CN102833761B - In multichannel many primary users cognition network, time user assists the method for primary user's relaying - Google Patents

Abstract

The present invention discloses time user in a kind of multichannel many primary users cognition network and assists the method for primary user's relaying, comprises step: the time is time slotted; At primary user's time slot, consider simultaneously all need the primary user of transmitting data speed and, make the speed of primary user and maximum, and set up optimization problem with this, distribute each user as via node; At secondary user's time slot: if certain time user wants to transmit data, could access when the contribution margin of and if only if this user is enough large, reduction current time slots has accessed the contribution margin of the secondary user of channel simultaneously; At primary user's time slot, be the allocation algorithm based on ant group algorithm according to the secondary algorithm with assistance primary user of optimization problem distribution.In the present invention, primary user is by time user as the assistance of via node, obtains the lifting of transmission rate, simultaneously, secondary user accesses secondary user's time slot that primary user reserves, obtain the right of access spectrum transmissions data, improve the throughput of whole cognition network, practicality and feasibility strong.

Description

In multichannel many primary users cognition network, time user assists the method for primary user's relaying

Technical field

What the present invention relates to is a kind of method of cognitive radio networks technical field, especially a kind of by relay application under multichannel scene, there is the mechanism of the cognitive radio networks of multipair primary user in each channel, is specifically related to time user in multichannel many primary users cognition network and assists the method for primary user's relaying.

Background technology

Cognitive radio technology be one for alleviating the application technology of the key of frequency spectrum resource scarcity problem.In order to realize cognitive radio system, there is a lot of design problem.A wherein very important problem is exactly realize coexisting of primary user and time user.

In traditional cognitive radio system, secondary user is by frequency spectrum perception technology, and namely " frequency spectrum cavity-pocket " that also exist in search surrounding spectrum space, do not have or transmission that the frequency range of the only authorized CU of part is come for its data yet.But time user only searches for not by the frequency spectrum resource that primary user takies passively in this mechanism, under the prerequisite of not interfere with primary users, access this frequency spectrum resource, to fail and primary user forms sufficient interaction, waste available frequency spectrum resource.

From the viewpoint of the interaction of pecuniary compensation primary and secondary user, the mechanism that a kind of primary user of realization and time user coexist is: when secondary user thinks access frequency spectrum resource time, the interference power that the access of secondary user produces quantizes by primary user, it is charged, the power of the access of secondary user is higher, needs the Qian Yue paid many.Primary user and time user consider respective total revenue (income of the income that the power comprising access obtains and money) respectively, by game theoretic method, realize coexisting of primary and secondary user.But this mechanism assumes that primary user has abundant frequency spectrum resource to be leased to time user, ensures that the communication requirement of oneself can not be subject to obvious impact simultaneously.But primary user often needs the High Data Rate exceeding frequency spectrum load.Therefore, in such scene, this mechanism is also improper.

The scene of higher data is had for primary user, from the viewpoint of the interaction of rate compensation primary and secondary user, another mechanism realizing that primary user and time user coexist is: on the one hand, when primary user has data to need transmission, secondary user is as relaying, assist primary user's transmission, it accelerates the transmission rate of primary user, primary user is transferred quickly want the data transmitted; On the other hand, when primary user does not need transmission data, frequency spectrum resource is distributed to the secondary user having assisted primary user to transmit.Generally speaking, improve the utilance of frequency spectrum.

Existing from the mechanism of rate compensation aspect consideration primary and secondary user interaction, being only applicable to multichannel, there is single scene to primary user in each channel.For multichannel, there is the scene of multipair primary user in each channel, unsuitable mechanism.Meanwhile, how frequency spectrum is leased to time user for primary user, also and have and do not have corresponding method.

Summary of the invention

The present invention is directed to multichannel, there is the scene of multipair primary user in each channel, provides a kind of mechanism from the viewpoint of rate compensation primary and secondary user interaction.

The present invention is achieved by the following technical solutions.

