Patent Description:
Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) refers to a communications network including base stations, or Node Bs, and for example radio network controllers (RNC). UTRAN allows for connectivity between the user equipment (UE) and the core network. The RNC provides control functionalities for one or more Node Bs. The RNC and its corresponding Node Bs are called the Radio Network Subsystem (RNS). In case of E-UTRAN (enhanced UTRAN), no RNC exists and radio access functionality is provided in the evolved Node B (eNodeB or eNB) or many eNBs. Multiple eNBs may be involved for a single UE connection, for example, in case of Coordinated Multipoint Transmission (CoMP) and in dual connectivity.

Long Term Evolution (LTE) or E-UTRAN provides a new radio access technology and refers to the improvements of UMTS through improved efficiency and services, lower costs, and use of new spectrum opportunities. In particular, LTE is a 3GPP standard that provides for uplink peak rates of at least, for example, <NUM> megabits per second (Mbps) per carrier and downlink peak rates of at least, for example, <NUM> Mbps per carrier. LTE supports scalable carrier bandwidths from <NUM> down to <NUM> and supports both Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD).

As mentioned above, LTE may also improve spectral efficiency in networks, allowing carriers to provide more data and voice services over a given bandwidth. Therefore, LTE is designed to fulfill the needs for high-speed data and media transport in addition to high-capacity voice support. Advantages of LTE include, for example, high throughput, low latency, FDD and TDD support in the same platform, an improved end-user experience, and a simple architecture resulting in low operating costs.

Certain releases of 3GPP LTE (e.g., LTE Rel-<NUM>, LTE Rel-<NUM>, LTE Rel-<NUM>, LTE Rel-<NUM>) are targeted towards international mobile telecommunications advanced (IMT-A) systems, referred to herein for convenience simply as LTE-Advanced (LTE-A).

LTE-A is directed toward extending and optimizing the 3GPP LTE radio access technologies. A goal of LTE-A is to provide significantly enhanced services by means of higher data rates and lower latency with reduced cost. LTE-A is a more optimized radio system fulfilling the international telecommunication union-radio (ITU-R) requirements for IMT-Advanced while keeping the backward compatibility.

In LTE (or LTE-A), there may be two downlink synchronization signals which are used by a UE to obtain cell identity and frame timing. These synchronization signals are referred to as the primary synchronization signal (PSS) and the secondary synchronization signal (SSS). The division of the synchronization signals into two signals is aimed at reducing the complexity of the cell search process.

<NUM> (5th generation mobile networks) refers to the new generation of radio systems and network architecture delivering extreme broadband and ultra-robust, low latency network connectivity. <NUM> networks are expected to support data rates of several tens of megabits per second for tens of thousands of users, to support several hundreds of thousands of simultaneous connections for massive sensor deployments, to significantly enhance spectral efficiency compared to LTE, to improve coverage, to enhance signaling efficiency, and to significantly reduce latency compared to LTE.

<CIT> describes a user apparatus configured to communicate with a base station in a radio communication system including a base station and the user apparatus, including: first reference signal reception means configured to measure a received power of first reference signals, transmitted from the base station, that are associated with a plurality of different identifiers, and to select a specific first reference signal; report means configured to report an identifier and a received power of the first reference signal selected by the first reference signal reception means to the base station or a macro cell base station; second reference signal reception means configured to receive a plurality of second reference signals transmitted from the base station; and measurement means configured to measure a reception quality of the second reference signals received by the second reference signal reception means, and to transmit feedback information based on the reception quality to the base station.

Present invention is defined by the independent claims. Some example embodiments are defined in the dependent claims. In the following, the invention is best understood in view of <FIG>, <FIG>. The remaining embodiments, aspects, or examples are included in order to help the reader better understand the invention.

For proper understanding of the disclosure, reference should be made to the accompanying drawings, wherein:.

It will be readily understood that the components of the disclosure, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of aspects of systems, methods, apparatuses, and computer program products for signal block mapping, as represented in the attached figures, is not intended to limit the scope of the disclosure, but is merely representative of some selected aspects of the disclosure.

The features, structures, or characteristics of the disclosure described throughout this specification may be combined in any suitable manner in one or more aspects. For example, the usage of the phrases "certain aspects," "some aspects," or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with the aspect may be included in at least one aspect of the present disclosure. Thus, appearances of the phrases "in certain aspects," "in some aspects," "in other aspects," or other similar language, throughout this specification do not necessarily all refer to the same group of aspects, and the described features, structures, or characteristics may be combined in any suitable manner in one or more aspects.

Additionally, if desired, the different functions discussed below may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the described functions may be optional or may be combined. As such, the following description should be considered as merely illustrative of the principles, teachings and aspects of this disclosure, and not in limitation thereof.

Certain aspects relate to frame structures for <NUM> cellular systems. <NUM> systems are expected to utilize a wide variety of different transceiver architectures that may range from low digital degree hybrid transceiver architectures to full digital solutions.

3GPP Technical Report <NUM>, titled "Radio Frequency (RF) requirement background for Active Antenna System (AAS) Base Station (BS) (Release <NUM>)," describes Base Station (BS) Radio Frequency (RF) requirements for Active Antenna System (AAS).

