Patent Description:
The technology discussed below relates generally to wireless communication systems, and more particularly, to design aspects of a wireless carrier that multiplexes communication signals having different numerologies.

Wireless communication networks continue to evolve to meet the growing demand for mobile broadband access. As these technologies continue to improve, additional use cases and capabilities become possible. Contemporary efforts are working to expand the domain of these wireless technologies to provide improved convenience and productivity, including enhanced mobile broadband communications, millimeter-wave communication, and ultra-reliable low-latency communication for mission-critical services. For a network to provide support for this broad array of areas there is a need for a flexible and dynamic scheme for multiplexing a variety of waveforms onto a single carrier. Relatedly, document <CIT> describes that a subcarrier spacing per portion or per carrier may be indicated in a broadcasted signal, and document <CIT> describes that a base station may indicate, to a user equipment (UE), a tone spacing scheme in a control channel, a sync channel or a reference signal. Document <CIT> describes encoding using two numerologies, document 3GPP R1-<NUM> describes use of three numerologies for a common downlink (DL) synchronization channel, document 3GPP R1-<NUM> describes predefined subcarrier spacings for synchronization signal and data, and document 3GPP R1-<NUM> mentions synchronization signal design.

Embodiments and aspects that do not fall within the scope of the claims are merely examples used for explanation of the invention.

Various aspects of the present disclosure provide for a sync signal (SS) enabling channel access for a mixed-numerology carrier. In one example, a single SS, having a given numerology, supports channel access for a plurality of numerologies on the mixed-numerology carrier. In another example, a plurality of numerologies on the mixed-numerology carrier each has its own respective SS, and a single, common numerology is used for all SS's. In still another example, a plurality of numerologies on the mixed-numerology carrier each has its own respective SS, where each SS has the same numerology as the numerology for which the SS provides channel access.

The radio access network <NUM> is further illustrated supporting wireless communication for multiple mobile apparatuses. A mobile apparatus may be referred to as user equipment (UE) in 3GPP standards, but may also be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. A UE may be an apparatus that provides a user with access to network services.

Within the present document, a "mobile" apparatus need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC), a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA), and a broad array of embedded systems, e.g., corresponding to an "Internet of things" (IoT). A mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player), a camera, a game console, etc. A mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid), lighting, water, etc.; an industrial automation and enterprise device; a logistics controller; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weaponry, etc. Still further, a mobile apparatus may provide for connected medicine or telemedicine support, i.e., health care at a distance. Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data.

As illustrated in <FIG>, a scheduling entity <NUM> may transmit downlink traffic <NUM> to one or more scheduled entities <NUM>.

Referring now to <FIG>, by way of example and without limitation, a schematic illustration of a RAN <NUM> is provided. In some examples, the RAN <NUM> may be the same as the RAN <NUM> described above and illustrated in <FIG>. The geographic area covered by the RAN <NUM> may be divided into cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification transmited from one access point or base station. <FIG> illustrates macrocells <NUM>, <NUM>, and <NUM>, and a small cell <NUM>, each of which may include one or more sectors (not shown). A sector is a sub-area of a cell. All sectors within one cell are served by the same base station. A radio link within a sector can be identified by a single logical identification belonging to that sector. In a cell that is divided into sectors, the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell.

Within the RAN <NUM>, the cells may include UEs that may be in communication with one or more sectors of each cell. Further, each base station <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be configured to provide an access point to a core network <NUM> (see <FIG>) for all the UEs in the respective cells. For example, UEs <NUM> and <NUM> may be in communication with base station <NUM>; UEs <NUM> and <NUM> may be in communication with base station <NUM>; UEs <NUM> and <NUM> may be in communication with base station <NUM> by way of RRH <NUM>; UE <NUM> may be in communication with base station <NUM>; and UE <NUM> may be in communication with mobile base station <NUM>. In some examples, the UEs <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM> may be the same as the UE/scheduled entity <NUM> described above and illustrated in <FIG>.

In a further aspect of the RAN <NUM>, sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs <NUM> and <NUM>) may communicate with each other using peer to peer (P2P) or sidelink signals <NUM> without relaying that communication through a base station (e.g., base station <NUM>). In a further example, UE <NUM> is illustrated communicating with UEs <NUM> and <NUM>. Here, the UE <NUM> may function as a scheduling entity or a primary sidelink device, and UEs <NUM> and <NUM> may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE may function as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example, UEs <NUM> and <NUM> may optionally communicate directly with one another in addition to communicating with the scheduling entity <NUM>. Thus, in a wireless communication system with scheduled access to time-frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources.

The air interface in the radio access network <NUM> may utilize one or more duplexing algorithms. Duplex refers to a point-to-point communication link where both endpoints can communicate with one another in both directions. Full duplex means both endpoints can simultaneously communicate with one another. Half duplex means only one endpoint can send information to the other at a time. In a wireless link, a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies. Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or time division duplex (TDD). In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from one another using time division multiplexing. That is, at some times the channel is dedicated for transmissions in one direction, while at other times the channel is dedicated for transmissions in the other direction, where the direction may change very rapidly, e.g., several times per slot.

The air interface in the radio access network <NUM> may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices. For example, <NUM> NR specifications provide multiple access for UL transmissions from UEs <NUM> and <NUM> to base station <NUM>, and for multiplexing for DL transmissions from base station <NUM> to one or more UEs <NUM> and <NUM>, utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP). In addition, for UL transmissions, <NUM> NR specifications provide support for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (also referred to as single-carrier FDMA (SC-FDMA)). However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided utilizing time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource spread multiple access (RSMA), or other suitable multiple access schemes. Further, multiplexing downlink (DL) or forward link transmissions from the base station <NUM> to UEs <NUM> and <NUM> may be provided utilizing time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes.

By way of illustration, various aspects of the present disclosure will be described with reference to an OFDM waveform, schematically illustrated in <FIG>. It should be understood by those of ordinary skill in the art that the various aspects of the present disclosure may be applied to a DFT-s-OFDMA waveform in substantially the same way as described herein below. That is, while some examples of the present disclosure may focus on an OFDM link for clarity, it should be understood that the same principles may be applied as well to DFT-s-OFDMA waveforms.

Referring now to <FIG>, an expanded view of an exemplary DL subframe <NUM> is illustrated, showing an OFDM resource grid <NUM>. However, as those skilled in the art will readily appreciate, the PHY transmission structure for any particular application may vary from the example described here, depending on any number of factors. Here, time is in the horizontal direction with units of OFDM symbols; and frequency is in the vertical direction with units of subcarriers.

