Patent Description:
As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP), a radio head, a transmit receive point (TRP), a <NUM> BS, a <NUM> Node B, and/or the like.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless communication devices to communicate on a municipal, national, regional, and even global level. <NUM>, which may also be referred to as New radio (NR), is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). <NUM> is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE and <NUM> technologies.

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. <NPL> [X] discusses NR-PBCH design. <CIT> discloses narrowband communications in a wireless communications system may include a common synchronization signal, such as a primary synchronization signal (PSS), secondary synchronization signal (SSS), or physical broadcast channel (PBCH). Content of the common synchronization signal may indicate a location of narrowband data transmissions in a narrowband region of a system bandwidth. The location of the narrowband region may be in-band within one or more wideband transmissions, within a guard-band bandwidth adjacent to the wideband transmissions bandwidth, or within a stand-alone bandwidth that is non-adjacent to the wideband transmissions. The common synchronization signal may be located within a predefined search frequency and may include an anchor synchronization channel present in certain resources of allocated narrowband communications resources. Narrowband data region resources may be distributed in other portions of the narrowband communications resources, and may be allocated to different users to provide transmit diversity.

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 (e.g., differential time signaling (DTS) modulation) 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, for example, <NUM>. In other words, when using some digital modulation modes (e.g., DTS), 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 allowed to operate in the United States (and certain other countries).

A base station may transmit discovery reference signals (DRS) for synchronization of UEs covered by the base station. A discovery reference signal as described herein may include, for example, a narrowband primary synchronization signal, a narrowband secondary synchronization signal, a narrowband physical broadcast channel (e.g., which may include a master information block), a system information block, a synchronization signal block, and/or the like. A discovery reference signal may be transmitted in a channel which may be termed an anchor channel. A frequency of the anchor channel may be known to UEs covered by the base station. In a legacy approach, the DRS may be transmitted periodically (e.g., regularly) on a single channel or RB. However, the base station may need to meet the minimum bandwidth requirement and the PSD limit with regard to the discovery reference signal.

Techniques and apparatuses described herein facilitate narrowband communication within the unlicensed frequency spectrum by simultaneously transmitting (e.g., in adjacent channels) a plurality of anchor channels. For example, the base station may simultaneously transmit at least three anchor channels of <NUM> each so that the <NUM> minimum bandwidth requirement is satisfied. Furthermore, the techniques and apparatuses described herein provide DRS structures to cause the different types of DRS to be repeated and/or transmitted on different anchor channels, which improves frequency diversity. In some aspects, the UE may determine, or the BS may indicate, a configuration of the at least three anchor channels based at least in part on a synchronization signal received on a first anchor channel (e.g., a cyclic shift of the synchronization signal received on the first anchor channel). Thus, synchronization in the NB-IoT-unlicensed (NB-IoT-u) spectrum is enabled while complying with PSD restrictions, and efficiency is improved over synchronization using a single anchor channel.

In aspects of the disclosure, a method, a user equipment (UE), a base station, an apparatus, and a computer program product are provided.

In some aspects, the method may by performed by a base station according to claim <NUM>.

In some aspects, the base station may include a 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 plurality of anchor channels, wherein a first anchor channel of the plurality of anchor channels includes at least one synchronization signal, and wherein at least two anchor channels of the plurality of anchor channels include a broadcast channel and/or an information block; simultaneously transmit the plurality of anchor channels to at least one UE; and communicate with the at least one UE based at least in part on the plurality of anchor channels.

An apparatus according to claim <NUM> is also provided.

In some aspects, the computer program product may include a non-transitory computer-readable medium storing one or more instructions. 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 plurality of anchor channels, wherein a first anchor channel of the plurality of anchor channels includes at least one synchronization signal, and wherein at least two anchor channels of the plurality of anchor channels include a broadcast channel and/or an information block; simultaneously transmit the plurality of anchor channels to at least one UE; and communicate with the at least one UE based at least in part on the plurality of anchor channels.

In some aspects, the method may by performed by a UE according to claim <NUM>.

In some aspects, the UE may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive at least one synchronization signal on a first anchor channel, wherein the first anchor channel is one of a plurality of anchor channels that were simultaneously transmitted; receive a broadcast channel and/or an information block on the first anchor channel and at least one other anchor channel of the plurality of anchor channels; and perform a synchronization operation based at least in part on the synchronization signal.

In some aspects, the apparatus may include means according "to claim <NUM>.