<FIG> illustrates an example of a general framework for radio architecture. As illustrated in the example of <FIG>, one transmitter unit (TXU) can be connected to {<NUM>. L} antenna elements depending on the transceiver unit (TXRU) virtualization, i.e., the mapping between TXRUs and Antenna Elements. The mapping may be either sub-array or full connection. In the sub-array model, one TXRU is connected to subset of antenna elements where different subsets are disjoint; while in the full connection model, each TXRU is connected to each antenna element.

Radio distribution network (RDN) performs antenna virtualization in the radio frequency (RF) domain. Virtualization is not frequency selective but common to resource elements (REs) and signals. RDN may utilize either sub array or full connection mapping between TXRUs and Antenna Elements.

In the transmitting direction, M antenna ports feed K TXRUs, and K TXRUs feed L antenna elements where M≤K≤L. Complexity and power consumption of baseband processing and analog/digital (A/D) conversion likely limits the number of antenna ports M and TXRUs K to be much less than L in the centimetre/millimetre wave (cmWave/mmWave) system where L can be from tens up to hundreds (or even thousands). Power consumption of TXU (excluding PA) is mainly due to digital-to-analog converter (DAC) of which power consumption is linearly proportional to bandwidth and exponentially proportional to the number of analog-to-digital converter (ADC) bits (P ~ Bx22R; where B is bandwidth and R is bits per sample). Typically, <NUM> bit ADCs are used, for example, in LTE. Thus, the power consumption of TXRU may limit the feasible number of TXRUs being less or significantly less than L. The number of TXRUs defines the number of signals that can be transmitted simultaneously per basic frequency resource like a subcarrier in an OFDM based system.

The framework illustrated in <FIG> may be used to describe digital beamforming, hybrid beamforming, and analog beamforming systems. In a digital Active Antenna System (AAS), one or more spatial layers per UE are provided, digital precoding only is supported, K=L (M≤K), and there is one-to-one mapping from TXRU to antenna element. In a hybrid Active Antenna System (AAS), one or more spatial layers per UE are provided, involves both analog and digital beamforming, K<L (M≤K), and there is one-to-many mapping from TXRU to antenna element. In an analog Active Antenna System (AAS), there is one spatial layer per UE, involves only analog beamforming (no digital precoding), M=<NUM>, K<L, and there is one-to-many mapping from TXRU to antenna element.

The deployment scenario, carrier frequency and system bandwidth largely determine the selected transceiver architecture. Similarly, the mode of operation will see different options that will be used depending on the above parameters. In certain scenarios, the cell may operate using a sector wide antenna beam pattern, while in other scenarios the cell may need to operate using narrow beams to meet the required link budget. As a complement to conventional cellular systems, operating with narrow beams would apply also for common control signalling between base stations (BSs) and user equipment (UEs). Practically, that means transmitting downlink common signalling and receiving uplink common control signalling in a sweeping manner. A target of the sweeping is to cover the whole sector by transmitting or receiving with one or multiple narrow beams at a time that can cover only portion of the sector, as illustrated in the example of a sweeping operation depicted in <FIG>. On the other hand, the cell may operate using sector beams or in case of narrow beams, the number of beams and time slots to transmit common control signaling may differ from one BS to another.

A general problem addressed by certain aspects is how to provide means to enable cell search and initial access in a way that the UE procedures remain the same independent of the cell operation mode and transceiver architecture at the BS. In other words, one objective is to build a common control signaling framework that can adapt to different transceiver architectures at the BS and number of beams and time slots needed for sweeping in case the BS operates in beam domain.

It may be assumed that certain discovery signaling block(s) allowing a UE to be able detect and measure the cell, as well as to be able to access to the cell will be defined. One block can be assumed to convey downlink common control signaling which can be transmitted in sweeping manner to the sector.

A more specific problem addressed by certain aspects is how to map those discovery signaling blocks on the subframes in order to provide common control signaling that scales across different transceiver architectures, different sweeping structures (total number of beams, number of parallel beams) and different operation scenarios (such as cell type, cell loading situation, number of active UEs, the need for energy saving at UE/eNB, etc.).

Therefore, aspects provide a scalable solution to map discovery signaling blocks on the subframes to enable BS transceiver architecture and antenna system agnostic initial access procedures.

According to one aspect, a discovery signal block (DSB), such as common control signaling, may be transmitted by the eNB according to a predefined amount of time and frequency resources common to all subframe types (e.g., three time domain symbols are allocated for a given DSB on a certain bandwidth and the corresponding resource elements such as subcarriers). The DSB may be transmitted from the network by using the same RF beams. Each DSB may be self-detectable and self-decodable.

In certain aspects, DSBs may be grouped together. One group may have one or multiple DSBs. Each DSB indicates its position within the group and provides the group's parameters. Configuration of DSB structure (how many DRBs in total and how many beams multiplexed per DSB) is configurable by the network. Configuration is not known a priori by UEs performing initial search and access (purpose is to enable agnostic initial search and access procedure for UE). Thus, each block may be self-detectable and self-decodable and provides UE information about beam and DSB structure, operation mode (etc.), and other such essential information and parameters to perform initial access. Grouping, as used herein, refers to a set of DSB blocks of which transmissions can cover the whole sector in spatial domain.