The resource grid <NUM> may be used to schematically represent time-frequency resources for a given antenna port. That is, in a MIMO implementation with multiple antenna ports available, a corresponding multiple number of resource grids <NUM> may be available for communication. The resource grid <NUM> is divided into multiple resource elements (REs) <NUM>. An RE, which is <NUM> subcarrier × <NUM> symbol, is the smallest discrete part of the time-frequency grid, and contains a single complex value representing data from a physical channel or signal. Depending on the modulation utilized in a particular implementation, each RE may represent one or more bits of information. In some examples, a block of REs may be referred to as a physical resource block (PRB) or more simply a resource block (RB) <NUM>, which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may include <NUM> subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB may include any suitable number of consecutive OFDM symbols in the time domain. Within the present disclosure, it is assumed that a single RB such as the RB <NUM> entirely corresponds to a single direction of communication (either transmission or reception for a given device).

A UE generally utilizes only a subset of the resource grid <NUM>. An RB may be the smallest unit of resources that can be allocated to a UE. Thus, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE.

Each <NUM> subframe <NUM> may consist of one or multiple adjacent slots. In the example shown in <FIG>, one subframe <NUM> includes four slots <NUM>, as an illustrative example. In some examples, a slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a slot may include <NUM> or <NUM> OFDM symbols with a nominal CP. Additional examples may include mini-slots having a shorter duration (e.g., one or two OFDM symbols). These mini-slots may in some cases be transmitted occupying resources scheduled for ongoing slot transmissions for the same or for different UEs.

An expanded view of one of the slots <NUM> illustrates the slot <NUM> including a control region <NUM> and a data region <NUM>. In general, the control region <NUM> may carry control channels (e.g., PDCCH), and the data region <NUM> may carry data channels (e.g., PDSCH or PUSCH). In various examples, a slot <NUM> may contain all DL, all UL, or at least one DL portion and at least one UL portion. The simple structure illustrated in <FIG> is merely exemplary in nature, and different slot structures may be utilized, and may include one or more of each of the control region(s) and data region(s).

Although the illustration of the slot <NUM> in <FIG> shows both the control and data regions <NUM> and <NUM>, respectively, appearing to occupy the entire bandwidth of the slot <NUM>, this is not necessarily the case. For example, a DL control region <NUM> may occupy only a portion of the system bandwidth. In some aspects of the present disclosure, the DL control region <NUM> may be a downlink common burst or a common control region. In this example, a common control region may be common, in that its bandwidth and location within the system bandwidth for that slot may be predetermined, or known to various devices in the RAN <NUM>.

Although not illustrated in <FIG>, the various REs <NUM> within a RB <NUM> may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs <NUM> within the RB <NUM> may also carry pilots or reference signals, including but not limited to a demodulation reference signal (DMRS) a control reference signal (CRS), or a sounding reference signal (SRS). These pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels within the RB <NUM>.

According to various aspects of the disclosure, a scheduling entity may transmit one or more synchronization (sync) signals or sync channels over its respective cell. A sync signal (SS) may be a narrowband signal. For example, out of a carrier bandwidth of <NUM>, an SS may have a bandwidth of <NUM>. However, this is merely an illustrative example and any suitable SS bandwidth may be utilized.

<FIG> is a schematic illustration of a design for an SS transmission as it may be implemented according to some aspects of the present disclosure. In <FIG>, two SS bursts <NUM> are illustrated, although an SS burst set may include any suitable number of SS bursts <NUM>. In some examples, an SS burst set may include periodic transmissions of the SS bursts <NUM>, e.g., every X milliseconds (X msec), every half-frame, etc., although any periodicity of SS bursts may be utilized. In other examples, aperiodic SS burst <NUM> transmissions may be utilized. Each SS burst <NUM> may include N SS blocks <NUM>, extending for a duration of Y microseconds (Y µsec). As a further illustrative example, each SS block <NUM> may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH) in consecutive OFDM symbols. Other examples may utilize greater or fewer than two synchronization signals; may include one or more supplemental channels in addition to the PBCH; may omit a PBCH; and/or may utilize nonconsecutive symbols for an SS block, within the scope of the present disclosure.

To gain access to the information on the carrier, a UE <NUM> may utilize a raster, or a list of hypotheses, to scan or search for an SS. That is, the UE <NUM> may tune its receiver to attempt to receive a sync signal at a given frequency in the air interface, re-tuning to the next candidate frequency until an SS is identified. As one non-limiting example, a UE <NUM> may have a raster with approximately <NUM> or <NUM> possible locations of the sync signal to search within a <NUM> bandwidth.

Utilization of the SS to gain access to the information on the carrier may take a variety of different forms. Some examples, described in further detail below, include the utilization of a single SS for a plurality of numerologies, or the utilization of multiple SS's, i.e., one SS for each of a plurality of numerologies. When utilizing multiple SS's, the respective SS's may share the same numerology as one another, or in other examples, an SS may have the same numerology as a corresponding numerology for communication of control and traffic information. These and other examples are described in further detail below.

Referring once again to <FIG>, according to aspects of a DL transmission, the transmitting device (e.g., scheduling entity <NUM>) may allocate one or more REs <NUM> (e.g., within a control region <NUM>) to carry DL control information <NUM> including one or more DL control channels, such as a physical control format indicator channel (PCFICH); a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH); and/or a physical downlink control channel (PDCCH), etc., to one or more scheduled entities <NUM>.

The PCFICH provides information to assist a receiving device in receiving and decoding the PDCCH. The PDCCH carries downlink control information (DCI) including but not limited to power control commands, scheduling information, a grant, and/or an assignment of REs for DL and UL transmissions. The PHICH carries HARQ feedback transmissions such as an acknowledgment (ACK) or negative acknowledgment (NACK). HARQ is a technique well-known to those of ordinary skill in the art, wherein the integrity of packet transmissions may be checked at the receiving side for accuracy, e.g., utilizing any suitable integrity checking mechanism, such as a checksum or a cyclic redundancy check (CRC). If the integrity of the transmission confirmed, an ACK may be transmitted, whereas if not confirmed, a NACK may be transmitted. In response to a NACK, the transmitting device may send a HARQ retransmission, which may implement chase combining, incremental redundancy, etc..

In an UL transmission, the transmitting device (e.g., the scheduled entity <NUM>) may utilize one or more REs <NUM> to carry UL control information <NUM> including one or more UL control channels, such as a physical uplink control channel (PUCCH), to the scheduling entity <NUM>. UL control information may include a variety of packet types and categories, including pilots, reference signals, and information configured to enable or assist in decoding uplink data transmissions. In some examples, the UL control information <NUM> may include a scheduling request (SR), i.e., request for the scheduling entity <NUM> to schedule uplink transmissions. Here, in response to the SR transmitted on the UL control channel <NUM>, the scheduling entity <NUM> may transmit DL control information <NUM> that may schedule resources for UL packet transmissions. UL control information <NUM> may also include HARQ feedback, channel state feedback (CSF), or any other suitable UL control information.

