CN103347246A - Method for finding adjacent user under embedded D2D circumstances in cellular network - Google Patents

Abstract

The invention discloses a method for finding an adjacent user under the embedded D2D circumstances in a cellular network. Based on an existing cellular network, the method for finding the adjacent user under the embedded D2D circumstances in the cellular network utilizes a base station as centre control and achieves efficient interference-free detection of the adjacent user. Due to the fact that the base station is introduced and used as the center control to join in the detection of the adjacent user, distribution of detection time-frequency resource blocks is optimized, the possibility of collision of detection signals is reduced, the possibility of network congestion is reduced, the detection time is shortened, and energy consumption of the detection is reduced. The base station gives full play to the coordination function, and takes an active part in detection of the adjacent user, so that a silent user is made to more easily obtain synchronous information in the process of the detection of the adjacent user, and the safety of the whole process is guaranteed. Due to the fact that the base station is used for storing distribution information of detection resources, the user only needs to conduct simple spectrum detection, to find occupied time-frequency resource block information and to upload the occupied time-frequency resource block information to the base station.

Description

Discover method between proximal subscribers under the embedded D2D environment in the cellular network

Technical field

The invention belongs to communication technical field, relate to the proximal subscribers discovery mechanism of the straight-through D2D of terminal, can be used for the cellular network of the follow-up evolution of IMT-A standard.

Background technology

The D2D technology is the radio communication new technology that a kind of academia in recent years and industrial quarters are paid close attention to and studied.So-called embedded D2D technology refers under the situation that does not influence the integral honeycomb network operation, sets up communication link between the terminal equipment in the cellular cell and carries out direct communication, does not pass through the Radio Transmission Technology of base station transfer.By introducing the D2D technology, can realize reusing, improve efficiency of transmission, reducing the terminal energy consumption of cell resource, and then significantly improve the overall performance of cellular system.

Present academic research direction mainly concentrates on system modelling, performance evaluation, model selection, power control, resource and distributes, disturbs control and offset and based on the cooperating relay of D2D and network code etc.And the discussion of these problems all is based on embedded D2D proximal subscribers discovery technique.

Two kinds of the active probe technology that mainly is divided into of proximal subscribers detection at present and passive detection technology.F. Baccelli, N. Khude, R. Laroia, et.al. article " On the Design of Device-to-Device Autonomous Discovery " has proposed a kind of active periodicity proximal subscribers Detection Techniques of the Wi-Fi of being applicable to network, this scheme is applicable to the non-licensed band D2D communication of no center control, introduces the base station in can not the maximum using cellular network under the embedded D2D environment and surveys the income brought and also can't finish detection process for the user of ongoing communication as center control participating user.

Jungha Lee, Jaheon Gu, et.al. the D2D communication link that article " A Session Setup Mechanism Based on Selective Scanning for Device-to-Device Communication in Cellular Networks " has proposed passive Event triggered is set up this scheme of mode and is compared the expense that has reduced the detecting periodically proximal subscribers with active probe, but in communication initiation process, carry out user's discovery, increased period of reservation of number, simultaneously this scheme only be applicable to discovery between the purpose user of source can't obtain source purpose user around proximal subscribers information, can't provide enough information to make the base station carry out effective and reasonable model selection and resource distribution.

In embedded D2D system, all registered users in the residential quarter may be the target acquisition users.How to realize in the IMT-A system that it is the problem that needs further research, solves that efficient, glitch-free proximal subscribers is surveyed.

Summary of the invention

The objective of the invention is the deficiency at above-mentioned prior art, propose a kind of in cellular network the detection method between proximal subscribers under the embedded D2D environment, namely on the basis of existing cellular network, utilize the base station to control as the center, realize efficient, glitch-free proximal subscribers detection.

