CN104812057A

CN104812057A - Data transmission method and device of D2D system

Info

Publication number: CN104812057A
Application number: CN201410260944.2A
Authority: CN
Inventors: 赵铮; 李迎阳; 张世昌
Original assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Current assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Priority date: 2014-01-29
Filing date: 2014-06-12
Publication date: 2015-07-29

Abstract

The invention discloses a data transmission method of a D2D system. The method comprises that synchronous detection is carried out on D2D UE; according to synchronous source information detected by the D2D UE, parameters of sequence and/or scrambling code initial value employed in subsequent D2D signal transmission are obtained, and D2D signals are sent correspondingly; and the D2D UE determines parameters of D2D signal sequence and/or D2D signal scrambling code initial value according to the synchronous source information detected by the D2D UE, and further detects D2D signals sent by other D2D UE. According to the method of the invention, interference of D2D transmission among D2D UE is randomized, the range of D2D UE of mutual discovery is ensured, and the detection complexity is reduced.

Description

Method and equipment for data transmission in D2D system

Technical Field

The present application relates to the field of mobile communication technologies, and in particular, to a method for generating a sequence and a scrambling code initial value of a D2D signal in a D2D system, and a user equipment.

Background

In a Long Term Evolution (LTE) system, DMRS (demodulation reference signal) is used for demodulation of a reference signal, and in an LTE uplink, the DMRS of each UE is transmitted within a transmission bandwidth of the UE. DMRS sequence generation for each UE is related to cell ID, and DMRS signals of different cells have low cross-correlation, thereby reducing interference from RSs transmitted on the same resource in other cells. DMRS sequence generation is also related to transmitting DMRS slot sequence numbers and cyclic shift parameters, which are reasonably allocated such that DMRSs are orthogonal between UEs.

D2D (Device-to-Device) communication is a new technology that allows Users (UE) to communicate directly by multiplexing cell resources under the control of the system, and it can increase the spectrum efficiency of the cellular communication system, reduce the terminal transmission power, and solve the problem of the lack of spectrum resources of the wireless communication system to some extent. One issue when conducting D2D communication is how to determine the sequence employed by the DMRS. The signals transmitted by the D2D UEs may not be centrally controlled by the base station (eNB), but rather are actively initiated by the UEs, e.g., when the UE transmitting the D2D signal is not covered by any cell, the signals transmitted by the D2D UEs cannot be centrally controlled by the eNB. This results in that the DMRS sequence generation parameters for D2D communication may not be centrally allocated by the base station. The application provides a method for generating the DMRS aiming at the requirement of D2D.

In a communication system, interference bits are scrambled with a random sequence, and although scrambling does not reduce the interference energy, interference can be randomized to "white noise" by scrambling an interference signal, thereby suppressing interference. In the D2D system, before information interaction is directly performed between users, each user needs to send a Discovery signal (Discovery signal) so that the surrounding users who can detect the signal can discover the existence of the user. However, there is currently no method for scrambling D2D discovery and transmission signals and generating DMRS sequences to reduce interference in D2D communications.

Disclosure of Invention

The application provides a method and equipment for data transmission in a D2D system, which can reduce the interference between sequences of D2D UE and D2D signals.

A method of data transmission in a D2D system, comprising:

A. the D2D UE detects the signal of the synchronization source, and for any D2D signal transmission, completes the synchronization process according to one of the detected synchronization sources;

B. determining parameters of a sequence and/or scrambling code initial value adopted when the D2D signal is transmitted by the D2D UE according to the detected information of the synchronization source; generating the sequence and/or the scrambling code initial value according to the determined parameters, and sending or detecting a corresponding D2D signal; the D2D signal refers to a physical D2D synchronization channel, a D2D data transmission signal, and/or a D2D discovery signal, the D2D data transmission signal including a D2D data control signal and/or a D2D data communication signal.

Preferably, the parameters of the sequence and/or scrambling code initial value determined according to the information of the synchronization source in step B are: parameters of sequence and/or scrambling code initial values adopted when transmitting physical D2D synchronization channel signals, D2D discovery signals and/or D2D data control signals;

the step B further comprises the following steps: according to the information in the physical D2D synchronous channel signal, the D2D discovery signal and/or the D2D data control signal, determining the parameters of the sequence and/or the scrambling code initial value adopted when the D2D data communication signal is transmitted, generating corresponding parameters, and then transmitting or detecting the D2D data communication signal.

Preferably, one scrambling code is selected from the preset N scrambling codes or is used as the scrambling code when the physical D2D synchronization channel signal, the D2D discovery signal and/or the D2D data control signal are transmitted according to the information of the synchronization source; and/or the presence of a gas in the gas,

and B, determining the parameters of the sequence and/or the initial value of the scrambling code adopted when the D2D data communication signal is transmitted according to the ID carried by the scheduling assignment included in the D2D data control signal.

Preferably, the D2D UE prohibits group hopping and sequence hopping when generating DMRS or scrambling code initial values; and/or the presence of a gas in the gas,

when the D2D UE generates the scrambling code, setting the sequence number of the subframe or the time slot as a fixed value; and/or the presence of a gas in the gas,

determining the offset of the subframe or the time slot for transmitting the D2D signal relative to a reference subframe or time slot as a subframe or time slot sequence number when the sequence or the scrambling code is generated; and/or the presence of a gas in the gas,

and if the D2D signal transmission adopts a TTI bundling mode, determining the sequence numbers of the sub-frames or the time slots of the D2D signals in all the sub-frames or the time slots of one-time TTI bundling scheduling to be the sub-frames or the time slots used for generating the sequence or the scrambling code.

Preferably, the reference subframe or slot is: a subframe or a slot for transmitting a synchronization signal, or a first subframe or a first slot in a scheduling allocation configuration period.

Preferably, the sequence number of the subframe for transmitting the D2D signal in a set of subframes for actually transmitting the D2D signal is determined as the subframe or slot sequence number when the sequence or scrambling code is generated.

A method of data transmission in a D2D system, comprising:

E. D2D UE carries out synchronous detection and acquires cluster ID;

F. D2D UE determines the parameters of the sequence and/or the scrambling code initial value adopted when the D2D signal is transmitted according to the acquired cluster ID; generating the sequence and/or the initial value of the scrambling code according to the determined parameters, and sending or detecting a corresponding D2D signal; the D2D signal refers to a physical D2D synchronization channel signal, a D2D data transmission signal, and/or a D2D discovery signal, the D2D data transmission signal including a D2D data control signal and/or a D2D data communication signal.

