CN102781108B - The combined wireless resource dispatching method that a kind of time delay is controlled - Google Patents

Abstract

The invention discloses the combined wireless resource dispatching method that a kind of time delay is controlled, including: step one, use the system clock of the reading TD LTE network of extra clock register timing, and by the notice wlan network of clock register timing, make wlan network keep Tong Bu with TD LTE network；Step 2, at the up-downlink direction of the MAC layer differentiated service of wlan network, and arranges up competition window and descending competition window, and window size is with reference to the up-downgoing time proportioning of TD LTE network；Step 3, for the business demand produced in wlan network, designs united virtual map mechanism so that WLAN data can be assigned to suitably carry rapidly be transmitted by TD LTE；Step 4, designs a kind of channel matched based on time delay rule, it is ensured that delay sensitive business.This invention ensures that the real-time access of high-priority service, it is ensured that the Qos demand of real time business, reduce a large amount of time delays produced when data service is transmitted in heterogeneous system, meet the different Q os business demand to time delay.

Description

The combined wireless resource dispatching method that a kind of time delay is controlled

Technical field

The invention belongs to mobile broadband wireless communication technical field, relate to the combined wireless resource scheduling that a kind of time delay is controlled Method.

Background technology

The direction of following wireless mobile communications development, it will be multiple wireless access technology and standard interconnection complementation, for Family provides ubiquitous information communication service ubiquitous, at all times.Next generation mobile communication topology of networks will progressively Evolution becomes at many levels, the dimensional network structure of eclipsed form.The same space exists different types of access network simultaneously, they There are respective feature and suitable application scenario, the WLAN skill that the TD-LTE technology accessed such as distance and short distance access Art.To the user being in remote villages, mountain area and extensive moving region, owing to optical cable cannot lay, cause this part User is chronically at information island.

In order to meet high ferro passenger for data communication and the communicating requirement of digital entertainment, support multiple in high-iron carriage Wireless communication technology standard, covers compartment by mobile relay, solves owing to compartment shields the signal attenuation caused, it may appear that car TD-LTE network that interior user terminal accesses in car outside LAN and car the scene deposited.When user terminal is the most frequent During handover network, can cause the repeatedly mapping of qos parameter, the so QoS index to former business can cause accumulation property change and Impact.Here, need to study the mapping mechanism that heterogeneous network is unified, propose all can effectively carry out QoS mapping at various networks General mechanism, and interior business concurrently access in the case of joint resource management distribution mechanism, reduce resource between heterogeneous system The extra latency that distribution brings, it is achieved wlan network and the real-time access performance of TD-LTE network, is fully dug by seamless fusion The performance advantage of pick heterogeneous network multiple radio resource, it is achieved the seriality of QoS in the concordance of end-to-end QoS and mobile handoff

In the environment of heterogeneous network based on high-speed mobile, in order to realize the seamless access of user terminal, the most also want Ensureing servicing user, user to be accessed and the QoS of switching user, designing a united RRM mechanism is Necessary, the most distributable Radio Resource is limited, how rationally to have on the basis of ensureing different user different QoS The distribution bandwidth of effect, the resource such as power are one and realize in compartment the user of high-speed mobile from diverse access point access mobile communication The key technology of standby backbone network.

Traditional joint resource management, due to frame structure difference, frequency spectrum, duplex mode and modulation coding mode etc. no With, need to increase sublayer on MAC layer, to carry out protocol translation, thus realize united resource management.Such as, 3GPP carries Concept and the functional module of common radio resources management (CRRM) are gone out, in order to improve what GSM/GPRS/EDGE and UMTS coexisted RRM in cellular network, the most only basic framework and concept, do not have concrete signaling process and embodiment. Generic link layer technology (GLL), can be seen as a communication layers increased on original protocol layer, is used for wireless connecing for different Entering mechanism provides unified link layer data to process.Existing 80221 media independent handover technology, pay close attention to 802 serial protocols, Agreement for 3GPP and its hetero-organization merges the most in process.Existing algorithm and model is failed to understand owing to merging target Really so that this sublayer technology slowly cannot effectively realize.And for the integration program of certain technology, also due to market is failed to understand Really, the slow of R&D process is caused.