For achieving the above object, technical scheme of the present invention comprises the steps:

The discover method between proximal subscribers under the embedded D2D environment comprises the steps: in a kind of cellular network

(1) when new user adds network, the user initiates the application that networks to the base station, and on standard cellular communication user access procedure basis, the base station is that new networking user divides the time that is used in the proximal subscribers detection;

(2) user that mourns in silence who initiates communication on official hour and frequency, sends known definite signal with firm power according to the time of distributing, and we are called detectable signal with this signal;

(3) user that mourns in silence passes through frequency spectrum detection at other idle time slots, survey the user's that mourns in silence in the surrounding environment detectable signal and communication user demodulated reference signal, utilize the detectable signal of reception and time, frequency and the received power class information of demodulated reference signal, form the tabulation of proximal subscribers power grade, and upload the base station, this power grade tabulation comprises time, the frequency that receives signal and arrives the power grade information that receives the user;

(4) user of ongoing communication comprises cellular communication user and D2D communication user, according to existing communication mechanism proper communication, does not carry out proximal subscribers and surveys;

(5) after the proximal subscribers power grade tabulation that the user sends is received in the base station, time-frequency resource allocating and user's mapping relations and communication user reference signal frequency and user's mapping relations are surveyed in contrast, retrieve user's proximal subscribers, and in conjunction with the average channel gain between in advance known detectable signal transmitted power and communication user transmitted power acquisition user and proximal subscribers;

(6) base station utilizes the user's that mourns in silence adjacent communication user profile, utilizes proximal subscribers and the power grade information of the reciprocity acquisition communication user of channel;

(7) base station is in conjunction with mourning in silence user's proximal subscribers power grade information and communication user proximal subscribers power grade information, obtain the mesh topology of the whole network, form the tabulation of the whole network channel gain, this whole network channel gain tabulation comprises that the user is to the average channel gain between base station and the user.

Described method, wherein the described base station of step (1) is that new networking user divides the time that is used in the proximal subscribers detection, carries out as follows:

(1a) new networking user's search cell master sync signal is realized sign synchronization; And according to master sync signal search auxiliary synchronous signals, achieve frame is synchronous;

After (1b) user realizes synchronously, obtain system information by broadcast channel and Physical Downlink Shared Channel, system information comprises bandwidth, uplink-downlink configuration information, accidental access channel parameter, power control parameters;

(1c) user sends random access lead code to base station eNB on Random Access Channel, after eNB solves lead code, calculates corresponding access-Radio Network Temporary Identifier at random, and eNB sends random access feedback messages by descending synchronous signal channel to the user;

(1d) base station eNB is according to surveying Resource Block identification sign operating position, for the user distributes the detection Resource Block identification sign that is not used and sets up detection Resource Block identification sign and the tabulation of Cell Radio Network Temporary Identifier/Identity, Cell-RNTI corresponding relation;

(1e) base station eNB will be surveyed Resource Block identification sign corresponding physical detection running time-frequency resource information at this moment and notify the user by transmitting system block of information SIB on Physical Downlink Shared Channel;

(1f) base station eNB is used identical time domain saltus step rule with the user, calculate this user after the physical detecting running time-frequency resource that uses during each the detection, the map listing of renewal physical detecting running time-frequency resource and Resource Block identification sign.

Described method, wherein the user that mourns in silence of step (3) passes through frequency spectrum detection at other idle time slots, survey the user's detectable signal of mourning in silence in the surrounding environment, utilize the time, frequency and the received power class information that receive detectable signal, form the tabulation of proximal subscribers power grade, and upload the base station, carry out as follows:

(2a) mourn in silence the user sending the detectable signal time in addition, all be in the state of intercepting;

(2b) user that mourns in silence utilizes matched filtering frequency spectrum detection technology to the signal that receives, and detects and receives time, the frequency information that contained detectable signal occurs in the signal;

(2c) receive signal and obtain test statistics after by the matched filtering frequency spectrum detection, the user that mourns in silence utilizes the minimum error probability criterion that test statistics is classified, and obtains the power detecting signal grade that receives; This detection statistic is the profiling product of the signal that receives and known detectable signal to be carried out related operation obtain;

(2d) user will receive time, frequency and the received power class information of detectable signal, form the tabulation of proximal subscribers power grade, and upload the base station;

(2e) user's repeating step (2a)-(2d) regular update is tabulated and is uploaded to the base station.