The grouping may, in one aspect, be associated with sweeping, as illustrated in <FIG>. There the number of DSBs is three, as a non-limiting example. For example, one DSB of the group is transmitted to one beam sector at a first time domain resource, which may be a subframe or a certain number (<NUM>, <NUM>, <NUM>,. N) of time domain symbols, a second DSB to a second sector, etc. In another aspect, the eNB may transmit all DSBs of the group for every narrow beam sector. For example, each DSB may be sent simultaneously by multiple beams, possibly to different directions (up to BS implementation). Simultaneously transmitted beams may be next to each other in spatial domain or separated (like a comb in spatial domain generated from parallel beams). Thus, one DSB covers a portion of the sector. Association of the beams of the cell to DSBs is according to BS implementation. In one aspect, the eNB may signal the association in each DSB block so that UE can learn the beam configuration of the cell. The UE detecting the one or more DSBs may then be able to identify beams of the block(s) (e.g. indices) among all the beams of the cell.

In one aspect, location of DSBs within a DSB group in subframes (e.g., downlink (DL) only or Special-DL subframes) can be configured by the BS. If the size of the group is one, the DSB may be located in DL control symbols or shared among DL control and data symbols. This may be because likely such system is fully digital and operates with sector beams and can have frequency selective beamforming, while hybrid architectures may utilize sweeping. If the size of the group is greater than one, DSBs may be located in the space reserved for DL data symbols (within a subframe). Each DSB may indicate the position of the DSB within the group and total number of DSBs within the group.

According to one aspect, subframes allocated for DSB transmissions may be used in a different manner by different transceiver units (antenna ports/ beam ports), and the BS may change the number of transceiver units allocated for DSB transmission over time.

It is noted that, in certain aspects, the DSB is mapped to a certain location in the subframe, and that certain antenna ports send the DSB periodically in a sweeping manner. That may mean that the DSB is transmitted systematically over the whole cell with certain periodicity from these antenna ports/beams. However, for full digital architecture, the sweeping may not take place and sector beams, which can be digitally precoded, may be used instead. In addition, aspects may provide simultaneous transmission of data and DSB in cases where the DSB covers only some part of the bandwidth.

In a first aspect, transceiver and antenna system agnostic access methods and systems are provided. In this aspect, a discovery signal block (DSB) is defined according to certain characteristics. For example, the DSB may have a predefined amount of time and frequency resources common to all subframe types and deployed architectures. The UE may assume that signals transmitted within a DSB are transmitted using the same RF beams at the BS, i.e. the BS is not allowed to change beamforming weights (digital and/or analog) within the DSB. For the UE, the property that it can assume signals transmitted using the same RF beams means that UE can determine beam level timing synchronization (PSS/SSS to acquire timing and beam RS/CSI-RS to beam acquisition). In co-operative multi-point (MP) scheme where multiple non-collocated remote radio heads share the same cell ID it may be beneficial in some scenarios if one block comprises beams only from one remote radio head (RRH) at a time so that UE can derive beam specific timing synchronization from synchronization signals, and radio head specific timing synchronization. DSB may also include information about mapping of beams transmitting DSB to transmission points of remote radio heads both in case RRH specific beams are in different DSBs or share the same DSBs.

In an aspect, the DSB may comprise multiple signals, for instance: synchronization signals for timing and partial or full physical layer cell ID acquisition, data channel (e.g., physical broadcast channel), and/or antenna port/beam port specific reference signals for physical broadcast channel (PBCH) demodulation, beam detection, paging detection and channel state information (CSI) acquisition.

Further, each DSB may be self-detectable and self-decodable. It is also possible to combine or average signals corresponding to different DSB transmissions instants towards the same spatial direction.

DSBs may be grouped together (see <FIG> discussed below), and each DSB may indicate its relationship within the group. A group of DSBs may have the following properties: a group may have one (cell operates with sector wide beams) or multiple DSBs (cell operates with beams narrower than sector wide beams), a BS transmits a group of DSBs within a certain period where the period may be, for instance, periodicity UE can assume for synchronization signal per spatial direction. DSBs within a group can be spread within a subframe or across multiple subframes.

<FIG> illustrates an example of DSB implementation options, according to an aspect. As depicted in <FIG>, a DSB may include a block capturing four signals: <NUM> synchronization signals, reference signal (beam reference signal/csi reference signal), and physical broadcast channel. It may also include signals and channels for paging support and distributing system information on frequency resources not reserved by synchronization signals and physical broadcast channel. As for physical broadcast channel, beam reference signal would be used as demodulation reference signal for other channels in the block as well. These frequency resources not reserved by synchronization signals and physical broadcast channel are depicted in <FIG> with the empty (white) blocks. The DSB in general can be seen to comprise also the shaded/marked blocks of <FIG>. The size and content of the DSB block may vary per eNB implementation and per detected transmission needs in the cell. DSB is considered to have a fixed amount of time and frequency domain resources independent of the transceiver architecture and configuration of DSBs (in predetermined location within the carrier). In this example, three time domain symbols may be allocated for DSB and a bandwidth of Bandwidth <NUM>. Bandwidth <NUM> may be, for example, a system bandwidth. Bandwidth <NUM> is a reduced bandwidth for certain signals and channels in DSB. DSB may comprise, for example, synchronization signal(s) for time and frequency synchronization, physical broadcast channel to convey system information, paging indicator and reference signal(s). In addition, there may be separate channels for most essential system information, paging and other system information distribution. Their periodicity may differ from each other, i.e. in certain block there may be only physical broadcast channel present while in some other block there may be physical broadcast channel, paging channel and channel for system information distribution present. All the signals and physical channels may be transmitted via multiple antenna ports in parallel. Antenna port/beam port specific reference signals may be allocated orthogonal resources in frequency (frequency domain multiplexing (FDM)/Interleaved FDM) and/or code domains. Reference signals may be used for demodulation reference signals for PBCH detection, mobility measurements, beam detection, tracking and selection, CSI acquisition, etc. PBCH may be transmitted using transmit diversity method across parallel antenna / beam ports in order to use one set of resources per DSB. For cell search and physical broadcast channel detection, the UE may operate only using reduced bandwidth option, Bandwidth <NUM>.

