Presence indication in a wireless communication system

The disclosed embodiments relate to, for example, wireless communication systems such as systems according to a set of standards by 3GPP Long Term Evolution (LTE) and 3GPP_LTE-A (LTE Advanced), and are particularly used in such systems. It is related to the presence notification of the user device to be performed.

Wireless communication systems are widely known. In wireless communication systems, a base station (BS) communicates with a user device (UE) within the range of BS (UE is a terminal, a subscriber, a subscriber station, a mobile station, etc.). May be mentioned).

A geographic area or range covered by one or more base stations is commonly referred to as a cell, typically a network that covers a wider geographic area more or less seamlessly with adjacent and / or overlapping cells. Many BSs are provided in place to form. (In this specification, "system" and "network" may be used as synonyms as long as there is no risk of confusion). Each BS divides the available bandwidth into individual resource allocation parts to allocate to the user equipment it manages. Since the user device is generally mobile (mobile station), it moves in the cell and promotes the necessary handover between the base stations of the adjacent cells. The user device can be in the area of multiple cells at the same time (ie, it is possible to detect signals from multiple cells at the same time), and one cell is entirely within a larger cell. In the simplest case, the UE communicates with one "serving" cell.

The communication direction from the base station to the UE is referred to as downlink (DL), and the communication direction from the UE to the base station is referred to as uplink (UL). At least the communication modes in the wireless communication system known to the inventor of the present application are the TDD (Time Division Duplex) system in which downlink and uplink transmissions have the same carrier frequency but are separated in time. , FDD (Frequency Division Duplex) system in which DL and UL transmit simultaneously using different carrier frequencies.

<p num="0005"><nplcit num="1"><text>Samsung: CoMP Feedback including preferred-TP indicator, 3GPP DRAFT: R1-121622 PLL_TP_INDICATOR_FINAL, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE; 650, ROUTE DES LUCIOLES; F-06921 SOPHIA-ANTIPOLIS CEDEX; FRANCE, vol. RAN WG, no.jeju, Korea; 20120326 --20120330, 20 March 2012 (2012-03-20), XP050599885</text></nplcit></p>

