WO2015078348A1 - Cluster head determination method and user equipment - Google Patents

Abstract

A cluster head determination method and user equipment (UE) are disclosed in the present application and are used for UE to look for the cluster head and determine whether the UE itself is the cluster head, and, especially in the situation that the current cluster head suddenly stops working, a new cluster head can be determined for continuing to provide a synchronization reference. A cluster head determination method provided in the present application includes that: when UE needs to determine the cluster head, the UE determines a length of search time used for searching the cluster head dedicated signal, wherein the cluster head dedicated signal is the signal used for identifying the cluster head; the UE searches the cluster head dedicated signal within the determined length of search time ; and, when the cluster head dedicated signal is not found within the determined length of search time , the UE determines itself as the cluster head.

Description

Cluster head determination method and user equipment

This application claims priority to Chinese Patent Application No. 201310627593.X, filed on November 28, 2013, and entitled "A Cluster Head Determination Method and User Equipment", the entire contents of which are incorporated by reference. In this application.

Technical field

The present application relates to the field of communications technologies, and in particular, to a cluster head determining method and user equipment.

Background technique

In the scenario where there is no network coverage, some UEs (User Equipments) can become cluster heads, and send synchronization signals to provide synchronization reference for other UEs around to achieve synchronous transmission. When the original cluster head in the system cannot continue to work for some reason, the UE in the cluster loses the synchronization reference, and some mechanism is needed to obtain a new cluster head to continue to maintain the synchronous transmission in the cluster. If each UE determines whether it is a cluster head according to its own measurement, there may be a conflict situation in which a plurality of neighboring UEs simultaneously become cluster heads.

In the traditional cellular communication technology, the data communication process between two UEs is as shown in FIG. 1. Services such as voice and data of UE1 and UE2 interact through respective resident eNBs (Evolved NodeBs) and core networks.

The D2D (Device-to-Device) technology, that is, the UE direct-through technology, refers to a method in which a neighboring UE can transmit data through a direct link in a short range without performing a central node (ie, a base station). Forward, as shown in Figure 2. D2D technology's short-range communication characteristics and direct communication methods have the following advantages:

The UE short-range direct communication mode can achieve higher data rate, lower delay and lower power consumption;

Utilizing the short-distance characteristics of widely distributed UEs and D2D communication links in the network, efficient use of spectrum resources can be realized;

D2D's direct communication method can adapt to the local data sharing requirements of services such as wireless P2P (Point to Point), and provide flexible and adaptable data services;

D2D direct communication can utilize a large number of widely distributed communication UEs in the network to expand the coverage of the network.

LTE (Long Term Evolution) D2D technology refers to the D2D discovery and communication process controlled by the LTE network operating on the LTE licensed frequency band. On the one hand, the advantages of D2D technology can be fully utilized, and the control of LTE network can also overcome some problems of traditional D2D technology, such as uncontrollable interference. The introduction of LTE D2D features will enable LTE technology to evolve from pure wireless mobile cellular communication technology to "Universal Connectivity Technology".

The LTE D2D technology includes two aspects of D2D discovery and D2D communication, where D2D discovery refers to one D2D UE to discover other D2D UEs in the vicinity, and D2D communication refers to data communication transmission between the D2D UE and other D2D UEs. No Whether it is for discovery or communication, the UE must first determine a synchronization reference and obtain the time to transmit or receive the D2D signal according to the synchronization reference.

In the LTE system, the UE obtains a synchronization reference for downlink reception and uplink transmission by receiving a downlink synchronization signal and a PBCH (Physical Broadcast Channel) transmitted by the base station. The downlink synchronization signal is composed of a primary synchronization signal and a secondary synchronization signal, and uses a ZC (Zradoff-chu sequence) sequence and an m sequence, respectively, occupying a fixed resource position. The UE can obtain the cell ID (Cell ID) of the cell by detecting the primary synchronization and the secondary synchronization signal of the cell, thereby performing a subsequent cell access procedure. The PBCH is the system information of some cells and the current radio frame number.

Figure 3, Figure 4, and Figure 5 show three scenarios of D2D transmission: network coverage, no network coverage, and partial network coverage. In a scenario with network coverage, the UE obtains a synchronization reference by using a method similar to the LTE system by using a downlink synchronization signal sent by the base station. In the scenario where there is no network coverage, in order for neighboring UEs to use the same transmission timing for orthogonal resource multiplexing, some UEs will become cluster head UEs, providing synchronization reference for neighboring UEs, so that UEs in one cluster use the same The synchronization reference sends a D2D signal.

However, there is no method for determining the cluster head in the prior art. In the case where the current cluster head suddenly stops working, it is necessary to determine a new cluster head to continue to provide the synchronization reference.

Summary of the invention

The embodiment of the present application provides a cluster head determining method and a user equipment, where the UE searches for a cluster head and determines whether it is a cluster head. In particular, if the current cluster head suddenly stops working, a new cluster head can be determined. Continue to provide a synchronization reference.

A method for determining a cluster head according to an embodiment of the present application includes:

When the user equipment UE needs to determine a cluster head, the UE determines a search time length for searching for a cluster head dedicated signal, wherein the cluster head dedicated signal is a signal for identifying a cluster head;

The UE searches for a cluster head dedicated signal within a determined search time length;

When no cluster head dedicated signal is searched within the determined search time length, the UE determines itself to be a cluster head.

In this way, the UE determines a search time length, and according to the cluster head dedicated signal search result within the search time length, determines whether it becomes a cluster head, and realizes the cluster head determination, and thus can be in the case that the current cluster head suddenly stops working, Make sure a new cluster head continues to provide a synchronization reference.