Owing on train, user is numerous, all kinds of service set are concurrent, even with wireless discharging-directly station, it is also difficult to ensure all The business fairness of user, is particularly difficult to ensure that the access delay of high-priority service.802/11e agreement adds industry The security mechanism of business Qos, it is possible at Mac layer to business classification transmission, but its type of service fails with the QCI in TD-LTE system Correspondence, TD system is it cannot be guaranteed that the Qos performance of WLAN business.

Summary of the invention

The technical problem to be solved is: provide the combined wireless resource dispatching method that a kind of time delay is controlled, should Method ensure that the Qos demand of real time business, reduces a large amount of time delays produced when data service is transmitted in heterogeneous system.

For solving above-mentioned technical problem, the present invention adopts the following technical scheme that.

The combined wireless resource dispatching method that a kind of time delay is controlled, comprises the following steps:

Step one, uses the system clock of the reading TD-LTE network of extra clock register timing, and passes through clock The notice wlan network of depositor timing, makes wlan network keep Tong Bu with TD-LTE network；

Step 2, at the up-downlink direction of the MAC layer differentiated service of wlan network, and arranges up competition window and descending Competition window, window size is with reference to the up-downgoing time proportioning of TD-LTE network；

Step 3, for the business demand produced in wlan network, designs united virtual map mechanism so that TD-LTE Can be assigned to WLAN data suitably carry rapidly be transmitted；

Step 4, designs a kind of channel matched based on time delay rule, it is ensured that delay sensitive business.

As a preferred embodiment of the present invention, in step 2, it is same that wlan network utilizes GP protection interval to carry out up-downgoing Step.

As the another kind of preferred version of the present invention, in step 2, wlan network is provided with avoids user in competition window The fallback mechanism of collision occurs；Described fallback mechanism is divided into 4 kinds of AC according to the MAC layer type of service of 802.11e, and every class AC is corresponding Different channel competition parameters carries out channel competition and back off procedure；Corresponding to 4 classes AC, each terminal is set up 4 AC and is sent team Row, the Frame of miscellaneous service is first mapped to different AC, and then puts into corresponding transmit queue；Each transmit queue uses The DCF independent competitive channel of mechanism.

As another preferred version of the present invention, during channel competition, race condition has:

1) between multiple transmit queues of same terminal inner because of competitive channel clash time, by a virtual scheduling Device selects the queue that priority is higher to be transmitted, and the competition window of other Low Priority Queuings doubles, and number of retransmissions adds 1；

2) when different terminals send simultaneously Frame collide time, each transmit queue collided will experience weight It is transmitted through journey, unrelated with queue priority height.

As another preferred version of the present invention, the particular content of described back off procedure is: in PLCP Header Up-downgoing diacritics position sf_LinkDirection is increased in coverage, if the value of sf_LinkDirection is 0 or 1, Wherein 0 represents descending, and 1 represents up；The Backoff window of up-downgoing business is according to the uplink/downlink frames form of described TD-LTE network Proportioning is formulated.

As another preferred version of the present invention, the ascending-descending subframes quantity ratio of described TD-LTE network is 3: 7, accordingly The up-downgoing service competition window interval time slot of wlan network be also 3: 7.

As another preferred version of the present invention, in described wlan network, when uplink service produces, according to described clock Depositor and described up-downgoing diacritics position judge whether to be in uplink traffic transmission process；Pass if it is, select to enter Pass queue；Otherwise wait for；In back off procedure, each AC monitor channel, if channel idle, then when one is idle Gap, fallback counter subtracts 1；When following two situation, fallback counter is hung up: have other AC to send data on a, channel；b、 Channel is carrying out downlink data transmission.

As another preferred version of the present invention, described united virtual map mechanism is: will produce in wlan network Business demand be mapped to the classification logotype QCI of the TD-LTE network carrying so that WLAN data can be distributed rapidly by TD-LTE It is transmitted in suitably carrying.