<p num="0006"> Resources in such a system have both a temporal dimension and a frequency dimension. In LTE, the dimension of time has a unit of symbol time or "slot" (slots typically have seven symbol time periods), as shown in FIG. Time domain resources are further organized in frame units, with each frame having multiple "subframes". The frames are continuous one by one, and each frame is given a system frame number (SFN).</p><p num="0007"> In the LTE 1-frame structure, a 10ms frame is divided into 20 slots of equal time length of 0.5ms, as shown in Figure 1. A subframe consists of two consecutive slots, and one radio frame contains 10 subframes. The FDD frame is formed so that 10 uplink subframes and 10 downlink subframes occur at the same time. In the case of TDD, 10 subframes are shared between UL and DL, and various downlink and uplink allocations for subframes are possible depending on the load status. Therefore, the subframe may be referred to as an uplink subframe or a downlink subframe.</p><p num="0008"> On the other hand, the frequency dimension is divided into subcarrier units. The BS scheduling function allocates a specified number of subcarriers to the UE over a predetermined period of time. Such allocations are typically made on a subframe-by-subframe basis. Resources are allocated for both downlink and uplink transmission (ie, for both downlink subframes and uplink subframes).</p><p num="0009"> As shown in FIG. 2, the signal transmitted in each slot is described by a resource grid of subcarriers and available OFDM (Orthogonal Frequency Division Multiplexing) symbols. Each element in the resource grid is called a resource element (RE), and each resource element corresponds to one symbol (in the time axis). Depending on whether a short or long cyclic prefix (CP) is used, each downlink slot contains a period T containing 7 or 6 symbols per slot._slotHave. N in total in the frequency domain_BWThere are a number of subcarriers, the specific number of which depends on the system bandwidth. A block occupied by 12 subcarriers x 7 or 6 symbols is called a resource block. A resource block is a basic unit of scheduling related to UE resource allocation.</p><p num="0010"> A base station typically has multiple antennas and is therefore capable of transmitting (receiving) multiple data streams simultaneously. Physical antennas controlled by the same base station may be geographically far apart, but this is not required. A group of physical antennas provides a logically distinct communication path to the UE and is referred to as an antenna port (also may be thought of as a virtual antenna). The antenna port may include any number of physical antennas. Various transmission modes are possible via the antenna port, including, for example, "transmission mode 9" for closed-loop multiple inputs and multiple outputs (MIMO) schemes (in the case of LTE-A). A portion of a group of physical antennas may all be geographically co-located and have different transmission points under the control of the same base station. It may be considered as point: TP). In general, there is a certain relationship between TPs and cells; each TP may define different cells in the network, but it is not required. In the present specification, the term "base station" may be used for individual TPs unless otherwise specified in the context.</p><p num="0011"> At various levels of abstraction in the network, multiple "channels" for data and signaling are defined. Figure 3 shows some LTE-defined channels at the logical, transport, and physical levels, and their correspondence.</p><p num="0012"> At the physical layer level of the downlink, the system information block (SIB) as well as the user data is contained in the transport channel DL-SCH and is carried by the physical downlink shared channel (PDSCH). As can be seen in Figure 3, PDSCH also carries paging channels at the transport layer level. There are various control channels in the downlink that carry out signaling (notification, notification information) for various purposes. In particular, the physical downlink control channel (PDCCH) is a base station (enhanced node B (eNodeB, eNB in LTE). ) Is used to carry, for example, scheduling information from) to individual UEs managed by the base station. The PDCCH is located at the first OFDM symbol in the slot.</p><p num="0013"> Each base station broadcasts various channels and signals to all UEs within its range, whether or not their cell is currently a serving cell for the UE. In this regard, in particular, in addition to the physical broadcast channel PBCH as shown in FIG. 3, a primary sync signal PSS and a secondary sync signal SSS (not shown) are included, which will be described later. The PBCH is responsible for the so-called master information block (MIB), which provides basic information, including system bandwidth, number of transmitting antenna ports, and system frame number, to any UE within reach of its signal. By reading the MIB, the UE will be able to receive and decrypt the above SIB. "Decoding" may be referred to as decoding.</p><p num="0014"> On the uplink, on the other hand, user data and some signaling data are carried by the physical uplink shared channel (PUSCH), the control channel includes the physical uplink control channel (PUCCH), and PUCCH is the channel quality indication (CQI) report. And used to carry signaling from the UE, including scheduling requests.</p><p num="0015"> The above-mentioned "channels" defined for various data and signaling purposes are referred to as "channels or propagation paths" in the sense of radio links that are subject to fading or interference between the UE and the serving base station. Should not be confused. To facilitate measurement by the UE (ie, measurement), the base station inserts a reference signal into the resource block, eg, as shown in Figure 4. Figure 4 shows the arrangement configuration of the downlink reference signal for transmission by one antenna port. As shown, one subframe has a reference signal, indicated by an "R", which is inserted into the individual resource element RE. Various types of reference signals can be utilized, and when many antenna ports are used, the structure and pattern of the reference signals may be different.</p><p num="0016"> In LTE (distinguished from LTE-A), the downlink reference signal is the cell-specific (or common) reference signal (CRS) and the MBMS FN reference signal used by the MBMS (not discussed in detail here). It can be classified into a reference signal unique to the user device (UE-specific RS or UE-individual RS, which is also referred to as a demodulation reference signal DM-RS). There is also a positioning reference signal.</p><p num="0017"> The CRS is sent to all UEs in the cell and used for channel estimation. The reference signal sequence bears the cell identifier. Cell-specific frequency shifts are applied when mapping the reference signal sequence to subcarriers. UE-specific reference signals are received by a particular UE or a particular UE group within a cell. UE-specific reference signals are used primarily by specific UEs or specific UE groups for data demodulation purposes.</p><p num="0018"> CRS is transmitted by all downlink subframes in cells making non-MBSFN transmissions and by all UEs in cells managed by eNodeB, regardless of the specific time / frequency resources assigned to the UEs. It is accessible (available). CRS is used by UEs to measure the characteristics of radio channels (so-called Channel State Information (CSI)). DM-RS, on the other hand, is only sent from eNodeB within a specific resource block that is assigned to be received by only some UEs in the cell.</p><p num="0019"> LTE of standard specifications after release 10 is referred to as LTE Advanced (LTE-Advanced: LTE-A). The new reference signal in LTE-A is the Channel State Information Reference Signal (CSI-RS). To minimize interference, CSI-RS is only transmitted every few subframes. For Release 10 standard specifications, the CSI-RS configuration pattern is specified for 1, 2, 4 or 8 antenna ports. These objectives are to improve channel estimation (than using CRS) for more than one cell when feeding back channel quality information and possibly other network-related parameters. CSI-RS patterns with respect to time and frequency can be configured at higher layers, providing enormous flexibility when resource elements (REs) embrace them.</p><p num="0020"> UEs that comply with LTE Release 10 can be configured with multiple CSI-RS patterns specific to serving cells: _One configuration: In this case, the UE must assume non-zero transmit power for CSI-RS; and _ Zero or more configuration: In this case, the UE must assume zero transmit power.</p><p num="0021"> The purpose of the "zero transmit power CSI-RS pattern" is to ensure that the cell so configured can safely assume that the UE will not transmit in the RE containing the CSI-RS of the cell in which the UE is involved. It is to be. Information in the presence of the zero transmit power CSI-RS pattern is available to the UE in Release 10 to mitigate the potentially impact on data transmission using PDSCH.</p><p num="0022"> The reference signal is also specified on the uplink, in particular the sounding reference signal transmitted by the UE, which provides channel information to the eNodeB.</p><p num="0023"> The UE receives two SRS configurations (how to configure SRS) from the network through RRC signaling. One is a UE-specific SRS setting that specifies information about SRS transmission such as period or frequency, offset, transmission comb index, position in the frequency domain, and frequency hopping pattern. The SRS is sent with the OFDM symbol at the end of the subframe whenever it is sent. On the other hand, there is also a cell-specific SRS configuration that is notified to all UEs when and where SRS is used, causing the UE to stop PUSCH transmission on resources in all relevant frequency and time domains. In LTE_Rel-10, the SRS may be periodic or aperiodic, depending on the configuration (if aperiodic, DL signaling is triggered by the network).