Preferably, the UE determines the length of the search time for searching for the cluster head dedicated signal, including:

The UE determines the length of the search time according to its own UE type or UE level; or

The UE determines the length of the search time according to the received strength of the cluster head dedicated signal sent by the original cluster head; or

The UE determines a search time length range, and determines its own search within the search time length according to a preset rule. Cable length.

In this way, the UE can determine a search time length by using a plurality of preset rules.

Preferably, the UE determines the length of the search time according to its own UE type or UE level, including:

The UE uses a search time length pre-configured in the device; or

The UE receives the search time length configuration information on the network side, and determines the search time length according to the information; or

Determining the corresponding UE priority according to the UE type of the UE, and determining the length of the search time according to the determined UE priority and the corresponding relationship between the preset UE priority and the search time length; or

The UE determines the length of the search time according to the UE type and the corresponding relationship between the preset UE type and the search time length; or

The UE determines the length of the search time according to its own UE level and the corresponding relationship between the preset UE level and the search time length.

In this way, the UE may determine the length of the search time according to its own UE type or UE level by using multiple preset rules.

Preferably, the UE determines the length of the search time according to the received strength of the cluster head dedicated signal sent by the original cluster head, including:

The UE determines the received strength of the cluster head dedicated signal sent by the original cluster head, and the UE determines the corresponding search time length according to the received strength and the corresponding relationship between the received intensity of the cluster head dedicated signal and the search time length.

In this way, the UE can use the preset correspondence between the received strength of the cluster head dedicated signal and the search time length to determine the search time length according to the received strength of the cluster head dedicated signal sent by the original cluster head.

Preferably, the UE determines the length of the search time length, and determines the length of the search time in the search time length according to the preset rule, including:

The UE determines the search time length range according to the UE type and the corresponding relationship between the preset UE type and the search time length range, or the UE determines the search time according to the UE level and the corresponding UE level and the search time length range. Length range; the UE determines the search time length in a random selection manner within a determined search time length, or the UE according to the preset UE parameter and the search time length, based on the UE parameter from the determined search time length Determine the length of the search time;

Alternatively, the UE determines the search time length in a random selection manner within a predetermined length of the search time, or the UE selects a predetermined search time based on the UE parameters according to the preset UE parameters and the search time length. The length of the search time is determined within the length range.

In this way, the UE may use multiple preset rules to determine the length of the search time range, and according to various presets. The rule determines its own search time length over the length of the search time.

Preferably, after the UE determines that it is a cluster head, the method further includes:

The UE sends a cluster head dedicated signal on the agreed physical resource.

Preferably, the UE sends the cluster head dedicated signal on the agreed physical resource, including:

The UE sends part or all of the information carried by the cluster head dedicated signal sent by the original cluster head as information carried by the cluster head dedicated signal.

In this way, in the case that the current cluster head suddenly stops working, a new cluster head can be determined and the synchronization reference can be continuously provided by sending the cluster head dedicated signal to provide synchronization reference and other information for the surrounding UE, thereby solving the synchronization of the networkless scene. Transmission issues and cluster head uniqueness issues.

Preferably, the method further comprises:

When the cluster head dedicated signal is searched within the determined search time length, the UE determines that it does not become a cluster head, and obtains synchronization reference information based on the detected cluster head dedicated signal.

Preferably, the UE determines that the cluster head needs to be determined when one of the following conditions is met:

The UE starts to access a cell or a cluster;

The UE does not detect the cluster head dedicated signal on the physical resource of the cluster head dedicated signal of the original cluster head;

The UE detects a cluster head dedicated signal.

Preferably, when the UE needs to determine a cluster head, the method further includes:

The UE uses the current time as the starting time point for searching for the cluster head dedicated signal.

A user equipment UE provided by the embodiment of the present application includes:

a time length determining unit, configured to determine a search time length for searching for a cluster head dedicated signal when the cluster head needs to be determined, wherein the cluster head dedicated signal is a signal for identifying a cluster head;

a search unit, configured to search for a cluster head dedicated signal within a determined search time length;

And a determining unit, configured to determine that the UE is a cluster head when no cluster head dedicated signal is searched within the determined search time length.

In this way, the UE determines a search time length, and according to the cluster head dedicated signal search result within the search time length, determines whether it becomes a cluster head, and realizes the cluster head determination, and thus can be in the case that the current cluster head suddenly stops working, Make sure a new cluster head continues to provide a synchronization reference.

Preferably, the time length determining unit is specifically configured to:

Use the length of the search time pre-configured in the device; or

Receiving a search time length configuration information on the network side, and determining a search time length according to the information; or

Determine the length of the search time according to its own UE type or level; or,

Determining the length of the search time according to the received intensity of the cluster head dedicated signal sent by the original cluster head; or

Determining a search time length range, and determining a length of the search time within the search time length according to a preset rule.

In this way, the UE can determine a search time length by using a plurality of preset rules.

Preferably, the time length determining unit is specifically configured to:

Determining a corresponding UE priority according to the UE type of the UE, and determining a search time length according to the determined UE priority and the corresponding relationship between the preset UE priority and the search time length; or

Determining the length of the search according to the type of the UE and the corresponding relationship between the preset UE type and the length of the search time; or

The length of the search time is determined according to the UE level of the UE and the corresponding relationship between the preset UE level and the search time length.

In this way, the UE may determine the length of the search time according to its own UE type or UE level by using multiple preset rules.

Preferably, the time length determining unit is specifically configured to:

The received intensity of the cluster head dedicated signal sent by the measured original cluster head is determined, and the corresponding search time length is determined according to the received strength and the corresponding relationship between the received intensity of the cluster head dedicated signal and the search time length.

In this way, the UE can use the preset correspondence between the received strength of the cluster head dedicated signal and the search time length to determine the search time length according to the received strength of the cluster head dedicated signal sent by the original cluster head.