Described method, wherein the described user of mourning in silence of step (3) passes through frequency spectrum detection at other idle time slots, survey communication user demodulated reference signal in the surrounding environment, utilize time, frequency and the received power class information of receiving demodulation reference signal, form the tabulation of proximal subscribers power grade, and upload the base station, carry out as follows:

(3a) user that mourns in silence in the demodulated reference signal sending time slots of communication user does not carry out detectable signal to send, and intercepts the demodulated reference signal of communication user in the surrounding environment this section user that mourns in silence period;

(3b) user that mourns in silence utilizes matched filtering frequency spectrum detection technology to the signal that receives, and detects and receives the frequency information that contained reference signal occurs in the signal;

(3c) receive signal and obtain test statistics after by the matched filtering frequency spectrum detection, the user that mourns in silence utilizes the minimum error probability criterion that test statistics is classified, and obtains the demodulated reference signal power grade that receives; This detection statistic is the profiling product of the signal that receives and known demodulated reference signal to be carried out related operation obtain;

(3d) user forms time, frequency and the received power class information of received training sequence the tabulation of proximal subscribers power grade, and uploads the base station;

(3e) user's repeating step (3a)-(3d) regular update is tabulated and is uploaded to the base station.

Described method, wherein the described base station of step (5) is in conjunction with the average channel gain between in advance known detectable signal transmitted power and communication user transmitted power acquisition user and proximal subscribers, refer to that the base station utilizes known detectable signal transmitted power and communication user transmitted power, and the power grade of uploading in conjunction with user tabulation, by the channel gain computing formula, obtain the average channel gain between user and proximal subscribers.

Described method, wherein the described base station of step (6) utilizes the user's that mourns in silence adjacent communication user profile, utilizes proximal subscribers and the power grade information of the reciprocity acquisition communication user of channel, carries out as follows:

(6a) base station retrieves communication user from the power grade tabulation that the user that mourns in silence uploads;

(6b) at a certain communication user, all find this user's the user that mourns in silence reverse find; These users that mourn in silence are the proximal subscribers of this communication user, and utilize the reciprocity of channel, can obtain communication user and its contiguous user's that mourns in silence average channel gain.

The present invention and no center (as the ad-hoc) proximal subscribers that controls environment is down surveyed to compare and is had the following advantages:

(1) because the introducing base station participates in the proximal subscribers detection as center control, optimized the distribution of surveying time, reduced the probability of detectable signal appearance collision, alleviated network and congested possibility occurred, reduced detection time and surveyed energy consumption;

(2) coordination function is given full play in the base station, plays an active part in the proximal subscribers detection process, makes the user that mourns in silence carry out proximal subscribers easier acquisition synchronizing information when surveying, and has guaranteed the fail safe of whole process;

(3) utilize the base station to surveying the storage of resource allocation information, each user only does simple frequency spectrum detection, finds that occupied running time-frequency resource block message uploads the base station.The base station is by the corresponding proximal subscribers of stored resource assignment information identification;

(4) take full advantage of the computing capability of base station, the mesh topology of the whole network obtains at the base station end, distributes, disturbs control, model selection for follow-up resource and provide support.

Description of drawings

Fig. 1 is the explore frame structure chart of the embedded D2D of the present invention;

Fig. 2 is the IMT-A cellular network scene schematic diagram that the present invention uses.

Embodiment

Be without loss of generality, apply the present invention to be illustrated in the network of being convenient to understand, transmission frame-form as shown in Figure 1, this transmission frame is significantly not change on the basis of original cellular communications transmissions frame structure, D2D user utilizes the cellular communication ascending resource to transmit.