In addition to control information, one or more REs <NUM> (e.g., within the data region <NUM>) may be allocated for user data or traffic data. Such traffic may be carried on one or more traffic channels, such as, for a DL transmission, a physical downlink shared channel (PDSCH); or for an UL transmission, a physical uplink shared channel (PUSCH). In some examples, one or more REs <NUM> within the data region <NUM> may be configured to carry system information blocks (SIBs), carrying information that may enable access to a given carrier.

The channels or carriers described above and illustrated in <FIG>, <FIG>, and <FIG> are not necessarily all the channels or carriers that may be utilized between a scheduling entity <NUM> and scheduled entities <NUM>, and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

In an OFDM carrier, to maintain orthogonality of the subcarriers or tones, the subcarrier spacing may be equal to the inverse of the symbol period. A numerology of an OFDM waveform refers to its particular subcarrier spacing and cyclic prefix (CP) overhead. A scalable numerology refers to the capability of the network to select different subcarrier spacings, and accordingly, with each spacing, to select the corresponding symbol duration, including the CP length. With a scalable numerology, a nominal subcarrier spacing (SCS) may be scaled upward or downward by integer multiples. In this manner, regardless of CP overhead and the selected SCS, symbol boundaries may be aligned at certain common multiples of symbols (e.g., aligned at the boundaries of each <NUM> subframe). The range of SCS may include any suitable SCS. For example, a scalable numerology may support a SCS ranging from <NUM> to <NUM>.

<FIG> is a schematic illustration of a mixed-numerology carrier <NUM>, multiplexing OFDM waveforms of two different numerologies utilizing FDM. In this example, a first subband <NUM> may have a first subcarrier spacing (SCS) of 2f, and a symbol duration of t. Further, a second subband <NUM> may have an SCS of half that of the first subband <NUM>, or 2f/<NUM> = f. In one non-limiting example, the subcarrier spacing f of the first numerology may be <NUM>, and the subcarrier spacing 2f of the second numerology may be <NUM>. As discussed above, because the SCS is reduced in the second subband <NUM>, the symbol duration in that subband <NUM> is correspondingly increased. Thus, in the second subband <NUM>, the numerology includes a symbol duration of twice that of the first subband <NUM>, or 2t.

In various examples, different UEs <NUM> may utilize different CPs, such as a normal CP (NCP) and an extended CP (ECP), generally under the control of the scheduling entity <NUM>. Because the CP is part of the OFDM symbol, within the present disclosure, any reference to a different numerology may refer to communication with different tone spacings and corresponding different symbol lengths, encompassing potentially different CPs within the different symbol lengths.

As illustrated in <FIG>, even within the same slot, and on the same carrier, different UEs <NUM> may be assigned REs having different numerologies when the different numerologies are FDM with one another. Thus, transmission on the DL from the scheduling entity <NUM> may be a mix or multiplexing of these different waveforms, constituting the mixed-numerology carrier <NUM>.

By supporting multiple numerologies, a RAN <NUM> can support multiple mixed-use cases, e.g., for different types of UEs, UEs with different requirements, UEs running different services, etc. As one example, a UE <NUM> utilizing a service that requires very low latency may better achieve that goal with a shorter slot length. Accordingly, that UE may be allocated resources in a numerology that has shorter symbol durations. In another example, a mixed-numerology carrier may provide for traffic offloading from a given set of resources. That is, as described further below, when resources corresponding to a first numerology become highly or fully occupied, then a scheduling entity <NUM> may be enabled to redirect one or more scheduled entities <NUM> to utilize resources of a second numerology. In another example, a scheduling entity <NUM> may redirect scheduled entities <NUM> for load balancing, e.g., to better balance traffic in different portions of the mixed-numerology carrier. Thus, a scheduling entity <NUM> may be enabled to redirect a subset of UEs camped on that cell onto a second numerology, while maintaining communication with another subset of one or more UEs using the first numerology.

When a carrier supports multiple numerologies, each numerology may provide a control channel, corresponding to data and traffic channels that utilize that numerology. However, this need not always be the case. In some examples, where a UE <NUM> is capable of utilizing resources with different numerologies, a common control channel may be utilized for each of a plurality of numerologies.

Further aspects of the disclosure will now be described in relation to a mixed-numerology carrier <NUM> illustrated schematically in <FIG>. This illustration provides a block or group of time-frequency resources in an OFDM waveform having two different numerologies multiplexed onto the mixed-numerology carrier <NUM>. In this example, for illustrative purposes all the slots shown on the carrier <NUM> are DL slots, including DL control and DL data regions. However, it is to be understood that other examples may include both DL and UL regions in a TDD carrier, without deviating from the scope of the present disclosure.

As illustrated, each numerology includes a set of slots, and each slot includes a common DL control region and a data region, as described above in relation to the slot <NUM> illustrated in <FIG>. Of course, any other suitable slot structure may be utilized in a given example, and the structure of a slot in a given implementation may differ from the examples in <FIG>.

Although two numerologies are multiplexed onto the carrier <NUM> in the illustrated example, those of ordinary skill in the art will recognize that in other examples, any suitable number of numerologies may be multiplexed onto a given mixed-numerology carrier. In the illustrated example, the subcarrier spacings of the different numerologies differ from one another. For example, in a first numerology <NUM>, the subcarrier spacing may be <NUM>, while in a second numerology <NUM>, the subcarrier spacing may be <NUM>. Because there may be <NUM> symbols per slot, a slot in the second numerology <NUM> is double the length of a slot in the first numerology <NUM>. Thus, this figure shows four slots for the first numerology <NUM>, and two slots for the second numerology <NUM>.

Each numerology <NUM> and <NUM> on the carrier <NUM> includes a plurality of slots. Among these slots, the first numerology <NUM> includes a first slot <NUM>, and the second numerology <NUM> includes a second slot <NUM>. Further, within each numerology <NUM> and <NUM>, each slot includes a common DL control region and a data region. For example, the first slot <NUM> of the first numerology <NUM> includes a common DL control region <NUM>, and the second slot <NUM> of the second numerology <NUM> includes a common DL control region <NUM>. In the described examples, the common DL control regions <NUM> and <NUM> within slots <NUM> and <NUM> may include control information, e.g., carried on a PDCCH. This control information may include a scheduling grant for resources on a shared traffic channel for that slot, such as a PDSCH. In the illustrated example, each slot's control region (e.g., control regions <NUM>, <NUM>, etc.) has the same, fixed bandwidth. In this way, a scheduling entity may provide a certain set of control information at a consistent, predictable location within the carrier <NUM>. Further, a scheduling entity can provide for compatibility with a broad range of UE types by suitably locating, and limiting the bandwidth of the control regions <NUM>, <NUM>, etc. That is, even UEs that lack the radio capabilities to receive wide-bandwidth signal signals can receive a relatively narrowband common control channel. Similarly, even UEs that are only capable of receiving transmissions within a small portion of the full frequency range of the carrier <NUM> can receive a suitably located common control channel.