<FIG> illustrates further implementation options for DSB to enable narrowband structure, according to an aspect. The example of <FIG> may be used in case part of the transceiver resources (e.g., some antenna ports) are performing periodical DSB transmission while others (e.g., some of the other antenna ports) are transmitting dedicated UE signalling on the DSB subframes.

<FIG> illustrates configuration options for DSB groups, according to one aspect. As illustrated in <FIG>, one group may have one or multiple DSBs. Each DSB indicates its position within the group and provides the group's parameters. DSBs within the group may be placed consecutively in time domain or may be discontinuously allocated in time. An opportunity for RF beam switching is provided between DSBs within a group. One OFDMA symbol may be reserved for such a guard time between DSB transmissions within a subframe. Other possibilities are to define certain number of samples for the explicit guard period or reuse first samples of the CP of the first symbol of the block for the guard period. Guard period used for link direction switching may also serve as a guard time between DSB transmissions (both within a subframe and between subframes).

In a second aspect, configurability for DSB location within subframes is provided. Location of DSBs within a DSB group in subframes (e.g., DL only or S-DL subframes) may be configured by the BS. The configuration may depend on the architecture used at the BS, as well as depending on the operation mode, but the UE does not need any assumption prior cell search. Thus, the configuration of the location of DSBs can be performed in a UE agnostic manner.

According to an aspect, the location of a DSB group may depend on the size of the group. For example, if the size of the group is one, the DSB may be located in DL control symbols or shared among DL control and data symbols. This is one possible configuration with digital architecture operating using sector beams because it minimizes consuming resource elements from data symbols while downlink control flexibility can be maintained because of having frequency selective digital beamforming capability at the BS.

If the size of the group is greater than one, the DSBs may be located in the space reserved for DL data symbols (within a subframe). For instance, DSB allocation may start from the end of the subframe (or from the end of DL data part of the subframe). This is a possible configuration with hybrid/analog architecture operating using narrow beams by not limiting flexibility for transmission of control symbols. It may be noted that demodulation reference signal (DMRS) may, in an aspect, be located at the beginning of data part of the subframe (to facilitate fast detection at the receiver). In case of low number of DSBs that together fill only part of the subframe, filling from the end of the subframe may provide data transmission capability for data symbols preceding DSB blocks. Assuming demodulation RS would precede data symbols, unused data symbols due to DSB blocks would be more far away from DMRS than used ones. Furthermore, possibilities for having DMRS available in the "shorted subframe" can be maximized with this approach.

In an aspect, the following rules may be defined for allocating DSB(s) of the DSB group into subframes. Each DSB may indicate the position of the DSB within the group and the total number of DSBs within the group. The maximum number of time domain DSB resources may be defined for subframe (e.g., <NUM>). The maximum number may be needed in order for the UE to derive resource elements which are used by the DSB group in case DSBs within a group are spread across multiple subframes. In one example, the number can be fixed and defined in the specification for the subframe per subframe type (maximum number may depend on subframe type as well). In another example, the number can be defined by the BS/network system. In that case, each DSB would include information to the UE. This information (related to target cell) may also be included in a handover command to the UE. Another approach could be to use, for example, another RAT in case of multi-radio connectivity applied (UE could be connected to LTE when searching <NUM> cells and LTE provides information). According to one aspect, if the number of DSBs within the group is greater than the maximum number of time domain DSB resources for the subframe, DSBs may be spread across consecutive subframes having downlink data symbols (e.g., consecutive DL only subframes). If the DSB group has only one DSB, it may be allocated into the downlink control symbols, partly over downlink control and partly over downlink data symbols, or anywhere in the subframe. In the case it is allocated anywhere in the subframe, the DSB includes information for the UE to derive its location (i.e., mapping information) in relation to current subframe structure. This may be needed as there may be a need to define DSB resources and subframe structure (including DL control resource dimensioning in the subframe) independently from each other. In some aspects, the mapping information is implicit (such as DSB is always mapped to the last symbol(s) of the subframe), whereas in other cases the DSB includes an explicit indication of the mapping information. On the other hand, DSB may indicate (OFDM) symbol timing within the subframe. Hence, DSB may include indication about those symbol number(s) on the subframe on which the detected DSB block is allocated upon.

In one aspect the UE may detect the subframe structure from the received DSB. One example is that DSB indicates for instance maximum number (max_num) of DBSs within subframe which may indicate indirectly how many symbols are actually allocated for downlink control in the subframe. For example, if max_num of DSBs within subframe is three, that could mean two control symbols, but if the max_num of DSBs within subframe is four that could mean only one downlink control symbol only. Further, certain value may indicate that there is no uplink control symbol in the subframe where at least one DSB is allocated.