According to an aspect of the present invention, time user in a kind of multichannel many primary users cognition network is provided to assist the method for primary user's relaying, by relay application under multichannel scene, there is the mechanism of the cognitive radio networks of multipair primary user in each channel, it comprises the steps:

Step (1): the time is time slotted;

Step (2): at primary user's time slot: consider simultaneously all need transmit data primary user speed and, make the speed of primary user and maximum, and set up optimization problem with this, according to the allocation algorithm proposed, distribute each user as via node, assist primary user to carry out transmission data; The secondary user of having transmitted having assisted primary user, increases its contribution margin L _k;

Step (3): at secondary user's time slot: if certain time user wants to transmit data, the contribution margin L of and if only if this user _kbe more than or equal to L _thtime, could access; Upgrade the contribution margin of each user: current time slots has accessed the secondary user contribution value L of channel simultaneously _kto reduce.

Preferably, in described step (1), adopt the method time slotted time, particularly, the time shaft of division does not stop repetition by slot cycle; Each slot cycle is made up of H primary user's time slot and 1 user's time slot: at each primary user's time slot, and primary user's selection is directly transmitted or some user assists it to transmit; At each user's time slot, secondary user can access its data of transmission.

Preferably, in described step (2), particularly, the method setting up optimization problem is:

Definition relay selection variable is:

Directly transmit if the primary user j on channel i adopts, then transmission rate is:

$C_{i,j}^{\mathrm{dir}}=w_i[\frac{1}{2}{\log }_2(1+\frac{{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2{P}_{s_{i,j}}}{N_{d_{i,j}}+P_{I_1}})+\frac{1}{2}{\log }_2(1+\frac{{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2{P}_{s_{i,j}}}{N_{d_{i,j}}+P_{I_2}})]$

Wherein

$P_{I_1}=\underset{j=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}{\left|a_{s_{{i,j}^{\′}}{d}_{i,j}}\right|}^2{P}_{s_{{i,j}^{\′}}}$

$P_{I_2}=\underset{j^{\′}=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}(1-\underset{k^{\′}=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{i,j^{\′},k}){\left|a_{s_{{i,j}^{\′}}{d}_{i,j}}\right|}^2{P}_{s_{{i,j}^{\′}}}+\underset{j^{\′}=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}\underset{k^{\′}=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{{i,j,k}^{\′}}{\left|a_{r_{k^{\′}}{d}_{i,j}}\right|}^2{P}_{r_{k^{\′}}}$

If the primary user j on channel i adopts time user k to transmit as relaying, then transmission rate is:

$C_{i,j,k}^{\mathrm{coop}}=w_i\min \{\log (1+{\mathrm{SNR}}_{\mathrm{sr}}{\left|a_{\mathrm{sr}}\right|}^2),\log (1+{\mathrm{SNR}}_{\mathrm{sd}}{\left|a_{\mathrm{sd}}\right|}^2+{\mathrm{SNR}}_{\mathrm{rd}}{\left|a_{\mathrm{rd}}\right|}^2)\}$

$=w_i\min \{\log (1+{\left|a_{s_{i,j}{r}_k}\right|}^2\frac{P_{s_{i,j}}}{N_{r_k}+P_{I_3}}),\log (1+{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2\frac{P_{s_{i,j}}}{N_{d_{i,j}}+P_{I_4}}+{\left|a_{r_k{d}_{i,j}}\right|}^2\frac{P_{r_k}}{N_{d_{i,j}}+P_{I_5}})\}$

Wherein

$P_{I_3}=\underset{j=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}{\left|a_{s_{{i,j}^{\′}}{r}_k}\right|}^2{P}_{s_{{i,j}^{\′}}}$

$P_{I_4}=\underset{j=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}{\left|a_{s_{{i,j}^{\′}}{d}_{i,j}}\right|}^2{P}_{s_{{i,j}^{\′}}}$

$P_{I_5}=\underset{j^{\′}=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}(1-\underset{k^{\′}=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{i,j^{\′},k}){\left|a_{s_{{i,j}^{\′}}{d}_{i,j}}\right|}^2{P}_{s_{{i,j}^{\′}}}+\underset{j^{\′}=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}\underset{k^{\′}=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{{i,j,k}^{\′}}{\left|a_{r_{k^{\′}}{d}_{i,j}}\right|}^2{P}_{r_{k^{\′}}}$