Preferably, the time length determining unit is specifically configured to:

Determining the search time length range according to the UE type and the corresponding relationship between the preset UE type and the search time length range, or determining the search time length range according to the UE level and the corresponding UE level and the search time length range. Determining the search time length in a random selection manner within a determined search time length range, or determining a search time length from the determined search time length range based on the UE parameter of the UE according to a preset correspondence between the preset UE parameter and the search time length ;

Or determining the length of the search time in a random selection manner within a predetermined length of the search time, or according to the preset relationship between the preset UE parameter and the search time length, based on the pre-defined search time length range based on the UE parameter of the UE. Determine the length of the search time.

In this way, the UE may determine the search time length range by using a plurality of preset rules, and determine the length of the search time within the search time length according to the preset multiple rules.

Preferably, the UE further includes:

a sending unit, configured to send a cluster head on the agreed physical resource after the determining unit determines that the UE is a cluster head Dedicated signal.

Preferably, the sending unit is specifically configured to:

Part or all of the information carried by the cluster head dedicated signal sent by the received original cluster head is transmitted as information carried by the cluster head dedicated signal.

In this way, in the case that the current cluster head suddenly stops working, a new cluster head can be determined and the synchronization reference can be continuously provided by sending the cluster head dedicated signal to provide synchronization reference and other information for the surrounding UE, thereby solving the synchronization of the networkless scene. Transmission issues and cluster head uniqueness issues.

Preferably, the determining unit is further configured to:

When the cluster head dedicated signal is searched within the determined search time length, the UE determines that it does not become a cluster head, and obtains synchronization reference information based on the detected cluster head dedicated signal.

Preferably, the time length determining unit determines that the cluster head needs to be determined when one of the following conditions is satisfied:

The UE starts to access a cell or a cluster;

The UE does not detect the cluster head dedicated signal on the physical resource of the cluster head dedicated signal of the original cluster head;

The UE detects a cluster head dedicated signal.

Preferably, the time length determining unit is further configured to: use the current time as a starting time point for searching for a cluster head dedicated signal when the cluster head needs to be determined.

DRAWINGS

1 is a schematic diagram of a data flow of UE communication in a cellular network in the background art;

2 is a schematic diagram of a data flow of UE direct connection communication in the background art;

3 is a schematic diagram of a network coverage scenario in the background art;

4 is a schematic diagram of a network coverage scenario in the background art;

5 is a schematic diagram of a partial network coverage scenario in the background art;

FIG. 6 is a schematic flowchart diagram of a method for determining a cluster head according to an embodiment of the present application;

FIG. 7 is a schematic structural diagram of a UE according to an embodiment of the present disclosure;

FIG. 8 is a schematic structural diagram of another UE according to an embodiment of the present disclosure.

detailed description

An embodiment of the present application provides a cluster head determining method and a user equipment, which are used to implement cluster head determination on a user equipment side. Specifically, the UE determines a search time length according to certain agreed rules, according to a cluster within a search time length. Head-specific signal search result, judging whether it is a cluster head to send a cluster head dedicated signal, providing a synchronization reference for surrounding UEs Other information enables a UE in a cluster to achieve synchronous transmission, thereby solving the problem of synchronous transmission and cluster head uniqueness in a network-free scene.

A detailed description of the technical solutions provided by the embodiments of the present application is given below.

The cluster head determining method provided by the embodiment of the present application includes three steps:

Step 1: When the UE needs to determine the cluster head, the UE uses one of the following methods to determine the search time length for searching for the cluster head dedicated signal.

Method 1: The UE determines the length of the search according to its own UE type or UE level.

The UE determines the corresponding UE priority according to the UE type of the UE, and determines the search time length according to the determined UE priority and the corresponding relationship between the preset UE priority and the search time length. For example, the higher the priority corresponding to the UE type, the shorter the search time length.

Alternatively, the UE determines the length of the search time according to the UE type of the UE and the corresponding relationship between the preset UE type and the search time length. For example, the search time length corresponding to the UE type one is T1, and the search time length corresponding to the UE type two is T2.

Alternatively, the UE determines the length of the search time according to its own UE level and the corresponding relationship between the preset UE level and the search time length.

Method 2: The UE determines the received strength of the cluster head dedicated signal sent by the original cluster head, and the UE determines the corresponding search according to the received strength and the corresponding relationship between the received strength of the cluster head dedicated signal and the search time length. length of time. For example, the measured reception intensity of the cluster head dedicated signal is quantized and corresponds to the search time length according to the quantization level, and the stronger the intensity, the shorter the search time. Based on this method, the UE closer to the original cluster head has a better chance of becoming a new cluster head, thereby reducing the influence of changing the cluster head on the cluster coverage.

Method 3: The UE determines a search time length range, and determines its own search time length within the search time length according to a preset rule.

The correspondence between the search time length range and the UE type or level may be preset (the predefined search time length range may be used instead of the corresponding relationship), and the search time length ranges corresponding to different UE types or levels are pre-agreed. That is, the UE determines the search time length range according to the UE type and the corresponding relationship between the preset UE type and the search time length range, or the UE determines the search according to the UE level and the preset UE level and the search time length range. a length of time range; the UE determines the length of the search time in a random selection manner within a determined length of the search time, or the UE according to the preset relationship between the preset UE parameters and the search time length, based on the UE parameters from the determined search time length range Determine the length of the search time. For example, the search time length corresponding to the UE type one is [0, T1], and the search time length corresponding to the UE type two is [T1, T2]. After determining the corresponding search time length range according to its own type or level, the UE determines its own search time according to certain rules. length. Specifically, the UE determines the search time length in a randomly selected manner within a determined search time length range, and the UE randomly selects one search time length among all possible search time length values in the search time length range; or, the UE according to the advance The correspondence between the agreed UE parameters and the length of the search time, and the length of the search time is determined from the determined length of the search time based on the UE parameters. The UE parameter may be the D2D ID of the UE, and the IMEI of the UE (International Mobile Equipment Identity, International mobile device identification) and other parameters. For example, the search time length t=K mod(T2-T1+1)+T1, where K is the D2D ID of the UE, and T1 and T2 are the minimum and maximum search time lengths of the determined search time length range, respectively.

