CN104486800A - Moderate service-based adaptive cooperative transmission method and system in wireless network - Google Patents

Abstract

The invention provides a moderate service-based adaptive cooperative transmission method and a moderate service-based adaptive cooperative transmission system in a wireless network. The method comprises the following steps of 1, initializing wireless users and idle frequency bands in the network; 2, acquiring related parameters of a known route, a QoS (quality of service) requirement and a spare network around a known node; 3, determining whether to trigger a cooperative mode or not; 4, if the cooperative mode is triggered, making a series of strategy sets. According to the method and the system, the network flow and the utilization rate can be maximized under the condition of meeting the QoS requirement of the users.

Description

Based on the adaptive cooperation retransmission method of appropriateness service and system in wireless network

Technical field

The present invention relates to a kind of adaptive cooperation retransmission method, particularly, relate to the adaptive cooperation retransmission method based on appropriateness service in a kind of wireless network.

Background technology

Growing along with social demand, various wireless communication technology is positive fast-developing and be applied in the every field of social life, cordless communication network is towards the future development of high speed, broadband, ubiquitousization, various wireless access technology is emerged in large numbers one after another, makes the frequency spectrum resource of future network more in short supply.Traditional frequency spectrum fixed allocation mode, causes authorizing frequency range and unauthorized frequency range load imbalance, causes the significant wastage of frequency spectrum resource.The continuous propelling that the commercialization of 3G system is popularized and 4G studies, the demand of wireless access grows with each passing day, and this causes radio spectrum resources day by day crowded, makes the matter worse to the frequency spectrum resource be becoming tight day.The cognition wireless network taking cognitive radio technology as core can by carrying out interactive perception to wireless network environment, intelligent planning, decision-making and scheduling, realize the intelligent networking of Wireless Heterogeneous Networks, effectively carry out the intelligent optimization of network resource management, allow the dynamic access of undelegated cognitive user opportunistic to idle authorized user frequency range, thus improve frequency spectrum resource utilization rate.

But, due to the intrinsic dynamic heterogeneous characteristic of cognition wireless network, make traditional cognitive radio opportunistic dynamic spectrum access mode (perception. access) have very much a challenge.In the process that cognitive user accesses at frequency spectrum, the perception of frequency spectrum must be carried out by continuous print, be taken by primary user once perceive frequency range, the information transmission that cognitive user then must stop oneself current immediately or the switching carrying out frequency spectrum.Frequency spectrum share under this mode is extremely passive, frequency spectrum access between cognitive user is subject to the larger constraint of primary user, but, primary user lacks natural activity, the responsibility maintaining overall network peaceful coexistence places on cognitive user completely, therefore, in realizing more complicated and be difficult to ensure network performance, the availability of frequency spectrum is still not high.

Collaboration communication is as a kind of emerging communication technology, the transmission of signal is optimized in physical layer and mac layer connection, be applied to application layer, there is the great potential increasing radio network information channel capacity, reduce transmitting power, reduce time delay, and flexible and changeable, autgmentability is strong, for the development of cognition wireless network is filled with new vitality.Adopt cooperative communication technology, under the condition not increasing system hardware resources, merge the advantage of diversity technique and relay transmission technology, multiple resources in current network is effectively utilized.The transfer of data of various high speed can be realized, significantly shorten data transmission period, effectively overcome shadow effect and decline, improve the reliability that data transmit, reduce communication interruption probability, expand network coverage, reduce network energy consumption, improve frequency spectrum resource utilization rate.

In order to the performance of more deep lifting cognitive radio networks, the cooperative cognitive wireless network having merged cooperative communication technology and cognitive radio technology arises at the historic moment.The technology such as collaborative spectrum sensing, cooperating relay transmission is applied in cognitive radio networks by cooperative cognitive network, give full play to the advantage of two kinds of technology, while the lifting availability of frequency spectrum, improve the communication performance such as network throughput, network coverage, cause the very big concern of academia in recent years.The existing research for the coordination mechanism in cognition wireless network, main concentrating is carried out in collaborative sensing and cooperation transmission between cognitive user, is improved the utilization ratio of frequency spectrum resource, promote network performance by information sharing to each other and frequency spectrum share.But, frequency spectrum share under which is based upon on the basis of frequency spectrum perception, still very passive, only have when under primary user's idle condition, the access carrying out frequency spectrum of cognitive user ability opportunistic, the dynamic of usable spectrum brings huge challenge to the selection of channel and access, meanwhile, primary user when carrying out transfer of data, the Internet resources of cognitive user cannot be made full use of, this makes frequency spectrum resource not be utilized, and the QoS service of cognitive user requires to be difficult to ensure.