</p><p num="0024"> The UE must properly perform cell search procedures and obtain synchronization with the cell before communicating with the network. Each cell is a physical layer cell It is identified by identity: PCI), and 504 are specified in LTE. These are hierarchically organized into 168 unique cell layer identifier groups, each containing three physical layer identifiers. Two signals are provided to carry the physical layer identifier and the physical layer cell identifier group, which are the primary and secondary synchronization signals (PSS and SSS). As specified in 3GPP_TS36.211 incorporated in the reference of this application, PSS specifies one of three values (0, 1, 2) to identify the physical layer identifier of the cell, and SSS is 168. Specify the group to which the cell belongs. Thus, PSS only needs to represent one of the three values, and SSS only needs to represent one of the 168 values. PSS is a 62-bit signal based on the Zadoff-Chu sequence, and SSS uses a combination of two 31-bit sequences and is scrambled using the sequence derived from the physical cell identifier. Both PSS and SSS are transmitted from all cells with constant resources, allowing them to be detected by any UE within reach of the signal. Traditionally, each of PSS and SSS is transmitted twice per frame, in other words with a 5ms cycle (ie, transmitted once every few subframes). For example, as shown in FIGS. 5A and 5B, both PSS and SSS are transmitted in the first and sixth subframes per (radio) frame. Figure 5A shows the configuration of PSS, SSS and PBCH in the case of FDD system (using normal CP), and Figure 5B shows the configuration in the case of TDD.</p><p num="0025"> After successfully decoding PSS and SSS, the UE can obtain the timing and identifier for the cell. When the UE decodes the PSS and SSS of the cell, the UE may notice the presence of the cell and decode the MIB of PBCH described above. Depending on whether the system is using FDD or TDD, PBCH is the slot before or after PSS and SSS (or) in the first subframe, as shown in the comparative examples in FIGS. 5A and 5B. Occupies the symbol). Similar to the sync signal SSS, the PBCH is scrambled using a sequence based on the cell identifier. PBCH is transmitted frame by frame, and the MIB is carried by four frames (symbols).</p><p num="0026"> The UE will then measure the cell's reference signal (RS). For the current LTE release, the first step is to identify the common reference signal CRS, whose position in the frequency domain depends on the PCI (Physical Cell Identifier). In the next step, the UE can decode the broadcast channel (PBCH). In addition, the UE can decode the PDCCH and receive control signaling. In particular, in the case of "transmission mode 9", the UE needs to measure the radio channel using the above channel state information RS (CSI-RS).</p><p num="0027"> After synchronizing with the network and decoding the MIB, the UE needs to get some uplink send resource to send data to the network.</p><p num="0028"> The physical random access channel PRACH is used to carry a random access channel (RACH) to access the network when the UE is not assigned any uplink transmit resources. When a scheduling request (SR) is triggered on the UE, for example when data is sent on the PUSCH, the SR is sent on a dedicated resource for this purpose if the PUSCH has not yet been assigned to the UE. If no such resource has been assigned to the UE, the RACH procedure is initiated. Sending an SR is effectively a request for PUSCH's uplink radio resources for data transmission.</p><p num="0029"> That is, RACH is provided so that the UE can transmit signals over the uplink when no individual resource is available, allowing one or more terminals to transmit simultaneously on the PRACH resource. The term "random access (RA)" is used because the identifier of the UE (or group of UEs) that uses the resource at a given point in time is not known to the network in advance (except in the case of non-collision RACH described below). Used (note that in this specification, "system" and "network" may be used interchangeably as long as there is no risk of confusion). By letting the UE use the preamble, eNodeB can distinguish between different sources (when the preamble is transmitted, it produces a signal with a signature identifiable by eNodeB).</p><p num="0030"> RACH can be used by the UE in both collision and non-collision modes. In the case of RA in collision mode (contention-based mode), the UE randomly selects some preamble, so if two or more UEs happen to select the same preamble, there is a risk of "collision" in eNodeB. "Collision" may be referred to as a conflict or the like. RA in non-collision mode (contention-free mode) avoids collisions by having eNodeB notify each UE of preambles that may be used.</p><p num="0031"> As shown in Figure 6, the physical random access channel (PRACH) procedure is typically as follows (in the case of collision access schemes, ie collision modes).</p><p num="0032"> (i) As mentioned above, UE10 receives the downlink broadcast channel PBCH of the associated cell (serving cell).</p><p num="0033"> (ii) The network represented by eNodeB20 notifies cell-specific information including the following information.</p><p num="0034"> Resources available for PRACH -Available preambles (at most 64) -Preamble for short and long message sizes.</p><p num="0035"> (iii) The UE selects the PRACH preamble depending on the collision access method available and the intended message size.</p><p num="0036"> (iv) UE10 sends a PRACH preamble (indicated by "1" in Figure 6 and referred to as "Message 1") on the serving cell uplink. The network (more specifically, the serving cell eNodeB) receives message 1 and estimates the UE transmission timing.</p><p num="0037"> (v) UE10 monitors the downlink channel specified for the response from the network (ie, from eNodeB). The "response" may be referred to as a response or the like. The "monitor" may be referred to as a monitor or the like. In response to the UE sending message 1, the UE 10 receives a random access response or RAR (indicated by "2" in Figure 6 and referred to as "message 2") from the network. Message 2 contains a UL grant (transmission permission signal) for transmitting PUSCH and a timing advance (TA) command for the UE to adjust the transmission timing.</p><p num="0038"> (vi) In response to receiving message 2 from the network, UE10 uses the UL grant and TA information contained in message 2 to send on PUSCH (indicated by "3" in Figure 6). And is referred to as "Message 3").</p><p num="0039"> (vii) If the eNodeB 20 receives the same preamble from more than one UE at the same time and more than one UE sends message 3, as indicated by "4", then a collision avoidance message ( contention resolution message) is sent from the network (in this example, from eNodeB 20).</p><p num="0040"> If the UE does not receive any response from eNodeB, the UE selects a new preamble and sends a new RACH subframe after a random backoff time.</p><p num="0041"> As mentioned above, the cells may overlap, or the smaller cells may be completely contained within the larger cells. This is, in particular, the so-called Heterogeneous Network.</p><p num="0042"> FIG. 7 generally shows a part of a heterogeneous network, in which the macro base station 10 covers the macro cell region MC, in which the pico base station 12 (picocell PC) and various femto base stations 14 (femtocell FC are formed). There are other overlapping cells formed by). As shown in FIG. 7, the UE 20 may communicate with one or more cells at the same time, and in this example, communicates with the macro cell MC and the pico cell PC. The cells do not have to have the same bandwidth, and typically macrocells have a wider bandwidth than pico / femtocells.</p><p num="0043"> The definitions of some terms are listed below.</p><p num="0044"> -Heterogeneous network: A network form in which more than one macro, pico, femto base station and / or relay station are mixed in the same spectrum.</p><p num="0045"> -Macro base station-Uses a dedicated backhaul and access is a conventional base station that is open to the public. Typical transmit power is ~ 43dBm and antenna gain is ~ 12-15dBi.</p><p num="0046"> Pico Base Station-Uses a dedicated backhaul and is a publicly available low power base station with access. Typical transmit power is ~ 23dBm-30dBm and antenna gain is 0-5dBi.</p><p num="0047"> Femto Base Station-A base station that can be deployed by a customer who uses the customer's broadband connection as a backhaul. Femto base stations may have limited associations (access may not be publicly available). A typical transmit power is &lt;23 dBm.</p><p num="0048"> -Relay station-A base station that uses the same radio spectrum for backhaul and access. The same transmission power as the pico base station may be used.</p><p num="0049"> A specific example of a femto base station in LTE is the so-called home eNodeB (HeNB).</p><p num="0050"> The situation in which network customers introduce base stations with limited network coverage cells (eg, femto base stations (home eNodeB)) is expected to become more prevalent in the future LTE form. Femto base stations or pico base stations can be installed, for example, in buildings, where network subscriber stations are subject to significant path loss when communicating (particularly transmitting) with macrocells. Femto and Pico base stations can be installed by the customer in the customer's building. The femtocells and picocells thus formed have the ability to improve network coverage, but when deployed within various cells, the femtocells and picocells are macrocells (more precisely, the base station "in FIG. 7". It is desirable to be in sync with each other under the control of (10 and referred to as MeNB). When formed in this way, the picocell may be considered not only as a transmission point of the base station, but also as a transmission point provided by the base station's own antenna port.</p><p num="0051"> The transmission point (TP) mentioned above includes the meanings of both the various antenna groups and the picocell at various geographical locations within the macrocell in the present application.</p><p num="0052"> For now, UE and LTE networks can only send and receive information about network coverage if the UE is at least connected to the network at the RRC level (although the UE may be in the RRC_IDLE state). The UE cannot notify the network of its presence prior to the urgent need to send UL data, and the network will find that certain broadcast signals (especially PSS / SSS and PBCH) are useful to nearby UEs. Whether or not it is, it must continue to be transmitted as before. Such a form cannot flexibly respond to the arrangement of UEs that change over time, and the current network design presupposes a fixed correspondence (association) between the transmission point (TP) and the cell. From the perspective of increasing flexibility for dynamic (UE) placement, effective use of network transmit power, and mitigation of interference, in future network architectures, UEs will move over time and UE services. It is desirable to be able to dynamically form or build a network near the UE as demand changes.</p>

