CN103686585B - A kind of terminal direct connection communication means based on multiple-input, multiple-output cooperative relaying - Google Patents

Abstract

The invention discloses a kind of terminal direct connection communication means based on multiple-input, multiple-output cooperative relaying, the method is the speed and outage probability for improving D2D systems so as to reach by introducing multiple antennas and relaying technique under D2D systems；The present invention is in broadband cellular GSM（IMT‑Advanced）In, a pair of phone users will carry out terminal direct connection, but because the distance between they are more than the coverage that D2D communicates, or the channel link qualities between them do not reach requirement, there is the UE user of substantial amounts of free time in cell, by the use of idle mobile as relaying, a pair of phone users are assisted to carry out D2D communications；The originator of a pair of terminal direct connection phone users is designated as D1, and receiving terminal is designated as D2, and relaying is designated as R；When D1 and R are communicated, the frequency resource of phone user and base station communication in D1 reuse patterns, at this moment D1 and R constitute a pair of D2D communications.

Description

A kind of terminal direct connection communication means based on multiple-input, multiple-output cooperative relaying

Technical field

The present invention relates to Computer Wireless Communication technical field, more particularly to a kind of end based on multiple-input, multiple-output cooperative relaying End direct communication method.

Background technology

Cellular mobile communication terminal direct connection technology (D2D, Device-to-Device) is that moving communicating field was new in recent years An emerging research topic.In traditional cell mobile communication systems, the communication between two mobile terminals has to pass through The scheduling of base station, distributes frequency spectrum resource and channel to be communicated by the scheduler of base station.After D2D technologies are introduced, Two mobile terminals in system are if it is intended to communication, may not be exactly to be forwarded by base station and communicated.D2D technologies are that a kind of terminal is arrived The communication mode of terminal direct connection, it is suggested can be as the subsidiary communications mode of LTE system, it is possible to lead in the movement in future Under letter system, most of mobile subscriber communicates by way of base station forwards, and the mobile subscriber that specified conditions are met on a small quantity passes through The mode of terminal direct connection communicates.

The core concept of the D2D communication technologys is, when two distance of mobile terminal are close, they can with direct communication, and Communication need not be forwarded by the uplink downlink of base station.Other this moment idle phone users in straight-through this cell of link selection Resource, terminal direct communication is realized by the frequency spectrum resource for being multiplexed phone user.D2D is straight-through be applied to when two mobile terminals away from Close to and situations such as needing to transmit online substantial amounts of video flowing, media or file-sharing, this kind of Large Copacity content is downloaded such as Fruit directly can enter the congestion that guild avoids causing base station by D2D.

The supplement that D2D communicates as cellular network, causes that mobile communication becomes more efficient, more square under some communication scenes Just.For the communication requirement of next generation cellular network, the advantage of D2D communications is apparent.It is further with the D2D communication technologys Study and deeply, the present invention believes that it can more effectively promote to meet following LTE systems for the performance improvement that cellular network brings The demand of system, therefore the research of the D2D communication technologys has profound significance.

But, when the distance between D2D user is more than the coverage that D2D communicates, or the channel link between them When can't meet the quality requirement, the speed or interruption rate of at this moment D2D communications do not reach requirement.Therefore, the speed of D2D systems how is improved Rate and reduction D2D outage probabilities turn into major issue urgently to be resolved hurrily.

The content of the invention

Present invention aim at proposing a kind of terminal direct connection communication means based on multiple-input, multiple-output cooperative relaying, the method It is the speed and outage probability for improving D2D systems so as to reach by introducing multiple antennas and relaying technique under D2D systems.

The technical scheme adopted by the invention to solve the technical problem is that：The present invention is in broadband cellular GSM (IMT-Advanced) in, a pair of phone users will carry out terminal direct connection, but because the distance between they communicate more than D2D Coverage, or channel link qualities between them do not reach requirement, the UE that there is the substantial amounts of free time in cell User, by the use of idle mobile as relaying, assists a pair of phone users to carry out D2D communications.A pair of terminal direct connection honeycombs are used The originator at family is designated as D1, and receiving terminal is designated as D2, and relaying is designated as R.When D1 and R are communicated, phone user in D1 reuse patterns With the frequency resource of base station communication, at this moment D1 and R constitute a pair of D2D communications；When R and D2 are communicated, R is also multiplexed honeycomb Community user and the frequency resource of base station communication (frequency resource with D1 is identical), at this moment a pair of D2D communications of R and D2 compositions.D2D The phone user that a pair are wanted to carry out D2D communications is namely divided into two pairs of D2D communications by trunking traffic, is D1-R and R-D2.