Preferably, when the cluster ID is a scheduling assignment ID, if the D2D UE does not have base station assistance, the manner for the D2D UE to obtain the cluster ID is as follows: the D2D UE selects one SA middle ID in the common scheduling assignment SA middle ID set as the cluster ID.

Preferably, when the D2D UE receives multiple cluster ID information in step E, step F determines the sequence and/or scrambling code initial value of the D2D signal according to different cluster IDs or the same cluster ID on different subframes; wherein the correspondence between the sub-frame and the cluster ID is determined or predefined by the D2D UE.

Preferably, the parameters of the sequence and/or scrambling code initial value determined according to the cluster ID in step F are: parameters of discovery sequence and/or scrambling code initial values adopted when transmitting the D2D data communication signals;

the scrambling code employed in transmitting the physical D2D synchronization channel signal, the D2D discovery signal, and/or the D2D data control signal is set to a constant.

Preferably, the cluster ID is an ID in SA;

the D2D UE generates a DMRS sequence for transmitting the D2D signal according to the ID in the SA, wherein the DMRS sequence comprises a root sequence and a cyclic shift.

Preferably, each value of the ID in the SA is used for corresponding delta used for generating the root sequence_ssDifferent values of (a); and/or the presence of a gas in the gas,

utilizing a number of bits occupied by an ID in the SA to correspond to indicate a delta for generating the root sequence_ssDifferent values of (a); and/or the presence of a gas in the gas,

using the result of the modulus of the ID in the SA according to a set value as delta for generating the root sequence_ss(ii) a And/or the presence of a gas in the gas,

utilizing each value of the ID in the SA to correspond to different values of the cyclic shift; and/or the presence of a gas in the gas,

correspondingly indicating different values of the cyclic shift by using a plurality of bits occupied by the ID in the SA; and/or the presence of a gas in the gas,

taking the result of modulus taking of the ID in the SA according to a set value as the value of the cyclic shift; and/or the presence of a gas in the gas,

setting the value of the cyclic shift as a fixed value.

Preferably, the cyclic shift is α defined in 3GPP TS36.211, or the cyclic shift is cyclic shift signaling notified by higher layer and physical layer signalingAnd

preferably, the DMRS sequence further comprises an orthogonal mask OCC;

and randomly selecting or determining the serial number of the OCC according to the ID in the SA.

A method of data transmission in a D2D system, comprising:

D2D UE randomly selects, or determines the cyclic shift parameter alpha and/or sequence group number u related parameter for generating DMRS according to the parameter or base station signaling configuration; and generating the DMRS used when the D2D signal is transmitted according to the determined alpha and/or sequence group number u related parameters.

Preferably, the D2D UE prohibits group hopping and sequence hopping when generating the DMRS.

A method of data transmission in a D2D system, comprising:

D2D UE detects the synchronization source, receives the broadcast information of eNB or D2D UE;

and the D2D UE determines parameters of a D2D signal sequence, a DMRS sequence and a D2D signal scrambling code initial value according to the received broadcast information, generates a sequence and a scrambling code initial value adopted when the D2D signal is transmitted, and sends or detects the corresponding D2D signal.

An apparatus for data transmission in a D2D system, comprising: a synchronization unit, a sequence and scrambling code initial value generation unit and a D2D signal processing unit;

the synchronization unit is used for detecting signals of synchronization sources and completing a synchronization process according to one of the detected synchronization sources for any D2D signal transmission;

the sequence and scrambling code initial value generating unit is used for determining the parameters of the sequence and/or scrambling code initial value adopted when the D2D signal is transmitted according to the synchronization source information detected by the synchronization unit; generating the sequence and/or the scrambling code initial value according to the determined parameters;

the D2D signal processing unit is used for transmitting or detecting a corresponding D2D signal according to the generated sequence and/or the scrambling code initial value; wherein the D2D signal refers to a D2D data transmission signal, and/or a D2D discovery signal.

the synchronization unit is used for carrying out synchronization detection and acquiring a cluster ID;

the sequence and scrambling code initial value generating unit is used for determining the parameters of the sequence and/or scrambling code initial value adopted when the D2D signal is transmitted according to the acquired cluster ID, and generating the sequence and/or scrambling code initial value according to the determined parameters;

the synchronization unit is used for detecting a synchronization source and receiving broadcast information of an eNB or a D2D UE;

the sequence and scrambling code initial value generating unit is used for determining parameters of a D2D signal sequence, a DMRS sequence and a D2D signal scrambling code initial value according to the broadcast information and generating a sequence and a scrambling code initial value adopted when a D2D signal is transmitted;

and the D2D signal processing unit is used for sending or detecting a corresponding D2D signal according to the determined sequence and the scrambling code initial value.

According to the technical scheme, the method for generating the sequence and the D2D signal scrambling code initial value is provided in the data transmission method and the data transmission equipment of the D2D system, so that the interference of D2D transmission between D2D UE can be randomized, the range of D2D UE which are mutually discovered is ensured, and the detection complexity is reduced.

Drawings

Fig. 1 is a general flowchart of a method for data transmission in a first D2D system according to the present application;

fig. 2 is a general flowchart of a method for data transmission in a second D2D system according to the present application;

FIG. 3 is a flowchart of a method according to a first embodiment of the present application;

FIG. 4 is a flowchart of a method according to a second embodiment of the present application;

FIG. 5 is a flowchart of a method according to a third embodiment of the present application;

fig. 6 is a flowchart of a method for data transmission in the third D2D system.

Detailed Description

For the purpose of making the objects, technical means and advantages of the present application more apparent, the present application will be described in further detail with reference to the accompanying drawings.

In the LTE D2D system, the D2D UE may first establish synchronization based on a synchronization source, where the synchronization source Signal may be a D2D synchronization Signal (D2D synchronization Signal), a Physical D2D synchronization Channel (Physical D2D synchronization Channel) sent by the D2D UE, a synchronization Signal sent by an eNB, a preamble sequence (preamble) sent by the D2D UE, or a Demodulation reference Signal (DMRS); then, based on this synchronization relationship, the D2D UE may transmit a subsequent D2D signal. For example, the subsequent D2D signal may be a physical D2D synchronization channel, a D2D discovery signal, or a signal for D2D data transmission, etc. The physical D2D synchronization channel may be composed of DMRS and a synchronization channel data portion, or may be demodulated using a D2D synchronization signal, so that the physical D2D synchronization channel only has the synchronization channel data portion; the D2D discovery signal may be composed of a Sequence (Sequence) and a Message (Message). The sequence (hereinafter referred to as a discovery sequence) may refer to a DMRS used for demodulating a message part, or may be a sequence independent of the DMRS, such as a preamble sequence; the signals for D2D data transmission may include two types, one is a D2D data control signal, also called Scheduling Assignment (SA), including signals for D2D data control channel and/or DMRS, and the other is a D2D data communication signal, including signals for DMRS and D2D data communication channel. The D2D data transmission may be broadcast (broadcast) or unicast (unicast). Here, assuming that the D2D UE has established synchronization based on the synchronization source, the present application proposes a method of handling subsequent D2D signal transmissions.