<p num="0053"> The transmission method according to one embodiment is A transmission method in a wireless communication system having at least one base station and at least one terminal controlling at least two transmission points controlled to broadcast a first signal. A step in which at least one transmission point broadcasts the first signal, A step in which the terminal discovers the transmission point by receiving the first signal broadcast from the transmission point. A step in which the terminal transmits a second signal having at least one characteristic determined by at least one characteristic of the received first signal. With the step of enabling the base station to broadcast the third signal from at least one transmission point when the transmission point receives the second signal from the terminal. It is a transmission method having.</p>

<figref num="1">The figure which shows the general frame structure used in LTE.</figref><figref num="2">The figure which shows the resource block (RB) and resource element (RE) in a downlink subframe.</figref><figref num="3">The figure which shows the correspondence relationship between a logical channel, a transport channel and a physical channel in LTE.</figref><figref num="4">The figure which shows an example of the insertion pattern of a reference signal in a downlink subframe.</figref><figref num="5A">The figure which shows the allocation method of the slot and the subframe about the synchronization signal and the broadcast channel in the case of the LTE system of the FDD system.</figref><figref num="5B">The figure which shows the allocation method of the slot and the subframe about the synchronization signal and the broadcast channel in the case of the LTE system of the TDD system.</figref><figref num="6">The figure which shows the normal RACH procedure in the LTE system.</figref><figref num="7">The figure which shows typically the heterogeneous network where macrocell, picocell and femtocell overlap.</figref><figref num="8">A flowchart showing the main steps included in the method according to the embodiment.</figref><figref num="9">The flowchart regarding the network response to the UE existence notification in one embodiment.</figref>

&lt;Outline of the embodiment&gt; The transmission method according to the first embodiment is A transmission method in a wireless communication system having at least one base station and at least one terminal controlling at least two transmission points controlled to broadcast a first signal. A step in which at least one transmission point broadcasts the first signal, A step in which the terminal discovers the transmission point by receiving the first signal broadcast from the transmission point. A step in which the terminal transmits a second signal having at least one characteristic determined by at least one characteristic of the received first signal. With the step of enabling the base station to broadcast the third signal from at least one transmission point when the transmission point receives the second signal from the terminal. It is a transmission method having.

Here, the second signal transmitted by the terminal is considered as a "presence indication" and will be described in detail below. This presence notification allows the terminal to automatically notify the network of the transmission point of the source of the signal that the terminal can receive. In one embodiment of the present application, the presence notification notifies the base station that the associated transmission point should start broadcasting a third signal.

In one embodiment, at least one feature of the first signal includes a synchronization sequence indicating the identifier of the transmission point.

Alternatively or additionally, at least one feature of the first signal includes the timing at which the first signal is broadcast.

Alternatively or additionally, at least one feature of the first signal indicates a list of possible transmission timings and / or frequencies (transmission schedule) for the second signal.

Also, preferably, the terminal automatically transmits the second signal at any timing allowed by the list of possible transmission timings.

At least one feature of the second signal, determined by at least one feature of the first signal received, is one or more timings at which the second signal may be transmitted, and the second. Includes any one or more frequencies through which the signal may be transmitted.

The timing may be, for example, individual subframes in a frame-based wireless communication system. The fact that the first signal is received from the transmission point in a specific first subframe means that the terminal can transmit the second signal in the second subframe having a predetermined relationship with the first subframe. Means.

The second signal may have features that include one or more of how the sounding reference signal is arranged and how the random access preamble is selected. In this way, the terminal receiving the particular first signal may transmit a sounding reference signal according to a predetermined arrangement or setting, or may transmit a random access preamble having an implicit meaning to the network. May be good. Combining both types of signals (called sounding reference signals and random access preambles) informs the network of one of a very large number of potentially states-that is, information about the terminal or its preferences. You may.

There are several types of information that the terminal may want to notify the network. In any of the above transmission methods, the characteristics of the second signal belong to a preferable state of a transmission point belonging to a plurality of transmission points found by the terminal and a plurality of transmission points found by the terminal. It may indicate at least one of the preferences for receiving transmissions from a plurality of specific transmission points. The latter preference is referred to as the device's aggregation preference.

The third signal, which is broadcast in response to receiving the second signal, can include any one or more of a broadcast channel, a paging channel, a reference signal and a synchronization sequence. This allows the transmit point to constrain the transmit power by broadcasting a third signal only when necessary (eg, in the presence of one or more terminals).

When the third signal is (or contains) a reference signal or a synchronization signal, the third signal has a density corresponding to the reception of the characteristics of the second signal and / or the second signal. May be broadcast on. In this way, it is possible to flexibly control the third signal with a degree of freedom that is not just an on / off state, and it is possible to adapt to terminals having different conditions regarding the reference signal and the synchronization signal, for example. is there. The third signal may be broadcast at a frequency different from that of the first signal.

In any of the above embodiments, the steps of the transmission method may be repeated for a plurality of transmission points controlled by the base station and discovered by the terminal. In other words, the terminal may transmit individual second signals to or in connection with the discovery of multiple transmission points. However, it is not essential for the terminal to transmit a second signal for all transmission points found by the terminal.

In the transmission method of one embodiment, if the terminal receives the first signal from the transmission point but does not receive a designated additional signal from the transmission point, the terminal receives the second signal. Is only allowed to send. This avoids, for example, giving unnecessary signaling to a transmitting terminal that has begun to transmit the specified additional signal if it is already operating in that way.

In another embodiment, the terminal is only allowed to transmit the second signal if the transmission point that receives the second signal changes, in other words, the terminal receives the second signal. This is the case when there is a change in the discovered transmission point group that is the source of the signal of 1.

Yet another form is also applicable to wireless communication systems in which transmission points provide different cells for uplinks and downlinks. The second signal from the terminal is transmitted on the uplink of one cell, but the (transmission) timing is based on the downlink of another cell.

The transmission method according to the second embodiment is A transmission method used in a wireless communication system having a network controlling at least two transmission points and at least one terminal. The network controls the first transmission point to transmit the first broadcast signal, Upon receiving the first broadcast signal, the terminal is formed to transmit an uplink signal having at least one feature determined by at least one feature of the received first broadcast signal. A network is a transmission method that causes a second broadcast signal to be transmitted from a second transmission point when an uplink signal is received from a terminal.

The transmission method according to the third embodiment is A transmission method used in a wireless communication system having a network controlling a transmission point and at least one terminal. The network controls the transmission point to send the first broadcast signal, Upon receiving the first broadcast signal, the terminal is formed to transmit a first uplink signal having at least one feature determined by at least one feature of the received first broadcast signal. The network ensures that when a first uplink signal is received from a terminal, a second broadcast signal is transmitted from the transmit point. When the terminal receives the second broadcast signal, it is a transmission method that transmits a second uplink signal having at least one feature determined by at least one feature of the received second broadcast signal.

Another embodiment according to the present application provides a wireless communication network formed to perform any of the above methods.

A further embodiment according to the present application provides a base station formed to use any of the above methods.

A further embodiment according to the present application provides a terminal formed to use any of the above methods.

Another embodiment relates to software in which a wireless transceiver device with a processor functions to form the terminal or base station described above. Such software may be recorded on a computer-readable storage medium (a medium that can be read by a computer).

In the specification, claims and drawings, the term "cell" is intended to include subcells as well.

An embodiment of the present application provides a novel method in which the UE automatically notifies the network from which transmission point (TP) the UE can receive a predetermined broadcast signal. For example, by receiving a physical identifier for a particular TP in a broadcast signal in the form of a synchronous sequence, the UE indicates that it is capable of receiving a broadcast signal from that TP, if desired (ie, within the coverage of that TP). Estimate when the UL should send a notification of existence). The network can then respond to it by performing appropriate actions such as adjusting network coverage, enabling or disabling other broadcast channels, controlling paging, and so on.