As another preferred version of the present invention, described channel matched rule based on time delay is: first do not differentiating between When user's service priority, jump the difference according to different user channel quality on different subchannels second, Select user's service that channel quality is best in each subchannel, jump AC business demand and second the most respectively by first and jump letter Mate one by one after road quality-ordered；Secondly, when distinguishing user's service priority, high-priority users is first serviced, high It is its service that priority users jumps, second, the channel selecting channel quality best, then jumps first and selects and the second hop channel The immediate subchannel of quality matches；If also having remaining subchannel after having serviced high-priority users, then according to not The situation distinguishing user's service priority distributes to low priority user.

As another preferred version of the present invention, concrete subchannel matching mechanisms is:

The first step: determine the service order of user according to the type of service of user and required transfer rate, first service High-priority users；Assuming to have in K user K1 high-priority users, remaining K-K1 user is low priority user, uses Transfer rate needed for the k of family is r_k(k∈Ω^K), wherein Ω^KRepresent the set of all users；

Second step: the service order of the user determined according to step one is jumped second and selected son to believe for high-priority users Road, uses Max C/I algorithm and channel to estimate, replaces C/I with SINR in an ofdm system, in conjunction with customer service to the bit error rate Demand, kth user selects subchannel according to the following formula until meeting its required transfer rate:

$j\left(k\right)=\arg \underset{j\∈A_j}{\max }{\mathrm{SINR}}_j^k,\underset{j\∈A_j}{\min }{\mathrm{BER}}_j^k$

Wherein,A_jRepresent unassigned sets of sub-channels；

3rd step: set the signal to noise ratio of subchannel j distributing to kth user in the second jumping asIn first jumping not The signal to noise ratio of AC (i) the class business demand of distribution subchannel isCarry out subchannel coupling according to the following formula:

$i\left(j\right)=\underset{i\∈B\left(j\right)}{\min }|{\mathrm{SINR}}_{s,r}^i-{\mathrm{SINR}}_{r,k}^j|$

Wherein, remaining customer service set in the first jumping after j-1 sub-channels before the second jumping has been mated in B (j) expression；

4th step: if also having remaining subchannel after having serviced high-priority users, then according to the son described in the 3rd step Remaining subchannel is distributed to low priority user by channel matched algorithm.

The beneficial effects of the present invention is: the controlled combined wireless resource dispatching method of time delay of the present invention for TD-LTE and WLAN technology, uses virtual Qos mapping mechanism and the access mechanism of improvement, it is ensured that high-priority service real-time Access；Improve the intervalometer in 802.11 agreements, up-downgoing mechanism and fallback mechanism, it is ensured that the Qos demand of real time business, Reduce a large amount of time delays produced when data service is transmitted in heterogeneous system, meet the different Q os business demand to time delay, Add the service efficiency of isomery frequency spectrum.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet of the controlled combined wireless resource dispatching method of time delay of the present invention；

Fig. 2 is that the clock of heterogeneous system synchronizes flow chart；

Fig. 3 is that business up-downgoing diacritics position arranges schematic diagram；

Fig. 4 is up-downgoing traffic collisions rollback schematic diagram；

Fig. 5 is minimal time delay channel matched schematic diagram.

Detailed description of the invention

The present invention relates to broadband wireless communications field, particularly relate to the heterogeneous network of group user based on service priority IP layer pre-switch technology, can be widely applied in following Ubiquitous Network wireless communication field.Heterogeneous network switching is the most wireless Problem particularly important in mobile communication, is also the problem of a difficult thorough solution of comparison.And the different nets of same place existence The addition of the factors such as the immeasurability of the diversity of network, the multiformity of business, the multimode of terminal and environment, compared to same net Handoff procedure in network, the complexity of problem is greatly increased.The horizontal handoff algorithm of relative maturity is the most inapplicable before, is conceived to Research in terms of service environment self adaptation in heterogeneous network, difficulty is very big especially.

The present invention, based on service priority, carries out the self-optimizing switching in group user heterogeneous network, touches at mobile terminal While sending out link layer switching, by using business pre-switch rank (level) and target BS weighted value, self adaptation is carried out Coupling between the two, and carry out the pre-switch connection of IP layer, improve customer service quality and switching efficiency, optimize network with equal Weighing apparatus load.