As described above, in the D2D transmission, after the D2D UE receives the synchronization source signal to establish synchronization, the D2D UE may further complete the discovery process or perform D2D data transmission. The application provides a method for generating the scrambling code/sequence of the D2DUE when the D2D signal is transmitted. Here, for the D2D discovery signal, it is necessary to determine the discovery sequence (e.g., preamble sequence) to be used by the D2D UE, the DMRS sequence (when the discovery sequence is a DMRS independent sequence) and the scrambling code of the discovery signal message part, wherein the discovery signal scrambling code may be used for scrambling of the discovery sequence and discovery signal message part information bits. For D2D data transmission, DMRS sequences for data demodulation and scrambling codes for data scrambling also need to be determined.

By adopting the method for determining the scrambling code/sequence, on one hand, the interference of D2D transmission between different D2D UEs can be randomized, and the detection complexity between D2D UEs carrying out D2D communication is reduced. Specifically, three methods for data transmission in the D2D system are provided in the present application.

Fig. 1 shows a method for data transmission in a D2D system according to a first embodiment of the present invention, where the method includes the following steps:

step 101: the D2D UE detects the synchronization source signal and completes the synchronization process based on one of the synchronization sources.

It is possible that the D2D UE may detect signals of multiple synchronization sources, and the synchronization relationship can only be determined from one synchronization source at a time of D2D transmission. For example, one D2D transmission herein may refer to D2D signaling within one subframe. The synchronization sources employed for D2D transmissions at different times may be the same or different. The synchronization source signal may be a signal structure of the existing LTE system, that is, including PSS/SSS, or may be another signal structure, which is not limited in this application.

Step 102: the D2D UE determines the parameters of the sequence and/or the initial value of the scrambling code used when the D2D signal is transmitted subsequently according to the detected information of the synchronization source, and then sends the D2D signal correspondingly.

Wherein the D2D signal may refer to a physical D2D synchronization channel, a D2D data transmission signal, and/or a D2D discovery signal. For the D2D discovery signal, the sequence and scrambling code initial values used in transmitting the signal include: parameters of initial values of a discovery sequence (e.g., a preamble sequence), a DMRS sequence of a discovery signal message part, and a pseudo random sequence generating a scrambling code; for a D2D data transmission signal, the sequence and scrambling code initial values used in transmitting the signal include: DMRS sequence and parameters of initial values of pseudo random sequences generating data scrambling codes.

At each transmission of the D2D signal, the D2D UE determines the sequence of the D2D signal and/or parameters of an initial value of a pseudo-random sequence generating a scrambling code according to the information of the synchronization source. The information of the synchronization source may be information carried by one synchronization source signal detected in step 101, and specifically may be information carried by one synchronization source signal randomly selected from the received synchronization sources, or may be information carried by a synchronization source signal used for completing a synchronization process, or may also be information carried by other detected synchronization source signals. Specifically, the information carried by the synchronization source may include one or more of a synchronization source ID, an original synchronization source ID, or a synchronization source of the second hop from the original synchronization source.

In order to ensure that UEs can discover each other based on different synchronization sources, and further D2D communication, the UEs may generate scrambling codes, DMRS sequences, and/or discovery sequences at different transmission times according to the detected synchronization source IDs, and then transmit D2D discovery signals, D2D data control channel signals, D2D data communication channel signals, and/or D2D data transmission DMRS sequences according to synchronization timing corresponding to the generated scrambling codes or sequence synchronization sources. When determining the corresponding parameters according to the information of the synchronization source, the following methods can be adopted:

for example, for a D2D UE that is within the coverage of a cell, its synchronization source ID may be simply the cell ID. Accordingly, the parameters of the sequence of the D2D signal and the initial value of the scrambling code are determined based on the information of the cell ID and the subframe number, etc.

For another example, for a D2D UE in the coverage of the cell, the D2D signal may also be transmitted according to the detected information of other synchronization sources different from the eNB of the cell. For example, in order to be able to transmit D2D signals with an out-of-cell D2D UE, the above-mentioned in-cell D2D UE may detect a synchronization source that an out-of-cell D2D UE may rely on, and transmit D2D signals according to the detected corresponding synchronization source information, and perform D2D communication with the D2D UE that depends on this synchronization source. At this time, information of the synchronization source ID of the D2D UE out of the cell coverage and the like may be used to determine parameters of the sequence of the D2D signal and the initial value of the scrambling code.

For another example, for a D2D UE out of the cell coverage, it may be the nth hop synchronization source forwarded by other D2D UEs, and establishes synchronization; the original synchronization source of the nth hop synchronization source may be a synchronization signal transmitted by a D2D UE out of coverage of one cell, or a synchronization signal of a cell. The D2D UE may transmit D2D signal according to the nth hop synchronization source, i.e. determine the parameters of the sequence of D2D signal and the initial value of the scrambling code according to the information of the nth hop synchronization source; alternatively, the D2D UE may parse the original synchronization source ID from the synchronization signal, and use the original synchronization source ID to determine the sequence of the D2D signal and the parameter of the initial value of the scrambling code.

In addition, when generating the D2D scrambling code, the cell ID of the scrambling parameter of the PUSCH in the conventional LTE release may be replaced with the synchronization source ID, or the slot number may be set to a fixed value, or when generating the scrambling code of the D2D data communication channel signal, the RNTI related to the PUSCH transmission may be replaced with the content obtained from the discovery signal and/or the D2D data control channel, such as the preamble sequence number in the discovery signal, or the ID in scheduling assignment, that is, the scrambling code of the D2D data communication signal may be generated based on the information extracted from the received discovery signal and/or the D2D data control channel signal.