The advantages of the embodiments include, for example: --The terminal (UE) does not need to know any explicit timing information in order to receive the broadcast signal and send the response. --Collision avoidance or conflict resolution is not required when multiple UEs notify their existence at the same time (unlike the conventional RACH procedure). --The point that the network can respond in the form of activating an additional broadcast channel to the UE's transmission of the presence notification signal. --Low transmission overhead and signaling for the network to ensure that the terminal is within the coverage / service area of a particular transmission point.

In general, unless expressly mentioned, the features described for certain embodiments in the present application are similarly or by any combination thereof, even if such a combination is explicitly referred to or described in the present application. If not, it may be applied to other embodiments.

As is clear from the above description, the present application transmits signals between a base station and a user device in a wireless communication system. The base station may take any form suitable for transmitting and receiving such signals. Base stations typically use the embodiments proposed in a set of standards for 3GPP_LTE and 3GPP_LTE-A, so the term eNodeB (eNB) (the term eNB) is appropriate in a variety of situations. , Including home eNodeB (HeNB)). However, depending on the functional conditions according to the present application, all or some of the base stations transmit signals to and receive signals from the user equipment, and the user is based on the fed-back channel state information. Other forms suitable for forming a signal for transmission to the device may be employed.

Similarly, in the present application, each of the user devices may employ any form suitable for transmitting a signal to the base station and receiving a signal from the base station. For example, the user equipment may adopt the form of a subscriber station, a mobile station (MS), or any other suitable fixed or movable form. It may be convenient to assume that the user device is a mobile handset so that the embodiment can be easily imagined (although at least some user devices are often considered to be mobile handset). Whatever the matter, it does not limit the disclosure of the present application.

&lt;Detailed description of the embodiment&gt; An embodiment will be described with reference to the accompanying drawings as a mere example.

The main situation envisioned in this application is a situation in which the UE operates with a large number of TPs that do not have to have a particular network structure (in the sense that it is not essential to be associated with a particular cell). .. Some higher level device, such as the macro eNodeB (MeNB), controls the TP, or such control may be made elsewhere. In any case, it is assumed that multiple TPs are synchronized. Specific resources available to the UE in many complex multiple frequency layer situations if the UE can directly obtain information about the network structure through broadcast signaling intended for multiple UEs. It will be possible to make decisions about interacting with the network without receiving the potentially vast amount of higher layer signaling that indicates. Such issues are discussed, for example, in International Application No. PCT / EP2012 / 051452. However, if the UE could automatically process such information by notifying the network of the TP in the area where the UE resides, the network (or TP) would respond accordingly in terms of coverage and resource readiness. You will be able to perform the process.

The main situation is not limited to the content of the present application, and for convenience of the description of the present application, both various antenna groups and picocells at various locations in the cell can be considered as TPs, which is an advantageous alternative. A typical situation is a situation in which layers of picocells are densely present due to the control performed by overlapping macrocells.

The embodiment is intended as a means by which the UE automatically notifies the network of the source TP of the signal received by the UE. This is referred to as "presence indication" in the following description. When applied to LTE, by receiving the primary and secondary synchronization sequences (PSS and SSS) from the TP and matching the physical cell identifier (PCI) they contain with the lookup table, the UE broadcasts if desired. Determine when the UL should send a notification indicating its ability to receive a signal (ie, a notification that it is within the coverage of that TP) (hereinafter referred to as the "presence notification"). In addition, the expression of transmitting such an existence notification to TP "to" or TP "to" is used, which means that the UE is transmitting a signal to (or to) the network related to a predetermined TP. It should be understood that it is a shorthand for that, and it is not essential that all TPs be prepared to receive signals from the UE.

In the following, the identifier indicated by the synchronization sequence is the "physical transmission point identity (PTPI)", and the TP transmits all signals that are generally associated with forming the basis of the LTE cell. Clarify what is not required and clarify that a new sequence with a physical identifier different from conventional PCI will be used. That is, the embodiment is deployed using a new version of PSS and / or SSS, which PSS / SSS bears an identifier that somehow identifies the TP, although it does not necessarily have to be PCI. This provides backward compatibility with traditional UEs that are unaware of the method according to the embodiment. Therefore, the following description is made mainly from the viewpoint of "synchronous sequence (SS)" rather than PSS and SSS.

FIG. 8 shows the outline of the flowchart of the method according to the embodiment.

In step 102, the TP broadcasts its own SS, which may be the traditional PSS / SSS of the LTE network as described above, and somehow includes the PTPI of its own TP, eg, the traditional PCI. You may be. As mentioned above, conventional PSS / SSS is formed from scrambled bit sequences by utilizing sequences derived from PCI. A similar method may be used in forming a new SS.

In step 104, the UE detects SS from one or more TPs that are within the current range (in range) of the signal.

In step 106, the UE then decodes each of the received SSs to derive the PTPI contained in the signal. For traditional PSS / SSS, upon successful decoding, the UE can identify the cell PCI used to scramble the sequence used to form the PSS / SSS.

In step 108, the UE can be used in response to the SS to estimate some information about the possibility or candidate to send its presence notification, eg, to send the presence notification related to the appropriate TP in UL. Estimate timing (and perhaps one or more frequencies). As mentioned above, this estimate is based on the value of PTPI, such as the numeric index contained in the table of possible values.

At step 110, the UE decides to send such an presence notification and operates accordingly. As will be further clarified from the description of the embodiment described later, the presence notification may include a combination of signals instead of a single transmission. The particular timing selected for sending the presence notification (a portion of the available timing or within a range) may suggest additional (further) information to the network.

Steps 106 through 110 have been described in relation to a single SS, but in principle they may be repeated for as many SSs as the UE has detected, and steps 110 are optional rather than mandatory. is there.

The UE may automatically make other decisions related to the presence notification before sending the presence notification, and the network responds by adjusting the network coverage and structure, enabling or disabling other broadcast channels. Appropriate actions such as sable and paging control can be performed.

An alternative form of the disclosure of this application is to use the PSS / SSS and subframe association as shown in International Application No. PCT / EP2012 / 051452, where the UE receives the PSS / SSS from the TP. It is to associate the subframe to be used with the subframe to which the UE may send the presence notification. "Association" may be referred to as associations, links, associations, and the like. Therefore, in such an example, the value of PTPI is not always required in order for the UE to determine the possible timing for presence notification.