Furthermore, if the number of DSBs within the group is greater than defined maximum number for allowed consecutive blocks, DSBs of the group may be allocated into clusters within the period. For example, if the maximum number for allowed consecutive blocks is <NUM> and there are <NUM> blocks in the group, <NUM> blocks are allocated consecutively in time and rest <NUM> blocks are allocated consecutively in time with some offset from the cluster of blocks defined by said first <NUM> blocks. For instance, the cluster of blocks defined by said second <NUM> blocks are allocated on the subframe(s) with time offset half of the period of the group to the said first cluster. Another example is to increase the periodicity of the DSBs by the number of created clusters of blocks. For example, if the basic periodicity is <NUM>, the BS has configured <NUM> blocks and the maximum number for allowed blocks is <NUM>, three clusters of DSBs are created within the group. The clusters are separated by <NUM> from each other or alternatively, basic periodicity for each DSB is increased by factor of three to <NUM> and clusters are separated by <NUM>. In another alternative, maximum allowed consecutive blocks is configured to infinite and using above assumptions, all <NUM> blocks are allocated consecutively in time domain (potentially omitting downlink and/or uplink control symbols) and spread across multiple consecutive subframes.

<FIG> illustrates example mappings of DSBs into subframe structures, according to an aspect. In the example of <FIG>, DSBs are depicted as narrowband blocks relative to the total system bandwidth. Alternatively, as discussed above, DSB block may have some signals that are allocated total system bandwidth. As one implementation option, beam RS bandwidth could be configurable and could be signaled via DSB. By default UE could always assume certain minimum bandwidth for beam RS in order to enable demodulation of PBCH using beam RS, initial measurements and beam selection when performing initial search and access to the cell. DSB may then indicate whether or not the beam RS is allocated over the full bandwidth or over narrow bandwidth.

In a third aspect, adaptability of multiplexing of DSBs is provided. In this aspect, subframes allocated for DSB transmissions may be used in different manner by different transceiver units (antenna ports/ beam ports). For example, certain transceiver resources may transmit DSBs and certain transceiver resources may be used (simultaneously) for dedicated UE signaling (control and data) in those subframes. In this case, it may be desirable to define DSB to be narrow bandwidth block used by dedicated transceiver units while the rest of the system bandwidth could be used for dedicated signaling by other transceiver units (in other words to apply FDM between user data and DSB). For instance, one or two transceiver units may be allocated for sweeping DSBs while other transceiver units may be allocated for serving only dedicated UE signaling (control and data). In subframes DSBs are not transmitted, all transceiver units may be allocated for dedicated UE signaling.

The BS may change number of transceiver units allocated for DSB transmission over time. For example, when the cell is empty, the BS may minimize the sweeping time by multiplexing all beam ports into one DSB transmission; while, when the cell is serving a high number of UEs, DSB transmissions may be performed by, for example, one or two antenna/beam ports. Here it is assumed that a single beam provides enough EIRP for common control signaling from link budget/coverage point of view and thus multiple beams can be transmitted in parallel to different spatial directions. In case of narrowband DSB, a possibility is to allocate some antenna ports to transmit DSBs in parallel and other antenna ports to transmit user plane data at the same time on the frequency resources not reserved by DSBs. When the cell is empty, energy consumption is determined by the time the BS needs to have its transmitter(s) on. Thus, assuming certain total number of beams for full sweep, the sweep can be made shorter in time if more beams can be transmitted in parallel. Narrowband DSB would allow such configurability, for example when cell is empty the BS uses all the antenna ports in parallel for sweep, when there is load in the cell (high load), some APs perform sweeping while other perform user plane data transmission, thus preventing creation of data transmission gaps in downlink user plane transmissions due to sweeping.

As the DSB indicates the number of multiplexed beam ports per DSB and the total number of beam ports, the UE can derive the configuration of the transceiver units for DSB transmission to be able to track BS beams.

<FIG> illustrates options for resource element use for the antenna / beam ports transmitting DSBs, according to an aspect. <FIG> depicts options for resource element use for the antenna / beam ports not transmitting DSBs on the subframes where DSB resources are defined, according to an aspect. If PDSCH data allocation covers DSB region, the corresponding (dedicated) data/RS can be either rate matched or punctured around resource elements covering DSB region.

In case of narrowband DSB definition, one alternative may be to allocate DSB resource elements onto the edge of the system bandwidth to enable continuous allocation in frequency domain possibility for the antenna ports not transmitting DSBs on the subframes having DSB allocations. That would be beneficial, for instance, with single carrier transmission modulation schemes because DSBs are not in the middle of the system bandwidth to break frequency domain into two clusters.

<FIG> illustrates an example of an apparatus <NUM> according to an aspect. In an aspect, apparatus <NUM> may be a node, host, or server in a communications network or serving such a network. For example, in certain aspects, apparatus <NUM> may be a network node or access node for a radio access network, such as a base station e.g., NodeB (NB) in UMTS or eNodeB (eNB) in LTE or LTE-A. However, in other aspects, apparatus <NUM> may be other components within a radio access network.

As illustrated in <FIG>, apparatus <NUM> includes a processor <NUM> for processing information and executing instructions or operations. While a single processor <NUM> is shown in <FIG>, multiple processors may be utilized according to other aspects.