In some aspects, the computer program product may include a non-transitory computer-readable medium storing one or more instructions. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to receive at least one synchronization signal on a first anchor channel, wherein the first anchor channel is one of a plurality of anchor channels that were simultaneously transmitted; receive a broadcast channel and/or an information block on the first anchor channel and at least one other anchor channel of the plurality of anchor channels; and perform a synchronization operation based at least in part on the synchronization signal.

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.

foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood.

It is noted that while aspects may be described herein using terminology commonly associated with <NUM> and/or <NUM> wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, such as <NUM> and later, including <NUM> technologies.

The network <NUM> may be an LTE network or some other wireless network, such as a <NUM> network. A BS is an entity that communicates with user equipment (UEs) and may also be referred to as a base station, a <NUM> BS, a Node B, a gNB, a <NUM> NB, an access point, a transmit receive point (TRP), and/or the like.

A BS may transmit signals for discovery and synchronization of a UE, such as discovery reference signals, synchronization signals, and/or the like.

A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, etc. A UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

MTC and eMTC UEs include, for example, robots, drones, remote devices, such as sensors, meters, monitors, location tags, etc., that may communicate with a base station, another device (e.g., remote device), or some other entity. Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as may be implemented as NB-IoT (narrowband internet of things) devices or NB-IoT-U (unlicensed) devices, which may operate in an unlicensed spectrum, as described in more detail elsewhere herein.

<FIG> shows a block diagram <NUM> of a design of BS <NUM> and UE <NUM>, which may be one of the base stations and one of the UEs in <FIG>. BS <NUM> may be equipped with T antennas 234a through 234t, and UE <NUM> may be equipped with R antennas 252a through 252r, where in general T ≥ <NUM> and R ≥ <NUM>.

At BS <NUM>, a transmit processor <NUM> may receive data from a data source <NUM> for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS(s) selected for the UE, and provide data symbols for all UEs. Transmit processor <NUM> may also process system information (e.g., for semi-static resource partitioning information (SRPI), and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. Transmit processor <NUM> may also generate reference symbols for reference signals (e.g., the cell-specific reference signal (CRS)) and synchronization signals (e.g., the narrowband primary synchronization signal (NPSS) and narrowband secondary synchronization signal (NSSS)).

At UE <NUM>, antennas 252a through 252r may receive the downlink signals from BS <NUM> and/or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. A receive (RX) processor <NUM> may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE <NUM> to a data sink <NUM>, and provide decoded control information and system information (e.g., from a master information block such as a narrowband master information block, a system information block, a narrowband physical broadcast channel, and/or the like) to a controller/processor <NUM>.

The symbols from transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to BS <NUM>. At BS <NUM>, the uplink signals from UE <NUM> and other UEs may be received by antennas <NUM>, processed by demodulators <NUM>, detected by a MIMO detector <NUM> if applicable, and further processed by a receive processor <NUM> to obtain decoded data and control information sent by UE <NUM>. BS <NUM> may include communication unit <NUM> and communicate to network controller <NUM> via communication unit <NUM>.

Controller/processor <NUM> of BS <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform one or more techniques associated with discovery reference signaling in a narrowband system with multiple anchor channels, as described in more detail elsewhere herein. For example, controller/processor <NUM> of BS <NUM>, controller/processor <NUM> of UE <NUM>, and/or any other component(s) of <FIG> may perform or direct operations of, for example, method <NUM> of <FIG>, method <NUM> of <FIG>, and/or other processes as described herein. Memories <NUM> and <NUM> may store data and program codes for BS <NUM> and UE <NUM>, respectively.

<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 stand-alone 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 Multicast Broadcast Single Frequency Network (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 radio resource control (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.

Other examples are possible and may differ from what was described in connection with <FIG>.

<FIG> is a diagram illustrating an example <NUM> of a NB discovery reference signal structure for a single anchor channel. The transmissions described in connection with <FIG> may be performed by a base station (e.g., BS <NUM>, etc.). As shown in <FIG>, NPBCH MIB blocks (hereinafter referred to as discovery reference signals (DRSs)) may be transmitted at a regular interval. For example, the DRS may be transmitted at an interval of <NUM> SFNs (e.g., <NUM>). In some aspects, the <NUM> most significant bits (MSB) of the MIB payload of the NPBCH MIB blocks may indicate the synchronization cycle. For example, and starting at SFN=<NUM>, the MIB payload of all <NUM> of the MIB blocks may be the same from an SFN # <NUM> · m to an SFN # <NUM> · m + <NUM> (e.g., an entire <NUM> segment). Thus, a synchronizing UE can identify the <NUM> segment during synchronization. In some aspects, the <NUM> segment may be referred to herein as an information block cycle.

