplink transmission in a third portion (e.g., UL data in the second portion <NUM> on CA0 in <FIG>) of a first carrier (e.g., CA0 in <FIG>) of the M carriers.

In certain other configurations, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern by receiving (at 513b) a second uplink transmission in the third portion (e.g., UL data in the second portion <NUM> on CA1 in <FIG>) of a second carrier (e.g., CA1 in <FIG>) of the M carriers. In certain aspects, the first uplink transmission and the second uplink transmission may be received concurrently. In certain other aspects, the third portion (e.g., UL data in the second portion <NUM> in <FIG>) may be adjacent to the second portion (e.g., second duration 440b in <FIG>) in the time domain.

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a base station (e.g., base station <NUM>, <NUM>, <NUM>, <NUM>, eNB <NUM>, apparatus <NUM>/<NUM>'). In <FIG>, optional operations are indicated with dashed lines.

At <NUM>, the base station may the base station <NUM> may transmit information indicating a narrowband frequency hopping pattern (e.g., frequency hopping patterns <NUM>, <NUM>, <NUM> in <FIG>, <FIG>, and <FIG>, respectively).

In certain aspects associated with the operation at <NUM>, the narrowband frequency hopping pattern (e.g., frequency hopping patterns <NUM>, <NUM>, <NUM> in <FIG>, <FIG>, and <FIG>, respectively) may include a plurality of frames (e.g., hopping frames 430a, 430b, 430c in <FIG>; hopping frames 430a, 430b in <FIG>).

In certain other aspects associated with the operation at <NUM>, each of the plurality of frames may include a plurality of anchor channels (e.g., anchor channels 404a, 404b, 404c in <FIG> and <FIG>) and at least one non-anchor channel (e.g., non-anchor channels 406a, 406b, 406c in the first hopping frame 430a in <FIG>; non-anchor channels 406b, 406c, 406d in the second hopping frame in <FIG>; non-anchor channels 406e, 406f, <NUM> in the third hopping frame in <FIG>; non-anchor channels 406a, 406b in the first hopping frame 430a in <FIG>; and non-anchor channels 406c, 406d in the second hopping frame 430b in <FIG>).

In certain aspects associated with the operations at <NUM>, the at least one non-anchor channel in each of the plurality of frames may include M non-anchor channels within a wideband. For example, referring to <FIG>, the frequency hopping pattern <NUM> includes non-anchor channels (406a, 406b, 406c; 406b, 406c, 406d; 406e, 406f, <NUM>) in each of the hopping frames 430a, 430b, 430c.

In certain other aspects associated with the operation at <NUM>, the M non-anchor channels may be grouped into M carriers across a plurality of frames. For example, referring to <FIG>, the M non-anchor channels are grouped across each of the hopping frames 430a, 430b, 430c in to carriers CA0, CA1, and CA2.

In certain other aspects associated with the operation at <NUM>, each of the M carriers may occupy a set of adjacent non-anchor channels in each of the plurality of frames. For example, referring to <FIG>, each of the M carriers are located in contiguous non-anchor channels (e.g., non-anchor channels 406a, 406b, 406c) within each of the hopping frames 430a, 430b, 430c.

In certain other aspects associated with the operation at <NUM>, the at least one non-anchor hopping channel may include a single non-anchor hopping channel. For example, referring to <FIG>, although each hopping frame 430a, 430b is illustrated as including two non-anchor channels, a single non-anchor hopping channel may be included in each hopping frame 430a, 430b without departing from the scope of the present disclosure.

In certain other aspects associated with the operation at <NUM>, each of the M carriers may be associated with a respective hopping sequence across a plurality of frames. For example, referring to <FIG>, when N = <NUM>, CA0 may be associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>], CA1 is associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>], and CA2 is associated with the non-anchor channel hopping sequence [<NUM>, <NUM>, <NUM>].