Method flow：

The invention provides a kind of single relay communication method based on terminal direct connection communication, the method is based on cellular system Single relaying implementation method, it comprises the following steps：

Step one：User D1 is intended to initiate to communicate with user D2, and session request is sent to base station, and base station receives user D1's Signal, sends answer signal, and starts to search for the position of user D2.

Step 2：Base station search starts to judge that whether D2D is met between user D1 and user D2 to be led to the position of user D2 The condition of letter, uses D2D communication patterns, user D1 and user D2 to start D2D communications if meeting.

Step 3：When user D1 and user D2 are unsatisfactory for D2D communication conditions, judge whether the communication between them meets The requirement of speed, uses legacy cellular pattern communication if meeting；If be unsatisfactory for, led to using the method for relaying auxiliary Letter.

Step 4：If desired, source broadcast RTS (Ready to send) information, destination broadcast CTS (Clear Tosend), the free subscriber of surrounding, according to signal RTS, CTS for receiving, reports that, to base station, base station determines ginseng as relaying With the free subscriber of relaying.

Step 5：When it is determined that the relaying for participating in communication is R, user D1 first sets out breath of delivering letters to relaying R, at this moment user D1 and relaying R carry out D2D one-way communications, and relaying R carries out D2D one-way communications with user D2 again after receiving information；When D2 is received To after information, the information that retransmits is routing the message to user D1 to relaying R, relaying R.

Step 6：User D1 and D2 confirm that communication process is completed, and send the request for terminating session to base station respectively, and base station is right Terminate the working condition of relaying R afterwards, whole conversation procedure terminates.

Beneficial effect：

1st, in the case of distance of the present invention between D2D user very big or channel link qualities difference, D2D is effectively increased The speed of total system, and reduce the outage probability of D2D total systems.

2nd, the present invention can effectively make many users carry out D2D communications by relaying technique.

3rd, the D2D total system speed of cell of the present invention is significantly improved, along with the raising of frequency spectrum resource utilization rate.

Brief description of the drawings

Fig. 1 is the D2D Principle of Communication figures based on relaying of the invention.

Fig. 2 is the D2D communication flow diagrams using single relaying of the invention.

Fig. 3 is the D2D communication system schematic diagrames of MIMO cooperative relayings of the invention.

Specific embodiment

The technical scheme invented is described in detail below in conjunction with the accompanying drawings

Embodiment one

As shown in figure 3, the D2D communication systems of MIMO cooperative relayings of the invention are in a cellular cell, the system Including a base station, a phone user, the user that carry out D2D pattern communications for a pair and a relaying, wherein D2D user and The antenna number of phone user is M, and the antenna number of relaying is N, and the antenna number of base station is I.D2D user and relaying are described in Fig. 3 Disturbed condition during multiplexing phone user's ascending resource.D1 and D2 are respectively the originator and receiving terminal of D2D user in Fig. 3, and R is represented Via node, C represents phone user.D1 represents the source node S in three nodes of relaying, and D2 represents the purpose section in three nodes of relaying Point D.Assuming that phone user is always in working order, then phone user can produce interference, the work of relaying to via node and D2 Mode is that time-division semiduplex mode, i.e. via node are received with two time slots and send information, then the communication of system is divided into two Individual time slot：

First time slot D1 sending signals in a broadcast manner：

D2 receives signal and is expressed as：

y_sd=H_sdx+H_cdx_c+n_sd (1)

R receives signal and is expressed as：

y_sr=H_srx+H_crx_c+n_sr (2)

The signal that second time slot R is crossed with dedicated channel transmission processe, the signal that D2 is received is：

y_rd=H_rdx_r+H_cdx_c+n_rd (3)

X represents the signal vector of D1 transmissions, x_cRepresent the signal vector of C transmissions, x_rRepresent the signal vector of R transmissions；tr(E [xx^H])=P_s、P_s、P_c、P_rIt is D1, C, R user's total transmission power.H_sd、H_sr、H_rd、H_cr、H_cdIt is Channel information between node S, D, R, C_UE, they are averages 0, and variance is Multiple Gauss random matrix, their matrix size be M × M, N × M, M × N, N × M, M × M.n_sd、n_sr、n_rdIt is that average is 0, Variance is σ²Multiple Gauss random noise matrix.