In addition, the physical D2D synchronization channel, D2D discovery signal, D2D data control signal and D2D data communication signal are different in the range of D2D UEs, the physical D2D synchronization channel, D2D discovery signal and D2D data control signal (especially D2D broadcast data control signal) need to be able to be detected by D2D UEs within a certain range, and the D2D data communication signal is only able to be received by UEs performing D2D communication; thus, the physical D2D synchronization channel, D2D discovery signal, or D2D data control signal may generate the sequence or scrambling code initial value with different parameters than the D2D data communication signal. For example, the D2D UE may determine the parameters of the sequence and/or scrambling code initial value adopted in the physical D2D synchronization channel, the D2D discovery signal, and/or the D2D data control signal according to the original synchronization source ID or the nth hop synchronization source ID and other information in the above step 102; then, the D2D UE determines parameters of a DMRS sequence or a data scrambling code initial value of the D2D data communication signal according to contents in the physical D2D synchronization channel signal, the D2D discovery signal, or the D2D data control signal. As another example, a simple scrambling code is employed for the physical D2D synchronization channel, the D2D discovery signal, or the D2D data control signal, which may be a fixed value or one selected from several fixed values based on the synchronization source ID, while the D2D data communication signal determines the scrambling code and sequence based on information in the D2D discovery signal or in the D2D data control signal, as determined based on the ID in the scheduling assignment (i.e., the ID carried in the scheduling assignment SA).

Step 103: the D2D UE determines the parameters of the sequence and/or the initial value of the scrambling code of the D2D signal in step 102 according to the information of one or more synchronization sources detected by the UE, and detects the D2D signal which is dependent on the same synchronization source D2D UE.

In order to reduce the UE detection complexity, the D2D signaling UE may blindly detect the DMRS in the D2D data control signal, and then infer partial information of the synchronization source ID of the D2D data control signal according to the DMRS sequence, if the receiving UE can deduce that the DMRS comes from a D2D UE under different synchronization sources according to the partial information D2D signal, and the UE under different synchronization sources do not have D2D communication, the UE may not detect the D2D data control channel corresponding to the DMRS, so that the number of detections for the D2D data control channel by the UE may be reduced. For example, there are two D2D UEs, UE A and UE B in cell 1, where UE A and UE C in cell 2 are in D2D communication. For UE A, synchronization signals of cell 1 and cell 2 are synchronization sources of UE A, if UE B receives a DMRS sent by UE C of an adjacent cell, the DMRS is generated according to cell 2 synchronization source information, and UE B does not perform D2D communication with UE under the cell 2 synchronization source, UE B does not detect a D2D data control signal corresponding to the DMRS.

Here, for one D2D UE, parameters of the sequence of the D2D signal and/or the initial value of the pseudo-random sequence of the scrambling code generating the D2D signal may be determined based on only one synchronization source information, thereby detecting only the D2D signal determined by the information of the one synchronization source. This synchronization source may be the synchronization source that the UE actually uses to establish synchronization. In this way, the number of blind detections of a UE can be reduced, since the sequence/scrambling code of the D2D signal it is to detect can be obtained from its own synchronization source information, but it also results in that one D2D UE cannot accept the D2D signal of a D2D UE synchronized to another synchronization source (where the other synchronization source originates from the same original synchronization source as the synchronization source on which the D2D UE establishes synchronization, or originates from a different original synchronization source, the next same as the synchronization source on which the D2D UE establishes synchronization). Alternatively, in order to receive as many potential D2D signals as possible, the UE may be a parameter of a sequence of the D2D signal determined from information of multiple synchronization sources and/or an initial value of a pseudo-random sequence of scrambling codes that generates the D2D signal, so that the D2DUE may detect the D2D signal of information transmission of multiple synchronization sources. With this approach, it is possible for a D2D UE to establish D2D communications with more D2D UEs. For example, the D2D UE may directly detect a D2D signal corresponding to a detected synchronization source according to the detected information of the synchronization sources; alternatively, it is also possible to determine information related to other synchronization sources according to the detected information of the synchronization source, and detect corresponding D2D signals; alternatively, to enable D2D UEs under different synchronization sources to use the same D2D signal scrambling code and D2D DMRS signal parameters, constant scrambling may be employed for certain D2D signals.

When the D2D signal is scrambled by a constant, in order to reduce the interference of the D2D signal on the PUSCH channels of the local cell and the neighboring cell and reduce the mutual interference when the D2D signal resources collide, the D2D signal data control channel may be transmitted with a lower power, for example, with a power lower than a set threshold, or with a transmission power much lower than the PUSCH; meanwhile, in order to ensure the receiving quality, the D2D signal may be repeatedly transmitted, and different UEs may share the same time-frequency resource based on code division multiple access. For example, data in the D2D data control channel is encoded by a spreading code with a spreading factor N and then transmitted.

To this end, the general flow of the data transmission method in the first D2D system ends. The following describes a data transmission method in the second D2D system.

In the D2D system, several D2D UEs form a Cluster (Cluster), and within a certain period, the D2D UEs in a Cluster can discover each other or can discover the same UE. For example, when D2D UEs broadcast (multicast/unicast) signals, the D2D UEs transmitting and receiving the broadcast (multicast/unicast) signals form a cluster. For example, for D2D communication within a broadcast group, a transmitting D2D UE and all receiving D2D UEs form a cluster; for unicast D2D communication, a pair of D2D UEs performing D2D communication constitute one cluster, and for multicast D2D communication, a group of D2D UEs performing D2D communication constitute one cluster.

Each Cluster may have one D2D UE acting as a Cluster Head (Cluster Head), the selection of which is not discussed in this application. Here, it is assumed that each cluster has a cluster ID, and the cluster ID may be carried by a synchronization signal, such as a synchronization signal sent by a certain D2D UE in the cluster, or information of sending the cluster ID is broadcast by a cluster head in the cluster, or is allocated by a base station, and the obtaining manner of the cluster ID is not limited in this application. The cluster ID may be D2D-rnti (radio Network Temporary identifier), may be an ID in the D2D UE scheduling assignment, or may be indirectly represented by a D2D signal resource pool ID.

Regarding the IDs in the scheduling assignment as the cluster IDs, when the UE sending the D2D signal is without the base station assistance, the D2D UE may select one Scheduling Assignment (SA) ID from several optional scheduling assignments as the cluster ID, where the number of the optional scheduling assignments is smaller than the total number of the scheduling assignments, further, the set of IDs in the optional SA and the set of IDs in the SA assigned by the base station may be disjoint, and this set of IDs in the optional SA is referred to as a common SA ID (common SA ID). If the UE receives the SA containing the ID in the public SA, the UE can detect the corresponding D2D data communication channel, or judge whether to detect the D2D data communication channel corresponding to the ID in the public SA according to high-level configuration. For example, outside the cell coverage, the D2D UE broadcasting the distress signal may employ ID broadcasting in the common SA. D2D UEs that should avoid cell coverage use the in-SA ID for public safety situations for advertising.