Each slot may further include a data region, which may carry DL data or DL traffic for a plurality of UEs. That is, traffic channels in the data region of a given slot may be shared by a plurality of UEs. For example, the DL data regions may include the PDSCH, scheduled according to the control information, e.g., carried on the PDCCH in that respective slot.

As illustrated in <FIG>, the data region of any given slot may have a different bandwidth than the control region of that same slot. Moreover, the bandwidth of the data regions in different slots may differ, and may vary from one slot to another. In some examples, the DL control information carried in the common control region (e.g., <NUM> and <NUM>) of a given slot may direct high-capability UEs to receive very wideband downlink traffic, and/or traffic in resource elements outside the frequency range occupied by the common control region. The DL control information may additionally direct low-capability UEs to receive DL traffic within a portion of the data region that occupies frequencies within the same range as the common control region.

With this degree of flexibility in the bandwidth of the respective slots' data regions, in a mixed-numerology carrier <NUM>, different numerologies may dynamically share resources, with their share varying over time. As illustrated in <FIG>, when the bandwidth of data regions in the first numerology <NUM> is wider, the bandwidth of data regions in the second numerology <NUM> is narrower; and when the bandwidth of data regions in the first numerology <NUM> is narrower, the bandwidth of data regions in the second numerology <NUM> is wider. In some examples, including the example illustrated in <FIG>, the data portion of a slot of one numerology may be configured not to overlap any portion of a slot of a different numerology. For example, a wide bandwidth PDSCH of the first numerology <NUM> may only be as wide as possible where it does not overlap with the control region or the data region of a slot of the second numerology. However, this is not intended to be a limiting example, and in other examples, transmissions of one numerology may overlap transmissions of another numerology.

In the illustrated example, some regions of the mixed-numerology <NUM> are unused. That is, the resources between the control region <NUM> of the first slot <NUM> of the first numerology <NUM>, and the control region <NUM> of the first slot <NUM> of the second numerology <NUM> are unused. However, in some examples according to an aspect of the present disclosure, these resources may be filled with any suitable transmissions.

In the illustrated mixed-numerology carrier <NUM>, within each slot, the control region shares the same numerology as its corresponding data region. However, this need not necessarily be the case, and in some examples, a control region of a given slot may have a different numerology than a traffic region of that same slot.

<FIG> is a block diagram illustrating an example of a hardware implementation for a scheduling entity <NUM> employing a processing system <NUM>. For example, the scheduling entity <NUM> may be a user equipment (UE) as illustrated in any one or more of <FIG> and/or <NUM>. In another example, the scheduling entity <NUM> may be a base station as illustrated in any one or more of <FIG> and/or <NUM>.

The scheduling entity <NUM> may be implemented with a processing system <NUM> that includes one or more processors <NUM>. Examples of processors <NUM> include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the scheduling entity <NUM> may be configured to perform any one or more of the functions described herein. That is, the processor <NUM>, as utilized in a scheduling entity <NUM>, may be used to implement any one or more of the processes and procedures described below and illustrated in <FIG>, <FIG>, <FIG>, and/or <NUM>.

In this example, 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> communicatively couples together various circuits including one or more processors (represented generally by the processor <NUM>), a memory <NUM>, and computer-readable media (represented generally by the computer-readable medium <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. A bus interface <NUM> provides an interface between the bus <NUM> and a transceiver <NUM>. The transceiver <NUM> provides a communication interface or means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface <NUM> (e.g., keypad, display, speaker, microphone, joystick) may also be provided. Of course, such a user interface <NUM> is optional, and may be omitted in some examples, such as a base station.

In some aspects of the disclosure, the processor <NUM> may include a scheduler <NUM> configured for various functions, including, for example, scheduling time-frequency resources for one or more scheduled entities. In further aspects, the processor <NUM> may include communication circuitry <NUM> configured for various functions, including, for example, controlling wireless communication utilizing the transceiver <NUM>, receiving data and control channels via receiver 710rx, and transmitting data channels, control channels, sync signals (SS's), SIBs, MIBs, etc., via transmitter 710tx. In still further aspects, the processor <NUM> may include a numerology selector <NUM> configured for various functions, including, for example, configuring the transceiver <NUM> to provide support for a given numerology, as needed.

One or more processors <NUM> in the processing system may execute software. The software may reside on a computer-readable medium <NUM>. The computer-readable medium <NUM> may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD)), a smart card, a flash memory device (e.g., a card, a stick, or a key drive), a random access memory (RAM), a read only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium <NUM> may reside in the processing system <NUM>, external to the processing system <NUM>, or distributed across multiple entities including the processing system <NUM>. The computer-readable medium <NUM> may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In one or more examples, the computer-readable storage medium <NUM> may include scheduling software <NUM> configured for various functions, including, for example, scheduling time-frequency resources for one or more scheduled entities. In further aspects, the computer-readable storage medium <NUM> may include communication software <NUM> configured for various functions, including, for example, controlling wireless communication utilizing the transceiver <NUM>, receiving data and control channels via receiver 710rx, and transmitting data channels, control channels, sync signals (SS's), SIBs, MIBs, etc., via transmitter 710tx. In still further aspects, the computer-readable storage medium <NUM> may include numerology selection software <NUM> configured for various functions, including, for example, configuring the transceiver <NUM> to provide support for a given numerology, as needed.

Of course, in the above examples, the circuitry included in the processor <NUM> is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable storage medium <NUM>, or any other suitable apparatus or means described in any one of the <FIG> and/or <NUM>, and utilizing, for example, the processes and/or algorithms described herein in relation to <FIG>, <FIG>, <FIG>, and/or <NUM>.

<FIG> is a conceptual diagram illustrating an example of a hardware implementation for an exemplary scheduled entity <NUM> employing a processing system <NUM>. In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a processing system <NUM> that includes one or more processors <NUM>. For example, the scheduled entity <NUM> may be a user equipment (UE) as illustrated in any one or more of <FIG> and/or <NUM>.

The processing system <NUM> may be substantially the same as the processing system <NUM> illustrated in <FIG>, including a bus interface <NUM>, a bus <NUM>, memory <NUM>, a processor <NUM>, and a computer-readable medium <NUM>. Furthermore, the scheduled entity <NUM> may include a user interface <NUM> and a transceiver <NUM> substantially similar to those described above in <FIG>. That is, the processor <NUM>, as utilized in a scheduled entity <NUM>, may be used to implement any one or more of the processes described below and illustrated in <FIG>.