The network scenarios that the present invention uses, as shown in Figure 2.Three users are respectively UE among Fig. 2 ₁, UE ₂And UE ₃, they are all in the coverage of base station eNB (evolved Node B), at current time UE ₃Communicate by letter with carrying out standard cellular between the base station, and UE ₂Be in intercepting the stage of detect cycle, UE ₁Be in the launching phase of detect cycle.Make g _Ij, i=1,2,3; J=1,2,3 is UE _iWith UE _jBetween channel gain, h _j, j=1,2,3 is UE _jAnd the channel gain between the base station eNB, P _j, j=1,2,3 is each user's transmitting power.PRB is in the LTE system, and control centre carries out least unit that resource distributes, and (frequency domain bandwidth is F ₀, the time domain time is T ₀), the time of PRBDIS for being used for surveying, PRBCOM is for being used for the time of communication.C-RNTI is Cell Radio Network Temporary Identifier/Identity, Cell-RNTI.D2D communication shares the cellular communication uplink transmission resource and is operated under the FDD mode.

Specific implementation process of the present invention is:

Step 1: work as UE ₁When adding network, UE ₁Initiate the application that networks to eNB, on standard cellular communication user access procedure basis, base station eNB is UE ₁Divide and be used in the time that proximal subscribers is surveyed.

(1a) UE ₁Search cell master sync signal (PSS) is realized sign synchronization; And according to master sync signal search auxiliary synchronous signals (SSS), achieve frame is synchronous;

(1b) UE ₁After realizing synchronously, obtain system information (system information comprises bandwidth, uplink-downlink configuration information, RACH parameter, power control parameters etc.) by broadcast channel (BCH) and Physical Downlink Shared Channel (PDSCH).

(1c) UE ₁On Random Access Channel, send random access lead code to eNB, after eNB solves lead code, calculate corresponding access-Radio Network Temporary Identifier at random (RA-RNTI), eNB by descending synchronous signal channel to UE ₁Send random access feedback messages.

(1d) eNB is user UE according to surveying Resource Block identification sign (PDRID) operating position in this cycle ₁Distribute the detection Resource Block identification sign that is not used, and set up and survey Resource Block identification sign and the tabulation of Cell Radio Network Temporary Identifier/Identity, Cell-RNTI (C-RNTI) corresponding relation, as shown in table 1.

Table 1 PDRID and the tabulation of C-RNTI corresponding relation

User identity	C-RNTI	PDRID
			UE 1	a	C(2,1)

This step (1d) specific implementation method is as follows:

PDRID is for surveying Resource Block identification sign, and T is for surveying the repetition period.Surveying in the repetition period for one has M radio frames, and some Physical Resource Block PRB that can be used for surveying are arranged in each radio frames.

Survey in the cycle period T at one, be divided into NT PRB from time domain; In the system bandwidth, be divided into NF PRB from frequency domain, the time one total K that then can be used for the proximal subscribers detection in a detect cycle is individual, K=NF*NT.

It is corresponding one by one with this K physical detecting time to survey Resource Block identification sign, and (I J) represents concrete some detection Resource Block identification signs to C, 0≤I≤NF-1 wherein, 0≤J≤NT-1.ENB is UE at random ₁Distribute untapped detection Resource Block identification sign.

(1e) eNB will survey Resource Block identification sign corresponding physical detection running time-frequency resource (PRBDIS) information and inform user UE by the SIB that sends at Physical Downlink Shared Channel ₁The specific implementation method is as follows:

It is individual to survey Resource Block identification sign one total K=NF*NT, C (I, J) the concrete some detection Resource Block identification signs of expression, corresponding physical is surveyed time PRBDIS also NF*NT, R (i, j) the concrete some physical detecting time of expression, 0≤i≤NF-1 wherein, 0≤j≤NT-1.