In certain other aspects associated with the operation at <NUM>, the respective hopping sequence may include a fixed offset between contiguous non-anchor hopping channels in the M carrier. In certain other aspects associated with the operation at <NUM>, the respective hopping sequence may comprise a pseudo-random hopping sequence. For example, referring to <FIG>, the fixed offset between the first non-anchor channel of a carrier in first hopping frame 430a and the second non-anchor channel of the same carrier in second hopping frame 430b is one non-anchor channel, and the fixed offset between the second non-anchor hopping channel of the same carrier in the second hopping frame 430b and the third non-anchor carrier of the same carrier in the third hopping frame 430c is four non-anchor hopping channels.

In certain other aspects associated with the operation at <NUM>, each of the M carriers may have a same frame structure. For example, as illustrated in <FIG>, CA0 includes a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>. CA1 may include a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>. CA <NUM> may include a first portion <NUM> for DL data, and a second portion <NUM> for UL data received from UE <NUM>.

In certain other aspects associated with the operation at <NUM>, a total bandwidth of each of the M carriers meets a bandwidth threshold criteria. For example, referring to <FIG>, each of the M carriers (CA0, CA1, CA2 in each hopping frame 430a, 430b, 430c) may have a bandwidth of at least, e.g.,<NUM>, <NUM>, <NUM> RB, etc..

At <NUM>, the base station may communicate with the at least one UE using the narrowband frequency hopping pattern. For example, referring to <FIG>, <FIG>, <FIG>, and <FIG>, the base station <NUM> may communicate (at 503a, 503b) with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern (e.g., frequency hopping patterns <NUM>, <NUM>, <NUM> in <FIG>, <FIG>, and <FIG>, respectively).

At <NUM>, the base station may communicate with the at least one UE using the narrowband frequency hopping pattern by transmitting a plurality of downlink transmissions to the at least one UE concurrently in each of the M carriers. For example, referring to <FIG> and <FIG>, the base station <NUM> may communicate with the first UE 504a and the second UE 504b by transmitting (at <NUM>) a plurality of downlink transmissions (e.g., DL data in the first portions <NUM>, <NUM>, <NUM> in <FIG>) to the first UE 504a and the second UE 504b concurrently in each of the M carriers (e.g., CA0, CA1, CA2 in <FIG>) in each hopping frame (e.g., hopping frames 430a, 430b, 430c in <FIG>).

In certain aspects associated with the operation at <NUM>, the one or more UEs include a single UE. In certain other aspects associated with the operation at <NUM>, the plurality of downlink transmissions may include an initial downlink transmission transmitted on one of the M carriers and downlink retransmissions transmitted on a subset of the M carriers. For example, referring to <FIG>, when the base station has DL data to schedule for a single UE instead of multiple UEs and the single UE is not served by all of the M carriers, the DL data in the second portion <NUM> may be transmitted on a first carrier of the M carrier, and a retransmission of the DL data in the second portion <NUM> may be transmitted on the remaining carriers of the M carriers to ensure that the minimum DL bandwidth is at least <NUM>.

In certain other aspects associated with the operation at <NUM>, the plurality of downlink transmissions may include a reservation signal on each of the M carriers when a data transmission is unavailable. For example, referring to <FIG> and <FIG>, when the base station <NUM> does not have any DL data to schedule for either the first UE 504a or the second UE 504b, the base station <NUM> may transmit a reservation signal in the downlink data portion of each of the M carriers (e.g., <NUM> on CA0, <NUM> on 4CA1, and <NUM> on CA2 in <FIG>).

At <NUM>, the base station may communicate with the at least one UE using the narrowband frequency hopping pattern by receiving a plurality of uplink transmissions from the at least one UE concurrently in the M carriers. For example, referring to <FIG> and <FIG>, the base station <NUM> may communicate with the first UE 504a and the second UE 504b by receiving (at 507a, 507b) a plurality of uplink transmissions (e.g., UL data in the second portions <NUM>, <NUM>, <NUM> in <FIG>) from the first UE 504a and the second UE 504b concurrently in the M carriers (e.g., CA0, CA1, and CA2 in <FIG>) in each hopping frame (e.g., hopping frames 430a, 430b, 430c in <FIG>).