In some aspects of the disclosure, the processor <NUM> may include SS raster search circuitry <NUM> configured for various functions, including, for example, searching a carrier for an SS, detecting the SS in coordination with the receiver 810rx, the SS raster list <NUM>, and the numerology selector <NUM>; and/or redirecting from one channel to another, e.g., by suitably configuring the transceiver <NUM>. In a further aspect, the processor <NUM> may include communication circuitry <NUM> configured for various functions, including, for example, controlling wireless communication utilizing the transceiver <NUM>; receiving data and control channels via receiver 810rx, and transmitting data and control channels via transmitter 810tx. In a further aspect, the processor <NUM> may include a numerology selector <NUM> configured for various functions, including, for example, configuring and/or redirecting the transceiver <NUM> to provide support for a given numerology as needed.

Of course, in the above examples, the circuitry included in the processor <NUM> is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable storage medium <NUM>, or any other suitable apparatus or means described in any one of the <FIG> and/or <NUM>, and utilizing, for example, the processes and/or algorithms described herein in relation to <FIG>.

Referring now to <FIG>, a mixed-numerology carrier <NUM> is schematically illustrated. As mentioned above, some aspects of the present disclosure provide for a mixed-numerology carrier that utilizes a single, common sync signal (SS) within the bandwidth of the carrier, for each of a plurality of numerologies. In this illustration, a single SS <NUM> is provided, to enable UE to access the carrier <NUM> on each of a plurality of numerologies <NUM> and <NUM>.

In some examples of a mixed-numerology carrier, an SS need not necessarily have the same numerology as any control channel, data channel, or any other channel on the carrier. That is, within the scope of the present disclosure, any suitable combination of numerologies between SS's, control channels, and data channels may be utilized. However, in the description that follows, with reference to the mixed-numerology carrier <NUM> illustrated in <FIG>, the carrier includes two numerologies, referred to as a primary numerology <NUM> and a second (<NUM>nd) or secondary numerology <NUM>. Further, the carrier <NUM> includes a single, common SS <NUM> within the bandwidth of the carrier <NUM>, and having the primary numerology <NUM>. That is, the primary numerology <NUM> may be referred to as primary because it is the numerology that carries the SS <NUM>. In this example, the second numerology <NUM> may omit a sync channel.

Further, in <FIG>, for ease of illustration, the SS <NUM> is shown in the same frequency range as other DL transmissions utilizing the primary numerology <NUM>. However, this need not be the case. Other examples within the scope of the present disclosure may locate the SS <NUM>, utilizing the primary numerology <NUM>, within a frequency range outside the frequency range utilized by other transmissions that utilize the primary numerology <NUM>.

The operation of a UE or scheduled entity <NUM> acquiring the mixed-numerology carrier <NUM> will now be described with reference to <FIG> and <FIG> is a flow chart illustrating an exemplary process <NUM> for a UE <NUM> to acquire a mixed-numerology carrier <NUM> in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process <NUM> may be carried out by the scheduled entity <NUM> illustrated in <FIG>. However, the process <NUM> is not limited thereto. In other examples, the process <NUM> may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block <NUM>, a UE <NUM> searches the mixed-numerology carrier <NUM> for a SS, having an SS numerology (e.g., the primary numerology <NUM>). That is, to gain access to the information on the mixed-numerology carrier <NUM>, a UE <NUM> may utilize an SS raster <NUM>, in coordination with a stored SS raster list <NUM> (e.g., a list of hypotheses or candidate frequency locations) to scan or search for an SS in the carrier <NUM>. The UE <NUM> may tune its receiver 810rx to attempt to receive a sync signal at a candidate frequency location in the air interface, re-tuning to the next candidate frequency until an SS is identified. As one non-limiting example, the SS raster list <NUM> may include approximately <NUM> or <NUM> candidate frequency locations to search for the SS within a <NUM> bandwidth.

According to an aspect of the disclosure, for the SS search, the UE <NUM> may configure its receiver 810rx to scan for an SS at the primary numerology, independent of any other numerologies that the UE <NUM> may be configured to use. That is, by virtue of the carrier <NUM> including a single, common numerology for the SS <NUM>, all UEs that seek to access the carrier <NUM> may search for an SS utilizing that common numerology.

At block <NUM>, during the search, the UE <NUM> detects an SS <NUM> on the carrier <NUM>. Once the SS <NUM> is detected, the UE <NUM> reads certain control information carried on the SS <NUM>, including configuration information or parameters for a common control channel <NUM> using the primary numerology <NUM>. That is, as described previously the SS <NUM> carries a physical broadcast channel (PBCH). The PBCH includes broadcast control information such as a master information block (MIB) that provides various configuration information or parameters for one or more channels on the carrier, such as a common control channel (e.g., PDCCH) <NUM>. In other words, the MIB in the SS <NUM> may map to a primary common control channel <NUM>. In some aspects of the disclosure, the configuration information or parameters (e.g., the MIB) may include information sufficient for the UE <NUM> to access the carrier.

The configuration information or parameters carried on the MIB may include the location within the carrier <NUM>, the bandwidth, and/or other information characterizing the primary common control channel <NUM>. In some examples, the MIB may be limited to critical information required for a UE <NUM> to access the primary common control channel <NUM>; in other examples, the MIB may include additional information for the UE <NUM>. Further, in some examples, where the SS may not necessarily share a numerology with a control channel, the MIB indicates the numerology of the primary common control channel on the carrier.

For each numerology <NUM>, <NUM> on the mixed-numerology carrier <NUM>, each slot may include a common control channel or common control region. Here, the common control channel corresponding to the numerology that includes the SS <NUM> may be referred to as the primary common control channel <NUM>. Once the UE <NUM> reads the MIB from the SS <NUM> and is informed of the characteristics of the primary common control channel <NUM> (e.g., its location, bandwidth, numerology, etc.), the UE <NUM> may monitor for the primary common control channel <NUM>.

Accordingly, at block <NUM>, the UE <NUM> may read the primary common control channel <NUM> to obtain information or parameters corresponding to a data channel <NUM>. That is, in addition to user data or traffic that may be carried on a PDSCH, the data channel <NUM> may also carry system information block (SIB) information about the carrier <NUM>. Thus, for example, the primary common control channel <NUM> may inform the UE <NUM> of resources on the carrier <NUM>, within the data channel <NUM>, which carry the SIBs. Accordingly, at block <NUM>, the UE <NUM> may read system information, or minimum SIB (MSIB) information, carried on the data channel, <NUM> to retrieve information sufficient for the UE <NUM> to access the carrier (e.g., the full system information for one or more numerologies on the mixed numerology carrier <NUM>).

At block <NUM>, according to some examples, the UE <NUM> may gain access to data resources on the carrier <NUM> by utilizing a random access channel (RACH). A RACH procedure is well-known to those of ordinary skill in the art, and is not described in detail herein. Very simply, when the UE <NUM> has a need for communication resources, the UE <NUM> may make a RACH transmission utilizing resources within the carrier <NUM>, which are defined in the MSIB. Because the illustration in <FIG> only shows DL signals, an UL RACH transmission as part of a random access procedure is not shown, but implied with the notation [RACH] <NUM>. After making the RACH transmission <NUM>, at block <NUM>, the UE <NUM> may monitor for a RACH response on the carrier <NUM>. In some examples, as illustrated in <FIG>, a RACH response may be located within a common control channel <NUM> in a slot subsequent to the RACH transmission <NUM>.