ENB calculates current time and surveys Resource Block identification sign corresponding physical detection time according to user's detection Resource Block identification sign and current repetition period sequence number t.Suppose NT=4, concrete rule is as follows:

Saltus step rule i (t)=i (t-1); J (t)=[j (t-1)+I] mod NT;

i(t)=i(0);?j(t)=[j(0)+t*I]?mod?NT;

Especially: t=0, i (t)=I; J (t)=J;

For user UE ₁: t=0, i (0)=2; J (0)=1;

t=1,?i(1)=2;?j(1)=[j(0)+I]?mod?NT=[1+2]?mod?4?=3;

t=2,?i(2)=2;?j(2)=[j(1)+I]?mod?NT?=[3+2]?mod?4=1;

……

(1f) eNB and user UE ₁Use identical time domain saltus step rule, calculate this user UE ₁After the physical detecting running time-frequency resource that uses (PRBDIS) when surveying, upgrade the map listing of PRBDIS and PDRID.

Step 2:UE ₁On official hour and frequency, send known definite signal with firm power according to the time of distributing, we are called detectable signal with this signal.

Step 3:UE ₂Pass through frequency spectrum detection at other idle time slots, survey mourn in silence in the surrounding environment user's detectable signal and communication user demodulated reference signal (DM RS), utilize the time, frequency and the received power class information that receive detectable signal and demodulated reference signal (DM RS), form the tabulation of proximal subscribers power grade, and upload the base station, this power grade tabulation comprises time, the frequency that receives signal and arrives the power grade information that receives the user;

(3a) mourn in silence the user sending the detectable signal time in addition, all be in the state of intercepting;

(3b) user that mourns in silence utilizes matched filtering frequency spectrum detection technology to the signal that receives, and detects and receives time, the frequency information that contained detectable signal occurs in the signal;

Matched filtering frequency spectrum detection principle is as follows:

The design criterion that matched filter detects is exactly to make the output signal-to-noise ratio SNR of signal at a time reach maximum.The signal to noise ratio snr expression formula is as follows:

$\mathrm{SNR}=\frac{2\mathrm{Es}}{N_0}$

Es is the energy of detection signal in the observation time section in the formula, N ₀Be noise power.

Channel also is superimposed with white Gaussian noise n (t) when the transmission signal, its average is zero, and bilateral power spectral density is N _0// 2, therefore receive signal waveform and be:

$r\left(t\right)=s\left(t\right)+n\left(t\right),0\≤t\≤T$

If the optimum linear filter H (ω) under the maximum output signal-to-noise ratio criterion is output as

$y\left(t\right)=s_o\left(t\right)+n_0\left(t\right)$

At t=t _mThe time, output signal-to-noise ratio is:

$\mathrm{\ρ}=\frac{s_o^2\left(t_m\right)}{n_o^2\left(t_m\right)}$

If S (j ω)=F[s (t)], through the output signal behind the matched filter be so

$s_o\left(t_m\right)=\frac{1}{2\mathrm{\π}}{\∫}_{-\∞}^{\∞}H\left(\mathrm{j\ω}\right)S\left(\mathrm{j\ω}\right)e^{\mathrm{j\ω}{t}_m}\mathrm{d\ω}$

The white noise power spectrum is | H (j ω) | ²N is so noise average power is

$\stackrel{\‾}{n_o^2\left(t\right)}=\frac{1}{2\mathrm{\π}}{\∫}_{-\∞}^{\∞}N{\left|H\left(\mathrm{j\ω}\right)\right|}^2\mathrm{d\ω}$

It doesn't matter noise average power and time as can be seen by top formula, so can draw:

$n_o^2\left(t\right)=\frac{1}{2\mathrm{\π}}{\∫}_{-\∞}^{\∞}N{\left|H\left(\mathrm{j\ω}\right)\right|}^2\mathrm{d\ω}$