In certain aspects associated with the operation at <NUM>, a first portion of each of theM carriers may be allocated for downlink transmissions and a second portion of each of the M carriers is allocated for uplink transmissions. In certain other aspects associated with the operation at <NUM>, the second portion may be located subsequent to the first portion in a time domain. For example, referring to <FIG>, <NUM>, <NUM>, <NUM> may be allocated for DL data for UE <NUM>, UE <NUM>, and UE <NUM> on CA <NUM>, CA <NUM>, and CA <NUM>, respectively, and <NUM>, <NUM>, <NUM> may be allocated for UL data from UE <NUM>, UE <NUM>, and UE <NUM> on CA <NUM>, CA <NUM>, and CA <NUM>, respectively.

At <NUM>, the base station may communicate with the at least one UE using the narrowband frequency hopping pattern by concurrently transmitting a DRS in each of the plurality of anchor channels at a start of each hopping frame. For example, referring to <FIG> and <FIG>, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the frequency hopping pattern by concurrently transmitting (at <NUM>) a DRS in each of the plurality of anchor channels (e.g., anchor channels 404a, 404b, 404c in <FIG>) at a start of each hopping frame (e.g., hopping frames 430a, 430b, 430c in <FIG>).

At <NUM>, the base station may communicate with the at least one UE using the narrowband frequency hopping pattern by concurrently transmitting a first downlink transmission to a first UE in a first portion. For example, referring to <FIG> and <FIG>, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern by concurrently transmitting (at 511a) a first downlink transmission to the first UE 504a in a first portion (e.g., second duration 440b in <FIG>) of each of the M carriers (e.g., CA0, CA1, CA2 in <FIG>).

At <NUM>, the base station may communicate with the at least one UE using the narrowband frequency hopping pattern by concurrently transmitting a second downlink transmission to a second UE in a second portion of each of the M carriers. In certain aspects, the second portion may be subsequent to the first portion in a time domain. For example, referring to <FIG> and <FIG>, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern by concurrently transmitting (at <NUM>1b) a second downlink transmission to the second UE 504a in a second portion (e.g., third duration 440c in <FIG>) of each of the M carriers (e.g., CA0, CA1, CA2 in <FIG>). In certain aspects, the second portion (e.g., third duration 440c in <FIG>) may be subsequent to the first portion (e.g., second duration 440b in <FIG>) in a time domain.

At <NUM>, the base station may communicate with the at least one UE using the narrowband frequency hopping pattern by receiving a first uplink transmission in a third portion of a first carrier of the M carriers. For example, referring to <FIG> and <FIG>, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern by receiving (at 513a) a first uplink transmission in a third portion (e.g., UL data in the second portion <NUM> on CA0 in <FIG>) of a first carrier (e.g., CA0 in <FIG>) of the M carriers.

At <NUM>, the base station may communicate with the at least one UE using the narrowband frequency hopping pattern by receiving a second uplink transmission in the third portion of a second carrier of the M carriers. In certain aspects, the first uplink transmission and the second uplink transmission may be received concurrently. In certain other aspects, the third portion may be adjacent to the second portion in the time domain. For example, referring to <FIG> and <FIG>, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern by receiving (at 513b) a second uplink transmission in the third portion (e.g., UL data in the second portion <NUM> on CA1 in <FIG>) of a second carrier (e.g., CA1 in <FIG>) of the M carriers. In certain aspects, the first uplink transmission and the second uplink transmission being received concurrently. In certain other aspects, the third portion (e.g., UL data in the second portions <NUM> in <FIG>) may be adjacent to the second portion (e.g., second duration 440b in <FIG>) in the time domain.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different means/components in an exemplary apparatus <NUM>. The apparatus may be a base station (e.g., base station <NUM>, <NUM>, <NUM>, <NUM>, eNB <NUM>, apparatus <NUM>') in communication with at least one UE <NUM> (e.g., UE <NUM>, <NUM>, first UE 504a, second UE 504b, the apparatus <NUM>/<NUM>'). The apparatus may include a reception component <NUM>, a frequency hopping pattern (FHP) component <NUM>, a DRS component <NUM>, a DL data component <NUM>, and a transmission component <NUM>.