Memory <NUM> may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and removable memory. For example, memory <NUM> can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, or any other type of non-transitory machine or computer readable media.

In some aspects, apparatus <NUM> may also include or be coupled to one or more antennas <NUM> for transmitting and receiving signals and/or data to and from apparatus <NUM>. Apparatus <NUM> may further include or be coupled to a transceiver <NUM> configured to transmit and receive information. In other aspects, transceiver <NUM> may be capable of transmitting and receiving signals or data directly.

Processor <NUM> may perform functions associated with the operation of apparatus <NUM> which may include, for example, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus <NUM>, including processes related to management of communication resources.

In an aspect, memory <NUM> may store software modules that provide functionality when executed by processor <NUM>.

In one aspect, apparatus <NUM> may be a network node or access node, such as a base station in UMTS or an eNB in LTE or LTE-A, for example. According to certain aspects, apparatus <NUM> may be controlled by at least one memory <NUM> and at least one processor <NUM> to configure a group of discovery signaling blocks (DSBs). Apparatus <NUM> may configure a DSB according to certain characteristics. For example, the DSB may have a predefined amount of time and frequency resources common to all subframe types and deployed architectures.

As mentioned above, in an aspect, the DSB may comprise multiple signals, for instance: synchronization signals for timing and partial or full physical layer cell ID acquisition, data channel (e.g. physical broadcast channel), and/or antenna port/beam port specific reference signals for physical broadcast channel (PBCH) demodulation, paging detection, beam detection, and channel state information (CSI) acquisition. <FIG> and <FIG> discussed in detail above illustrate examples of a DSB configuration.

In addition, DSBs may be grouped together as illustrated in <FIG> discussed above, and each DSB may indicate its relationship within the group. The group may include one or multiple DSBs. In an aspect, apparatus <NUM> may configure the location of DSBs within a DSB group in subframes (e.g., DL only or S-DL subframes). According to one aspect, DSBs of the group may be located consecutively in time or in a clustered manner in time. One DSB may include transmission of a plurality of signals from one or multiple radio frequency beams, and the one or more radio frequency beams used for the transmission of the signals in a given DSB are the same.

In an aspect, apparatus <NUM> may be further controlled by at least one memory <NUM> and at least one processor <NUM> to map the DSBs of the group onto a subframe structure, and to include the group information into the DSBs. According to one aspect, mapping information may also be included into the DSBs. In an aspect, when mapping DSB(s) of the DSB group into subframes, each DSB may indicate the position of the DSB within the group (i.e., mapping information) and the total number of DSBs within the group (i.e., group information). According to one example, the maximum number of time domain DSB resources may be defined for a subframe. In one aspect, the maximum number may be fixed and defined in the specification for the subframe. In another aspect, the maximum number may be defined by apparatus <NUM>. In one aspect, apparatus <NUM> may be further controlled by at least one memory <NUM> and at least one processor <NUM> to transmit the DSBs in the subframe structure.

According to one aspect, apparatus <NUM> may be controlled by at least one memory <NUM> and at least one processor <NUM> to map the DSBs onto the subframe structure based on a size of the group and/or based on the subframe structure type configured in the cell. In an aspect, the DSBs are not allocated upon downlink and/or uplink control channel symbols if a number of subframes upon which blocks are mapped in a consecutive manner is below a given value.

When the number of consecutive subframes that the DSBs are allocated upon is greater than a given value, there may be another value indicating on how many subframes control symbols are remaining. <FIG>, <FIG>, and <FIG> illustrate examples of DSBs allocation. For example, the first value could be <NUM> and the second value is <NUM>, as non-limiting examples and other values are possible. These values may be pre-stored in the transmitting and receiving entities. In case the number of consecutive subframes is greater than four (=first value), e.g. six, then downlink control symbols are remained on the two (according to second value) edge subframes of the subframes DSBs are allocated upon and control symbols are omitted from other subframes. Alternatively, there may be some pattern on which subframes control symbols are remained in case the number of consecutive subframes DSBs are allocated is greater than given value (first value). The values may refer to a number of subframes. Downlink and uplink control symbols may be needed, for instance, for transmitting and receiving HARQ ack/nack feedback on previous subframes (data subframes) and sending scheduling grants for coming subframes.

Returning to <FIG>, in an aspect, apparatus <NUM> may be controlled by at least one memory <NUM> and at least one processor <NUM> to map the DSBs in a subframe starting from the end of the data symbols, when the group size is greater than one. For example, the blocks of the group may be mapped upon last downlink symbols of the subframe. In another aspect, apparatus <NUM> may be controlled by at least one memory <NUM> and at least one processor <NUM> to map the DSBs in a subframe starting from a downlink control symbol and/or downlink data symbol when the group size is one. Applying only one DSB block may mean that the BS can cover the whole sector at once. In one aspect, in hybrid/analog beamforming, even if there is only one DSB block in the group, that one DSB may be situated at the end of the subframe (one or more of the last symbols of the subframe).

In one aspect, the number of radio frequency beams per block may be configured by apparatus <NUM>. According to one aspect, at least one radio frequency beam is transmitting block and at least one other radio frequency block is transmitting data symbols simultaneously. Radio resources for DSBs and data symbols may be separated in frequency domain.

<FIG> illustrates an example of an apparatus <NUM> according to another aspect. In an aspect, apparatus <NUM> may be a node or element in a communications network or associated with such a network, such as a UE, mobile device, mobile unit, machine type UE or other device. For instance, in some aspects, apparatus <NUM> may be UE in LTE or LTE-A.