In general, unless otherwise noted, the embodiments described below are based on LTE, the network operates with FDD and has one or more eNodeB / MeNB, each with one or more downlink cells. Each of the downlink cells corresponds to an uplink cell. Each DL cell contains one or more terminals (UEs), which receive and decode the signal transmitted from the serving cell. During the normal operating period of the current system, each cell broadcasts a large number of signals and channels (eg, PSS, SSS, CRS, PBCH), regardless of whether the cell is a serving cell of the UE. Sending to UE. These include timing information, PCI, and other basic system information common to cells. Other information is transmitted to the UEs in the cell on the channel containing the PDCCH. If a UE is in a cell, that cell may be referred to as the UE's serving cell. The PDCCH message typically indicates whether the data transmission is uplink (PUSCH) or downlink (PDSCH), transmission resources and other information (eg, transmission mode, number of antenna ports, data rate, etc.). It also shows the number of codewords enabled, etc.). In addition, the PDCCH may indicate which reference signal is used to derive the phase reference for demodulation of the DL transmission. Reference signals from different antenna ports that occupy the same location (time and frequency locations) are distinguished by different spreading codes.

However, in the case of LTE, the network does not need to transmit any signals and channels just to perform the operation of the embodiment, except for PSS and / or SSS or equivalent SS.

(a) UE existence notification by SRS transmission In the first embodiment, the group of TPs involved transmit their own SS responsible for the PTPI. Each PTPI characterizes a particular TP, but it is not essential that each TP be restricted to one PTPI. Other broadcast signals are not always transmitted. A UE capable of receiving a specific PTPI can receive the fact that it can be received as a good permission to send an SRS according to a predetermined setting at a specific subframe number m, and its existence. Notify the network. A set of UE-specific SRS configurations can be used with traditional UL channel SRS sounding applications.<u style="single">Distinction</u>It may be reserved in the standard specifications for the purpose of using it. Multiple UEs transmitting with the same UE-specific SRS configuration can be distinguished by having different amounts of cyclic shift in their SRS sequence. However, it is not essential that the network be able to identify exactly how many UEs have notified their presence at a given point in time.

If the SS is LTE_PSS and LTE_SSS, which are responsible for the conventional PCI, this will allocate a part of the PCI to the function indicating the subframe number permitted to transmit the UE presence notification.

Embodiments include (i) allowing the network to be notified that the UE is in the vicinity of a particular TP, and (ii) UL channel quality information about that TP (whether or not it is actually used). It has at least a dual effect of providing).

In a variant of this embodiment, in a situation where a macrocell contains a dense group of TPs that are not organized or systematized (when the TP cells and macrocells overlap), the macro eNodeB is subjected to RRC. You can notify the reserved SRS configurations and change them as needed (eg, depending on the needs of MeNB's traditional sounding). Proper allocation of SRS resources may depend on how many active UEs are in the macrocell coverage area.

(b) UE existence notification by PRACH transmission The second embodiment is similar to the first embodiment, except that permission is given to the UE transmitting the PRACH. To make a clear distinction between conventional uses and embodiments of PRACH, some RA preambles of the RA preambles can be reserved for use for that purpose. For UEs that do not have an RRC connection to the network and cannot access PBCH transmissions (discussed below), some of the PRACH resources are reserved RA preambles for the purposes of the embodiment, as above. It is possible to specify or secure the transmission of the above in the standard specifications. Upon receiving the RA preamble associated with the embodiment, the network does not engage in the normal RA, but follows the process as described in the embodiments of the present application.

In this embodiment, if more than one UE selects the same preamble, they will simply be received by the network in the same subframe. This "hides" the number of true UEs, but can still signal that at least one UE exists.

In a variant of this embodiment, in a situation where a macrocell contains an unorganized, dense set of TPs (when the TP cells and macrocells overlap), the macro eNodeB is reserved by RRC. You can notify PRACH resources and change them as needed.

Dividing the preamble into subsets is described, for example, in International Application Nos. PCT / EP2011 / 067048 and PCT / EP2012 / 051144, which are incorporated into the references of this application.

(c) UE presence notification by transmission of both SRS and RACH In a third embodiment, the first and second embodiments are combined so that the UE notifies its presence by transmitting SRS in a particular subframe m1 and PRACH in subframe m2. Will be done. m1 and m2 may be the same or different, m2 may be a function of m1 (m2 may be derived from m1), and the relationship between m1 and m2 is The reverse may be true.

When SRS and PRACH provide the same presence notification redundantly, the reliability of detecting the presence notification of the UE is improved.

On the other hand, the presence notification may be formed by the combination of SRS and PRACH, instead of individually notifying by SRS and PRACH. Such a combination of signals makes it possible to signal the possibility of a large number of states, for example making it possible to distinguish a large number of UEs, as referred to in a fourth embodiment described below. Allows you to be notified of additional information.

(d) Multiple UL subframe grants for UE notification In the fourth embodiment, the subframe number m in the third embodiment or the like is extended to allow a plurality of subframes {m1, m2, ...}, in which the UE represents an existence notification. A signal may be transmitted. The selection of the UE as to which particular subframe is used will inform the network of information about the TP from the perspective of the UE, which includes, for example: --Preferred status of TP in what was received. For example, an aptitude state that is "high" means that (i) the UE can receive the TP, and (ii) among the TPs that the UE can receive, further transmissions from that TP ( For example, PDSCH transmission) indicates that it is preferable to do; the aptitude state of being "low" means that (i) the UE can receive its TP, but (ii) the UE Indicates that it will notify the "high" aptitude status for at least one other TP. Such information can assist in scheduling decisions at TPs or higher aggregation levels, such as eNodeB (already mentioned).

--TP aggregation preference. For example, the UE may be in a high preference from that TP, along with at least one other TP indicated by subframe selection, to make further transmissions, such as PDSCH. Aggregation of TPs may be done in antenna ports (LTE terminology) or other forms of transmission. One choice of subframe can signal that the UE prefers its single TP.

These aptitudes or preferences may be based on measurement of the received power level of PSS and / or SSS from the TP. Depending on the number of subframes allowed to the UE, the choice of number of states may be notified. This embodiment may be combined with a third embodiment to allow more status notifications.

In a variant of this embodiment, the UE is allowed to transmit in as many presentation subframes as the selection, pattern or number of subframes used to indicate the above-mentioned conditions.

(e) Notification of the existence of multiple frequencies The fifth embodiment is the same as the above embodiment, but the UE transmits an existence notification to the TP at an uplink frequency different from the uplink frequency of the uplink related to the SS responsible for the PTPI received by the UE. The difference is that it is allowed. This allows the TP to limit the use of UEs that can transmit in a particular band, or to direct UE presence notifications to TPs that receive other frequencies.

In a variant, the UE is allowed to send presence notifications simultaneously on more than one frequency, with more than one frequency being the primary and secondary LTE carriers provided, for example, by the TPs or by the individual TPs. .. From the viewpoint of avoiding unnecessary notification of the existence of essential multicarriers from the UE, it is preferable that this modification is set by the RRC of the existing connection rather than being specified separately in the standard specifications. This allows the TP to change the frequency at which the PTPI is transmitted over time, depending on factors such as each frequency and the load used by the TP.

Figure 9 shows a possible network response procedure to an presence notification sent by the UE.

In step 202, the network receives each presence notification transmitted from the UE according to any of the above embodiments.