Summary of the invention

For defect of the prior art, technical problem to be solved by this invention is to provide the adaptive cooperation retransmission method based on appropriateness service in a kind of wireless network, the present invention, when meeting the qos requirement of user, makes network traffics and utilance reach maximum as far as possible.

According in a kind of wireless network provided by the invention based on appropriateness service adaptive cooperation retransmission method, comprise the following steps:

Step 1: initialization is carried out to network internal radio subscriber and idle frequency band;

Step 2: known routed path, qos requirement, the relevant parameter of known node ambient network free time are obtained;

Step 3: to whether triggered cooperative pattern is determined;

Step 4: if triggered cooperative pattern, make a series of set of strategies.

Preferably, described step 3 comprises the following steps:

Step 3.1: check whether known routed path all meets qos requirement, and will the path P of qos requirement do not met _ijput into set P to be solved, wherein, P _ijrepresent the path between node i and node j;

Step 3.2: check each P in set P to be solved _ijwhether ambient network is idle, if the free time is then by P _ijassignment is true, otherwise assignment is false;

Step 3.3: if each P in set P to be solved _ijbe all true, then make a policy: triggered cooperative pattern; Otherwise, do not trigger.

Preferably, in described step 3.1, need to check whether known routed path meets qos requirement and compute dependent data, is specially:

Step 3.1.1: compare the delay requirement in the propagation delay time sum and qos requirement gathering all elements in D, upgrade the bandwidth requirement in qos requirement, wherein, set D has deposited known routed path P _ij;

Step 3.1.2: each element P in traversal set D _ij, compare P _ijtransmission bandwidth and qos requirement in bandwidth requirement, then will not meet the path P of QoS _ijput into set P to be solved;

Step 3.1.3: finally limit according to qos requirement and resource, in order to each element P in set P _ijcalculate Δ S _ij, wherein, Δ S _ijbe expressed as the amount of bandwidth meeting qos requirement and needs increase.

Preferably, described step 3.1.1, is specially:

If the propagation delay time sum of all elements is greater than the delay requirement in qos requirement in set D, then represent that in qos requirement, time delay does not meet, represent that the propagation delay time sum of all elements in set D is greater than the difference of the delay requirement in qos requirement with Δ t, Δ t is represented as the time delay size meeting qos requirement and needs minimizing simultaneously; According to Δ t, calculate Δ S by the conversion formula between Δ t and Δ S, Δ S is expressed as the total bandwidth size meeting qos requirement and needs increase; Element in order in traversal set D, calculates Δ S and adds minimum transmission bandwidth, and make comparisons with the bandwidth requirement during current QoS requires, the greater is updated to the bandwidth requirement in qos requirement;

Wherein, the conversion formula between Δ t and Δ S is as follows:

$t_1=\frac{C}{S_1}+T_0+T$

$t_2=\frac{C}{S_2}+T_0+T$

$\begin{array}{c}\mathrm{\Δt}=t_1-t_2\\ =\frac{C}{S_1}-\frac{C}{S_2}\\ =\frac{C}{S_1}-\frac{C}{S_1+\mathrm{\ΔS}}\end{array}$

$\mathrm{\ΔS}=\frac{S_1}{1-\frac{\mathrm{\Δt}}{C}}$

Wherein, S ₁for the path bandwidth before cooperation, S ₂for the bandwidth in the path after cooperation, C is data block length, t ₁for the propagation delay time before cooperation, t ₂for the propagation delay time after cooperation, for the transmission delay before cooperation, for the transmission delay after cooperation, T ₀for propagation delay, T is processing delay.

Preferably, described step 4 comprises the steps:

Step 4.1: the element in set P is sorted from small to large according to bandwidth;

Step 4.2: according to broadband lifting values, to each element P in set P _ijdetermine collaborative path.

Preferably, in described step 4.2, convert ungratified for qos requirement situation to bandwidth lifting values, be specially:

If bandwidth does not meet in qos requirement, bandwidth lifting values is directly for the bandwidth requirement in qos requirement deducts P _ijcurrent bandwidth;

If time delay does not meet in qos requirement, time delay lifting values is P _ijcurrent time delay deduct delay requirement in qos requirement, according to time delay lifting values, by time delay bandwidth conversion computation bandwidth lifting values.