In some aspects, apparatus <NUM> may also include or be coupled to one or more antennas <NUM> for transmitting and receiving signals and/or data to and from apparatus <NUM>. In other aspects, transceiver <NUM> may be capable of transmitting and receiving signals or data directly.

Processor <NUM> may perform functions associated with the operation of apparatus <NUM> including, without limitation, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus <NUM>, including processes related to management of communication resources.

In an aspect, memory <NUM> stores software modules that provide functionality when executed by processor <NUM>.

As mentioned above, according to one aspect, apparatus <NUM> may be a mobile device, such as a UE in LTE or LTE-A. In one aspect, apparatus <NUM> may be controlled by at least one memory <NUM> and at least one processor <NUM> to detect one or more DSBs, determine a beam configuration applied for the detected one or more DSBs, determine the group structure of the detected one or more DSBs, and determine a mapping of the detected one or more DSBs on one or more subframes. Apparatus <NUM> may also be controlled by at least one memory <NUM> and at least one processor <NUM> to determine a structure of the one or more subframes based on the determined group structure and the determined mapping, and to perform initial access to a cell of the network based on the result of the determining steps.

<FIG> illustrates an example flow diagram of a method, according to one aspect of the disclosure. In certain aspects, the method of <FIG> may be performed by a network node, such as a base station or eNB. As illustrated in <FIG>, the method includes, at <NUM>, configuring a group of discovery signaling blocks (DSBs). The group of DSBs may be configured according to certain characteristics. For example, the DSB may have a predefined amount of time and frequency resources common to all subframe types and deployed architectures.

As mentioned above, in an aspect, the DSB comprises multiple signals, such as synchronization signals for timing and partial or full physical layer cell ID acquisition, data channel (e.g. physical broadcast channel), and/or antenna port/beam port specific reference signals for physical broadcast channel (PBCH) demodulation, paging detection, beam detection, and channel state information (CSI) acquisition.

In addition, DSBs may be grouped together as illustrated in <FIG> discussed above, and each DSB may indicate its relationship within the group. The group may include one or multiple DSBs. In an aspect, the configuring may include configuring the location of DSBs within a DSB group in subframes (e.g., DL only or S-DL subframes). According to one aspect, DSBs of the group may be located consecutively in time or in a clustered manner in time. One block may include transmission from one or multiple radio frequency beams.

In an aspect, the method further includes, at <NUM>, mapping the DSBs of the group onto a subframe structure, and, at <NUM>, including the group information into each of the DSB(s). According to one aspect, the including may further comprise including the mapping information in the DSBs. In an aspect, when mapping DSB(s) of the DSB group into subframes, each DSB may indicate the position of the DSB within the group and the total number of DSBs within the group. According to one example, the maximum number of time domain DSB resources may be defined for a subframe. In one aspect, the maximum number may be fixed and defined in the specification for the subframe. In another aspect, the maximum number may be defined by the base station or eNB. The method further includes, at <NUM>, transmitting the DSB(s) in the subframe structure.

According to one aspect, the mapping may include mapping the DSBs onto the subframe structure based on a size of the group and/or based on the subframe structure type configured in the cell. In an aspect, the DSBs are not allocated upon downlink and/or uplink control channel symbols if a number of subframes upon which blocks are mapped in a consecutive manner is below a given value. In an aspect, the mapping may include mapping the DSBs in a subframe starting from the end of the data symbols, when the group size is greater than one. In another aspect, the mapping may include mapping the DSBs in a subframe starting from a downlink control symbol and/or downlink data symbol when the group size is one.

In one aspect, the number of radio frequency beams per block may be configured by the base station or eNB. According to one aspect, at least one radio frequency beam is transmitting block and at least one other radio frequency block is transmitting data symbols simultaneously. Radio resources for DSBs and data symbols may be separated in frequency domain.

<FIG> illustrates an example flow diagram of a method, according to another aspect of the disclosure. In certain aspects, the method of <FIG> may be performed by a device, such as a UE in LTE or LTE-A. As illustrated in <FIG>, the method includes, at <NUM>, detecting one or more DSBs. At <NUM>, the method includes, determining a beam configuration applied for the detected one or more DSBs. The method further includes, at <NUM>, determining the group structure of the detected one or more DSBs, and, at <NUM>, determining a mapping of the detected one or more DSBs on one or more subframes. The method also includes, at <NUM>, determining a structure of the one or more subframes based on the determined group structure and the determined mapping. The method then includes, at <NUM>, performing initial access to a cell of the network based on the result of the determining steps.

<FIG> illustrates a block diagram of an apparatus <NUM>, according to one aspect. As illustrated in the example of <FIG>, apparatus <NUM> may include a processing unit or means <NUM> for controlling apparatus <NUM> and for carrying out instructions of a computer program, for example, by performing arithmetic, logical, control and input/output (I/O) operations specified by the instructions. Apparatus <NUM> may also include a storage unit or means <NUM> for storing information including, but not limited to, computer program instructions or software modules that provide functionality when executed by processing unit <NUM>. Apparatus <NUM> may further include a transceiving unit or means <NUM> for receiving or transmitting information. Apparatus <NUM> may also include a configuring unit or means <NUM> and a mapping unit or means <NUM>. In an aspect, the configuring unit <NUM> may configure a group of discovery signaling blocks (DSBs). The group of DSBs may be configured according to certain characteristics. For example, the DSB may have a predefined amount of time and frequency resources common to all subframe types and deployed architectures.