D2D UE gets synchronization first, and through getting cluster ID, cluster ID can be according to cluster head broadcast, base station distribution, configuration in advance or UE selection confirm; then, based on this cluster ID, the D2D UE may transmit a subsequent D2D signal. That is, after the D2D UE obtains the cluster ID, the cluster ID is used to determine the discovery signal sequence, and/or DMRS sequence, and/or scrambling code initial value in the D2D UE D2D signal. The D2D signal here refers to the D2D data transmission signal and/or the D2D discovery signal. By adopting the method, the interference of D2D transmission between D2D UEs in different clusters is randomized, the detection of the discovery signal is only needed to be carried out according to the cluster ID, the blind detection times of the discovery signal can be reduced, and the D2D UEs needing to be discovered mutually are ensured to be possibly discovered. As shown in fig. 2, the method comprises the steps of:

step 201: the D2D UE performs synchronization detection and acquires a cluster ID and related parameters.

The D2D UE detects the synchronization source signal and obtains the cluster ID. The cluster ID is determined by the cluster head UE according to parameters such as the corresponding UE ID, or determined by base station assisted determination, pre-configuration, or UE selection, and will not be discussed in detail herein.

Step 202: and the D2D UE obtains a sequence adopted when the D2D signal is transmitted subsequently and/or parameters of an initial value of a pseudo-random sequence generating scrambling codes according to the obtained cluster ID information, and then sends a corresponding D2D signal, wherein the D2D signal is a physical D2D synchronous channel signal, a D2D discovery signal, a D2D data control signal or a D2D data communication signal.

The D2D UEs may belong to multiple clusters, and may detect multiple cluster ID information, e.g., the D2D UEs belong to multiple multicast communications. Generally, only one cluster of D2D UEs can communicate at one D2D transmission. For example, one D2D transmission herein may refer to a D2D signal transmission within one subframe. Thus, D2D for different sub-frames transmit the generation sequence and/or scrambling code initial value parameters according to different cluster IDs. For example, assuming that the D2D UE transmits the D2D discovery signal after obtaining the cluster ID, the D2D UE may generate the discovery sequence, the DMRS sequence of the discovery message, and the scrambling code initial value of the discovery message on different subframes according to the detected cluster ID, so as to be discoverable by the D2D UEs in multiple clusters, wherein the corresponding relationship between the subframes and the cluster ID may be determined or preset by the D2D UEs.

In addition, the range of D2D UEs acted upon by the D2D discovery signal, and the D2D broadcast data control channel and D2D data transmission signal, and the D2D broadcast data communication signal, are different; thus, the D2D discovery signal, and the D2D broadcast data control channel and D2D communication signal, and the D2D broadcast data communication signal may employ different parameter generation sequences or scrambling code initial values. For example, the D2D UE may determine only the parameters of the sequence and/or scrambling code initial value adopted in the D2D data communication signal according to the information such as the cluster ID in the above-mentioned manner in step 202; the scrambling codes and sequences of the D2D UE D2D discovery signal and the D2D data control signal are determined by other means, such as by making the scrambling codes constant.

When the D2D UE is in the coverage of the cell, the D2D UE performing D2D communication may know the ID information in the scheduling assignment before transmitting the data control signal, and then the UE may generate the sequence and/or scrambling code in the data control signal according to the ID in the scheduling assignment, or the location or sequence number of the scheduling assignment resource, that is, the ID information in the scheduling assignment is a parameter for generating the sequence and scrambling code in the unicast data control signal. Thus, the problem of control signal resource collision can be reduced, compared with the channel estimation error caused by DMRS resource collision.

The DMRS in the D2D signal may be determined according to the ID in the SA. The DMRS sequence includes a root sequence and a cyclic shift, or may further include an orthogonal mask.

The parameter Δ is needed for generating the root sequence_ssHow to utilize Delta_ssDMRS is generated, see 5.5.2 of 3GPP ts36.211v10.2.0. Can make each serial number of ID in SA correspond to a delta_ssFor example, in SA, the ID is composed of 8 bits, and has 64 sequence numbers, and the 64 sequence numbers can be respectively corresponding to delta_ssOne of the 30 serial numbers of (1); or several bits of ID in SA indicate Δ_ssE.g. 5 bits in the ID in SA indicate delta_ssOne of the 30 values of (a); or the value obtained by taking the ID in the SA modulo a certain value is delta_ssFor example, modulus of 30 is applied to ID in SA to obtain Δ_ss。

When the cyclic shift parameter is generated, each serial number of the ID in the SA can be corresponding to a cyclic shift valueFor example, in SA, the ID is formed by 8 bits, and corresponds to 64 sequence numbers, and 64 sequence numbers can be made to correspond to 12 (or 8) sequence numbers of cyclic shift respectively; or a plurality of bits of the ID in the SA indicate a value of cyclic shift, for example, 3 bits of the ID in the SA indicate one of eight values of cyclic shift; or obtaining cyclic shift for the value obtained by modulus taking of the ID in the SA according to a certain value, for example, obtaining cyclic shift for the ID in the SA according to modulus taking of 12; alternatively, the cyclic shift is made to a fixed value, such as 0. The cyclic shift here can correspond to the cyclic shift α defined in 3GPP TS36.211, or the cyclic shift signaling signaled by the higher layer and physical layer signalingAnd

according to LTE release 10, the cyclic shift α is formed by adding three components, which are signaled by the higher layerAnd physical layer notificationAnd n_PRS(n_s). In the present application, the cyclic shift α may still be added by three components, and n may be added_PRS(n_s) Generating n for a fixed value (e.g. 0), or as specified in 3GPP TS36.211v10.2.0_PRS(n_s) However, the required cell ID is a fixed value between 504 and 511, and the required time slot number n_sSet to a fixed value or, as described in this application, the slot number is determined relative to the offset of a reference slot.

When the DMRS in the D2D discovery signal, the D2D data control signal, or the D2D data communication signal uses an Orthogonal mask (OCC), the Orthogonal mask number of the UE needs to be indicated, and the OCC number of the UE may be randomly selected, or determined according to the ID in the SA, for example, one bit of the ID in the SA indicates the OCC, and for example, a value obtained by performing a certain operation (e.g., modulo-2 addition) on all bits of the ID in the SA indicates the OCC.

Step 203: the D2D UE determines the sequence of the D2D signal determined in step 202 and/or parameters of the pseudo-random sequence initial value of the scrambling code generating the D2D signal according to the information of the one or more cluster IDs it detects, thereby detecting the D2D signal transmitted by the D2D UEs in the corresponding cluster.