Preferably, described step 4.2, comprises the steps:

Step 4.2.1: traversal P _ijsurrounding network nodes, finds node N ₁make node i and node N ₁communication bandwidth be more than or equal to Δ S, simultaneously node j and node N ₁communication bandwidth be more than or equal to Δ S;

Step 4.2.2: find qualified node N ₁time, stop traversal;

Step 4.2.3: by path P _iN1and P _jN1add former routed path set, wherein, P _iN1represent from node i to N ₁between path, P _jN1represent from node N ₁path between node j.

According in a kind of wireless network provided by the invention based on appropriateness service adaptive cooperation repeater system, in described wireless network based on appropriateness service adaptive cooperation repeater system use in above-mentioned wireless network based on appropriateness service adaptive cooperation retransmission method.

Compared with prior art, the present invention has following beneficial effect:

The present invention, when meeting the qos requirement of user, makes network traffics and utilance reach maximum as far as possible.The present invention requires not meet mainly for the transmission QoS in cognitive radio networks and ambient network is idle time, by the cooperation transmission of neighbor node, the qos requirement of As soon as possible Promising Policy user.Effectively network utilization can be promoted based on the adaptive cooperation retransmission method of appropriateness service in this wireless network.

Accompanying drawing explanation

By reading the detailed description done non-limiting example with reference to the following drawings, other features, objects and advantages of the present invention will become more obvious:

Fig. 1 is the flow chart based on the adaptive cooperation retransmission method of appropriateness service in wireless network of the present invention.

Fig. 2 limits according to qos requirement and resource, in order to element P each in P _ijcalculate Δ S _ij.

Fig. 3 is according to Δ S _ij, in order to element P each in P _ijdetermine the principle schematic of collaborative path.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in detail.Following examples will contribute to those skilled in the art and understand the present invention further, but not limit the present invention in any form.It should be pointed out that to those skilled in the art, without departing from the inventive concept of the premise, some distortion and improvement can also be made.These all belong to protection scope of the present invention.

As shown in Figure 1, comprise the following steps based on the adaptive cooperation retransmission method of appropriateness service in wireless network of the present invention:

Step 1: initialization is carried out to network internal radio subscriber and idle frequency band;

Step 2: known routed path, qos requirement, the relevant parameter of ambient network free time are obtained;

Step 3: to whether triggered cooperative pattern is determined;

Step 4: if triggered cooperative pattern, make a series of set of strategies;

Step 5, verifies that this set of strategies is the approximation of maximize network capacity.

Wherein, described step 3 comprises the following steps:

Step 3.1: check whether known routed path all meets qos requirement;

Step 3.2: check each P in set P to be solved _ijwhether ambient network is idle, if the free time is then by P _ijassignment is true, otherwise assignment is false;

Step 3.3: if each is all true in P, then make a policy: triggered cooperative pattern; Otherwise, do not trigger.

Preferably, need in described step 3.1 to check whether known routed path meets qos requirement and compute dependent data, first the delay requirement in the propagation delay time sum of all elements in D and qos requirement is compared, if the former is greater than latter and represents that in qos requirement, time delay does not meet, represent both differences with Δ t, be represented as the time delay size meeting qos requirement and needs minimizing simultaneously.According to Δ t, can be expressed as by formulae discovery Δ S, Δ S the total bandwidth size meeting qos requirement and needs increase.Travel through the element in D in order, calculate Δ S and add minimum transmission bandwidth, and make comparisons with the bandwidth requirement during current QoS requires, larger that is updated to the bandwidth requirement in qos requirement.Then each element P in D is traveled through _ij, compare P _ijtransmission bandwidth and qos requirement in bandwidth requirement, then will not meet the path P of QoS _ijput into set P to be solved; Finally limit according to qos requirement and resource, in order to element P each in P _ijcalculate Δ S _ij;

Described step 4 comprises the following steps:

Step 4.1: the element in P is sorted from small to large according to bandwidth;

Step 4.2: according to broadband lifting values, to element P each in P _ijdetermine collaborative path.

Preferably, P is searched in described step 4.2 _ijsurrounding network nodes, finds node N ₁make node i and node N ₁communication bandwidth be more than or equal to Δ S, simultaneously node j and node N ₁communication bandwidth be more than or equal to Δ S; When finding qualified node, stop traversal; By path P _iN1and P _jN1add former routed path set D.

Make further information below in conjunction with specific embodiment to technical scheme of the present invention to describe, whole invention implementation procedure is as follows:

Step 1: initialization is carried out to network internal radio subscriber and idle frequency band

Suppose that bandwidth allocation methods is known, according to corresponding bandwidth allocation methods, network internal radio subscriber and idle frequency band are distributed.