The MSIB-RACH procedure is not intended to be limiting in nature. That is, in some examples, the MIB carried on the sync channel <NUM> (e.g., within the PBCH) may include sufficient information to enable the UE <NUM> to engage in a random access procedure. In such an example, the UE <NUM> may make a RACH transmission immediately after, or soon after reading the SS <NUM>, e.g., prior to the MSIB <NUM>.

In some examples, where a UE <NUM> would communicate utilizing the primary numerology <NUM>, the common control channel <NUM> might include control information (e.g., a PDCCH) scheduling resources for that UE utilizing the primary numerology <NUM>. However, according to a further aspect of the disclosure, the control information carried in the common control channel <NUM> may include a redirection indication, configured to redirect the UE <NUM> to the second numerology <NUM>. For example, at block <NUM>, the UE <NUM> may determine whether the control information in the common control channel <NUM> includes a redirection indication, including information about a control channel having the second numerology <NUM>. That is, the redirection indication may be configured to redirect the UE <NUM> to the second numerology <NUM>. Such a redirection indication may be provided to the UE <NUM> utilizing any suitable control signaling, including but not limited to radio resource control (RRC) signaling carried on the DL common control channel <NUM>. In another example (not illustrated), a redirection indication may be provided to the UE <NUM> on the PDSCH. In this example, the location of the redirection indication within the data region of a slot may be provided to the UE <NUM> in scheduling information, or a grant, in the DL common control channel <NUM>. A redirection request, or redirection indication, may include information about a second common control channel <NUM>, such as its location on the carrier <NUM>, its numerology, and/or any other suitable information.

If the UE <NUM> is not redirected, then at block <NUM>, the UE <NUM> may communicate over the mixed-numerology carrier <NUM>, remaining on the primary numerology <NUM>. That is, the UE <NUM> may maintain a configuration of its transceiver <NUM> to communicate over the mixed-numerology carrier <NUM> utilizing the primary numerology. However, if the UE <NUM> receives a redirection indication, then at block <NUM>, the UE <NUM> may redirect to a secondary common control channel <NUM>, having the second numerology <NUM>.

In some examples, the secondary common control channel <NUM> may use a different numerology (e.g., the second numerology <NUM>) than that of the primary common control channel <NUM> (the primary numerology <NUM>). In an example where the secondary common control channel <NUM> is a different numerology than that of the primary common control channel <NUM>, the UE <NUM> may be informed of the numerology of the secondary common control channel <NUM> via control information in the primary control channel <NUM>, via the MSIB carried in a data channel <NUM>, or via any other suitable channel or signal. When the UE <NUM> is redirected to the secondary common control channel <NUM> having a different numerology, the UE <NUM> may alter, or change a configuration of its receiver 810rx and/or its transmitter 810tx to monitor for control information on the secondary common control channel <NUM>.

In other examples, the secondary common control channel <NUM> may use the same numerology as that of the primary common control channel <NUM>.

Once the UE <NUM> redirects to the secondary common control channel <NUM>, at block <NUM>, the UE <NUM> may receive the secondary common control channel <NUM>. The secondary common control channel <NUM>, and/or a secondary data channel <NUM>, may carry system information (e.g., SIBs) corresponding to one or more channels having the second numerology <NUM>. That is, the secondary common control channel <NUM> may include information to direct the UE <NUM> to locate a secondary MSIB corresponding to the second numerology <NUM> within a data region <NUM>, similar to the procedure described above for the primary numerology <NUM>, at block <NUM>. However, in another example, the secondary common control channel <NUM> need not necessarily direct the UE <NUM> to a secondary MSIB. That is, the system information carried in the data channel <NUM> in the primary numerology <NUM> may provide system information characterizing the second numerology <NUM>, e.g., the secondary common control channel <NUM>. In either case, the UE <NUM> may read SIBs corresponding to an MSIB to obtain the system information corresponding to the second numerology <NUM>.

In some examples, second system information for the second numerology <NUM> may differ from the system information from the MSIB corresponding to the primary numerology <NUM>. For example, the second system information for the second numerology <NUM> may indicate a different numerology for the PDSCH for a given slot than that of the secondary control channel <NUM>. The second system information may further indicate a different bandwidth for a secondary data channel <NUM> (e.g., a PDSCH). That is, the bandwidth of the secondary data channel <NUM> may differ from that of the secondary common control channel <NUM>, and the bandwidth of the secondary data channel <NUM> in one numerology may differ from the bandwidth of a data channel in another numerology. Furthermore, the bandwidth of data channels in a given numerology may vary from slot to slot, on a dynamic basis. In some examples, the system information may include information to enable an overlapping between resources for one or more channels of different numerologies.

After the UE <NUM> is redirected to the secondary common control channel <NUM>, and obtains system information for the second numerology <NUM>, at block <NUM>, the UE <NUM> may monitor the secondary common control channel <NUM> to obtain any grant for a data channel <NUM> (e.g., a downlink data channel PDSCH).

In some examples, the secondary downlink data channel <NUM> may use the second numerology <NUM>. That is, a slot having the secondary control channel <NUM> of the second numerology <NUM> may remain with the same second numerology in its data portion <NUM>.

In a further aspect of the disclosure, a redirection to a second numerology does not preclude an advanced UE <NUM> from monitoring more than one numerology at the same time. That is, such an advanced UE <NUM>, when it receives such a redirection indication, may simply add the secondary control channel <NUM> to a list of control channels to monitor on the mixed-numerology carrier <NUM>, while still monitoring the primary control channel <NUM> at the primary numerology <NUM>.

As mentioned above, another aspect of the disclosure provides for multiple numerologies to be multiplexed onto a mixed-numerology carrier, where each numerology has its own respective SS. In this example, by utilizing a single, common numerology for SS's at all numerologies within a mixed-numerology carrier <NUM>, a network may be enabled to add new numerologies over time without affecting compatibility with legacy UEs.

<FIG> is a schematic illustration of an illustrative example of a mixed-numerology carrier <NUM>, which multiplexes communications with different numerologies <NUM> and <NUM>, according to one aspect of the present disclosure. In the example illustrated in <FIG>, a first numerology <NUM> is multiplexed with a second numerology <NUM> within a single carrier <NUM> utilizing FDM. However, unlike the example described above with a single SS, in this illustration, multiple SS's may be transmitted on the carrier <NUM>. For example, a first SS <NUM> may be transmitted for the first numerology <NUM>, and a second SS <NUM> may be transmitted for the second numerology <NUM>. In the particular example of <FIG>, the first SS <NUM> and the second SS <NUM> each use the same numerology as one another (e.g., the first numerology). That is, in some aspects of the disclosure, a single, common SS numerology may be utilized for each of a plurality of SS's <NUM> and <NUM>, wherein the respective SS's <NUM> and <NUM> map to different respective common control channels <NUM> and <NUM>. Furthermore, the respective common control channels <NUM> and <NUM> may have different numerologies from one another, and/or different numerologies than their respective SS <NUM>, <NUM>. Thus, to gain access to the carrier <NUM>, for any given numerology, a UE <NUM> may search for an SS with a given (e.g., predetermined) SS numerology.