In certain configurations, the FHP component <NUM> may be configured to determine a frequency hopping pattern for narrowband communications in the unlicensed frequency spectrum. In certain other aspects, each of the plurality of frames may include a plurality of anchor channels and at least one non-anchor channel. In certain aspects, the at least one non-anchor channel in each of the plurality of frames may include M non-anchor channels within a wideband. In certain other aspects, the M non-anchor channels may be grouped into M carriers across a plurality of frames. In certain other aspects, each of the M carriers may occupy a set of adjacent non-anchor channels in each of the plurality of frames. In certain other aspects, the at least one non-anchor hopping channel may include a single non-anchor hopping channel. In certain other aspects, each of the M carriers may be associated with a respective hopping sequence across a plurality of frames. In certain other aspects, the respective hopping sequence may include a fixed offset between contiguous non-anchor hopping channels in the M carrier. In certain other aspects, the respective hopping sequence may comprise a pseudo-random hopping sequence. In certain other aspects, each of the M carriers may have a same frame structure. In certain other aspects, a total bandwidth of each of the M carriers meets a bandwidth threshold criteria.

The FHP component <NUM> may be configured to send a signal associated with the FHP to the transmission component <NUM>. The transmission component <NUM> may be configured to transmit information associated with the FHP to the UE <NUM>.

In certain configurations, the reception component <NUM> and the transmission component may be configured to communicate with the at least one UE <NUM> using the FHP.

In certain aspects, the transmission component <NUM> may be configured to communicate with the at least one UE <NUM> using the narrowband frequency hopping pattern by transmitting a plurality of downlink transmissions to the at least one UE <NUM> concurrently in each of the M carriers. In certain configurations, the at least one UE <NUM> may include a single UE. In certain aspects, the plurality of downlink transmissions may include an initial downlink transmission transmitted on one of the M carriers and downlink retransmissions transmitted on a subset of the M carriers. In certain other aspects, the plurality of downlink transmissions may include a reservation signal on each of the M carriers when a data transmission is unavailable.

In certain other aspects, the reception component <NUM> may be configured to communicate with the at least one UE <NUM> using the narrowband frequency hopping pattern by receiving a plurality of uplink transmissions from the at least one UE <NUM> concurrently in the M carriers. In certain other aspects, a first portion of each of the M carriers may be allocated for downlink transmissions and a second portion of each of the M carriers is allocated for uplink transmissions. In certain other aspects, the second portion may be located subsequent to the first portion in a time domain.

In certain other configurations, the DRS component <NUM> may be configured to generate one or more DRS transmissions. The DRS component <NUM> may be configured to send a signal associated with the one or more DRS to the transmission component <NUM>.

In certain other configurations, the transmission component <NUM> may be configured to communicate with the at least one UE <NUM> using the narrowband frequency hopping pattern by concurrently transmitting a DRS in each of the plurality of anchor channels at a start of each hopping frame.

In certain other configurations, the DL data component <NUM> may be configured to generate DL data for the at least one UE <NUM>. The DL data component <NUM> may be configured to send a signal associated with the DL data to the transmission component <NUM>.

In certain other configurations, the transmission component <NUM> may be configured to communicate with the at least one UE <NUM> using the narrowband frequency hopping pattern by concurrently transmitting a first downlink transmission to a first UE in a first portion.