In some aspects, as described in connection with <FIG>, above, the NPBCH MIB blocks may include different information. For example, each MIB block may include particular information that identifies the portion of the <NUM> segment associated with the MIB block. Furthermore, each NPBCH MIB block may be self-decodable. Thus, a UE <NUM> may identify the current NPBCH MIB block and the current portion of the <NUM> segment based at least in part on descrambling or receiving a single NPBCH MIB block.

However, in certain systems, such as unlicensed spectrum systems, regulations may require a minimum bandwidth greater than that of the single anchor channel. Thus, it may be beneficial to provide a discovery reference signal structure that uses a bandwidth greater than the minimum bandwidth. Such a discovery reference signal structure is described below.

Other examples are possible and may differ from what was described 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>, the apparatus <NUM>/<NUM>') operating in DTS mode and a UE (e.g., UE <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.

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 hopping 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., N non-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 404e, the (N - <NUM>)th non-anchor channel 404f, 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 N 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 hopping 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. As shown in <FIG>, and by reference number <NUM>, downlink (DL) data on CA0 may be provided in a portion indicated by a first fill pattern. As shown by reference number <NUM>, UL data on CA0 for UE <NUM> may be provided in a portion indicated by a second fill pattern. As shown by reference number <NUM>, DL data on CA1 may be provided in a portion indicated by a third fill pattern. As shown by reference number <NUM>, UL data on CA1 for UE <NUM> may be provided in a portion indicated by a fourth fill pattern. As shown by reference number <NUM>, DL data on CA <NUM> may be provided in a portion indicated by a fifth fill pattern. As shown by reference number <NUM>, UL data on CA2 for UE <NUM> may be provided in a portion indicated by a sixth fill pattern.

In certain configurations, the DL data portions 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 DL data portions 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 DL data portions may be reserved for DL data transmitted to UE <NUM>; a second duration 440b of each of the DL data portions may be reserved for DL data transmitted to UE <NUM>; and a third duration 440c of each of the DL data portions 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 (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 may be transmitted on a first carrier of the M carrier (e.g., CA0 in <FIG>), and a retransmission of the DL data 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 bandwidth threshold. 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 disclosure may be able to meet the bandwidth threshold 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.

Other examples may differ from what was described in connection with <FIG>.

<FIG> is a diagram illustrating an example <NUM> of a synchronization cycle for multiple anchor channels in a narrowband system. In example <NUM>, a BS <NUM> (not shown) may transmit a plurality of anchor channels to at least one UE <NUM> (also not shown). In example <NUM>, and as shown by reference number <NUM>, a plurality of anchor channels is transmitted every <NUM> subframes (e.g., <NUM>), which corresponds to a hopping frame (e.g., shown as M-frame). As used herein, a hopping frame may be <NUM>, <NUM>, the same length as an NB-IoT-u frame (n-frame), an MTC frame (m-frame), and/or the like. As shown, each transmission of the plurality of anchor channels includes a first anchor channel <NUM>, a second anchor channel <NUM>, and a third anchor channel <NUM>. In some aspects, the plurality of anchor channels may include a different number of anchor channels, such as <NUM> anchor channels, <NUM> anchor channels, <NUM> anchor channels, or a different number of anchor channels. The BS <NUM> may transmit the plurality of anchor channels so that a minimum bandwidth (e.g., associated with an unlicensed spectrum, a digital transmission requirement, and/or the like) is satisfied. For example, each anchor channel may include <NUM> resource block (e.g., RB). In some aspects, each anchor channel may have a bandwidth of approximately <NUM>, <NUM>, and/or the like, so that a minimum bandwidth of <NUM> is satisfied for the plurality of anchor channels. As shown above the left-most transmission of the plurality of anchor channels, in some aspects, each transmission of the plurality of anchor channels may be approximately <NUM> in length. In some aspects, a transmission of the plurality of anchor channels may be longer or shorter than <NUM>.

As shown by reference number <NUM>, at least one synchronization signal (e.g., a NPSS and/or an NSSS) may be included in a first anchor channel of each transmission of the plurality of anchor channels. Here, the first anchor channel is shown as a topmost anchor channel (e.g., channel <NUM>). However, the at least one synchronization signal may be included in any anchor channel of the plurality of anchor channels. In some aspects, the at least one synchronization signal may be included in the same anchor channel (e.g., in terms of frequency) in each transmission of the plurality of anchor channels. In some aspects, the at least one synchronization signal may be included in a different anchor channel (e.g., in terms of frequency) in two or more transmissions of the plurality of anchor channels.