Alternatively, the length of the search time of the UE is pre-agreed, and the length of the search time is determined according to a certain rule within the length of the search time, that is, the UE determines the search by using a random selection manner within a predetermined length of the search time. The length of time, or the UE determines the length of the search time from the pre-defined length of the search time according to the preset relationship between the preset UE parameters and the length of the search time, including:

The UE determines the length of the search time in a randomly selected manner within a predetermined length of the search time; specifically, the UE randomly selects a length of time among all possible time length values within the agreed search time length range; or

The UE determines the length of the search time from the pre-defined length of the search time according to the pre-agreed UE parameter and the length of the search time. The UE parameter may be the D2D ID of the UE, the IMEI of the UE, and the like. For example, the search time length t=K mod(T2-T1+1)+T1, where K is the D2D ID of the UE, and T1 and T2 are the minimum and maximum search time lengths of the agreed search time length range, respectively.

Method 4: The UE adopts a search time length pre-configured in the device;

Based on this method, the length of the search time is pre-configured in the device as a preset parameter, for example, in a UICC (Universal Integrated Circuit Card) or an ME (Mobile Equiment) of the device.

Method 5: The UE receives the search time length configuration information on the network side, and determines the search time length according to the information.

The UE may directly receive signaling on the network side to obtain search time length configuration information, and may also receive search time length configuration information of network configuration that other UEs forward through the synchronization channel.

The UE type described in the method 1 and the method 3 includes at least different types of UEs determined according to any one of the following manners:

Whether it can receive the synchronization signal or synchronization channel sent by the base station (in the case of a type, if not, it is a type, the same below);

Whether it can receive the broadcast channel sent by the base station;

Whether it can receive the synchronization signal sent by the independent cluster head;

Whether it can receive the cluster head dedicated signal;

Whether it can be synchronized with GPS (Global Positioning System);

Whether it has resource scheduling capabilities.

The UE level described in the method 1 and the method 3 includes at least the UE level determined by using any one of the following methods:

The UE level divided according to the length of the synchronization time obtained;

UE level determined according to different QoS (Quality of Service);

UE level according to D2D ID or application;

The UE level divided according to the power consumption tolerance of the UE.

The search time length may be a multiple of the period of the cluster head dedicated signal, and further, the multiple may be used as a unit for characterizing the search time length. For example, when the search time length is 1, the search time length is specifically a cluster. When the period of the header dedicated signal is 1 times and the search time length is 2, it means that the search time length is specifically twice the period of the cluster head dedicated signal, and so on.

Wherein, when one of the following conditions is met, the UE determines that the cluster head needs to be determined:

Condition 1: The UE starts to access the cell or cluster;

For example, if the UE enters a communication state or turns on a specific communication function (such as D2D) that requires a cluster head, it will start searching for a cell or a cluster. In this case, the cluster head needs to be determined first, and the UE uses the time point at this time as a search window. Starting time point. For another example, when the UE starts the search for the synchronization signal sent by other UEs, this time point is used as the starting time point of the search window.

Condition 2: The UE does not detect the cluster head dedicated signal on the physical resource of the cluster head dedicated signal of the original cluster head;

For example, the UE continuously detects the corresponding cluster head dedicated signal on the physical resource used by the cluster head dedicated signal of the original cluster head (for example, detecting on a fixed time-frequency resource in a fixed period), and the UE does not detect the cluster head in a certain period. For the dedicated signal, the cluster head needs to be re-determined, and the UE uses the time point at this time as the starting time point of the search window. At this time, the UE enters the process of searching for the cluster head dedicated signal, that is, the first step is started.

Condition 3: The UE detects the cluster head dedicated signal;

For example, after the UE completes the detection of the cluster head dedicated signal, the UE uses the current time point as the starting time point of the search window, and starts searching for the next cluster head dedicated signal of the cluster head within the search time length to determine Whether the cluster head still exists or changes.

Step 2: The UE detects the cluster head dedicated signal within the determined search time length.

The UE detects the cluster head dedicated signal on the agreed physical resource;

Before the cluster head dedicated signal is searched, the UE may still transmit and/or receive signals according to the synchronization reference obtained from the original cluster head, or may not transmit and/or receive signals.

The UE may search for all cluster head dedicated signals in the system, or may only search for cluster head dedicated signals transmitted by cluster heads of certain specific UE types. For example, the UE may only search for the cluster head dedicated signal sent by the independent cluster head, and may not search for the cluster head dedicated signal forwarded by the UE, or search for both signals; the UE may only search for clusters sent by the cluster head with resource scheduling capability. Head-specific signals, without searching for cluster head-specific signals sent by other cluster heads, can also be searched for both signals.

Step 3: The UE determines whether to become a cluster head according to the detection result, and sends a cluster head dedicated signal after determining to become a cluster head.

If the UE detects the target cluster head dedicated signal in the second step, a synchronization reference is obtained according to the detected cluster head dedicated signal.

If the UE does not detect the target cluster head dedicated signal within the search time length, it determines that it is the cluster head and transmits the cluster head dedicated signal on the agreed physical resource. Specifically, the UE may send part or all of the information carried by the cluster head dedicated signal sent by the original cluster head as information carried by the cluster head dedicated signal, or may add other information according to its own parameters.