In certain other configurations, the transmission component <NUM> may be configured to communicate with the at least one UE <NUM> using the narrowband frequency hopping pattern by concurrently transmitting a second downlink transmission to a second UE in a second portion of each of the M carriers. In certain aspects, the second portion may be subsequent to the first portion in a time domain.

In certain other configurations, the reception component <NUM> may be configured to communicate with the at least one UE <NUM> using the narrowband frequency hopping pattern by receiving a first uplink transmission in a third portion of a first carrier of the M carriers.

In certain other configurations, the reception component <NUM> may be configured to communicate with the at least one UE <NUM> using the narrowband frequency hopping pattern by receiving a second uplink transmission in the third portion of a second carrier of the M carriers. In certain aspects, the first uplink transmission and the second uplink transmission may be received concurrently. In certain other aspects, the third portion may be adjacent to the second portion in the time domain.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. The processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware components, represented by the processor <NUM>, the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and the computer-readable medium / memory <NUM>. The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system <NUM> may be coupled to a transceiver <NUM>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium. The transceiver <NUM> receives a signal from the one or more antennas <NUM>, extracts information from the received signal, and provides the extracted information to the processing system <NUM>, specifically the reception component <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission component <NUM>, and based on the received information, generates a signal to be applied to the one or more antennas <NUM>. The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium / memory <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system <NUM> further includes at least one of the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The components may be software components running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware components coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the base station <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM>.

In certain configurations, the apparatus <NUM>/<NUM>' for wireless communication may include means for transmitting information indicating a narrowband frequency hopping pattern to at least one UE. In certain aspects, the narrowband frequency hopping pattern may include a plurality of frames. In certain other aspects, each of the plurality of frames may include a plurality of anchor channels and at least one non-anchor channel. In certain other aspects, each of the plurality of frames may include a plurality of anchor channels and at least one non-anchor channel. In certain aspects, the at least one non-anchor channel in each of the plurality of frames may include M non-anchor channels within a wideband. In certain other aspects, the M non-anchor channels may be grouped into M carriers across a plurality of frames. In certain other aspects, each of the M carriers may occupy a set of adjacent non-anchor channels in each of the plurality of frames. In certain other aspects, the at least one non-anchor hopping channel may include a single non-anchor hopping channel. In certain other aspects, each of the M carriers may be associated with a respective hopping sequence across a plurality of frames. In certain other aspects, the respective hopping sequence may include a fixed offset between contiguous non-anchor hopping channels in the M carrier. In certain other aspects, the respective hopping sequence may comprise a pseudo-random hopping sequence. In certain other aspects, each of the M carriers may have a same frame structure. In certain other aspects, a total bandwidth of each of the M carriers meets a bandwidth threshold criteria. In certain other configurations, the apparatus <NUM>/<NUM>' for wireless communication may include means for communicating with the at least one UE using the narrowband frequency hopping pattern by transmitting a plurality of downlink transmissions to the at least one UE concurrently in each of the M carriers. In certain configurations, the at least one UE may include a single UE. In certain aspects, the plurality of downlink transmissions may include an initial downlink transmission transmitted on one of the M carriers and downlink retransmissions transmitted on a subset of the M carriers. In certain other aspects, the plurality of downlink transmissions may include a reservation signal on each of the M carriers when a data transmission is unavailable. In certain aspects, the means for communicating with the at least one using the narrowband frequency hopping pattern may be configured to concurrently transmit a DRS in each of the plurality of anchor channels at a start of each hopping frame. In certain other aspects, the means for communicating with the at least one using the narrowband frequency hopping pattern may be configured to receive a plurality of uplink transmissions from the at least one UE concurrently in the M carriers. In certain other aspects, a first portion of each of the M carriers may be allocated for downlink transmissions and a second portion of each of the M carriers is allocated for uplink transmissions. In certain other aspects, the second portion may be located subsequent to the first portion in a time domain. In certain other aspects, the means for communicating with the at least one using the narrowband frequency hopping pattern may be configured to receive a first uplink transmission in a third portion of a first carrier of the M carriers. In certain other aspects, the means for communicating with the at least one using the narrowband frequency hopping pattern may be configured to receive a second uplink transmission in the third portion of a second carrier of the M carriers. In certain aspects, the first uplink transmission and the second uplink transmission may be received concurrently. In certain other aspects, the third portion may be adjacent to the second portion in the time domain.