The transmission rate of the primary user j then on channel i is expressed as:

$U_{i,j}=(1-\underset{k=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{i,j,k})\·C_{i,j}^{\mathrm{dir}}+\underset{k=1}{\overset{Q}{\mathrm{\Σ}}}(x_{i,j,k}\·C_{i,j,k}^{\mathrm{coop}})$

Total primary user's speed and being expressed as:

$S=\underset{i=1}{\overset{M}{\mathrm{\Σ}}}\underset{j=1}{\overset{P_i}{\mathrm{\Σ}}}{U}_{i,j}$

Relay selection variable meets following restrictive condition:

$\underset{i=1}{\overset{M}{\mathrm{\Σ}}}\underset{j=1}{\overset{P_i}{\mathrm{\Σ}}}{x}_{i,j,k}=0\mathrm{or}1,(k=\mathrm{1,2},...,Q)$

Preferably, in described step (3), particularly, exceeding all of threshold value to contribution margin wants the secondary user of transmitting data according to contribution margin L _ksort, according to contribution margin sequence, each time user selects the channel best for its channel condition to access according to its transmission rate at each channel successively.

Preferably, at primary user's time slot, distribute time user according to optimization problem and assist the algorithm of primary user to be allocation algorithm based on ant group algorithm.

Preferably, at primary user's time slot, distribute time user according to optimization problem and assist the algorithm of primary user to be allocation algorithm based on ant group algorithm, specifically comprise the steps:

The first step, initialization information element τ ₀(i, j, k) and heuristic information η _n(i, j, k), wherein, heuristic information formula is:

${\mathrm{\η}}_n(i,j,k)=\left\{\begin{array}{cc}{C}_{i,j,k}^{\′\mathrm{coop}}& \∀k\∈\{\mathrm{1,2},...,Q\}\\ C_{i,j,k}^{\′\mathrm{dir}}& k=Q+1.\end{array}\right.$

Wherein

$C_{i,j,k}^{\′\mathrm{coop}}=w_i\min \{\log (1+{\left|a_{s_{i,j}{r}_k}\right|}^2\frac{P_{s_{i,j}}}{N_{r_k}}),\log (1+{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2\frac{P_{s_{i,j}}}{N_{d_{i,j}}}+{\left|a_{r_k{d}_{i,j}}\right|}^2\frac{P_{r_k}}{N_{d_{i,j}}})$

$C_{i,j,k}^{\′\mathrm{dir}}=w_i{\log }_2(1+\frac{{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2{P}_{s_{i,j}}}{N_{d_{i,j}}});$

Second step, constructs the solution space of every ant according to following formula:

$p_{i,j,k}=\frac{{\mathrm{\τ}}_n^{\mathrm{\α}}(i,j,k){\mathrm{\η}}_n^{\mathrm{\β}}(i,j,k)}{{\underset{k=1}{\overset{Q+1}{\mathrm{\Σ}}}}_{k\∈{\mathrm{\θ}}_{i,j}}{\mathrm{\τ}}_n^{\mathrm{\α}}(i,j,k){\mathrm{\η}}_n^{\mathrm{\β}}(i,j,k)},$

3rd step, calculates the target function value that every ant is corresponding, the ant that select target functional value is maximum, remembers that the target function value of its correspondence is S ^best, the choice variable of its correspondence is

4th step, lastest imformation element:

τ _n+1(i，j，k)←(1-ρ)τ _n(i，j，k)+Δτ _n

5th step, repeats described second step, the 3rd step, and the 4th step, until reach maximum iteration time N _max; According to the choice variable x of the optimum of trying to achieve _{i, j, k}distribute time user and assist primary user.