As shown by reference number <NUM>, in some aspects, the first anchor channel may include one or more NPBCHs and/or one or more MIBs. For example, a first transmission of the first anchor channel, at SFN <NUM>, includes NPBCHs that include MIBs <NUM> and <NUM>. MIBs <NUM> and <NUM> may correspond to self-decodable blocks <NUM> and <NUM>, described in connection with <FIG>, above. Note that self-decodable blocks <NUM> and <NUM> of <FIG> are included in the first <NUM> subframes of the segment shown in <FIG>. MIBs <NUM> and <NUM> may be scrambled similarly to self-decodable blocks <NUM> and <NUM> so that UE <NUM> can determine timing information based at least in part on MIBs <NUM> and <NUM>. Similarly, a second transmission of the first anchor channel, at SFN <NUM>, includes MIBs <NUM> and <NUM>, and so on. In some aspects, a first MIB (e.g., MIB <NUM>, MIB <NUM>, etc.) may alternate with a second MIB (e.g., MIB <NUM>, MIB <NUM>, etc.). Additionally, or alternatively, the first anchor channel may include a single transmission of a first MIB and a second MIB. Additionally, or alternatively, the first anchor channel may include multiple consecutive transmissions of the first MIB and multiple consecutive retransmissions of the second MIB. In some aspects, in SFN = <NUM> · m to <NUM> · m + <NUM> (i.e., the m-th <NUM> segment relative to SFN = <NUM>), the MIB payload may be determined at the start of the <NUM>th hopping frame, and the SFN index of the MIB may be the <NUM> most significant bits (MSB) bits of SFN = <NUM>m.

As shown by reference number <NUM>, in some aspects, a second anchor channel may include one or more NPBCHs and/or one or more MIBs. For example, a first transmission of the second anchor channel, at SFN <NUM>, includes NPBCHs that include MIBs <NUM> and <NUM>. MIBs <NUM> and <NUM> may correspond to self-decodable blocks <NUM> and <NUM>, described in connection with <FIG>, above. For example, MIBs <NUM> and <NUM> may be scrambled similarly to self-decodable blocks <NUM> and <NUM> so that UE <NUM> can determine timing information based at least in part on MIBs <NUM> and <NUM>. Similarly, a second transmission of the second anchor channel, at SFN <NUM>, includes MIBs <NUM> and <NUM>, and so on. In some aspects, a first MIB (e.g., MIB <NUM>, MIB <NUM>, etc.) may alternate with a second MIB (e.g., MIB <NUM>, MIB <NUM>, etc.). Additionally, or alternatively, the second anchor channel may include a single transmission of a first MIB and a second MIB. Additionally, or alternatively, the second anchor channel may include multiple consecutive transmissions of the first MIB and multiple consecutive retransmissions of the second MIB.

As shown by reference number <NUM>, in some aspects, a third anchor channel may include one or more NPBCHs and/or one or more MIBs. This may be similar to the second anchor channel described above. The frequencies of each anchor channel may be known to the UE <NUM> before the synchronization operation is performed.

In some aspects, the third anchor channel (shown by reference number <NUM>) may include a system information block (SIB) (not shown). For example, the third anchor channel may include a SIB-a or a different type of SIB. In some aspects, the SIB may store frequency hopping information for the UE <NUM>. For example, the UE <NUM> may perform frequency hopping based at least in part on a frequency hopping whitelist. The SIB may store the frequency hopping whitelist. UE <NUM> may use the SIB to determine the frequency hopping whitelist so that UE <NUM> can communicate with BS <NUM> based at least in part on the at least one synchronization signal, the NPBCH, and/or the SIB. In some aspects, the frequency hopping whitelist may be conveyed in the MIB. In such a case, the MIB and the corresponding NPDSCH may use TBCC (tail-biting convolutional coding), which may conserve a cyclic redundancy check bit if the frequency hopping whitelist and the MIB are encoded jointly. In some aspects, the frequency hopping whitelist may be transmitted in a last anchor channel, a next-to-last anchor channel, and/or the like. In some aspects, the frequency hopping whitelist may be transmitted in any anchor channel.

In some aspects, the at least one synchronization signal (shown by reference number <NUM>) may indicate a configuration of the plurality of anchor channels. For example, NB-IoT-u (e.g., NB-IoT in the unlicensed spectrum) may require different numbers of anchor channels in different regions (e.g., at least three anchor channels in the United States, and one anchor channel in the European Union, although these are provided merely as examples). The BS <NUM> may determine the at least one synchronization signal to indicate the configuration of the plurality of anchor channels. Thus, the UE <NUM> may determine the configuration while performing synchronization on the first anchor channel to avoid blind searching.