Forward mode on via node R, the present invention discussion herein AF patterns and DF patterns.During AF patterns, in It is amplified after the signal only to receiving, is then forwarded to destination node；During DF patterns, via node is first to receiving Signal decode and then encoded again, relays to destination node.

When relaying is operated in AF patterns：

x_r=Fy_sr=FH_srx+FH_crx_c+Fn_sr (4)

Then (4) formula (3) formula is substituted into obtain：

(5) Part II of formula is total interference, and wherein F is the amplification matrix of relaying.

System velocity is analyzed：

Present invention discusses the problem rate of the D2D communication systems of MIMO cooperative relayings.Assuming that via node and purpose section Point both knows about channel condition information.The system is divided into three kinds of situations by the present invention：The first is only S-D links, is for second Only repeated link S-R-D, the third is that S-D links and repeated link S-R-D have.The present invention is asked according to three kinds of situations The speed of solution system.

Direct link (S-D)：

The system velocity that can draw S-D links according to relevant knowledge is：

Wherein, R_x=E [xx^H] and

When the present invention distributes equal-wattage on the every antenna of D1 user, thenSubstitute into (8) rate representation that formula can obtain the direct link S-D under constant power distribution is：

When the present invention is distributed on the every antenna of D1 user differs power, orderCan obtain MatrixCharacteristic value be { λ₁...λ_i...λ_M}.The present invention solves the transmission power of single antenna with water flood below, can To draw：

Wherein (x)⁺Expression max (0, x).

The present invention can draw distribution power on every antenna do not wait under the rate equation of S-D links be：

Relaying AF mode links (S-R-D)：

The total speed that can draw S-R-D links by MIMO technology is：

Wherein,

Solve forwarding matrix F below, the present invention is divided in two situation to solve F, and a kind of is the amplification factor of each antenna Identical, another kind is that the amplification factor of each antenna is different.

The F=AI when amplification factor is identical_N, A is amplification factor, can be from formulaWithDraw：

When amplification factor is different, the present invention solves F using the method for singular value decomposition (SVD), such that it is able to draw The expression formula of the singular value decomposition of amplification matrix F and channel condition information：

Wherein,

F can be solved with Lagrangian method_i：

Wherein,C_i=r_cψ_i+ 1, v can be byObtain.

The amplification factor f for trying to achieve above_iFormula can be in the hope of using not in substituting into formula (16) under out-trunk AF patterns Link rate during with amplification factor.

Relaying DF mode links (S-R-D)：

When seeking the speed of DF patterns, because the speed of two time slots is independent, it is possible to individually try to achieve, then system Total speed is to compare two speed sizes of time slot, and small speed is total speed of system:

Wherein,With

With

Outage probability is analyzed：

The present invention analyzes the outage probability problem of the D2D communication systems of MIMO cooperative relayings, and outage probability is to be The signal to noise ratio of system is less than probability during certain target signal to noise ratio, and the size of signal-noise ratio threshold value directly affects system break probability Size.Assuming that via node and destination node both know about channel condition information, the present invention derives direct link, relaying DF moulds respectively Outage probability formula in the case of formula, three kinds of relaying AF patterns.

The outage probability of direct link：

Present invention assumes that the threshold value of system signal noise ratio is r₀, the noise of direct link receiving terminal can be drawn by (1) formula Than for：

Wherein | | | |_FThe F- norms of representing matrix.

The present invention can show that the outage probability expression formula of direct link is：

Wherein,

Wherein,

M represents the antenna number of user；

r₀It is system signal noise ratio threshold value；

σ²It is the variance of multiple Gauss random noise matrix；

P_sRepresent the transmission power of D2D user；

P_rRepresent the transmission power of relaying；

P_cRepresent the emission function of phone user；

||.||_FThe F- norms of representing matrix；

Represent the variance of the multiple Gauss random matrix between base station and D2D user；

Represent the variance of the multiple Gauss random matrix between base station and relaying；

Represent the variance of the multiple Gauss random matrix between relaying and D2D user；

Represent the variance of the multiple Gauss random matrix between phone user and relaying；

Represent the variance of the multiple Gauss random matrix between phone user and D2D user.