Step 2: routed path, qos requirement, the relevant parameter of ambient network free time are obtained

Suppose that routed path is known, leave in set D, each section is expressed as P _ij, i and j represents two different nodes.For each element P in D _ij, need to obtain its propagation delay time, transmission bandwidth.Also to obtain the qos requirement in whole piece path, only need delay requirement and bandwidth requirement here.Finally the relevant parameter of ambient network free time is obtained, need to judge that whether this localized network is idle according to known formula.

Step 3: to whether triggered cooperative pattern is determined;

Step 3.1: check whether known routed path meets qos requirement and compute dependent data.

Step 3.1.1: compare the delay requirement in the propagation delay time sum of all elements in D and qos requirement.

If the former is greater than latter and represents that in qos requirement, time delay does not meet, represent both differences with Δ t, be represented as the time delay size meeting qos requirement and needs minimizing simultaneously.According to Δ t, can be expressed as by formulae discovery Δ S, Δ S the total bandwidth size meeting qos requirement and needs increase.Travel through the element in D in order, calculate Δ S and add minimum transmission bandwidth, and make comparisons with the bandwidth requirement during current QoS requires, larger that is updated to the bandwidth requirement in qos requirement.

Wherein, the conversion formula between Δ t and Δ S is as follows:

$t_1=\frac{C}{S_1}+T_0+T$

$t_2=\frac{C}{S_2}+T_0+T$

$\begin{array}{c}\mathrm{\Δt}=t_1-t_2\\ =\frac{C}{S_1}-\frac{C}{S_2}\\ =\frac{C}{S_1}-\frac{C}{S_1+\mathrm{\ΔS}}\end{array}$

$\mathrm{\ΔS}=\frac{S_1}{1-\frac{\mathrm{\Δt}}{C}}$

Wherein, S ₁for the path bandwidth before cooperation, S ₂for the bandwidth in the path after cooperation, C is data block length, t ₁for the propagation delay time before cooperation, t ₂for the propagation delay time after cooperation, for the transmission delay before cooperation, for the transmission delay after cooperation, T ₀for propagation delay, T is processing delay.

Step 3.1.2: each element P in traversal D _ij, compare P _ijtransmission bandwidth and qos requirement in bandwidth requirement, then will not meet the path P of QoS _ijput into set P to be solved;

Step 3.1.3: limit according to qos requirement and resource, in order to element P each in P _ijcalculate Δ S _ij;

Convert ungratified for qos requirement situation to Δ S _ij, wherein Δ S _ijit is the amount of bandwidth for meeting qos requirement and needs increase.If bandwidth does not meet in qos requirement, Δ S _ijdirectly for the bandwidth requirement in qos requirement deducts P _ijcurrent bandwidth.Result as shown in Figure 2.

Step 3.2: check that whether ambient network is idle

To each P in set P to be solved _ijthe relevant parameter of ambient network free time calculate, judge whether the free time.If idle, then by P _ijassignment is true, otherwise assignment is false;

Step 3.3: to whether triggered cooperative pattern makes a policy

If each is all true in P, then make a policy: triggered cooperative pattern; Otherwise, do not trigger.

Step 4: if triggered cooperative pattern, make a series of set of strategies

Step 4.1: the element in P is sorted from small to large according to bandwidth

Step 4.2: according to Δ S _ij, in order to element P each in P _ijdetermine collaborative path.

Step 4.2.1: search P _ijsurrounding network nodes, finds node N ₁make node i and node N ₁communication bandwidth be more than or equal to Δ S, simultaneously node j and node N ₁communication bandwidth be more than or equal to Δ S;

Step 4.2.2: when finding qualified node, stops traversal;

Step 4.2.3: by path P _iN1and P _jN1add former routed path set D.Result is as shown in Figure 3:

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 (8)

1. in wireless network based on appropriateness service an adaptive cooperation retransmission method, it is characterized in that, comprise the following steps:

Step 1: initialization is carried out to network internal radio subscriber and idle frequency band;

Step 2: known routed path, qos requirement, the relevant parameter of known node ambient network free time are obtained;

Step 3: to whether triggered cooperative pattern is determined;

Step 4: if triggered cooperative pattern, make a series of set of strategies.

2. in wireless network according to claim 1 based on appropriateness service adaptive cooperation retransmission method, it is characterized in that, described step 3 comprises the following steps:

Step 3.1: check whether known routed path all meets qos requirement, and will the path P of qos requirement do not met _ijput into set P to be solved, wherein, P _ijrepresent the path between node i and node j;

Step 3.2: check each P in set P to be solved _ijwhether ambient network is idle, if the free time is then by P _ijassignment is true, otherwise assignment is false;

Step 3.3: if each P in set P to be solved _ijbe all true, then make a policy: triggered cooperative pattern; Otherwise, do not trigger.