The operation of a UE or scheduled entity <NUM> acquiring the mixed-numerology carrier <NUM> will now be described with reference to <FIG> and <FIG> is a flow chart illustrating an exemplary process <NUM> for a UE <NUM> to acquire a mixed-numerology carrier <NUM> in accordance with some aspects of the disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process <NUM> may be carried out by the scheduled entity <NUM> illustrated in <FIG>. However, the process <NUM> is not limited thereto. In other examples, the process <NUM> may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block <NUM>, a UE <NUM> may search the mixed-numerology carrier <NUM> for an SS, having the SS numerology. That is, to gain access to the information on the mixed-numerology carrier <NUM>, a UE <NUM> may utilize an SS raster <NUM>, in the same way as described above with respect to <FIG>. Similar to the example described above in <FIG>, by virtue of the carrier <NUM> including a single, common numerology for the SS's <NUM> and <NUM>, all UEs that seek to access the carrier <NUM> may search for an SS utilizing that common SS numerology.

At block <NUM>, during the search, the UE <NUM> may identify a first SS, e.g., SS <NUM>. Once the first SS <NUM> is identified, the UE <NUM> may read control information such as a MIB carried on a PBCH on the SS <NUM>. This control information may include configuration information or parameters for a first common control channel <NUM>, such as its location, its bandwidth, its numerology, etc. That is, as in the single SS example described above in relation to <FIG>, here, an SS <NUM> may include a MIB that maps to a common control channel <NUM>. However, unlike the single SS example described above, in a further aspect of the disclosure, there is no primary and secondary common control channel. That is, each control channel <NUM> and <NUM>, and each numerology <NUM> and <NUM>, may essentially be on equal footing with its own SS <NUM> or <NUM>, each having a respective MIB that maps to a corresponding common control channel <NUM> or <NUM>.

In this example, because a plurality of SS's <NUM> and <NUM> share the same SS numerology, but those SS's may not correspond to communication slots with the same numerology, the UE <NUM> may not know which numerology communication channel it has located in its search. The MIB in the first SS <NUM> may indicate a numerology for that SS's corresponding common control channel <NUM>. Here, as illustrated in <FIG>, the common control channels <NUM> and <NUM> may have different numerologies from one another. Any other suitable differences may exist as well within different MIBs.

Thus, when the UE <NUM> identifies an SS via its search, such as the first SS <NUM>, the UE <NUM> may read its MIB to obtain configuration information or parameters for the corresponding common control channel <NUM>, including, for example, its numerology.

In an aspect of the disclosure, at block <NUM>, the UE <NUM> may determine whether it supports the numerology of the common control channel <NUM> corresponding to the identified SS <NUM>. For example, if the MIB carried in the SS <NUM> indicates a numerology that the UE <NUM> does not support, then at block <NUM>, the UE <NUM> may forgo to receive the common control channel <NUM> corresponding to the identified SS <NUM>, and return to block <NUM>, continuing to search the carrier for another SS. In another aspect of the disclosure, the SS <NUM> may include information about the location of one or more other SS's in the mixed-numerology carrier <NUM>. In this way, if the UE <NUM> does not support the numerology indicated in the identified SS <NUM>, the UE <NUM> may not be required to resume its search for another SS within the mixed-numerology carrier <NUM>. Rather, at optional block <NUM>, the UE <NUM> may easily direct to the second SS (e.g., SS <NUM>) based on the information contained in the received SS <NUM>, and the process may proceed to block <NUM>, as described above.

When the UE <NUM> finds a numerology it can support, then at block <NUM>, the UE <NUM> may utilize the configuration information or parameters received in the MIB to monitor the corresponding common control channel <NUM>. From that common control channel <NUM>, the UE <NUM> may obtain control information corresponding to a data channel, such as a grant or other information corresponding to SIBs in the data channel <NUM>. Accordingly, the UE <NUM> may receive the data channel <NUM> and may read the MSIB to retrieve the full system information.

In a further aspect of the disclosure, different system information from different MSIBs in different traffic channels <NUM> and <NUM> may specify the same channel within the carrier <NUM>, but with different numerologies. That is, the same resources within the mixed-numerology carrier <NUM> may be handled as having different numerologies by different UEs in the cell that acquired the different respective SS's.

As with the above examples, once the UE <NUM> obtains the system information, at block <NUM> the UE <NUM> may gain access to the carrier <NUM> through a RACH procedure <NUM>, utilizing resources defined in the MSIB. After making the RACH transmission <NUM>, at block <NUM>, the UE <NUM> may monitor for a RACH response on the carrier <NUM>. In some examples, as illustrated in <FIG>, a RACH response may be located within a common control channel <NUM> in a slot subsequent to the RACH transmission <NUM>. Subsequently, at block <NUM>, the UE <NUM> may communicate over the carrier <NUM> utilizing the supported numerology (e.g., the first numerology <NUM>), e.g., by receiving a grant in the DL control channel <NUM>, identifying resources in a corresponding data channel (e.g., PDSCH) <NUM>; and subsequently, receiving DL data in the identified PDSCH resources.

In a further aspect of the disclosure, a scheduling entity <NUM> may still redirect a UE <NUM> to a different numerology, e.g., through RRC signaling as described above in relation to <FIG> corresponding to the single, common SS example, if there is need (e.g., for offloading or load balancing).

As mentioned above, another aspect of the disclosure provides for multiple numerologies to be multiplexed onto a mixed-numerology carrier, where each numerology has its own respective SS, and where the respective SS's have different numerologies than one another.

<FIG> is a schematic illustration of an illustrative example of a mixed-numerology carrier <NUM>, which multiplexes communications with different numerologies <NUM> and <NUM>, according to a further aspect of the present disclosure. In the example illustrated in <FIG>, a first numerology <NUM> is multiplexed with a second numerology <NUM> within a single carrier <NUM> utilizing FDM. However, unlike the examples described above, in this illustration, multiple SS's having different numerologies may be transmitted on the carrier <NUM>. For example, a first SS <NUM> may be transmitted for the first numerology <NUM>, and a second SS <NUM> may be transmitted for the second numerology <NUM>. In the particular example of <FIG>, the first SS <NUM> uses the first numerology <NUM>, and the second SS uses the second numerology <NUM>. Furthermore, the first SS <NUM> maps to a first common control channel <NUM> using the first numerology <NUM>, and the second SS <NUM> maps to a second common control channel <NUM> using the second numerology <NUM>. Thus, to gain access to the carrier <NUM>, a UE <NUM> may search for an SS using a selected numerology from among a plurality of numerologies on the mixed-numerology carrier <NUM>.