In some aspects, the DRS (e.g., NPSS and/or NSSS) on the first transmission of the plurality of anchor channels may be used to provide the configuration. This may allow a UE <NUM> to determine the configuration more quickly than using a MIB, and may be more reliable than using a MIB. In some aspects, the BS <NUM> may use a time-domain cyclic shift applied to the NSSS to convey the configuration. For example, the NSSS associated with a single anchor carrier may use <NUM> time domain cyclic shifts (l = <NUM>,<NUM>,<NUM>,<NUM>) to indicate <NUM> segments within a duration of <NUM>, or to signal the second and third least significant bits of the SFN. In NB-IoT-u, the DRS has a period of <NUM> or <NUM> (e.g., according to the hopping frame length), so the cyclic shifts of the NSSS may not be used to indicate the <NUM> segments. Techniques and apparatuses described herein may use the four potential values of the cyclic shift to indicate a configuration of the plurality of anchor channels. For example, one or more values of the cyclic shift may indicate a number of anchor channels of the plurality of anchor channels, or may indicate that a single anchor channel is to be used (e.g., instead of the plurality of anchor channels). Additionally, or alternatively, one or more values of the cyclic shift may indicate whether a particular anchor channel is to include a NPBCH/MIB or a SIB. In this way, the BS <NUM> may signal a configuration of the anchor channel(s) to the UE <NUM> using the NPSS, which conserves resources of other parts of the anchor channel and enables efficient synchronization.

<FIG> is a diagram illustrating an example <NUM> of synchronization according to a plurality of anchor channels.

As shown in <FIG>, and by reference number <NUM>, a BS <NUM> may determine a plurality of anchor channels. As further shown, the plurality of anchor channels may include at least one synchronization signal (e.g., an NPSS and an NSSS), an NPBCH (which may include a MIB), and a SIB-a. For example, the SIB-a may carry a frequency hopping whitelist and/or other information. In some aspects, the at least one synchronization signal may indicate a configuration for the plurality of anchor channels. The plurality of anchor channels is described above in more detail in connection with <FIG>, <FIG>, and <FIG>.

As shown by reference number <NUM>, the BS <NUM> may simultaneously transmit the plurality of anchor channels. For example, and as shown, the BS <NUM> may transmit the plurality of anchor channels at the beginning of each hopping frame (e.g., every <NUM>, every <NUM>, etc.). In some aspects, the BS <NUM> may simultaneously transmit the plurality of anchor channels to at least one UE (e.g., the UE <NUM>).

As shown by reference number <NUM>, the UE <NUM> may receive the at least one synchronization signal on the first anchor channel. For example, the UE <NUM> may receive the first anchor channel as part of a synchronization procedure of the UE <NUM>. To perform the synchronization procedure, at initial synchronization, the UE <NUM> may search for the NPSS and the NSSS and decode the NPBCH in the first anchor channel. In some aspects, the UE <NUM> may determine a configuration for the plurality of anchor channels based at least in part on the NPSS and/or the NSSS, as described in more detail elsewhere herein.

As shown by reference number <NUM>, the UE <NUM> may receive the NPBCH in the second anchor channel. For example, if the UE <NUM> does not receive the NPBCH in the first anchor channel, the UE <NUM> may receive the NPBCH in the second anchor channel. Additionally, or alternatively, the UE <NUM> may tune to the second anchor channel when the NPBCH is not successfully received in the first anchor channel (e.g., at the beginning of the next frame or m-frame). In some aspects, if the UE <NUM> does not successfully decode the NPBCH in the second anchor channel, the UE <NUM> may tune to the third anchor channel, attempt to decode the NPBCH in the third anchor channel, and so on. In this way, simultaneous transmission of multiple anchor channels improves frequency diversity of the anchor channels, thereby increasing likelihood of success of synchronization.

As shown by reference number <NUM>, the UE <NUM> may receive the SIB-a on the third anchor channel and may determine the frequency hopping whitelist based at least in part on the SIB-a. As shown by reference number <NUM>, the UE <NUM> may communicate with the BS <NUM> based at least in part on the frequency hopping whitelist. For example, the UE <NUM> may tune to a first set of frequencies and may transmit and/or receive traffic on carriers associated with the first set of frequencies. Then, the UE <NUM> may tune back to receive the second transmission of the plurality of anchor channels. Next, the UE <NUM> may tune to a second set of frequencies (e.g., which may be the same as or different than the first set of frequencies), to transmit and/or receive traffic on carriers associated with the second set of frequencies, and so on.