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a UE (e.g., UE <NUM>, <NUM>, 504a, 504b, <NUM>, apparatus <NUM>/<NUM>'). In <FIG>, optional operations are indicated with dashed lines.

At <NUM>, the UE may receive information indicating a narrowband frequency hopping pattern (e.g., frequency hopping patterns <NUM>, <NUM>, <NUM> in <FIG>, <FIG>, and <FIG>, respectively) from a base station.

In certain other aspects associated with the operation at <NUM>, each of the plurality of frames may include a plurality of anchor channels (e.g., anchor channels 404a, 404b, 404c in <FIG> and <FIG>) and at least one non-anchor channel (e.g., non-anchor channels 406a, 406b, 406c in the first hopping frame 430a in <FIG>; non-anchor channels 406b, 406c, 406d in the second hopping frame in <FIG>; non-anchor channels 406e, 406f, <NUM> in the third hopping frame in <FIG>; non-anchor channels 406a, 406b in the first hopping frame 430a in <FIG>; and non-anchor channel 406c, 406d in the second hopping frame 430b in <FIG>).

At <NUM>, the UE may communicate with the base station using the narrowband frequency hopping pattern. For example, referring to <FIG>, <FIG>, <FIG>, and <FIG>, the base station <NUM> may communicate (at 503a, 503b) with the first UE 504a and the second UE 504b using the narrowband frequency hopping pattern (e.g., frequency hopping patterns <NUM>, <NUM>, <NUM> in <FIG>, <FIG>, and <FIG>, respectively).

At <NUM>, the UE may communicate with the base station using the narrowband frequency hopping pattern by receiving a DRS in each of the plurality of anchor channels at a start of each hopping frame. For example, For example, referring to <FIG> and <FIG>, the base station <NUM> may communicate with the first UE 504a and the second UE 504b using the frequency hopping pattern by concurrently transmitting (at <NUM>) a DRS in each of the plurality of anchor channels (e.g., anchor channels 404a, 404b, 404c in <FIG>) at a start of each hopping frame (e.g., hopping frames 430a, 430b, 430c in <FIG>).

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different means/components in an exemplary apparatus <NUM>. The apparatus may be a UE (e.g., UE <NUM>, <NUM>, 504a, 504b, <NUM>, the apparatus <NUM>') in communication with a base station <NUM> (e.g., base station <NUM>, <NUM>, <NUM>, the apparatus <NUM>/<NUM>') The apparatus includes a reception component <NUM>, a FHP component <NUM>, a DRS component <NUM>, a UL data component <NUM>, and a transmission component <NUM>.

The reception component <NUM> may be configured to receive information indicating a narrowband frequency hopping pattern from a base station. In certain aspects, the narrowband frequency hopping pattern may include a plurality of frames. In certain other aspects, each of the plurality of frames may include a plurality of anchor channels and at least one non-anchor channel. In certain aspects, the at least one non-anchor channel in each of the plurality of frames may included non-anchor channels within a wideband. In certain other aspects, the M non-anchor channels may be grouped into M carriers across a plurality of frames. In certain other aspects, each of the M carriers may occupy a set of adjacent non-anchor channels across in each of the plurality of frames. In certain other aspects, the at least one non-anchor hopping channel may include a single non-anchor hopping channel. In certain other aspects, each of the M carriers may be associated with a respective hopping sequence across a plurality of frames. In certain other aspects, the respective hopping sequence may include a fixed offset between contiguous non-anchor hopping channels in the M carrier. In certain other aspects, the respective hopping sequence may comprise a pseudo-random hopping sequence.