The cluster head dedicated signal described in the embodiment of the present application is a signal for identifying a cluster head. The cluster head dedicated signal sent by the UE in the embodiment of the present application may include information such as a synchronization signal, a synchronization channel, and a broadcast channel. The synchronization signal and the synchronization channel are used to provide a synchronization reference for the receiving end. For example, the synchronization signal may be a D2DSS (Device to Device Synchronization singal), and the synchronization channel may be a PD2DSCH (Physical Device to Device Synchronization Channel)/PSBCH (Physical Sidelink Broadcast Channel). The synchronization channel or the broadcast channel may carry a subframe number, a radio frame number, cluster head UE information, bandwidth information, cluster information, and the like. The cluster head dedicated signal may be transmitted only by an independent cluster head, or may be forwarded by a specific UE that receives the cluster head dedicated signal.

Several specific embodiments are exemplified below.

Embodiment 1:

The UE starts the D2D function and determines the length of the search time, which is determined according to the UE type of the UE. For example, the correspondence between the UE type and the search time length is as follows:

UE type	Search length
		UE with scheduling capability	10ms
UE synchronized with GPS	50ms
		Other UE	100ms

Assuming that the UE is a UE synchronized with GPS, the corresponding search time length is 50 ms.

The UE detects a cluster head dedicated signal sent by the cluster head within a determined search time length, and the cluster head dedicated signal includes A synchronization signal that is sent periodically and transmitted on an agreed fixed physical resource at an agreed cycle. The UE only needs to detect whether there is a synchronization signal on the agreed bandwidth. For example, the UE traverses all possible synchronization sequences to correlate with the received signal, and determines whether a synchronization signal is present based on the correlation result.

If the UE does not detect the cluster head dedicated signal within the search time length, it determines that it is a cluster head and transmits the cluster head dedicated signal on the agreed fixed physical resource at an agreed cycle. The sequence ID used for the cluster head dedicated signal generation is determined by the UE itself.

If the UE detects a certain cluster head dedicated signal within the search time length, the synchronization reference signal is obtained according to the detected cluster head dedicated signal.

The UE always tracks the synchronization reference signal of the cluster head according to the cluster head dedicated signal as a synchronous reference for transmitting and/or receiving other signals.

Embodiment 2:

The UE receives a cluster head dedicated signal sent by a cluster head on the agreed fixed physical resource, where the cluster head dedicated signal includes a periodically transmitted synchronization signal, the period is pre-agreed, and the UE obtains a synchronization reference from the synchronization signal;

If the UE does not receive the cluster head dedicated signal sent by the cluster head at a certain time, the UE enters the following search process;

Determining the length of the search time, the length of the search time is determined according to the average received intensity of the cluster head dedicated signal of the original cluster head obtained by the measurement, and the correspondence between the receiving strength of the cluster head dedicated signal and the search time length may be pre-agreed. For example, the correspondence between the reception strength of the cluster head dedicated signal and the search time length is as follows:

Assuming that the average received strength of the cluster head dedicated signal received by the UE is between a and b, the corresponding search time length is 5 cluster head dedicated signal periods.

Among them, a, b, and k are preset numbers greater than 0.

The UE detects the cluster head dedicated signal sent by the cluster head on the agreed fixed physical resource within the determined search time length, and the UE only needs to detect whether the synchronization signal exists on the agreed bandwidth. For example, the UE traverses all possible synchronization sequences to correlate with the received signal, and determines whether a synchronization signal is present based on the correlation result.

If the UE does not detect the cluster head dedicated signal within the search time length, it determines that it becomes a cluster head and transmits the cluster head dedicated signal on the agreed fixed physical resource at an agreed cycle. The cluster head dedicated signal is also a synchronization signal, which is identical to the cluster head dedicated signal transmitted by the original cluster head (including the time-frequency resources used).

If the UE detects a cluster head dedicated signal (possibly the same signal as the previously received cluster head dedicated signal, or may be another cluster head dedicated signal sent by another cluster head) within the length of the search time, then The detected cluster head dedicated signal obtains a synchronous reference signal.

The UE performs transmission and reception of other signals according to the newly obtained synchronization reference signal.

Embodiment 3:

The UE receives a cluster head dedicated signal sent by a cluster head on the agreed fixed physical resource, where the cluster head dedicated signal includes a periodically transmitted synchronization signal and a synchronization channel, the cycle is pre-agreed, and the UE synchronizes the signal and the synchronization channel. Get a synchronization reference. The synchronization signal includes a synchronization sequence, and the synchronization channel includes a radio frame number.

The UE does not receive the cluster head dedicated signal sent by the cluster head at a certain time, and then enters the following search process:

The UE determines the length of the search time according to the agreed length of the search time. Specifically, the UE determines the search time length in a randomly selected manner within a predetermined search time length range. For example, if the agreed search time length ranges from 1 to 50 cluster head dedicated signal periods, the UE randomly selects a value from 1-50 to determine the search time length in units of cluster head dedicated signal periods;

The UE detects the cluster head dedicated signal transmitted by the cluster head on the agreed fixed physical resource within the determined search time length. The UE first detects whether a synchronization signal exists on the agreed bandwidth. For example, the UE traverses all possible synchronization sequences to correlate with the received signal, and determines whether a synchronization signal is present based on the correlation result. If there is a synchronization signal, the corresponding synchronization channel of the synchronization signal is detected according to a fixed resource mapping relationship. If the synchronization signal and the corresponding synchronization channel are detected, it is considered that the cluster head dedicated signal is detected, otherwise it is not detected.