Because output signal is real number, so signal to noise ratio is

$\mathrm{\ρ}=\frac{s_o^2\left(t_m\right)}{n_o^2\left(t_m\right)}=\frac{{\left|{\∫}_{-\∞}^{\∞}H\left(\mathrm{j\ω}\right)S\left(\mathrm{j\ω}\right)e^{\mathrm{j\ω}{t}_m}\mathrm{d\ω}\right|}^2}{2\mathrm{\πN}{\∫}_{-\∞}^{\∞}{\left|H\left(\mathrm{j\ω}\right)\right|}^2\mathrm{d\ω}}$

According to Cauchy-history gas inequality

${\left|{\∫}_{-\∞}^{\∞}H\left(\mathrm{j\ω}\right)S\left(\mathrm{j\ω}\right)e^{\mathrm{j\ω}{t}_m}\mathrm{d\ω}\right|}^2\≤{\∫}_{-\∞}^{\∞}{\left|H\left(\mathrm{j\ω}\right)\right|}^2\mathrm{d\ω}{\∫}_{-\∞}^{\∞}{\left|S\left(\mathrm{j\ω}\right)\right|}^2\mathrm{d\ω}$

In order to make signal to noise ratio obtain maximum, that is to say to make top inequality obtain equal sign, when matched filter satisfies: $H\left(\mathrm{j\ω}\right)=k[S\left(\mathrm{j\ω}\right)e^{\mathrm{j\ω}{t}_m}{]}^{*}=\mathrm{kS}(-\mathrm{j\ω})e^{-j{\mathrm{\ωt}}_m}$ ；

The signal to noise ratio maximum of filter output is:

${\mathrm{\ρ}}_{\max }=\frac{s_o^2\left(t_m\right)}{n_o^2\left(t_m\right)}=\frac{1}{2\mathrm{\πN}}{\∫}_{-\∞}^{\∞}{\left|S\left(\mathrm{j\ω}\right)\right|}^2\mathrm{d\ω}$

At this moment, the frequency domain relational expression of matched filter is:

$H\left(\mathrm{j\ω}\right)=\mathrm{kS}{(-\mathrm{j\ω})e}^{-j{\mathrm{\ω}}_m}$

Corresponding time domain relational expression is $h\left(t\right)=F^{-1}\left[H\left(\mathrm{j\ω}\right)\right]={\mathrm{ks}}^{*}(t_m-t)$ ；

The function that can be drawn the matched filtering frequency spectrum detection by top derivation is equivalent to the signal that receives and the profiling product of known detectable signal are carried out related operation:

$y\left(t\right)=r\left(t\right)*h\left(t\right)=(s\left(t\right)+n\left(t\right))*s^{*}(t_m-t)$

Be that the threshold value of test statistics and setting relatively can judge to receive in the signal whether have detectable signal by the output result with matched filter, and then obtain to receive time, the frequency information that contained detectable signal occurs in the signal.

(3c) receive signal and obtain test statistics after by the matched filtering frequency spectrum detection, the user that mourns in silence utilizes the minimum error probability criterion that test statistics is classified, and obtains the power detecting signal grade that receives.This detection statistic is exactly the output of matched filter;

(3d) user will receive time, frequency and the received power class information of detectable signal, form the tabulation of proximal subscribers power grade, and upload the base station;

(3e) user's repeating step (3a)-(3d) regular update is tabulated and is uploaded to the base station.

Step 4:UE ₃According to existing communication mechanism proper communication, do not carry out proximal subscribers and survey.

Step 5: UE is received in the base station ₂After the proximal subscribers power grade tabulation that sends, time-frequency resource allocating and user's mapping relations and communication user reference signal frequency and user's mapping relations are surveyed in contrast, retrieve user's proximal subscribers, and in conjunction with the average channel gain between in advance known detectable signal transmitted power and communication user transmitted power acquisition user and proximal subscribers;

Work as t=1, during NT=4, UE ₂The proximal subscribers power grade tabulation that is uploaded to the base station is as shown in table 2.