Compared with prior art, the invention has the beneficial effects as follows: be applicable to multichannel, there is the scene of multipair primary user in each channel.Under this scene: (1) primary user as the assistance of via node, obtains the lifting of transmission rate by time user; (2) secondary user accesses secondary user's time slot that primary user reserves, and obtains the right of access spectrum transmissions data; (3) improve the throughput of whole cognition network, therefore improve the utilance of frequency spectrum.

Accompanying drawing explanation

The schematic diagram of the matching algorithm that Fig. 1 adopts at primary user's time slot for the present invention;

Fig. 2 be the present invention at 3 channels, each channel primary user is 10,8,6 to number, when secondary user is 20, total primary user's transmitted bit number is with the curve chart of arrival rate of bag;

Fig. 3 be the present invention at 3 channels, each channel primary user is 10,8,6 to number, when secondary user is 20, total secondary user's transmitted bit number is with the curve chart of arrival rate of bag.

Embodiment

Below in conjunction with accompanying drawing, embodiments of the invention are elaborated: the present embodiment is implemented under premised on technical solution of the present invention, give detailed execution mode and concrete operating process, but protection scope of the present invention is not limited to following embodiment.

The present embodiment carries out in the experiment scene of a 1000m × 1000m.The number of channel is 3, and all channels have identical bandwidth w=1kHz, and each channel primary user logarithm is respectively: 8,7,9, secondary user's number: 20, launches signal to noise ratio 60dB.In the present embodiment, get H=8, the duration of each time slot is T _slot=1s, the size of each bag is 500bits, and each user's bag arrival rate obeys the independently Poisson process that parameter is λ (individual/s), altogether continues 20 slot cycles.And arranging maximum iteration time is 50 times, α=1, β=0.8, γ=0.0001, ρ=0.05.Specific implementation method is:

(1) at each primary user's time slot: consider simultaneously all need transmit data primary user speed and, make the speed of primary user and maximum, and set up optimization problem with this, according to the allocation algorithm proposed, distribute each user as via node, assist primary user to carry out transmission data.The secondary user of having transmitted having assisted primary user, by its contribution margin L _kadd 1.

The method specifically setting up optimization problem is:

Definition relay selection variable is:

Directly transmit if the primary user j on channel i adopts, then transmission rate is:

$C_{i,j}^{\mathrm{dir}}=w_i[\frac{1}{2}{\log }_2(1+\frac{{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2{P}_{s_{i,j}}}{N_{d_{i,j}}+P_{I_1}})+\frac{1}{2}{\log }_2(1+\frac{{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2{P}_{s_{i,j}}}{N_{d_{i,j}}+P_{I_2}})]$

Wherein

$P_{I_1}=\underset{j=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}{\left|a_{s_{{i,j}^{\′}}{d}_{i,j}}\right|}^2{P}_{s_{{i,j}^{\′}}}$

$P_{I_2}=\underset{j^{\′}=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}(1-\underset{k^{\′}=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{i,j^{\′},k}){\left|a_{s_{{i,j}^{\′}}{d}_{i,j}}\right|}^2{P}_{s_{{i,j}^{\′}}}+\underset{j^{\′}=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}\underset{k^{\′}=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{{i,j,k}^{\′}}{\left|a_{r_{k^{\′}}{d}_{i,j}}\right|}^2{P}_{r_{k^{\′}}}$

If the primary user j on channel i adopts time user k to transmit as relaying, then transmission rate is:

$C_{i,j,k}^{\mathrm{coop}}=w_i\min \{\log (1+{\mathrm{SNR}}_{\mathrm{sr}}{\left|a_{\mathrm{sr}}\right|}^2),\log (1+{\mathrm{SNR}}_{\mathrm{sd}}{\left|a_{\mathrm{sd}}\right|}^2+{\mathrm{SNR}}_{\mathrm{rd}}{\left|a_{\mathrm{rd}}\right|}^2)\}$

$=w_i\min \{\log (1+{\left|a_{s_{i,j}{r}_k}\right|}^2\frac{P_{s_{i,j}}}{N_{r_k}+P_{I_3}}),\log (1+{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2\frac{P_{s_{i,j}}}{N_{d_{i,j}}+P_{I_4}}+{\left|a_{r_k{d}_{i,j}}\right|}^2\frac{P_{r_k}}{N_{d_{i,j}}+P_{I_5}})\}$