To reduce UE detection complexity, a D2D-signaling UE may blindly detect DMRSs in a D2D data control signal and then infer whether itself is the receiving UE of the D2D data control signal based on parameters of blindly detecting the DMRS, thereby determining whether to decode the D2D data control channel. For example, all the IDs in the scheduling assignment may be divided into several groups, which group the ID in the SA belongs to can be inferred from the DMRS sequence, and whether to decode the D2D data control channel may be determined from the ID information in the scheduling assignment. For example, when the ID in the detected SA and the ID in the SA of the D2D UE belong to different groups, the signal of the D2D data control channel may not be decoded. In this way, the number of D2D data control channel detections by the UE may be reduced.

To this end, the overall flow of the data transmission method in the second D2D system ends.

In the D2D system, because the D2D UE may autonomously select resources for transmitting D2D signals, and the D2D UE in the current cell may be allocated by different base stations from the D2D signal resources used by the D2D UEs in the neighboring cell, DMRS signals required for D2D transmission sent by different D2D UEs may collide, and when the signals of two D2DUE collide, the detection accuracy of the D2D signal may be reduced. In order to reduce the probability of collision, D2D UEs may be randomly selected, or D2D UEs may be generated according to parameters, or a base station configures cyclic shift α and/or sequence group number u related parameters required for generating DMRSs and D2D discovery signals through higher layer signaling or physical layer signaling, and how to generate DMRSs using α and u is shown in 5.5.2 of 3GPP ts 36.211v10.2.0.

For example, when the UE transmits a communication signal using a discovery signal of type 2(type2) or using a mode 1(mode1), DMRS cyclic shift and/or sequence group number related parameters required for the discovery signal and/or the communication signal are specified by the base station; or, for another example, when the UE transmits a communication signal using a discovery signal of type 1(type1) or using mode 2(mode2), DMRS cyclic shift and/or sequence group number related parameters required for the discovery signal and/or the communication signal are autonomously generated by the D2D UE, and may be randomly generated, or the UE transmitting the D2D signal may be determined according to known parameters thereof, where the known parameters may be D2D RNTI, ID in SA, ID of the transmitting or receiving UE, and the like.

According to the existing LTE release, when a DMRS and a scrambling code are generated, a UE needs to know a slot number, in a D2D system, when the UE is out of cell coverage, and the like, a method for determining the slot number of the existing LTE system is not applicable, and one processing method is to prohibit group hopping (group hopping) and sequence hopping (sequence hopping) for generating the DMRS in the D2D system, and at this time, the UE may generate the DMRS without depending on the slot number. Such as D2D DMRS forbidden group hopping and sequence hopping for out-of-cell-coverage UEs. Alternatively, for the case that the D2D UE is out of the cell coverage, etc., the subframe (or slot) number may be set to a fixed value, for example, 0, in generating the scrambling code. Alternatively, the offset of the subframe (or slot) for transmitting the D2D signal from a reference subframe (or slot) is determined as the sequence number of the subframe (or slot), and then the sequence and scrambling code are generated using the sequence number. For example, the reference subframe (or slot) is a subframe (or slot) for transmitting a synchronization signal, or the reference subframe (or slot) is a first subframe (or slot) in a scheduling allocation configuration period. Alternatively, if D2D signaling is in TTI bundling, where multiple D2D subframes are scheduled by one scheduling assignment in TTI bundling, the sequence numbers of D2D subframes (or slots) in several subframes (or slots) scheduled in one TTI bundling are the subframe (or slot) sequence numbers that generate the scrambling code and DMRS sequence. The method for determining the sequence number of the subframe (or slot) according to the reference subframe (or slot) may be only used in the case that the UE is out of cell coverage, or may also be applied in all D2D scenarios, where all D2D scenarios refer to not only the cell coverage of the D2D UE, but also include the case that the subframe sequence number is used in any D2D signal generation, for example, when generating PD2DSCH, the subframe sequence number may adopt the method described in this application.

In D2D, only a portion of the subframes may be used for D2D transmissions within one period. For example, for D2D in the cell coverage, if a subframe with the same sequence number in each radio frame is a D2D subframe, the sequence number refers to the sequence number of the subframe in the radio frame, and the generation scrambling code and DMRS sequence are related to the sequence number of the subframe in the radio frame, then the subframe sequence number parameters used in generating the D2D DMRS sequence and scrambling code of each subframe are the same, which results in that the D2D DMRS sequence and scrambling code of each subframe are the same, and the interference averaging function is lost. In order to distinguish the scrambling code and DMRS sequence on each subframe, the subframe (or slot) number required for D2D scrambling and DMRS generation may be made the number of one subframe actually transmitting D2D signal in all subframes actually used for D2D transmission. For example, between two subframes for transmitting synchronization signals, N subframes transmit D2D signals, and the subframe number for generating the scrambling code and DMRS sequence is the sequence number of the subframe in the N D2D subframes.

In addition, since the UE may transmit a physical D2D synchronization channel, a D2D discovery message channel, a D2D data control channel, or a D2D data communication channel, where the D2D UE may locate the DMRS, according to a cyclic shift α, an orthogonal mask (OCC), or other cyclic shift parameters of the DMRS obtained by blindly detecting the D2D signal DMRS, the UE may scramble and transmit signals of the corresponding channels using the parameters, which may be obtained by blindly detecting, as scrambling parameters. The receiving D2D UE may detect the signal of the corresponding channel by using the α, OCC or other cyclic shift parameter determined by blind detection as the scrambling parameter of the channel. The following describes how to apply information such as synchronization source information and/or cluster ID information when determining the sequence of D2D and the parameter of the initial value of the scrambling code, by using two embodiments. The present invention is not limited to the implementation methods in the following two embodiments.

The first embodiment is as follows:

this embodiment discusses a specific implementation of the data transmission method in the second D2D system.

Step 301: the D2D UE performs synchronization detection and acquires information such as a cluster ID.

Wherein the cluster ID information may be obtained through intra-cluster synchronization signal or cluster head broadcasting.

Step 302: determining the parameters of the sequence for transmitting the D2D signal and the initial value of the scrambling code according to the cluster ID, and generating the sequence, the DMRS sequence and the initial value c of the scrambling code_initAnd transmits a corresponding signal.

The method for generating the scrambling code sequence initial value according to the cluster ID may be:

or,

<math> <mrow> <msub> <mi>c</mi> <mi>init</mi> </msub> <mo>=</mo> <mi>c</mi> <mo>·</mo> <msup> <mn>2</mn> <mn>9</mn> </msup> <mo>+</mo> <msubsup> <mi>N</mi> <mi>ID</mi> <msub> <mi>Sync</mi> <mi>source</mi> </msub> </msubsup> </mrow> </math>

whereinDetection of the ith cluster ID, n, for the D2D UE_sIs the time slot number, N isThe number of binary bits. When the D2D UE detects multiple cluster ID information, in each subframe transmitting discovery signals or D2D data transmission, the UE selects a cluster to transmit corresponding signals, or determines a cluster to transmit corresponding signals according to a preset mapping relationship between clusters and subframes.