<FIG> is a flow chart of a method <NUM> of wireless communication. The method may be performed by a base station (e.g., the BS <NUM> of <FIG>, the apparatus <NUM>/<NUM>', and/or the like).

At <NUM>, the base station (e.g., using controller/processor <NUM> and/or the like) may determine a plurality of anchor channels. For example, the base station may determine (e.g., generate, map, encode, etc.) a plurality of anchor channels. In some aspects, the plurality of anchor channels may be adjacent to each other. In some aspects, some of the plurality of anchor channels may be non-adjacent to each other. The plurality of anchor channel collectively occupy a bandwidth that satisfies a required minimum bandwidth (e.g., for an unlicensed spectrum). In some aspects, a first anchor channel, of the plurality of anchor channels, may indicate a configuration for the plurality of anchor channels (e.g., using an NSSS and/or the like). In the present invention, at least two anchor channels, of the plurality of anchor channels, may include at least one of a broadcast channel or an information block.

At <NUM>, the base station (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) may simultaneously transmit the plurality of anchor channels to at least one UE. For example, the base station may simultaneously transmit the plurality of anchor channels. In some aspects, the base station may perform a first transmission of the plurality of anchor channels. For example, the base station may repeatedly transmit the plurality of anchor channels (e.g., at beginnings of hopping frames), as described in more detail below.

At <NUM>, the base station (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) may communicate with the at least one UE based at least in part on the plurality of anchor channels. For example, the base station may facilitate synchronization with the UE based at least in part on the plurality of anchor channels. Additionally, or alternatively, the base station may communicate with the at least one UE based at least in part on frequency hopping, and frequency hopping information for the at least one UE may be provided by the base station in the plurality of anchor channels.

At <NUM>, the base station (e.g., using controller/processor <NUM>, transmit processor <NUM>, TX MIMO processor <NUM>, MOD <NUM>, antenna <NUM>, and/or the like) may optionally simultaneously transmit the plurality of anchor channels in a second transmission. For example, the base station may perform a second transmission of the plurality of anchor channels. The second transmission may be different from the first transmission. For example, the second transmission may include a different NPBCH, a different MIB, and/or the like, from the first transmission.

Method <NUM> may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

The first anchor channel is one of the at least two anchor channels that include the at least one of the broadcast channel or the information block. In the present invention, the plurality of anchor channels are simultaneously transmitted in a first transmission, and the base station may simultaneously transmit the plurality of anchor channels in a second transmission after the first transmission. In some aspects, the first transmission is in a first hopping frame, and the second transmission is in a second hopping frame. In some aspects, the information block included in the first transmission includes a first information block and a second information block of an information block cycle, and wherein an information block included in the second transmission is a third information block and a fourth information block of an information block cycle. In some aspects, the plurality of anchor channels are transmitted periodically or repeatedly. In some aspects, the information block includes a self-decodable master information block. In some aspects, at least one of the at least one synchronization signal, the broadcast channel, or the information block is a discovery reference signal. In the present invention, the plurality of anchor channels comprises discovery reference signal channels. In some aspects, the information block identifies a frequency hopping whitelist for the at least one UE.

In some aspects, the at least one synchronization signal is transmitted in the first anchor channel, the information block is a first information block and is transmitted in a second anchor channel of the plurality of anchor channels, and a second information block comprising a master information block is transmitted with the broadcast channel in a third anchor channel of the plurality of anchor channels. In some aspects, the at least one synchronization signal indicates a configuration of the plurality of anchor channels. In some aspects, the at least one synchronization signal indicates the configuration of the plurality of anchor channels based at least in part on a cyclic shift of the at least one synchronization signal.

Although <FIG> shows example blocks of a method of wireless communication, in some aspects, the method may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those shown in <FIG>. Additionally, or alternatively, two or more blocks shown in <FIG> may be performed in parallel.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different modules/means/components in an example apparatus <NUM>. The apparatus <NUM> may be a base station such as an eNB or gNB (e.g., BS <NUM>). In some aspects, the apparatus <NUM> includes a reception module <NUM>, a determination module <NUM>, and/or a transmission module <NUM>.

The reception module <NUM> may receive signals <NUM> from a wireless communication device <NUM> (e.g., a UE <NUM>, the apparatus <NUM>/<NUM>', and/or the like). The signals <NUM> may include communications, synchronization information, and/or the like. For example, the reception module <NUM> and/or the transmission module <NUM> may communicate with at least one UE (e.g., the wireless communication device <NUM>) based at least in part on a plurality of anchor channels.