The tabulation of table 2 proximal subscribers power grade

Received power	Running time-frequency resource
		P 21	R(2,3)
P 23	PRB

PRB is UE ₃The running time-frequency resource of the proper communication that distributes.The base station calculates user's PDRID according to physical detecting running time-frequency resource information and the detection running time-frequency resource saltus step rule that the user uploads, and utilizes table 1 to obtain the corresponding relation of PDRID and C-RNTI.And according to the channel gain formula:

$H_{\mathrm{ij}}=\frac{P_r}{P_t}$

Obtain UE ₂With UE ₁And UE ₂With UE ₃Between channel gain H ₂₁, H ₂₃

Step 6: the base station utilizes the user's that mourns in silence adjacent communication user profile, utilizes the reciprocity of channel oppositely to obtain proximal subscribers and the power grade information of communication user;

Step 7: the base station is in conjunction with mourning in silence user's proximal subscribers power grade information and communication user proximal subscribers power grade information, obtain the mesh topology of the whole network, form the whole network channel gain tabulation 3, the tabulation of this whole network channel gain refers to that the base station knows each user to the channel condition information of base station, and the average channel gain between the user.

The tabulation of table 3 the whole network channel gain

Should be understood that, for those of ordinary skills, can be improved according to the above description or conversion, and all these improvement and conversion all should belong to the protection range of claims of the present invention.

Claims (6)

1. the discover method between proximal subscribers under the embedded D2D environment in the cellular network is characterized in that, comprises the steps:

(1) when new user adds network, the user initiates the application that networks to the base station, and on standard cellular communication user access procedure basis, the base station is that new networking user divides the time that is used in the proximal subscribers detection;

(2) user that mourns in silence who initiates communication on official hour and frequency, sends known definite signal with firm power according to the time of distributing, and we are called detectable signal with this signal;

(3) user that mourns in silence passes through frequency spectrum detection at other idle time slots, survey the user's that mourns in silence in the surrounding environment detectable signal and communication user demodulated reference signal, utilize the detectable signal of reception and time, frequency and the received power class information of demodulated reference signal, form the tabulation of proximal subscribers power grade, and upload the base station, this power grade tabulation comprises time, the frequency that receives signal and arrives the power grade information that receives the user;

(4) user of ongoing communication comprises cellular communication user and D2D communication user, according to existing communication mechanism proper communication, does not carry out proximal subscribers and surveys;

(5) after the proximal subscribers power grade tabulation that the user sends is received in the base station, time-frequency resource allocating and user's mapping relations and communication user reference signal frequency and user's mapping relations are surveyed in contrast, retrieve user's proximal subscribers, and in conjunction with the average channel gain between in advance known detectable signal transmitted power and communication user transmitted power acquisition user and proximal subscribers;

(6) base station utilizes the user's that mourns in silence adjacent communication user profile, utilizes proximal subscribers and the power grade information of the reciprocity acquisition communication user of channel;

(7) base station is in conjunction with mourning in silence user's proximal subscribers power grade information and communication user proximal subscribers power grade information, obtain the mesh topology of the whole network, form the tabulation of the whole network channel gain, this whole network channel gain tabulation comprises that the user is to the average channel gain between base station and the user.

2. method according to claim 1 is characterized in that, wherein the described base station of step (1) is that new networking user divides the time that is used in the proximal subscribers detection, carries out as follows:

(1a) new networking user's search cell master sync signal is realized sign synchronization; And according to master sync signal search auxiliary synchronous signals, achieve frame is synchronous;

After (1b) user realizes synchronously, obtain system information by broadcast channel and Physical Downlink Shared Channel, system information comprises bandwidth, uplink-downlink configuration information, accidental access channel parameter, power control parameters;

(1c) user sends random access lead code to base station eNB on Random Access Channel, after eNB solves lead code, calculates corresponding access-Radio Network Temporary Identifier at random, and eNB sends random access feedback messages by descending synchronous signal channel to the user;

(1d) base station eNB is according to surveying Resource Block identification sign operating position, for the user distributes the detection Resource Block identification sign that is not used and sets up detection Resource Block identification sign and the tabulation of Cell Radio Network Temporary Identifier/Identity, Cell-RNTI corresponding relation;

(1e) base station eNB will be surveyed Resource Block identification sign corresponding physical detection running time-frequency resource information at this moment and notify the user by transmitting system block of information SIB on Physical Downlink Shared Channel;

(1f) base station eNB is used identical time domain saltus step rule with the user, calculate this user after the physical detecting running time-frequency resource that uses during each the detection, the map listing of renewal physical detecting running time-frequency resource and Resource Block identification sign.