In generating the DMRS, a cluster ID may be used to derive a sequence group shift offset Δ required for generating the DMRS sequence_ss，

<math> <mrow> <msub> <mi>Δ</mi> <mi>ss</mi> </msub> <mo>=</mo> <msubsup> <mi>N</mi> <mi>ID</mi> <mi>cluster</mi> </msubsup> <mi>mod</mi> <msup> <mn>2</mn> <mn>5</mn> </msup> <mo>.</mo> </mrow> </math>

When the DMRS is generated, the physical layer cyclic shift may be determined according to the cluster ID, and f (m) is set as the physical layer cyclic shift, whereAnd f (m) is determined according to the preset mapping relation between m and f (m), and a mapping relation between values of m and f (m) is given in table 2.

TABLE 2

M	0	1	2	3	4	5	6	7
									f(m)	0	6	2	4	2	8	10	9

When the D2D UE is located in the cell coverage, the corresponding parameter may be further determined according to the cell ID and the cluster ID, for example, the initial value of the scrambling code may be set to be

WhereinDetection of the ith cluster ID, n, for the D2D UE_sIs a time slot number, and is a time slot number,for cell ID, from the cluster ID, the D2D UE sent in the sub-frame is for the secondDiscovery signals or data transmission signals of D2D UEs within a cluster. When the D2D UE detects multiple cluster ID information, in each subframe transmitting discovery signals or D2D data transmission, the UE selects a cluster to transmit corresponding signals, or determines a cluster to transmit corresponding signals according to a preset mapping relationship between clusters and subframes.

Step 303: the D2D UE determines the sequence of the D2D signal determined in step 302 and/or the parameters of the pseudo-random sequence initial value of the scrambling code generating the D2D signal according to the information of the one or more cluster IDs detected by the UE, and so on, thereby detecting the D2D signal transmitted by other D2D UEs.

Example two:

this embodiment discusses a specific implementation of the data transmission method in the first D2D system. Fig. 4 is a schematic flow chart of the method in this embodiment, which includes the following steps:

step 401: after UE and synchronous source are synchronized, synchronous source ID is obtainedAnd so on.

When the UE synchronizes with the synchronization source, the UE may synchronize with the base station, or synchronize with the base station by receiving a synchronization sequence forwarded by another UE.

Step 402: and the D2D UE generates corresponding parameters of the D2D sequence, the DMRS sequence and the D2D signal scrambling code initial value according to the information such as the synchronization source ID determined in the step 401, and sends corresponding signals.

For example, cyclic shift of higher layer setting, cyclic shift of physical layer setting, and sequence group shift offset Δ_ssAre all set to zero according to the number of symbols in a time slotGenerating a DMRS;

for another example, the initial value of the D2D signal scrambling code is:

is the synchronization source ID.

Step 403: information of synchronization source detected by D2D UEDetermining parameters of the sequence of the D2D signal determined in step 402 and/or a pseudo-random sequence initial value of a scrambling code generating the D2D signal, thereby detecting the D2D signals transmitted by other D2D UEs.

Example three:

this embodiment discusses a specific implementation of the data transmission method in the second D2D system. Wherein, the ID in the SA is taken as the cluster ID. Fig. 5 is a schematic flow chart of a corresponding method, as shown in fig. 5, specifically including:

step 501: and D2D UE carries out synchronous detection, receives SA and obtains information such as SA ID.

Step 502: and generating parameters of the DMRS sequence in the D2D data transmission signal according to the SA ID, and generating the sequence.

Step 503: the D2D UE receives the DMRS at a specific location according to the SA indication, and performs operations such as channel estimation based on the parameters determined in step 502 and the received DMRS.

The following describes a method for data transmission in the third D2D system in the present application.

The method proposes a method for generating parameters of a D2D signal sequence, a DMRS sequence and an initial value of a D2D signal scrambling code for RRC Idle UE in a cell coverage area. The RRC Connect UE may generate parameters of the D2D signal sequence, the DMRS sequence, and the D2D signal scrambling code initial value in the same method as the RRC idle UE. Fig. 6 is a schematic flow chart of the method. As shown in fig. 6, the method specifically includes:

step 601: the D2D UE in RRC Idle state detects the synchronization source and receives the information of parameters generating the D2D signal sequence, DMRS sequence, and D2D signal scrambling code initial value broadcast by the eNB or D2D UE.

The information broadcasted by the eNB may directly carry the relevant parameters of the D2D UE generation sequence, the DMRS sequence, and the D2D signal scrambling code initial value. For example, these parameters may be cyclic shift of higher layer, sequence group shift offset Δ_ssAnd the number of symbols in a slotThe D2D UE in RRC Idle state may receive the broadcast information of the enbs to determine the corresponding parameters.

In addition to receiving eNB broadcast information, the D2D UE may also receive signals transmitted by other D2D UEs to determine cluster ID and other information of synchronization sources different from the own cell. The cluster ID and the information of the synchronization source can be obtained in the corresponding manner in the previous two D2D signaling and detecting methods. And will not be described in detail herein.

Step 602: when the D2D UE is in the RRC idle state, the parameters corresponding to the sequence, the DMRS sequence, and the D2D signal scrambling code initial value are generated according to the parameters determined in step 601, and a corresponding D2D signal is transmitted.

Here, the physical layer cyclic shift required to generate the DMRS may be set to a constant, and the UE C-RNTI required to generate the initial value of the D2D signal scrambling code may also be set to a constant, for example, 0.

Meanwhile, as described in step 601, the D2D UE may also determine the cluster ID and the information of the synchronization source. If the D2D UE can determine the cluster ID information, in this step, the corresponding parameters of the generated sequence, the DMRS sequence, and the initial value of the D2D signal scrambling code may also be determined according to the cluster ID information according to the second method of the present application.

If the D2D UE can determine the information of the synchronization source, in this step, the corresponding parameters of the generated sequence, the DMRS sequence and the initial value of the D2D signal scrambling code may also be determined according to the first method of the present application.

Step 603: the D2D UE determines the sequence of the D2D signal determined in step 602 and/or the parameters of the pseudo-random sequence initial value of the scrambling code generating the D2D signal according to the received parameters such as broadcast information, thereby detecting the D2D signal transmitted by other D2D UEs.