The operation of a base station or scheduling entity <NUM> transmitting the mixed-numerology carrier <NUM> will now be described with reference to <FIG> and <FIG> is a flow chart illustrating an exemplary process <NUM> for a base station <NUM> to transmit a mixed-numerology carrier <NUM> in accordance with some aspects of the disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process <NUM> may be carried out by the scheduling entity <NUM> illustrated in <FIG>. However, the process <NUM> is not limited thereto. In other examples, the process <NUM> may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block <NUM>, the scheduling entity <NUM> may transmit a first SS <NUM> using a first numerology <NUM> on a mixed-numerology carrier <NUM>. Here, the first SS <NUM> may include first configuration information or parameters corresponding to a first channel (e.g., a first common control channel) <NUM> on the carrier <NUM>. At block <NUM>, the scheduling entity <NUM> may transmit a second SS <NUM> using a second numerology <NUM> on a mixed-numerology carrier <NUM>. Here, the second SS <NUM> may include second configuration information or parameters corresponding to a second channel (e.g., a second common control channel) <NUM> on the carrier <NUM>.

In this example, like the example of <FIG>, each SS <NUM> and <NUM> may carry MIB information, and the MIB in different SS's may carry different information from one another. However, in this example shown in <FIG>, the SS may not necessarily include information about the numerology of its corresponding common control channel. That is, the numerology of the SS itself may map to the numerology of its corresponding common control channel, such that an explicit indication of the numerology of the common control channel may not be needed.

In this example, for a UE <NUM> to gain access to the carrier <NUM>, the UE <NUM> may be preconfigured for a preferred or supported numerology. Thus, the UE <NUM> may search for a particular SS in that preferred or supported numerology. When conducting the search, the UE <NUM> would not identify any SS with a numerology different from the preferred or supported numerology, and would only identify SS's with the preferred or supported numerology.

In an aspect of the disclosure, providing different SS's with different numerologies can enable placement of the respective SS's on different SS rasters, to speed up a UE's search. That is, SS's of different numerologies may be located in a different set of possible locations in the carrier <NUM>. Accordingly, a UE <NUM> searching for an SS of a particular numerology need only search for SS's having that particular numerology, reducing the scope of its search and potentially improving search speed.

In some examples, different (e.g., neighboring) base stations or scheduling entities <NUM> may transmit SS's of the same numerology, utilizing the same raster. In this way, neighbor cell monitoring may be eased for UEs, since a UE <NUM> may not be required to retune its receiver 810rx in order to monitor SS transmissions from a neighbor cell.

When a UE <NUM> identifies an SS <NUM>, the UE <NUM> may read a MIB carried on a PBCH, to obtain configuration information or parameters for a corresponding common control channel <NUM>. That is, the SS <NUM> maps to a corresponding common control channel <NUM> (e.g., a channel using the same numerology as the SS). With the MIB, the UE <NUM> may monitor the common control channel to obtain the control information corresponding to a data channel, such as a grant or other information corresponding to SIBs in the data channel <NUM>. Accordingly, the UE <NUM> may receive the data channel <NUM> and may read the MSIB to retrieve the full system information.

In a further aspect of the disclosure, different system information from different MSIBs carried in different common control channels may specify the same traffic channel, with different numerologies. That is, the same resources within the mixed-numerology carrier <NUM> may be handled as having different numerologies by different UEs in the cell that acquired the different respective SS's.

As in the above example, once the UE <NUM> obtains the system information, the UE <NUM> may gain access to the carrier <NUM> via a RACH procedure <NUM>, utilizing resources defined in the MSIB. After making the RACH transmission <NUM>, the UE <NUM> may monitor for a RACH response on the carrier <NUM>. In some examples, as illustrated in <FIG>, a RACH response may be located within a common control channel <NUM> in a slot subsequent to the RACH transmission <NUM>. Subsequently, the UE <NUM> may communicate over the carrier <NUM> utilizing the corresponding numerology (e.g., the first numerology <NUM>), e.g., by receiving a grant in the DL control channel <NUM>, identifying resources in a corresponding data channel (e.g., PDSCH) <NUM>; and subsequently, receiving DL data in the identified PDSCH resources.

In a further aspect of the disclosure, as in the single SS example described above, here, a scheduling entity <NUM> may redirect a UE <NUM> to different numerologies, e.g., through RRC signaling, for offloading or load balancing across numerologies.

<FIG> is a flow chart illustrating an exemplary process <NUM> for a base station <NUM> to transmit a mixed-numerology carrier in accordance with further aspects of the disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process <NUM> may be carried out by the scheduling entity <NUM> illustrated in <FIG>. However, the process <NUM> is not limited thereto. In other examples, the process <NUM> may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block <NUM>, the scheduling entity <NUM> may transmit a first SS using a first numerology on a mixed-numerology carrier. Here, the first SS may include first configuration information or parameters corresponding to a first channel (e.g., a first common control channel) on the carrier. At block <NUM>, the scheduling entity <NUM> may transmit the first channel on the carrier, using a first numerology. Here, the first channel may carry control information corresponding to a first data channel on the carrier. Further, at block <NUM>, the scheduling entity <NUM> may transmit the first data channel according to the control information. Here, the first data channel may carry information sufficient for a UE to access the carrier (e.g., the MSIB).

At block <NUM>, the scheduling entity <NUM> may transmit the second channel (e.g., a second common control channel) using the second numerology. Here, the second channel may carry control information corresponding to a second data channel on the carrier. Further, at block <NUM>, the scheduling entity <NUM> may transmit the second data channel according to the control information. Here, the second data channel may carry information sufficient for a UE to access the carrier (e.g., the MSIB).

Claim 1:
A method of wireless communication operable at a user equipment, UE (<NUM>), comprising:
searching (<NUM>) a carrier for a sync signal, SS (<NUM>), having an SS numerology, wherein the carrier comprises waveforms of a plurality of numerologies including the SS numerology, a first numerology (<NUM>), and a second numerology (<NUM>), wherein the SS numerology differs from the first numerology (<NUM>);
detecting (<NUM>) the SS (<NUM>) and reading configuration information carried on the SS (<NUM>), wherein the configuration information corresponds to one or more channels on the carrier and indicates the numerology of a first channel of the one or more channels, wherein the first channel is a common control channel and wherein the configuration information is included in a master information block, MIB, which is included in a physical broadcast channel, PBCH, carried by the SS (<NUM>); and
receiving the first channel of the one or more channels based on the configuration information, the first channel having the first numerology (<NUM>).