3. method according to claim 1, it is characterized in that, wherein the user that mourns in silence of step (3) passes through frequency spectrum detection at other idle time slots, survey the user's detectable signal of mourning in silence in the surrounding environment, utilize the time, frequency and the received power class information that receive detectable signal, form the tabulation of proximal subscribers power grade, and upload the base station, carry out as follows:

(2a) mourn in silence the user sending the detectable signal time in addition, all be in the state of intercepting;

(2b) user that mourns in silence utilizes matched filtering frequency spectrum detection technology to the signal that receives, and detects and receives time, the frequency information that contained detectable signal occurs in the signal;

(2c) receive signal and obtain test statistics after by the matched filtering frequency spectrum detection, the user that mourns in silence utilizes the minimum error probability criterion that test statistics is classified, and obtains the power detecting signal grade that receives; This detection statistic is the profiling product of the signal that receives and known detectable signal to be carried out related operation obtain;

(2d) user will receive time, frequency and the received power class information of detectable signal, form the tabulation of proximal subscribers power grade, and upload the base station;

(2e) user's repeating step (2a)-(2d) regular update is tabulated and is uploaded to the base station.

4. method according to claim 1, it is characterized in that, wherein the described user of mourning in silence of step (3) passes through frequency spectrum detection at other idle time slots, survey communication user demodulated reference signal in the surrounding environment, utilize time, frequency and the received power class information of receiving demodulation reference signal, form the tabulation of proximal subscribers power grade, and upload the base station, carry out as follows:

(3a) user that mourns in silence in the demodulated reference signal sending time slots of communication user does not carry out detectable signal to send, and intercepts the demodulated reference signal of communication user in the surrounding environment this section user that mourns in silence period;

(3b) user that mourns in silence utilizes matched filtering frequency spectrum detection technology to the signal that receives, and detects and receives the frequency information that contained reference signal occurs in the signal;

(3c) receive signal and obtain test statistics after by the matched filtering frequency spectrum detection, the user that mourns in silence utilizes the minimum error probability criterion that test statistics is classified, and obtains the demodulated reference signal power grade that receives; This detection statistic is the profiling product of the signal that receives and known demodulated reference signal to be carried out related operation obtain;

(3d) user forms time, frequency and the received power class information of received training sequence the tabulation of proximal subscribers power grade, and uploads the base station;

(3e) user's repeating step (3a)-(3d) regular update is tabulated and is uploaded to the base station.

5. method according to claim 1, it is characterized in that, wherein the described base station of step (5) is in conjunction with the average channel gain between in advance known detectable signal transmitted power and communication user transmitted power acquisition user and proximal subscribers, refer to that the base station utilizes known detectable signal transmitted power and communication user transmitted power, and the power grade of uploading in conjunction with user tabulation, by the channel gain computing formula, obtain the average channel gain between user and proximal subscribers.

6. method according to claim 1, it is characterized in that, wherein the described base station of step (6) utilizes the user's that mourns in silence adjacent communication user profile, utilizes proximal subscribers and the power grade information of the reciprocity acquisition communication user of channel, carries out as follows:

(6a) base station retrieves communication user from the power grade tabulation that the user that mourns in silence uploads;

(6b) at a certain communication user, all find this user's the user that mourns in silence reverse find; These users that mourn in silence are the proximal subscribers of this communication user, and utilize the reciprocity of channel, can obtain communication user and its contiguous user's that mourns in silence average channel gain.

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