The determination module <NUM> may determine a plurality of anchor channels, wherein a first anchor channel of the plurality of anchor channels includes at least one synchronization signal, and wherein at least two anchor channels of the plurality of anchor channels include at least one of a broadcast channel or an information block. The determination module may provide data <NUM> to the transmission module <NUM>.

The transmission module <NUM> may transmit signals <NUM> based at least in part on the data <NUM>. The signals <NUM> may carry the plurality of anchor channels (e.g., at least one transmission of the plurality of anchor channels). For example, the transmission module <NUM> may simultaneously transmit the plurality of anchor channels to at least one UE.

The apparatus may include additional modules that perform each of the blocks of the algorithm in the aforementioned method <NUM> of <FIG> and/or the like. As such, each block in the aforementioned method <NUM> of <FIG> and/or the like may be performed by a module and the apparatus may include one or more of those modules. The modules may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. The apparatus <NUM>' may be a base station such as an eNB or gNB.

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 modules, represented by the processor <NUM>, the modules <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 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 module <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission module <NUM>, and based at least in part 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 further includes at least one of the modules <NUM>, <NUM>, and <NUM>. The modules may be software modules running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware modules coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the BS <NUM> and may include the memory <NUM> and/or at least one of the TX MIMO processor <NUM>, the receive processor <NUM>, and/or the controller/processor <NUM>.

In some aspects, the apparatus <NUM>/<NUM>' for wireless communication includes means for determining a plurality of anchor channels; means for simultaneously transmitting the plurality of anchor channels to at least one UE; means for communicating with the at least one UE based at least in part on the plurality of anchor channels; and means for simultaneously transmitting the plurality of anchor channels in a second transmission. The aforementioned means may be one or more of the aforementioned modules of the apparatus <NUM> and/or the processing system <NUM> of the apparatus <NUM>' configured to perform the functions recited by the aforementioned means. As described supra, the processing system <NUM> may include the TX MIMO processor <NUM>, the receive processor <NUM>, and/or the controller/processor <NUM>. As such, in one configuration, the aforementioned means may be the TX MIMO processor <NUM>, the receive processor <NUM>, and/or the controller/processor <NUM> configured to perform the functions recited by the aforementioned means.

Other examples are possible and may differ from what was described in connection with <FIG>.

<FIG> is a flow chart of a method <NUM> of wireless communication. The method may be performed by a user equipment (e.g., the UE <NUM> of <FIG>, the apparatus <NUM>/<NUM>', and/or the like).

At <NUM>, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may receive at least one synchronization signal on a first anchor channel of a plurality of anchor channels. For example, the at least one synchronization signal may include a discovery reference signal (e.g., NPSS, NSSS, etc.). In some aspects, the at least one synchronization signal may be received periodically or regularly. The at least one synchronization signal may be received on a first anchor channel, wherein the first anchor channel is one of a plurality of anchor channels that were simultaneously transmitted.

At <NUM>, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may optionally tune to at least one other anchor channel of the plurality of anchor channels. For example, if the UE does not successfully receive an NPBCH, MIB, or SIB on the first anchor channel, the UE may tune to at least one other anchor channel of the plurality of anchor channels. In this way, the UE achieves frequency diversity by receiving discovery reference signals on multiple, different anchor channels.

At <NUM>, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may receive at least one of a broadcast channel or an information block on the first anchor channel and the at least one other anchor channel of the plurality of anchor channels. For example, the UE may receive the plurality of anchor channels (e.g., irrespective of an anchor channel to which the UE is tuned). The plurality of anchor channels may include the at least one synchronization signal on a first anchor channel, and may include a broadcast channel (e.g., NPBCH, etc.) and/or an information block (e.g., MIB, SIB, etc.) on two or more anchor channels.

At <NUM>, the UE (e.g., using antenna <NUM>, DEMOD <NUM>, MIMO detector <NUM>, receive processor <NUM>, controller/processor <NUM>, and/or the like) may perform a synchronization operation based at least in part on the at least one synchronization signal. For example, the UE may synchronize with the base station (e.g., BS <NUM>) based at least in part on the at least one synchronization signal. In some aspects, the UE may use multiple transmissions of the plurality of anchor channels to perform the synchronization operation.

At <NUM>, the UE (e.g., using controller/processor <NUM> and/or the like) may optionally determine a configuration of the plurality of anchor channels based at least in part on the at least one synchronization signal. For example, the UE may determine how many anchor channels are in the plurality of anchor channels, may determine particular types of information carried by the plurality of anchor channels, and/or the like. In some aspects, the UE may receive or detect other anchor carriers, of the plurality of anchor carriers, based at least in part on the configuration.