3. in wireless network according to claim 2 based on appropriateness service adaptive cooperation retransmission method, it is characterized in that, in described step 3.1, need to check whether known routed path meets qos requirement and compute dependent data, is specially:

Step 3.1.1: compare the delay requirement in the propagation delay time sum and qos requirement gathering all elements in D, upgrade the bandwidth requirement in qos requirement, wherein, set D has deposited known routed path P _ij;

Step 3.1.2: each element P in traversal set D _ij, compare P _ijtransmission bandwidth and qos requirement in bandwidth requirement, then will not meet the path P of QoS _ijput into set P to be solved;

Step 3.1.3: finally limit according to qos requirement and resource, in order to each element P in set P _ijcalculate Δ S _ij, wherein, Δ S _ijbe expressed as the amount of bandwidth meeting qos requirement and needs increase.

4. in wireless network according to claim 3 based on appropriateness service adaptive cooperation retransmission method, it is characterized in that, described step 3.1.1, is specially:

If the propagation delay time sum of all elements is greater than the delay requirement in qos requirement in set D, then represent that in qos requirement, time delay does not meet, represent that the propagation delay time sum of all elements in set D is greater than the difference of the delay requirement in qos requirement with Δ t, Δ t is represented as the time delay size meeting qos requirement and needs minimizing simultaneously; According to Δ t, calculate Δ S by the conversion formula between Δ t and Δ S, Δ S is expressed as the total bandwidth size meeting qos requirement and needs increase; Element in order in traversal set D, calculates Δ S and adds minimum transmission bandwidth, and make comparisons with the bandwidth requirement during current QoS requires, the greater is updated to the bandwidth requirement in qos requirement;

Wherein, the conversion formula between Δ t and Δ S is as follows:

$t_1=\frac{C}{S_1}+T_0+T$

$t_2=\frac{C}{S_2}+T_0+T$

$\begin{array}{c}\mathrm{\Δt}=t_1-t_2\\ =\frac{C}{S_1}-\frac{C}{S_2}\\ =\frac{C}{S_1}-\frac{C}{S_1+\mathrm{\ΔS}}\end{array}$

$\mathrm{\ΔS}=\frac{S_1}{1-\frac{\mathrm{\Δt}}{C}}$

Wherein, S ₁for the path bandwidth before cooperation, S ₂for the bandwidth in the path after cooperation, C is data block length, t ₁for the propagation delay time before cooperation, t ₂for the propagation delay time after cooperation, for the transmission delay before cooperation, for the transmission delay after cooperation, T ₀for propagation delay, T is processing delay.

5., based on the adaptive cooperation retransmission method of appropriateness service in the wireless network according to claim 2 or 4, it is characterized in that, described step 4 comprises the steps:

Step 4.1: the element in set P is sorted from small to large according to bandwidth;

Step 4.2: according to broadband lifting values, to each element P in set P _ijdetermine collaborative path.

6. in wireless network according to claim 5 based on appropriateness service adaptive cooperation retransmission method, it is characterized in that, in described step 4.2, convert ungratified for qos requirement situation to bandwidth lifting values, be specially:

If bandwidth does not meet in qos requirement, bandwidth lifting values is directly for the bandwidth requirement in qos requirement deducts P _ijcurrent bandwidth;

If time delay does not meet in qos requirement, time delay lifting values is P _ijcurrent time delay deduct delay requirement in qos requirement, according to time delay lifting values, by time delay bandwidth conversion computation bandwidth lifting values.

7. in wireless network according to claim 5 based on appropriateness service adaptive cooperation retransmission method, it is characterized in that, described step 4.2, comprises the steps:

Step 4.2.1: traversal P _ijsurrounding network nodes, finds node N ₁make node i and node N ₁communication bandwidth be more than or equal to Δ S, simultaneously node j and node N ₁communication bandwidth be more than or equal to Δ S;

Step 4.2.2: find qualified node N ₁time, stop traversal;

Step 4.2.3: by path P _iN1and P _jN1add former routed path set, wherein, P _iN1represent from node i to N ₁between path, P _jN1represent from node N ₁path between node j.

8. in a wireless network based on appropriateness service adaptive cooperation repeater system, it is characterized in that, in described wireless network, use the adaptive cooperation retransmission method of serving based on appropriateness in the wireless network according to any one of claim 1 to 7 based on the adaptive cooperation repeater system of appropriateness service.