If the UE does not detect the cluster head dedicated signal within the search time length, it determines that it becomes a cluster head and transmits the cluster head dedicated signal on the agreed fixed physical resource at an agreed cycle. The cluster head dedicated signal also includes a synchronization signal and a synchronization channel, wherein the synchronization signal is the same as the previously received synchronization signal transmitted by the cluster head, but the radio frame number in the synchronization channel is determined according to the UE's own timing.

If the UE detects a cluster head dedicated signal (possibly the same signal as the previously received cluster head dedicated signal, or may be another cluster head dedicated signal sent by another cluster head) within the length of the search time, then The detected cluster head dedicated signal obtains a synchronous reference.

In summary, referring to FIG. 6, a method for determining a cluster head according to an embodiment of the present application includes:

S101. When the user equipment UE needs to determine a cluster head, the UE determines a search time length for searching for a cluster head dedicated signal, where the cluster head dedicated signal is a signal for identifying a cluster head;

S102. The UE searches for a cluster head dedicated signal within a determined search time length.

S103. When no cluster head dedicated signal is searched within the determined search time length, the UE determines that it is a cluster head.

Referring to FIG. 7, a user equipment UE provided by an embodiment of the present application includes:

The time length determining unit 11 is configured to determine a search time length for searching for a cluster head dedicated signal when the cluster head needs to be determined, wherein the cluster head dedicated signal is a signal for identifying a cluster head;

a searching unit 12, configured to search for a cluster head dedicated signal within a determined search time length;

The determining unit 13 is configured to determine that the UE is a cluster head when no cluster head dedicated signal is searched within the determined search time length.

Preferably, the time length determining unit 11, the search unit 12, and the determining unit 13 may be devices such as a processor.

Preferably, the UE further includes:

The sending unit 14 is configured to send a cluster head dedicated signal on the agreed physical resource after the determining unit determines that the UE is a cluster head.

Preferably, the transmitting unit 14 can be a device such as a transmitter.

Referring to FIG. 8, another UE provided by the embodiment of the present application includes:

The processor 801 is configured to read a program in the memory 804 and perform the following process:

Determining a search time length for searching for a cluster head dedicated signal when the cluster head needs to be determined, wherein the cluster head dedicated signal is a signal for identifying a cluster head; searching for a cluster head dedicated signal within a determined search time length; When the cluster head dedicated signal is not searched within the determined search time length, the UE is determined to be a cluster head.

The transceiver 802 is configured to receive and transmit data under the control of the processor 801.

Preferably, the processor 801 is specifically configured to:

Use the length of the search time pre-configured in the device; or

Receiving a search time length configuration information on the network side, and determining a search time length according to the information; or

Determine the length of the search time according to its own UE type or level; or,

Determining the length of the search time according to the received intensity of the cluster head dedicated signal sent by the original cluster head; or

Determining a search time length range, and determining a length of the search time within the search time length according to a preset rule.

Preferably, the processor 801 is specifically configured to:

Determining a corresponding UE priority according to the UE type of the UE, and determining a search time length according to the determined UE priority and the corresponding relationship between the preset UE priority and the search time length; or

Determining the search time according to the UE type of the UE and the corresponding relationship between the preset UE type and the search time length Length; or,

The length of the search time is determined according to the UE level of the UE and the corresponding relationship between the preset UE level and the search time length.

Preferably, the processor 801 is specifically configured to:

The received intensity of the cluster head dedicated signal sent by the measured original cluster head is determined, and the corresponding search time length is determined according to the received strength and the corresponding relationship between the received intensity of the cluster head dedicated signal and the search time length.

Preferably, the processor 801 is specifically configured to:

Determining the search time length range according to the UE type and the corresponding relationship between the preset UE type and the search time length range, or determining the search time length range according to the UE level and the corresponding UE level and the search time length range. Determining the search time length in a random selection manner within a determined search time length range, or determining a search time length from the determined search time length range based on the UE parameter of the UE according to a preset correspondence between the preset UE parameter and the search time length ;

Or determining the length of the search time in a random selection manner within a predetermined length of the search time, or according to the preset relationship between the preset UE parameter and the search time length, based on the pre-defined search time length range based on the UE parameter of the UE. Determine the length of the search time.

Preferably, the UE type includes at least different types of UEs determined by one of the following ways:

Whether it can receive the synchronization signal or synchronization channel sent by the base station;

Whether it can receive the broadcast channel sent by the base station;

Whether it can receive the synchronization signal sent by the independent cluster head;

Whether it can receive the cluster head dedicated signal;

Whether it can be synchronized with GPS GPS;

Whether it has resource scheduling capabilities.

Preferably, the UE level includes at least a UE level determined by one of the following methods:

The UE level divided according to the length of the synchronization time obtained;

UE level determined according to different quality of service QoS;

The UE level divided according to the inter-device identification D2D ID or application;

The UE level divided according to the power consumption tolerance of the UE.

Preferably, the processor 801 is specifically configured to:

Search all cluster head specific signals in the system; or

Only the cluster head dedicated signals sent by the cluster head of a specific UE type are searched.

Preferably, the processor 801 is further configured to:

After the determining unit determines that the UE is a cluster head, the cluster head dedicated signal is transmitted by the transceiver 802 on the agreed physical resource.

Preferably, the processor 801 is specifically configured to:

Part or all of the information carried by the cluster head dedicated signal transmitted by the original cluster head received by the transceiver 802 is transmitted as information carried by the cluster head dedicated signal.

Preferably, the processor 801 is further configured to:

When the cluster head dedicated signal is searched within the determined search time length, the UE determines that it does not become a cluster head, and obtains synchronization reference information based on the detected cluster head dedicated signal.