In some aspects, the at least one synchronization signal is received in a first transmission of the plurality of anchor channels, and the at least one of the broadcast channel or the information block is received on the at least one other anchor channel in a second transmission of the plurality of anchor channels. In some aspects, the at least one of the broadcast channel or the information block is received in the second transmission based at least in part on reception of the at least one of the broadcast channel or the information block on the first anchor channel in the first transmission being unsuccessful.

In some aspects, the UE may tune to the at least one other anchor channel to receive the at least one of the broadcast channel or the information block. In some aspects, the plurality of anchor channels is transmitted periodically or repeatedly. In some aspects, the information block includes a self-decodable master information block. In some aspects, at least one of the at least one synchronization signal, the broadcast channel, or the information block is a discovery reference signal.

In some aspects, the plurality of anchor channels comprise discovery reference signal channels. In some aspects, the information block identifies a frequency hopping whitelist for the UE. In some aspects, the UE may determine a configuration of the plurality of anchor channels based at least in part on the at least one synchronization signal. In some aspects, the determination is based at least in part on a cyclic shift of the at least one synchronization signal.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different modules/means/components in an example apparatus <NUM>. The apparatus <NUM> may be a UE. In some aspects, the apparatus <NUM> includes a reception module <NUM>, a synchronization module <NUM>, a determination module <NUM>, and/or a transmission module <NUM>.

The reception module <NUM> may receive signals <NUM> from a base station <NUM> (e.g., the BS <NUM>, the apparatus <NUM>/<NUM>', etc.). The signals <NUM> may include at least one synchronization signal on a first anchor channel, wherein the first anchor channel is one of a plurality of anchor channels that were simultaneously transmitted. Additionally, or alternatively, the signals <NUM> may include a broadcast channel and/or an information block on the first anchor channel and at least one other anchor channel of the plurality of anchor channels. The reception module <NUM> may provide the signals <NUM> to the synchronization module <NUM> as data <NUM> or the determination module <NUM> as data <NUM>.

The synchronization module <NUM> may perform a synchronization operation based at least in part on the synchronization signal, as described in more detail elsewhere herein. The synchronization module <NUM> may provide data <NUM> to the transmission module <NUM>, which may communicate based at least in part on the data <NUM> by transmitting signals <NUM>.

The determination module <NUM> may determine a configuration of the plurality of anchor channels based at least in part on the at least one synchronization signal. In some aspects, the determination module may provide data <NUM> to the synchronization module <NUM> and/or the reception module <NUM> indicating the configuration.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. The apparatus <NUM>' may be a UE.

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 modules, represented by the processor <NUM>, the modules <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 module <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission module <NUM>, and based at least in part 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 further includes at least one of the modules <NUM>, <NUM>, <NUM>, and <NUM>. The modules may be software modules running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware modules 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 MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>.

In some aspects, the apparatus <NUM>/<NUM>' for wireless communication includes means for receiving at least one synchronization signal on a first anchor channel; means for receiving a broadcast channel and/or an information block on the first anchor channel and at least one other anchor channel of the plurality of anchor channels; means for performing a synchronization operation based at least in part on the synchronization signal; means for tuning to the at least one other anchor channel to receive the broadcast channel and/or the information block; and means for determining a configuration of the plurality of anchor channels based at least in part on the at least one synchronization signal. The aforementioned means may be one or more of the aforementioned modules of the apparatus <NUM> and/or the processing system <NUM> of the apparatus <NUM>' configured to perform the functions recited by the aforementioned means. As described supra, the processing system <NUM> may include the TX MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>. As such, in one configuration, the aforementioned means may be the TX MIMO processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM> configured to perform the functions recited by the aforementioned means.

It is understood that the specific order or hierarchy of blocks in the processes / flow charts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes / flow charts may be rearranged.

Claim 1:
A method of wireless communication performed by a base station (<NUM>, <NUM>), comprising:
determining (<NUM>, <NUM>) a plurality of anchor channels (<NUM>) wherein the plurality of anchor channels comprises discovery reference signal channels, wherein a first anchor channel (<NUM>) of the plurality of anchor channels includes at least one narrowband synchronization signal, and wherein at least two anchor channels of the plurality of anchor channels (<NUM>, <NUM>) include at least one of a narrowband physical broadcast channel or a narrowband master information block;
simultaneously (<NUM>, <NUM>) transmitting the plurality of anchor channels to at least one user equipment, UE, the plurality of anchor channels collectively occupying a bandwidth that satisfies a minimum bandwidth requirement for the unlicensed frequency spectrum; and
communicating (<NUM>) with the at least one UE based at least in part on the plurality of anchor channels.