The group may include one or multiple DSBs. In an aspect, the configuring unit <NUM> may configure the location of DSBs within a DSB group in subframes (e.g., DL only or S-DL subframes). According to one aspect, DSBs of the group may be located consecutively in time or in a clustered manner in time. One block may include transmission from one or multiple radio frequency beams.

In an aspect, mapping unit <NUM> may map the DSBs of the group onto a subframe structure. The configuring unit <NUM> may cause the including of the group information and optionally the mapping information into the DSBs. In an aspect, when mapping DSB(s) of the DSB group into subframes, each DSB may indicate the position of the DSB within the group and the total number of DSBs within the group. According to one example, the maximum number of time domain DSB resources may be defined for a subframe. In one aspect, the maximum number may be fixed and defined in the specification for the subframe. In another aspect, the maximum number may be defined by apparatus <NUM>. Transceiving unit or means <NUM> may cause the transmitting of the DSBs in the subframe structure.

According to one aspect, the mapping unit <NUM> may map the DSBs onto the subframe structure based on a size of the group and/or based on the subframe structure type configured in the cell. In an aspect, the DSBs are not allocated upon downlink and/or uplink control channel symbols if a number of subframes upon which blocks are mapped in a consecutive manner is below a given value. In an aspect, the mapping unit <NUM> may map the DSBs in a subframe starting from the end of the data symbols, when the group size is greater than one. In another aspect, the mapping unit <NUM> may map the DSBs in a subframe starting from a downlink control symbol and/or downlink data symbol when the group size is one.

<FIG> illustrates a block diagram of an apparatus <NUM>, according to one aspect. As illustrated in the example of <FIG>, apparatus <NUM> may include a processing unit or means <NUM> for controlling apparatus <NUM> and for carrying out instructions of a computer program, for example, by performing arithmetic, logical, control and input/output (I/O) operations specified by the instructions. Apparatus <NUM> may also include a storage unit or means <NUM> for storing information including, but not limited to, computer program instructions or software modules that provide functionality when executed by processing unit <NUM>. Apparatus <NUM> may further include a transceiving unit or means <NUM> for receiving or transmitting information. Apparatus <NUM> may also include a detecting unit <NUM> and a determining unit <NUM>.

In an aspect, detecting unit <NUM> may detect one or more DSBs. Determining unit <NUM> may determine a beam configuration applied for the detected one or more blocks, determine the group structure of the detected one or more DSBs, determine a mapping of the detected one or more DSBs on one or more subframes, and determine a structure of the one or more subframes based on the determined group structure and the determined mapping. The transceiving unit or means <NUM> may cause the performing of initial access to a cell of the network based on the result of the determining steps.

Aspects of the disclosure provide several advantages and technical improvements. For example, aspects support all possible BS architectures (fully digital, hybrid, fully analog). In addition, aspects are UE agnostic. In other words, the UE does not need to know the BS architecture in advance. Further, aspects may support both beamformed and conventional (sector beam approach) approaches for the common control plane (PBCH, PRACH). Certain aspects have built-in support for efficient usage of BS TXRU (and other hardware resources). Also, aspects allow for minimizing the duration of one sweep of beamformed control channel transmission. Hence, it has a positive impact on the UEs power consumption (i.e., UE power consumption is reduced). Additionally, aspects allow simultaneous transmission of data and DSB. This will minimize the system overhead of DSB transmission.

According to aspects, programs, also called program products or computer programs, including software routines, applets and macros, may be stored in any apparatus-readable data storage medium and they include program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out aspects. The one or more computer-executable components may be at least one software code or portions of it. Modifications and configurations required for implementing functionality of an aspect may be performed as routine(s), which may be implemented as added or updated software routine(s). Software routine(s) may be downloaded into the apparatus.

Software or a computer program code or portions of it may be in a source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. The computer readable medium or computer readable storage medium may be a non-transitory medium.

In other aspects, the functionality of any method or apparatus described herein may be performed by hardware, for example through the use of an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another aspect, the functionality may be implemented as a signal, a non-tangible means that may be carried by an electromagnetic signal downloaded from the Internet or other network.

According to an aspect, an apparatus, such as a node, device, or a corresponding component, may be configured as a computer or a microprocessor, such as single-chip computer element, or as a chipset, including at least a memory for providing storage capacity used for arithmetic operation and an operation processor for executing the arithmetic operation.

Claim 1:
A method (9A) comprising:
configuring (<NUM>), by a network node, a group of discovery signaling blocks, where a discovery signaling block comprises at least a synchronization signal and a physical broadcast channel;
mapping (<NUM>), by the network node, the discovery signaling blocks of the group onto a subframe structure;
including (<NUM>), by the network node, mapping information and group information into each of the discovery signaling blocks for a user equipment to derive a group structure and the mapping of the discovery signaling blocks of the group onto the subframe structure, wherein the mapping information indicates where a discovery signaling block is located in the subframe structure and the group information comprises information on how many discovery signaling blocks are in the group; and
transmitting (<NUM>), by the network node, the discovery signaling blocks in the subframe structure.