In step 204, the network matches the presence notification with the transmission point through which the presence notification has passed or the transmission point that has received the presence notification. This is whether or not the UE is currently receiving a signal from a given TP, and if so, roughly how many UEs it is.<u style="single">Net</u>Make the work visible.

In step 206, the network appropriately controls the TP according to its confirmation or judgment. For example, the TP may be controlled to turn on or off any of the paging channel, broadcast channel or reference signal.

The following sixth to ninth embodiments show specific examples in such a case.

(f) Paging / tracking area control In the sixth embodiment, when the presence notification of the UE is received by a certain number of TPs (at least one), the physical transmission of the PCH is restricted to the local area near the TP where the relevant presence notification is received. As such, the network uses presence notifications to control the transmission of paging channels (PCHs). Regarding limiting the physical means of transmission, for example, a group of TPs geographically close to the place where the presence notification was received may be selected for transmission of the PCH, and the TPs have a receiver. It is assumed that it is associated with that or in the vicinity of the receiver. This embodiment avoids wastefully transmitting PCH from a TP that is known (or presumed to be) not present in the vicinity of the UE. This information can also be used by higher layers to update the UE tracking area.

(g) PBCH transmission control In the seventh embodiment, it is not mandatory for TP to send PBCH by default. When a certain number of TPs (at least one) receive the UE presence notification, the network activates the transmission of PBCH from at least some TPs in the TP group. After that, if the network no longer receives the presence notification for the TP, the network can stop sending PBCH from the TP. The advantages of this form are that the transmitted power consumed can be reduced and the cell-to-cell interference due to PBCH can be reduced.

In this way, the network does not necessarily transmit PBCH from the TP unless it confirms that the UE is likely to be in the vicinity where it can receive PBCH.

(h) PSS and SSS transmission control The eighth embodiment is similar to the seventh embodiment, except that TP does not necessarily transmit even PSS and SSS by default. In this embodiment, at least the first, second, and third embodiments of the present application are used when the UE is currently present where PSS and SSS are available. When the UE moves, the network can estimate the direction of the UE's movement based on the TP no longer receiving presence notifications from the UE, and the network geographically determines that the UE is likely to move. It is possible to activate PSS and SSS in the region.

In this way, the network does not necessarily send PSS / SSS from the TP unless it confirms that the UE is likely to be in the vicinity where it can receive PSS / SSS. Thus, while the above embodiments according to the present application will operate in such areas, transmission power can be saved.

(i) CRS transmission control The ninth embodiment is similar to the eighth embodiment, but the cell-specific reference signal from the specific TP is similar to the above embodiment, depending on the TP received by the network via the UE presence notification. The transmission of (CRS) is controlled, which can avoid unnecessary transmission of CRS.

(j) UE permission restrictions due to the existence of PBCH In the tenth embodiment, the UE is not allowed to perform the processing according to the above embodiment by default. Instead, the UE is only allowed to send an presence notification to the (source) TP if it is detecting a PSS / SSS transmission, rather than detecting a PBCH transmission. In this way, the already active TP does not receive useless signaling indicating that it should start transmitting, and the UE does not need to send such signaling, saving transmission power. Interference by PRACH or SRS can be reduced.

In a variant, the transmission of the UE proposed by the present application may be suppressed by the UE detecting a reference signal such as a CRS (rather than a PBCH).

In this regard, when multiple TPs coexist and form a conventional cell, at least some TPs are PSS, regardless of whether any UE is found or presumed to be present in the cell. / SSS, CRS and PBCH are different from the conventional technology that always transmits.

(k) UE permission control by changing SS reception status In the eleventh embodiment, as in the tenth embodiment, the UE is not allowed to perform the processing according to the above embodiment by default. Instead, the UE is only allowed to send an presence notification to the TP if there is a change in the set of SSs that the UE can receive. In this way, the UE does not send unnecessary presence notifications if it remains immutable from a network perspective.

(l) Existence notification resource provided by SS subframe association The twelfth embodiment is similar to the above embodiment, except that the related group of TPs transmit SS according to a predetermined subframe format schedule, which schedule is at least a TP within a predetermined geographical area. Adjusted in. A UE that can receive SS in subframe n from a specific TP may send SRS that it has been received in accordance with the predetermined setting of subframe m specified by m, which is a function of at least n. Can be taken as permission. The basic principles of this embodiment relate to the embodiment set forth in International Application No. PCT / EP2012 / 051452 by the Applicant, the international application of which is incorporated into the reference of the present application.

(m) UE synchronization adjustment LTE-A_Rel-11 has introduced a "new carrier type (NTC)", which is not backwards compatible with Rel-10 and its predecessors. The network may provide both traditional and new carriers to the UE, and at least in some circumstances, the UE needs to acquire synchronization for the new carrier separately from the traditional carrier in such situations. .. A "traditional carrier or legacy carrier" is a carrier suitable for use with Rel-10 and conventional UEs, which may be referred to herein as conventional UEs or legacy UEs.

In the thirteenth embodiment, the TP transmits PSS / SSS separately on the NCT and the conventional carrier. The UE utilizes PSS / SSS to obtain coarse synchronization in NCT, but after receiving an presence notification from the UE in a legacy carrier, the network can send CRS or CSI-RS, for example in NCT. , UE can use it to fine-tune synchronization to NTC.

The traditional RACH procedure (see Figure 6) may be considered as a form of presence notification, in a variant where the UE performs the traditional RACH procedure in NCT to get coarse timing and properly notify presence in NCT. It may be provided, and thereafter, RS, CSI-RS, etc. may be enabled by NCT so that fine timing can be acquired.

The difference from the conventional RACH is that the RACH procedure according to the present application does not require the UE to receive the CRS or PBCH in the new carrier. Rather, CRS and / or PBCH in the new carrier is activated after RACH. The system information (MIB) normally received by the UE by the PBCH prior to the RACH may be transmitted by other means. The UE can receive that information, for example, from the signaling of a legacy carrier.

(n) Expandable reference signal for UE presence notification In the fourteenth embodiment, the presence notification is used to control a certain degree of freedom (extent) rather than simply turning on / off the transmission of the reference signal. For example, by default in NCT there is no timing / reference signal (like PSS / SSS and / or CRS and / or CSI-RS), or the timing / reference signal is only present in sparse form. If the UE notifies the presence of the UE on a legacy carrier or NCT, the default settings will be changed to increase the density of time and / or frequency to help synchronize the UE on the NCT. Similar principles can be applied to legacy carriers based on system standards.

In the case of CRS, this limits the transmission of CRS in the default case to, for example, the central 6RB portion of the system bandwidth, and probably also applies the subframe form so that it is not transmitted in all subframes. By doing so, it can be realized. Upon receipt of the UE presence notification, the density with respect to time and / or frequency is appropriately increased and is probably applicable to all Release 8 specifications (ie, per RB and per cell reserved for CRS). 8 to 24 REs). The density of CRS may be reduced based on the UE's synchronization with sufficient certainty.