The reception component <NUM> may be configured to send a signal associated with the FHP to the FHP component <NUM> and/or the transmission component <NUM>. The FHP component <NUM> may be configured to maintain information associated with the FHP.

In certain configurations, one or more of the reception component <NUM> and/or the transmission component <NUM> may be configured to communicate with the base station using the narrowband frequency hopping pattern.

In certain configurations, the reception component <NUM> may be configured to communicate with the base station using the narrowband frequency hopping pattern by receiving a DRS in each of the plurality of anchor channels at a start of each hopping frame. The reception component <NUM> may be configured to send a signal associated with the DRS to the DRS component <NUM>. The DRS component <NUM> may be configured to maintain information associated the DRS and/or configured to perform cell acquisition based on the DRS.

The UL data component <NUM> may be configured to generate UL data for the base station <NUM>. The UL data component <NUM> may be configured to send a signal associated with the UL data to the transmission component <NUM>.

The transmission component <NUM> may be configured to transmit the UL data to the base station <NUM> using the FHP.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. The processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware components, represented by the processor <NUM>, the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and the computer-readable medium / memory <NUM>. The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system <NUM> may be coupled to a transceiver <NUM>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium. The transceiver <NUM> receives a signal from the one or more antennas <NUM>, extracts information from the received signal, and provides the extracted information to the processing system <NUM>, specifically the reception component <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission component <NUM>, and based on the received information, generates a signal to be applied to the one or more antennas <NUM>. The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium / memory <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system <NUM> further includes at least one of the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The components may be software components running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware components coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM>.

In certain configurations, the apparatus <NUM>/<NUM>' for wireless communication includes means for receiving information indicating a narrowband frequency hopping pattern from a base station. In certain aspects, the narrowband frequency hopping pattern may include a plurality of frames. In certain other aspects, each of the plurality of frames may include a plurality of anchor channels and at least one non-anchor channel. In certain aspects, the at least one non-anchor channel in each of the plurality of frames may include M non-anchor channels within a wideband. In certain other aspects, the M non-anchor channels may be grouped into M carriers across a plurality of frames. In certain other aspects, each of the M carriers may occupy a set of adjacent non-anchor channels in each of the plurality of frames. In certain other aspects, the at least one non-anchor hopping channel may include a single non-anchor hopping channel. In certain other aspects, each of the M carriers may be associated with a respective hopping sequence across a plurality of frames. In certain other aspects, the respective hopping sequence may include a fixed offset between contiguous non-anchor hopping channels in the M carrier. In certain other aspects, the respective hopping sequence may comprise a pseudo-random hopping sequence. In certain other configurations, the apparatus <NUM>/<NUM>' for wireless communication may include means for communicating with the base station using the narrowband frequency hopping pattern. In certain aspects, the means for communicating with the base station using the narrowband frequency hopping pattern may be configured to receive a DRS in each of the plurality of anchor channels at a start of each hopping frame. In certain other configurations, the apparatus <NUM>/<NUM>' for wireless communication may include means for transmitting UL data to the base station based on the frequency hopping pattern.

Claim 1:
A method of wireless communication of a base station, comprising:
transmitting, on a plurality of anchor channels, information indicating a narrowband frequency hopping pattern to at least one user equipment, UE, the narrowband frequency hopping pattern including a plurality of frames, the plurality of frames including at least one non-anchor channel and the plurality of anchor channels, the at least one non-anchor channel in each of the plurality of frames includes M non-anchor channels within a wideband, the M non-anchor channels are grouped into M carriers across a plurality of frames, and each of the M carriers occupying a set of adjacent non-anchor channels in each of the plurality of frames; and
communicating with the at least one UE using the narrowband frequency hopping pattern, wherein communication on the plurality of anchor channels occurs during the plurality of frames.