Outage probability under relaying AF patterns：

In the case of ignoring direct link, can be drawn in relay selection AF pattern forward signals by relaying technique knowledge When, total signal to noise ratio expression formula of S-R-D links is：

The final expression formula of outage probability that can be obtained under out-trunk AF patterns is：

Wherein,Outage probability under relaying DF patterns：

In the case of ignoring direct link, S-R link receiving terminal signal to noise ratios and R-D links can be drawn by formula (2) and (3) Receiving terminal signal to noise ratio is：

The expression formula of system signal noise ratio under relaying DF patterns is：

r_df=min (r_sr,r_rd)

So the outage probability under relaying DF patterns can be expressed as：

Following expression formula can be drawn by the derivation formula of direct link outage probability：

Wherein,

Wherein,

M represents the antenna number of user；

r₀It is system signal noise ratio threshold value；

σ²It is the variance of multiple Gauss random noise matrix；

P_sRepresent the transmission power of D2D user；

P_rRepresent the transmission power of relaying；

P_cRepresent the emission function of phone user；

||.||_FThe F- norms of representing matrix；

Represent the variance of the multiple Gauss random matrix between base station and D2D user；

Represent the variance of the multiple Gauss random matrix between base station and relaying；

Represent the variance of the multiple Gauss random matrix between relaying and D2D user；

Represent the variance of the multiple Gauss random matrix between phone user and relaying；

Represent the variance of the multiple Gauss random matrix between phone user and D2D user.

Can be in the hope of the system break probability under out-trunk DF patterns during (19) formula is substituted into (18) formula.

Embodiment two

As shown in figure 1, the present invention is in broadband cellular GSM (IMT-Advanced), a pair of phone users will Terminal direct connection is carried out, but because the distance between they are more than the coverage that D2D communicates, or the channel chain between them Road can't meet the quality requirement, the UE user that there is the substantial amounts of free time in cell, by the use of idle mobile as relaying, assist Helping a pair of phone users carries out D2D communications.The originator of a pair of terminal direct connection phone users is designated as D1, and receiving terminal is designated as D2, relaying It is designated as R.When D1 and R are communicated, the frequency resource of phone user and base station communication in D1 reuse patterns, at this moment D1 and R structures Into a pair of D2D communications；When R and D2 are communicated, R be also multiplexed honeycomb residence user and base station communication frequency resource (and The frequency resource of D1 is identical), at this moment R and D2 constitutes a pair of D2D communications.D2D trunking traffics are namely wanted to carry out D2D a pair The phone user of communication is divided into two pairs of D2D communications, is D1-R and R-D2.

As shown in Fig. 2 the invention provides a kind of single relay communication method based on terminal direct connection communication, the method is base In single relaying implementation method of cellular system, it comprises the following steps：

Step one：User D1 is intended to initiate to communicate with user D2, and session request is sent to base station, and base station receives user D1's Signal, sends answer signal, and starts to search for the position of user D2.

Step 2：Base station search starts to judge that whether D2D is met between user D1 and user D2 to be led to the position of user D2 The condition of letter, uses D2D communication patterns, user D1 and user D2 to start D2D communications if meeting.

Step 3：When user D1 and user D2 are unsatisfactory for D2D communication conditions, judge whether the communication between them meets The requirement of speed, uses legacy cellular pattern communication if meeting；If be unsatisfactory for, led to using the method for relaying auxiliary Letter.

Step 4：If desired, source broadcast RTS (Ready to send) information, destination broadcast CTS (Clear to Send), the free subscriber of surrounding, according to signal RTS, CTS for receiving, reports that, to base station, base station determines to participate in as relaying The free subscriber of relaying.

Step 5：When it is determined that the relaying for participating in communication is R, user D1 first sets out breath of delivering letters to relaying R, at this moment user D1 and relaying R carry out D2D one-way communications, and relaying R carries out D2D one-way communications with user D2 again after receiving information；When D2 is received To after information, the information that retransmits is routing the message to user D1 to relaying R, relaying R.

Step 6：User D1 and D2 confirm that communication process is completed, and send the request for terminating session to base station respectively, and base station is right Terminate the working condition of relaying R afterwards, whole conversation procedure terminates.