In this embodiment, the network may control the presence (or presence) of PSS / SSS and / or CRS and / or CSI-RS in the NCT to meet the conditions of the UE for a particular release. For example, a release 8 UE may require a complete set of PSS / SSS and / or CRS.

Similar principles may apply to CSI-RS transmission, but eNodeB does not have to replace the default form, but sets an additional CSI-RS subframe form to the default form. (LTE-A Release 11 may tend to allow more than one non-zero transmit power CSI-RS pattern configured for the UE).

(o) Change settings from NCT to legacy carrier In the fifteenth embodiment, the TP is set so that all carriers are NCT. Specific parameters used for presence notification in the first to fourth embodiments (for example, a specific RA preamble is selected from a group of presence notifications) when the TP receives the presence notification from the legacy UE. If an presence notification is identified from within the group by or being restricted to selection by the UE, the TP will provide the relevant reference signal and / or synchronization to provide a legacy carrier. It is possible to temporarily reset the signal transmission.

(p) A form in which the presence notification of one cell is based on the timing of another cell. The sixteenth embodiment can be based on any of the above embodiments applicable when the cell uses different resources for uplinks and downlinks, and the number of UEs is greater than one. It can be set to serving cells, each of which has a different uplink resource. The existence notification is transmitted on the uplink of one cell, but is transmitted at a timing based on the downlink timing of another cell. When applied to LTE, the UE may be configured to utilize a primary cell (Pcell) and a secondary cell (Scell). The network may require the UE to send PRACH on the Scell uplink based on the downlink timing of the Pcell, or it may require the UE to send on the Pcell based on the current timing of the uplink transmission. You may request it. It is not mandatory that such a "request or request" be made explicitly, and the network may simply enable the transmission of presence notifications. The UE may be somewhat independent of the situation regarding the timing of presence notifications. Scell operations that only allow "UL-only" may be performed, but the Pcell must receive some response to the PRACH sent by the Scell.

A further feature of this form is whether the timings of the two cells (eg, Pcell and Scell) are close enough to assume synchronization, at least based on the timing of only one that applies to the UE. , The network can be determined from the presence notification (PRACH in Scell in this example). Alternatively, if the assumption of synchronization does not hold, the network can use the appropriate signal (eg, PSS / SSS, CRS) according to the fourth embodiment.

Various modifications are possible within the scope of disclosure of the present application.

Although the embodiments have been described in terms of LTE_FDD, they are also applicable to LTE_TDD and to other communication systems such as UMTS.

With respect to the "cell" in the present application, a one-to-one correspondence between the cell and the base station or transmission point is not essential. Different cells may be specified for downlinks and uplinks. Multiple cells may be provided by the same transmission point. The term "cell" is broadly interpreted to include, for example, subcells, cell sectors, and the like.

Although embodiments have been described in connection with macrocells and pico-antenna ports, this does not limit the network structure to which the embodiments apply.

The above embodiments may generally be combined, for example, the 7th and 9th embodiments may be combined so that the PBCH and CRS are transmitted together.

Activating and deactivating transmissions from TPs as described in embodiments may be determined locally by the TPs or at some higher level, such as eNodeB, which controls multiple TPs. It may be determined by aggregation. Activation may be referred to as activation or activation and the like. Inactivation may be referred to as deactivation or deactivation and the like. Not all TPs that receive presence notifications from the UE are required to perform the processing of the method described in the embodiment.

The proposed UE behavior may be predetermined by standard specifications, or may be configured by higher layer signaling using, for example, an already existing RRC connection.

In general, it is not essential for the UE to send an existence notification to all (that is, to any) of the source TPs that sent the SS responsible for the PTPI that the UE could receive. This brings, for example, the following advantages.

--It is possible to prevent the network load from becoming excessive (overload) due to the signaling of existence notification.

--By controlling the presence notification (how to notify), it is possible to provide appropriate information to the network (or, when appropriate, indicate to the network that the UE has a specific view on the network. , That view may differ from what the network actually has).

For example, a UE capable of detecting signals from multiple TPs may choose to respond to one TP with the strongest signal.

It is possible to prevent some transmissions such as CRS and PSS / SSS from being transmitted by NCT, or to ensure that they are transmitted with low density in the time and frequency directions. The principles of the embodiments of the present application are applicable to activate or deactivate such transmissions not only in new carrier types but also in conventional carriers. Although this is particularly relevant to the fifth embodiment, it may be applied in combination with the fifth embodiment and the sixth, seventh, eighth and ninth embodiments.

In summary, embodiments of the present application provide a novel way for the UE to automatically notify the network from which transmission point (TP) the UE can receive a given broadcast signal. For example, by receiving a physical identifier for a particular TP in a broadcast signal in the form of a synchronous sequence, the UE indicates that it is capable of receiving a broadcast signal from that TP, if desired (ie, within the coverage of that TP). Estimate when the UL should send a notification of existence). The network can then respond to it by performing appropriate actions such as adjusting network coverage, enabling or disabling other broadcast channels, controlling paging, and so on.

The advantage of the embodiments of the present application is that the UE does not need to know any explicit timing information in order to receive the broadcast signal and transmit the response. This is different from the traditional RACH procedure, for example, in which case the timing of the initial PRACH transmission from the UE is the broadcast signaling and downlink timing (PSS / SSS monitoring, PBCH) of the PRACH resources contained in the SIB. Is set by trying to decode). Also, unlike the conventional PRACH, when multiple URs simultaneously notify their existence, the conventional conflict resolution process is unnecessary.

In an embodiment of the present application, the network response to the presence notification sent by the UE is notified in the form of activating an additional broadcast channel. Reducing transmission overhead and / or signaling is necessary for the network to verify the presence of terminals within the coverage / service area of a particular transmission point.

The various features of any of the embodiments described above may be realized in hardware or software modules running on two or more processors. The features of one embodiment may be applied to any other embodiment.

The present application provides a computer program or computer program product for performing any of the methods described above, and also provides a computer-readable storage medium for storing a program for performing any of the methods described herein.

The computer program for realizing the embodiments may be stored in a computer-readable storage medium, or may be realized in the form of a signal, such as a downloadable data signal provided by an internet website. It may be realized in any other form.

<u style="single">Industrial applicability</u> The embodiments according to the present application provide an effective means superior to the prior art, and enable the formation and construction of a wireless network dynamically according to the arrangement of UEs in the network. Embodiments can make existing cellular architectures even more flexible and accommodate changing coverage demands. This improves the cost-effectiveness of the key operations that operate such networks and enables the effective use of resources. More specifically, the UE can notify the network of its ability to receive signals from the TP without the need to set up an RRC connection. This provides a situation where the network can receive information that the UE automatically determines suitability without requiring configuration signaling from the network. Such information has superior properties in terms of suitability, timeliness, etc., as compared to information from measurement reports, which have been made independently in conventional networks, and therefore system scheduling and system scheduling. It is possible to further improve resource utilization efficiency.