Wherein

$P_{I_3}=\underset{j=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}{\left|a_{s_{{i,j}^{\′}}{r}_k}\right|}^2{P}_{s_{{i,j}^{\′}}}$

$P_{I_4}=\underset{j=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}{\left|a_{s_{{i,j}^{\′}}{d}_{i,j}}\right|}^2{P}_{s_{{i,j}^{\′}}}$

$P_{I_5}=\underset{j^{\′}=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}(1-\underset{k^{\′}=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{i,j^{\′},k}){\left|a_{s_{{i,j}^{\′}}{d}_{i,j}}\right|}^2{P}_{s_{{i,j}^{\′}}}+\underset{j^{\′}=1,j^{\′}\≠j}{\overset{P_i}{\mathrm{\Σ}}}\underset{k^{\′}=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{{i,j,k}^{\′}}{\left|a_{r_{k^{\′}}{d}_{i,j}}\right|}^2{P}_{r_{k^{\′}}}$

The transmission rate of the primary user j then on channel i is expressed as:

$U_{i,j}=(1-\underset{k=1}{\overset{Q}{\mathrm{\Σ}}}{x}_{i,j,k})\·C_{i,j}^{\mathrm{dir}}+\underset{k=1}{\overset{Q}{\mathrm{\Σ}}}(x_{i,j,k}\·C_{i,j,k}^{\mathrm{coop}})$

Total primary user's speed and being expressed as:

$S=\underset{i=1}{\overset{M}{\mathrm{\Σ}}}\underset{j=1}{\overset{P_i}{\mathrm{\Σ}}}{U}_{i,j}$

Relay selection variable meets following restrictive condition:

$\underset{i=1}{\overset{M}{\mathrm{\Σ}}}\underset{j=1}{\overset{P_i}{\mathrm{\Σ}}}{x}_{i,j,k}=0\mathrm{or}1,(k=\mathrm{1,2},...,Q)$

(2) at certain time user's time slot: if certain user wants to transmit data, the contribution margin L of and if only if this user _kbe more than or equal to L _thtime (being set to 3 in this emulation), could access.Concrete access way is: allly want to transmit the secondary user of data according to contribution margin L _kcarry out sort (the secondary user that the contribution margin that only sorts exceedes threshold value), according to contribution margin sequence, each time user selects the channel best for its channel condition to access according to its transmission rate at each channel successively.Upgrade the contribution margin of each user: current time slots has accessed the secondary user contribution value L of channel simultaneously _kto reduce.

At primary user's time slot, be the allocation algorithm based on ant group algorithm according to the secondary algorithm with assistance primary user of optimization problem distribution, its step is as follows:

The first step, initialization information element τ ₀(i, j, k) and heuristic information η _n(i, j, k).Wherein, heuristic information formula is:

${\mathrm{\η}}_n(i,j,k)=\left\{\begin{array}{cc}{C}_{i,j,k}^{\′\mathrm{coop}}& \∀k\∈\{\mathrm{1,2},...,Q\}\\ C_{i,j,k}^{\′\mathrm{dir}}& k=Q+1.\end{array}\right.$

Wherein

$C_{i,j,k}^{\′\mathrm{coop}}=w_i\min \{\log (1+{\left|a_{s_{i,j}{r}_k}\right|}^2\frac{P_{s_{i,j}}}{N_{r_k}}),\log (1+{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2\frac{P_{s_{i,j}}}{N_{d_{i,j}}}+{\left|a_{r_k{d}_{i,j}}\right|}^2\frac{P_{r_k}}{N_{d_{i,j}}})$

$C_{i,j,k}^{\′\mathrm{dir}}=w_i{\log }_2(1+\frac{{\left|a_{s_{i,j}{d}_{i,j}}\right|}^2{P}_{s_{i,j}}}{N_{d_{i,j}}})$