Preferably, the time length determining unit determines that the cluster head needs to be determined when one of the following conditions is satisfied:

The UE starts to access a cell or a cluster;

The UE does not detect the cluster head dedicated signal on the physical resource of the cluster head dedicated signal of the original cluster head;

The UE detects a cluster head dedicated signal.

Preferably, the time length determining unit is further configured to: use the current time as a starting time point for searching for a cluster head dedicated signal when the cluster head needs to be determined.

In FIG. 8, a bus architecture (represented by bus 800), bus 800 may include any number of interconnected buses and bridges, and bus 800 will include one or more processors and memory 804 represented by general purpose processor 801. The various circuits of the memory are linked together. The bus 800 can also link various other circuits, such as peripherals, voltage regulators, and power management circuits, as is known in the art, and therefore, will not be further described herein. Bus interface 803 provides an interface between bus 800 and transceiver 802. Transceiver 802 can be an element or a plurality of elements, such as multiple receivers and transmitters, providing means for communicating with various other devices on a transmission medium. For example, transceiver 802 receives external data from other devices. The transceiver 802 is configured to send the processed data of the processor 801 to other devices. Depending on the nature of the computing system, a user interface 805 can also be provided, such as a keypad, display, speaker, microphone, joystick.

The processor 801 is responsible for managing the bus 800 and the usual processing, running the general purpose operating system as described above. The memory 804 can be used to store data used by the processor 801 when performing operations.

Optionally, the processor 801 may be a CPU (Central Embedded Device), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a CPLD (Complex Programmable Logic Device). , complex programmable logic devices).

In summary, the present application introduces a cluster head determination method. The UE determines a search time length according to certain agreed rules, and determines whether to become a cluster head to send a cluster according to a cluster head dedicated signal search result within a search time length. Head-specific signal, providing synchronization reference and other information for surrounding UEs, thus solving synchronous transmission and clusters without network scenes Head uniqueness issue.

With this scheme, even if the original cluster head in the cluster suddenly stops working, a new cluster head can be generated within a certain time, thereby ensuring that the UEs in the cluster are mutually synchronized, and the UE type with higher rank can also be preferentially become the cluster head. Moreover, the cluster head obtained by this method is generally unique, avoiding the case where multiple UEs simultaneously become cluster heads and interfere with each other.

It will be apparent to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit and scope of the application. Thus, it is intended that the present invention cover the modifications and variations of the present invention.

Claims (26)

1. A cluster head determining method, the method comprising:

   When the user equipment UE needs to determine a cluster head, the UE determines a search time length for searching for a cluster head dedicated signal, wherein the cluster head dedicated signal is a signal for identifying a cluster head;

   The UE searches for a cluster head dedicated signal within a determined search time length;

   When no cluster head dedicated signal is searched within the determined search time length, the UE determines itself to be a cluster head.
2. The method according to claim 1, wherein the UE determines a search time length for searching for a cluster head dedicated signal, comprising:

   The UE adopts a search time length pre-configured in the device; or

   Receiving, by the UE, search time length configuration information on the network side, and determining a search time length according to the information; or

   Determining, by the UE, a search time length according to its own UE type or UE level; or

   Determining, by the UE, the length of the search time according to the received strength of the cluster head dedicated signal sent by the original cluster head; or

   The UE determines a search time length range, and determines its own search time length within the search time length range according to a preset rule.
3. The method according to claim 2, wherein the UE determines the length of the search according to the UE type or the UE level, including:

   Determining, according to the UE type of the UE, the corresponding UE priority, and determining the length of the search time according to the determined UE priority and the corresponding relationship between the preset UE priority and the search time length; or

   Determining, by the UE, the length of the search according to the type of the UE and the corresponding relationship between the preset UE type and the length of the search time; or

   The UE determines the length of the search according to its own UE level and the corresponding relationship between the preset UE level and the search time length.
4. The method according to claim 2, wherein the UE determines the length of the search time according to the received strength of the cluster head dedicated signal sent by the original cluster head, including:

   Determining, by the UE, the received strength of the cluster head dedicated signal sent by the original cluster head, and determining the corresponding search time according to the received strength and the corresponding relationship between the received intensity of the cluster head dedicated signal and the search time length. length.
5. The method according to claim 2, wherein the UE determines a search time length range, and determines its own search time length within the search time length according to a preset rule, including:

   The UE determines the search time length range according to the UE type and the corresponding relationship between the preset UE type and the search time length range, or determines the search according to the UE level and the preset UE level and the search time length range. a length of time range; and determining a length of the search time in a random selection manner within a determined length of the search time, or a UE according to a preset relationship between the preset UE parameters and the search time length, based on the UE parameters from the determined search time length range Determine the length of the search time;

   Alternatively, the UE determines the search time length in a random selection manner within a predetermined length of the search time, or the UE according to the preset UE parameter and the search time length, based on the UE parameters of the UE. The length of the search time is determined within the length of the search time.
6. The method according to claim 2, 3 or 5, wherein the UE type comprises at least different types of UEs determined by one of the following ways:

   Whether it can receive the synchronization signal or synchronization channel sent by the base station;

   Whether it can receive the broadcast channel sent by the base station;

   Whether it can receive the synchronization signal sent by the independent cluster head;

   Whether it can receive the cluster head dedicated signal;

   Whether it can be synchronized with GPS GPS;

   Whether it has resource scheduling capabilities.
7. The method according to claim 2, 3 or 5, wherein the UE level comprises at least a UE level determined by one of the following ways:

   The UE level divided according to the length of the synchronization time obtained;

   UE level determined according to different quality of service QoS;

   The UE level divided according to the inter-device identification D2D ID or application;

   The UE level divided according to the power consumption tolerance of the UE.
8. The method according to claim 1, wherein the UE searches for a cluster head dedicated signal within a determined length of search time, including:

   The UE searches for all cluster head dedicated signals in the system; or

   The UE only searches for cluster head dedicated signals transmitted by cluster heads of a specific UE type.
9. The method according to claim 1, wherein after the UE determines that it is a cluster head, the method further includes:

   The UE sends a cluster head dedicated signal on the agreed physical resource.
10. The method according to claim 9, wherein the UE sends a cluster head dedicated signal on the agreed physical resource, including:

    The UE sends part or all of the information carried by the cluster head dedicated signal sent by the original cluster head as information carried by the cluster head dedicated signal.
11. The method of claim 1 further comprising:

    When a cluster head dedicated signal is searched within the determined search time length, the UE determines that it does not become a cluster head, and obtains synchronization reference information based on the detected cluster head dedicated signal.
12. The method of claim 1 wherein the UE determines that a cluster head needs to be determined when one of the following conditions is met:

    The UE starts to access a cell or a cluster;

    The UE does not detect the cluster head dedicated signal on the physical resource of the cluster head dedicated signal of the original cluster head;

    The UE detects a cluster head dedicated signal.
13. The method according to claim 1, wherein when the UE needs to determine a cluster head, the method further comprises:

    The UE uses the current time as the starting time point for searching for the cluster head dedicated signal.
14. A user equipment UE, characterized in that the UE includes:

    a time length determining unit, configured to determine a search time length for searching for a cluster head dedicated signal when the cluster head needs to be determined, wherein the cluster head dedicated signal is a signal for identifying a cluster head;

    a search unit, configured to search for a cluster head dedicated signal within a determined search time length;

    And a determining unit, configured to determine that the UE is a cluster head when no cluster head dedicated signal is searched within the determined search time length.
15. The UE according to claim 14, wherein the time length determining unit is specifically configured to:

    Use the length of the search time pre-configured in the device; or

    Receiving a search time length configuration information on the network side, and determining a search time length according to the information; or

    Determine the length of the search time according to its own UE type or level; or,

    Determining the length of the search time according to the received intensity of the cluster head dedicated signal sent by the original cluster head; or

    Determining a search time length range, and determining a length of the search time within the search time length according to a preset rule.
16. The UE according to claim 15, wherein the time length determining unit is specifically configured to:

    Determining a corresponding UE priority according to the UE type of the UE, and determining a search time length according to the determined UE priority and the corresponding relationship between the preset UE priority and the search time length; or

    Determining the length of the search according to the type of the UE and the corresponding relationship between the preset UE type and the length of the search time; or

    The length of the search time is determined according to the UE level of the UE and the corresponding relationship between the preset UE level and the search time length.
17. The UE according to claim 15, wherein the time length determining unit is specifically configured to:

    The received intensity of the cluster head dedicated signal sent by the measured original cluster head is determined, and the corresponding search time length is determined according to the received strength and the corresponding relationship between the received intensity of the cluster head dedicated signal and the search time length.
18. The UE according to claim 15, wherein the time length determining unit is specifically configured to:

    Determining the search time length range according to the UE type and the corresponding relationship between the preset UE type and the search time length range, or determining the search time length range according to the UE level and the corresponding UE level and the search time length range. Determining the search time length in a random selection manner within a determined search time length range, or determining a search time length from the determined search time length range based on the UE parameter of the UE according to a preset correspondence between the preset UE parameter and the search time length ;

    Or determining the length of the search time in a random selection manner within a predetermined length of the search time, or according to the preset relationship between the preset UE parameter and the search time length, based on the pre-defined search time length range based on the UE parameter of the UE. Determine the length of the search time.
19. The UE according to claim 15, 16 or 18, wherein the UE type comprises at least different types of UEs determined by one of the following ways:

    Whether it can receive the synchronization signal or synchronization channel sent by the base station;

    Whether it can receive the broadcast channel sent by the base station;

    Whether it can receive the synchronization signal sent by the independent cluster head;

    Whether it can receive the cluster head dedicated signal;

    Whether it can be synchronized with GPS GPS;

    Whether it has resource scheduling capabilities.
20. The UE according to claim 15, 16 or 18, wherein the UE level comprises at least a UE level determined by one of the following ways:

    The UE level divided according to the length of the synchronization time obtained;

    UE level determined according to different quality of service QoS;

    The UE level divided according to the inter-device identification D2D ID or application;

    The UE level divided according to the power consumption tolerance of the UE.
21. The UE according to claim 14, wherein the searching unit is specifically configured to:

    Search all cluster head specific signals in the system; or

    Only the cluster head dedicated signals sent by the cluster head of a specific UE type are searched.
22. The UE according to claim 14, wherein the UE further comprises:

    And a sending unit, configured to send a cluster head dedicated signal on the agreed physical resource after the determining unit determines that the UE is a cluster head.
23. The UE according to claim 22, wherein the sending unit is specifically configured to:

    Part or all of the information carried by the cluster head dedicated signal sent by the received original cluster head is transmitted as information carried by the cluster head dedicated signal.
24. The UE according to claim 14, wherein the determining unit is further configured to:

    When the cluster head dedicated signal is searched within the determined search time length, the UE determines that it does not become a cluster head, and obtains synchronization reference information based on the detected cluster head dedicated signal.
25. The UE according to claim 14, wherein the time length determining unit determines that the cluster head needs to be determined when one of the following conditions is satisfied:

    The UE starts to access a cell or a cluster;

    The UE does not detect the cluster head dedicated signal on the physical resource of the cluster head dedicated signal of the original cluster head;

    The UE detects a cluster head dedicated signal.
26. The UE according to claim 14, wherein the time length determining unit is further configured to: use the current time as a starting time point for searching for a cluster head dedicated signal when the cluster head needs to be determined.

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