Claims (2)

1. a kind of terminal direct connection communication means based on multiple-input, multiple-output cooperative relaying, it is characterised in that methods described includes as follows Step：

Step one：User D1 is intended to initiate to communicate with user D2, and session request is sent to base station, and base station receives the letter of user D1 Number, answer signal is sent, and start to search for the position of user D2；

Step 2：Whether base station search starts to judge meet what D2D communicated between user D1 and user D2 to the position of user D2 Condition, uses D2D communication patterns, user D1 and user D2 to start D2D communications if meeting；

Step 3：When user D1 and user D2 are unsatisfactory for D2D communication conditions, judge whether the communication between them meets speed Requirement, if meet just use legacy cellular pattern communication；If be unsatisfactory for, communicated using the method for relaying auxiliary；

Step 4：If desired, source broadcast RTS information, destination broadcast CTS, the free subscriber of surrounding as relaying, according to connecing Signal RTS, the CTS for receiving, report to base station, base station determines to participate in the free subscriber of relaying；

Step 5：When it is determined that the relaying for participating in communication is R, user D1 first sets out breath of delivering letters to relaying R, at this moment user D1 and Relaying R carries out D2D one-way communications, and relaying R carries out D2D one-way communications with user D2 again after receiving information；When D2 receives letter After breath, the information that retransmits is routing the message to user D1 to relaying R, relaying R；

Step 6：User D1 and D2 confirm that communication process is completed, and send the request for terminating session, base station and then knot to base station respectively The working condition of Shu Zhongji R, whole conversation procedure terminates；

Methods described includes direct link, relaying AF mode links, relaying DF three kinds of links of mode link；Direct link, in After under AF mode links, relaying DF three kinds of links of mode link, the outage probability that D2D relaying mimo systems have been derived respectively is public Formula；

The outage probability expression formula of the direct link is：

$P_{out}^{sd}\left(r_0\right)=\mathrm{Pr}(r_{sd}=\frac{P_s\left|\right|H_{sd}|{|}_F^2}{P_c\left|\right|H_{cd}|{|}_F^2+{\mathrm{M\σ}}^2}\≤r_0)=1-\frac{e^{-b}}{(M^2-1)!}\underset{k=0}{\overset{M^2-1}{\Σ}}\underset{i=0}{\overset{k}{\Σ}}{C}_k^i{a}^i{b}^{k-i}\frac{(M^2+i-1)!}{k!{(a+1)}^{M^2+i}}---\left(14\right)$

Wherein,

Wherein,

M represents the antenna number of user；

r₀It is system signal noise ratio threshold value；

σ²It is the variance of multiple Gauss random noise matrix；

P_sRepresent the transmission power of D2D user；

P_rRepresent the transmission power of relaying；

P_cRepresent the emission function of phone user；

||.||_FThe F- norms of representing matrix；

Represent the variance of the multiple Gauss random matrix between base station and D2D user；

Represent the variance of the multiple Gauss random matrix between base station and relaying；

Represent the variance of the multiple Gauss random matrix between relaying and D2D user；

Represent the variance of the multiple Gauss random matrix between phone user and relaying；

Represent the variance of the multiple Gauss random matrix between phone user and D2D user；

Outage probability under the relaying AF patterns is：

In relay selection AF pattern forward signals, total signal to noise ratio expression formula of S-R-D links is：

$r_{af}=\frac{r_{sr}{r}_{rd}}{r_{sr}+r_{rd}+1}=\frac{\frac{P_s\left|\right|H_{sr}|{|}_F^2}{P_c\left|\right|H_{cr}|{|}_F^2+{\mathrm{N\σ}}^2}\frac{P_r\left|\right|H_{rd}|{|}_F^2}{P_c\left|\right|H_{cd}|{|}_F^2+{\mathrm{M\σ}}^2}}{\frac{P_s\left|\right|H_{sr}|{|}_F^2}{P_c\left|\right|H_{cr}|{|}_F^2+{\mathrm{N\σ}}^2}+\frac{P_r\left|\right|H_{rd}|{|}_F^2}{P_c\left|\right|H_{cd}|{|}_F^2+{\mathrm{M\σ}}^2}+1}---\left(15\right)$

The final expression formula of outage probability under out-trunk AF patterns is：

$P_{out}^{af}\left(r_0\right)=1-\frac{e^{-\frac{r_0}{2}(\frac{1}{r_1{\mathrm{\σ}}_{sr}^2}+\frac{1}{r_2{\mathrm{\σ}}_{rd}^2})}}{\mathrm{\Γ}\left(MN\right){\left(2r_2\right)}^{MN}{\left({\mathrm{\σ}}_{rd}^2\right)}^{MN-1}}\·\underset{n=0}{\overset{MN-1}{\Σ}}\underset{k=0}{\overset{n}{\Σ}}\underset{i=0}{\overset{MN-1}{\Σ}}\frac{C_n^k{C}_{MN-1}^i{(r_0+1)}^k{r}_0^i}{n!{\left(2r_1{\mathrm{\σ}}_{sr}^2\right)}^n}g(k,i)---\left(16\right)$