Second step, constructs the solution space of every ant according to following formula:

$p_{i,j,k}=\frac{{\mathrm{\τ}}_n^{\mathrm{\α}}(i,j,k){\mathrm{\η}}_n^{\mathrm{\β}}(i,j,k)}{{\underset{k=1}{\overset{Q+1}{\mathrm{\Σ}}}}_{k\∈{\mathrm{\θ}}_{i,j}}{\mathrm{\τ}}_n^{\mathrm{\α}}(i,j,k){\mathrm{\η}}_n^{\mathrm{\β}}(i,j,k)}$

3rd step, calculates the target function value that every ant is corresponding, the ant that select target functional value is maximum, remembers that the target function value of its correspondence is S ^best, the choice variable of its correspondence is

4th step, lastest imformation element:

τ _n+1(i，j，k)←(1-ρ)τ _n(i，j，k)+Δτ _n

5th step, repeats described second step, the 3rd step, and the 4th step, until reach maximum iteration time N _max.According to the choice variable x of the optimum of trying to achieve _{i, j, k}distribute time user and assist primary user.

Fig. 2 gives the curve chart of the arrival rate of the total transmitted bit number of primary user with bag; Fig. 3 gives the curve chart of the arrival rate of time total transmitted bit number of user with bag.As seen from Figure 2: use the method having relaying, the transmitted bit number that primary user is total is all many than using the bit number of traditional non-relay method transmission.As seen from Figure 3, use and have the method for relaying, the total transmitted bit number of secondary user is more than the bit number using traditional non-relay method to transmit.

Above specific embodiments of the invention are described.It is to be appreciated that the present invention is not limited to above-mentioned particular implementation, those skilled in the art can make various distortion or amendment within the scope of the claims, and this does not affect flesh and blood of the present invention.

Claims (3)

1. in multichannel many primary users cognition network, time user assists a method for primary user's relaying, and it is characterized in that, by relay application under multichannel scene, each channel exists the mechanism of the cognitive radio networks of multipair primary user, and it comprises the steps:

Step (1): the time is time slotted;

Step (2): at primary user's time slot: consider simultaneously all need transmit data primary user speed and, make the speed of primary user and maximum, and set up optimization problem with this, according to the allocation algorithm proposed, distribute each user as via node, assist primary user to carry out transmission data; The secondary user of having transmitted having assisted primary user, increases its contribution margin L _k;

Step (3): at secondary user's time slot: if certain time user wants to transmit data, the contribution margin L of and if only if this user _kbe more than or equal to L _thtime, could access; Upgrade the contribution margin of each user: current time slots has accessed the secondary user contribution value L of channel simultaneously _kto reduce; L _thfor threshold value;

The method setting up optimization problem is:

Definition relay selection variable is:

Directly transmit if the primary user j on channel i adopts, then transmission rate is

If the primary user j on channel i adopts time user k to transmit as relaying, then transmission rate is

The transmission rate of the primary user j then on channel i is expressed as:

Total primary user's speed and being expressed as:

Wherein, M represents the quantity of channel, P _irepresent the quantity of primary user on channel i, Q represents the quantity of time user k;

At primary user's time slot, distribute time user according to optimization problem and assist the algorithm of primary user to be allocation algorithm based on ant group algorithm.

2. in multichannel many primary users cognition network according to claim 1, time user assists the method for primary user's relaying, it is characterized in that, in described step (1), adopt the method time slotted time, particularly, the time shaft of division does not stop repetition by slot cycle; Each slot cycle is made up of H primary user's time slot and 1 user's time slot: at each primary user's time slot, and primary user's selection is directly transmitted or some user assists it to transmit; At each user's time slot, secondary user can access its data of transmission.

3. in multichannel many primary users cognition network according to claim 1, time user assists the method for primary user's relaying, it is characterized in that, in described step (3), particularly, exceeding all of threshold value to contribution margin wants the secondary user of transmitting data according to contribution margin L _ksort, according to contribution margin sequence, each time user selects the channel best for its channel condition to access according to its transmission rate at each channel successively.