The data transmission method flow in the third D2D system ends up.

The application also provides three data transmission devices in the D2D system, which can be used for implementing the three data transmission methods.

Specifically, the device for data transmission in the first D2D system comprises a synchronization unit, a sequence and scrambling code initial value generation unit, and a D2D signal processing unit.

The synchronization unit is used for detecting signals of synchronization sources, and for any transmission of the D2D signals, the synchronization process is completed according to one of the detected synchronization sources. A sequence and scrambling code initial value generating unit, configured to determine, according to the information of the synchronization source detected by the synchronization unit, a parameter of a sequence and/or scrambling code initial value adopted when the D2D signal is transmitted; and generating the sequence and/or the scrambling code initial value according to the determined parameters. A D2D signal processing unit, for transmitting or detecting the corresponding D2D signal according to the generated sequence and/or the scrambling code initial value; wherein, the D2D signal refers to the D2D data transmission signal, and/or the D2D discovery signal.

The data transmission device in the second D2D system comprises: a synchronization unit, a sequence and scrambling code initial value generation unit and a D2D signal processing unit.

The synchronization unit is used for performing synchronization detection and acquiring a cluster ID. And the sequence and scrambling code initial value generating unit is used for determining the parameters of the sequence and/or scrambling code initial value adopted when the D2D signal is transmitted according to the acquired cluster ID, and generating the sequence and/or scrambling code initial value according to the determined parameters. A D2D signal processing unit, for transmitting or detecting the corresponding D2D signal according to the generated sequence and/or the scrambling code initial value; wherein, the D2D signal refers to the D2D data transmission signal, and/or the D2D discovery signal.

The data transmission device in the third D2D system includes: a synchronization unit, a sequence and scrambling code initial value generation unit and a D2D signal processing unit.

The synchronization unit is configured to detect synchronization and receive broadcast information of the eNB or the D2D UE. And the sequence and scrambling code initial value generating unit is used for determining parameters of the D2D signal sequence, the DMRS sequence and the D2D signal scrambling code initial value according to the broadcast information and generating the sequence and scrambling code initial value adopted when the D2D signal is transmitted. And the D2D signal processing unit is used for transmitting or detecting a corresponding D2D signal according to the determined sequence and the initial value of the scrambling code.

The method and the device aim at the characteristics of synchronous discovery signals of a D2D system, the DMRS and the initial values of the discovery signals are generated by using the ID information of a synchronous source or a cluster, the interference among D2D signals of different cells and different clusters is reduced, the blind detection times of the D2D signals are reduced while the receiving range of the D2D signals is ensured, the uplink spectrum utilization rate is improved, and the power consumption of the D2D is saved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A method for data transmission in a D2D system, comprising:

2. The method according to claim 1, wherein the parameters of the sequence and/or scrambling code initial value determined according to the information of the synchronization source in step B are: parameters of sequence and/or scrambling code initial values adopted when transmitting physical D2D synchronization channel signals, D2D discovery signals and/or D2D data control signals;

3. The method of claim 2, wherein one of N pre-set scrambling codes is selected or one of the N pre-set scrambling codes is selected as the scrambling code for transmitting the physical D2D synchronization channel signal, the D2D discovery signal and/or the D2D data control signal according to the information of the synchronization source; and/or the presence of a gas in the gas,

4. The method of claim 1, wherein group hopping and sequence hopping is prohibited when the D2D UE generates DMRS or scrambling code initial values; and/or the presence of a gas in the gas,

5. The method of claim 4, wherein the reference subframe or slot is: a subframe or a slot for transmitting a synchronization signal, or a first subframe or a first slot in a scheduling allocation configuration period.

6. The method of claim 1, wherein the sequence number of the sub-frame transmitting the D2D signal in the set of sub-frames actually transmitting the D2D signal is determined as the sub-frame or slot sequence number when generating the sequence or scrambling code.

7. A method for data transmission in a D2D system, comprising:

E. D2D UE carries out synchronous detection and acquires cluster ID;

8. The method of claim 7, wherein when the cluster ID is a scheduling assignment ID, if the D2D UE has no base station assistance, the D2D UE obtains the cluster ID by: the D2D UE selects one SA middle ID in the common scheduling assignment SA middle ID set as the cluster ID.

9. The method of claim 7, wherein when the D2D UE receives multiple cluster ID information in step E, step F determines the sequence and/or scrambling code initial value of D2D signal according to different cluster ID or same cluster ID on different sub-frames; wherein the correspondence between the sub-frame and the cluster ID is determined or predefined by the D2D UE.

10. The method according to claim 7, wherein the parameters of the sequence and/or scrambling code initial value determined according to the cluster ID in step F are: parameters of discovery sequence and/or scrambling code initial values adopted when transmitting the D2D data communication signals;

11. The method of claim 7, wherein the cluster ID is a SA middle ID;

12. The method of claim 11,

utilizing each value of the ID in the SA to correspond to a delta used for generating the root sequence_ssDifferent values of (a); and/or the presence of a gas in the gas,

setting the value of the cyclic shift as a fixed value.

13. The method of claim 12, wherein the cyclic shift is α defined in 3GPP TS36.211, or wherein the cyclic shift is cyclic shift signaling for higher layer and physical layer signalingAnd

14. the method of claim 11, in which the DMRS sequence further comprises an orthogonal mask, OCC;

15. The method of claim 7, wherein group hopping and sequence hopping is prohibited when the D2D UE generates DMRS or scrambling code initial values; and/or the presence of a gas in the gas,

16. The method of claim 15, wherein the reference subframe or slot is: a subframe or a slot for transmitting a synchronization signal, or a first subframe or a first slot in a scheduling allocation configuration period.

17. The method of claim 7, wherein the sequence number of the sub-frame transmitting the D2D signal in the set of sub-frames actually transmitting the D2D signal is determined as the sub-frame or slot sequence number when generating the sequence or scrambling code.

18. A method for data transmission in a D2D system, comprising:

19. The method of claim 18, wherein group hopping and sequence hopping is prohibited for the D2D UE generating the DMRS.

20. A method for data transmission in a D2D system, comprising:

21. An apparatus for data transmission in a D2D system, comprising: a synchronization unit, a sequence and scrambling code initial value generation unit and a D2D signal processing unit;

22. An apparatus for data transmission in a D2D system, comprising: a synchronization unit, a sequence and scrambling code initial value generation unit and a D2D signal processing unit;

23. An apparatus for data transmission in a D2D system, comprising: a synchronization unit, a sequence and scrambling code initial value generation unit and a D2D signal processing unit;