Wherein,

Outage probability under the relaying DF patterns is expressed as：

$P_{out}^{df}=\mathrm{Pr}(r_{df}\≤r_0)=\mathrm{Pr}\left(min\right(r_{sr},r_{rd})\≤r_0)=1-\[1-\mathrm{Pr}(r_{sr}\≤r_0)\]\[1-\mathrm{Pr}(r_{rd}\≤r_0)\]---\left(18\right)$

Following expression formula is drawn by the derivation formula of direct link outage probability：

$\begin{array}{c}\mathrm{Pr}\left(r_{sr}\≤r_0\right)=1-\frac{e^{-b_0}}{\left(MN-1\right)!}\underset{k=0}{\overset{MN-1}{\mathrm{\Σ}}}\underset{i=0}{\overset{k}{\mathrm{\Σ}}}{C}_k^i{a}_0^i{b}_0^{k-i}\frac{\left(MN+i-1\right)!}{k!{\left(a_0+1\right)}^{MN+i}}\\ \mathrm{Pr}\left(r_{rd}\≤r_0\right)=1-\frac{e^{-b_1}}{\left(M^2-1\right)!}\underset{k=0}{\overset{MN-1}{\mathrm{\Σ}}}\underset{i=0}{\overset{k}{\mathrm{\Σ}}}{C}_k^i{a}_1^i{b}_1^{k-i}\frac{\left(M^2+i-1\right)!}{k!{\left(a_1+1\right)}^{M^2+i}}\end{array}---\left(19\right)$

Wherein,

$a_0=\frac{r_0{\mathrm{\σ}}_{cr}^2{P}_c}{P_s{\mathrm{\σ}}_{sr}^2},b_0=\frac{r_0{\mathrm{N\σ}}^2}{2P_s{\mathrm{\σ}}_{sr}^2},a_1=\frac{r_0{\mathrm{\σ}}_{cd}^2{P}_c}{P_r{\mathrm{\σ}}_{rd}^2},b_1=\frac{r_0{\mathrm{M\σ}}^2}{2P_r{\mathrm{\σ}}_{rd}^2}$

Wherein,

M represents the antenna number of user；

N is the antenna number of relaying；

r₀It is system signal noise ratio threshold value；

σ²It is the variance of multiple Gauss random noise matrix；

P_sRepresent the transmission power of D2D user；

P_rRepresent the transmission power of relaying；

P_cRepresent C user's total transmission power；

||.||_FThe F- norms of representing matrix；

Represent the variance of the multiple Gauss random matrix between base station and D2D user；

Represent the variance of the multiple Gauss random matrix between base station and relaying；

Represent the variance of the multiple Gauss random matrix between relaying and D2D user；

Represent the variance of the multiple Gauss random matrix between phone user and relaying；

Represent the variance of the multiple Gauss random matrix between phone user and D2D user；

H_sd、H_sr、H_rd、H_cr、H_cdRepresent the channel information between node S, D, R, C_UE；

Wushu (19) substitutes into the system break probability just obtained under relaying DF patterns in formula (18).

2. a kind of terminal direct connection communication means based on multiple-input, multiple-output cooperative relaying according to claim 1, its feature exists In methods described includes：A pair of phone users carry out terminal direct connection in broadband cellular GSM；A pair of phone users Between distance more than the coverage that D2D communicates；By the use of idle mobile as relaying, a pair of phone users are assisted to carry out D2D communicates；The originator of a pair of terminal direct connection phone users is designated as D1, and receiving terminal is designated as D2, and relaying is designated as R, when D1 and R are led to During letter, the frequency resource of phone user and base station communication in D1 reuse patterns, at this moment D1 and R constitute a pair of D2D communications；Work as R When being communicated with D2, R is also multiplexed the frequency resource of honeycomb residence user and base station communication；The frequency resource and D1 of R multiplexings Frequency resource is identical；R and D2 constitutes a pair of D2D communications；A pair of phone users are divided into two pairs of D2D communications by D2D trunking traffics, are D1-R and R-D2.