The invention discloses the combined wireless resource dispatching method that a kind of time delay is controlled, can be applicable to optical cable and cannot arrive district In the broadband access on a large scale in territory and high-speed mobile environment, the large-scale wireless of real time business accesses, as rural area, mountain area, shade decline Fall critical regions and bullet train etc..The present invention utilizes TD-LTE technology as long range propagation passage, utilizes WLAN technology to make For short distance user's access technology, user terminal can run multiple data service, and the Qos grade of every kind of data service is different.This The application premise of invention is, two kinds of wireless standard precise synchronizations, it is therefore desirable to the synchronous signaling process of two kinds of networks of design, and root Corresponding priority valve, the mapper of design scheduling of resource so that business is calculated according to QoS grade, channel matched degree, CQI information Reach Optimum Matching between demand, priority valve and available channel three, meet the Qos demand of real time business.In order to avoid with The collision of family business, in addition it is also necessary to design WLAN user is at the fallback mechanism intercepted on channel, and fallback mechanism needs to consider TD-LTE The up-downgoing time proportioning of frame format, thus reduce the queuing time of user's up-downgoing business.

Below in conjunction with the accompanying drawings the detailed description of the invention of the present invention is described in further detail.

Embodiment one

The present embodiment provides the combined wireless resource dispatching method that a kind of time delay is controlled, as it is shown in figure 1, include following step Rapid:

1, extra clock register is used, the system clock of the reading TD-LTE of timing, and fixed by clock register Time notice wlan network so that wlan network and TD-LTE network keep Tong Bu.

TD-LTE is the LTE technology of time division duplex, and all wireless channels both correspond to the unique resource in time domain, and WLAN Use Carrier Sense Multiple Access/conflict avoidance CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance), it is a kind of half-duplex media access control protocol seizing type, is the most also a kind of Dual-mode based on TDD.

(Timing Synchronization Function determines to propose timing synchronization function TSF in IEEE 802.11 Time synchronous function) method that realizes Ad hoc (point-to-point) network timing synchronization, but the method is along with the increase of network size, Timing accuracy drastically declines, and seriously limits the extensibility of Ad hoc network.Document is had to propose TSF is improved, Solve the problem that when number of network node increases, TSF performance drastically declines to a certain extent, but when number of network node is bigger, still deposit At bigger timing offset.For the many AP framework on bullet train, the asynchronous meeting of business increases the weight of the processing load of IP layer, with Time two kinds of wireless standards use different work clocks, will also result in the asynchronous communication of data, add the length of data queue. In order to accurately dispatch the time-domain resource of different systems, the work clock of two kinds of wireless standards need to keep synchronizing.Synchronization scenario has three Kind, little net synchronizes with external GPS clock with netting greatly the while that net Tong Bu, big being netted greatly with little net synchronization or little net, and latter two scheme needs Change the information updating mechanism in big net, be therefore difficult to realize.The present invention uses extra clock register, the reading of timing Take the system clock of TD-LTE, and by the notice wlan network of clock register timing, so that wlan network and TD-LTE Network keeps synchronizing.

2, it is designed to reduce the fallback mechanism of queuing delay, it is to avoid user occurs collision in competition window.

LTE proposes very high request to the transmission delay in RAN user face, and i.e. minimum one-way transmission delays to control at 5ms Within.The harsh conditions producing queuing delay is the competition time serious lock-out of TD-LTE up-downgoing time and WLAN, makes Become data queue to be required to wait in line on different MAC, cause the delay of multiple framing bit.In order to reduce business queuing further Time delay, at the up-downlink direction of the MAC layer differentiated service of WLAN, and arranges up competition window (Uplink Contention Window) and descending competition window (Downlink Contention Window), window size is with reference to the up-downgoing of TD-LTE Time proportioning, utilizes GP (guard period) protection interval to carry out synchronization simultaneously.In order to avoid user is in contention window Collision occurs in mouthful, needs the fallback mechanism being designed to reduce queuing delay.Fallback mechanism is also according to the MAC layer of 802.11e Type of service, is divided into 4 kinds of AC (Access Category), and the corresponding different channel competition parameter of every class AC carries out channel competition And back off procedure.

3, united virtual map mechanism is designed so that WLAN data can be assigned to rapidly suitably carry by TD-LTE On be transmitted.

In the present invention, design united virtual map mechanism, for the business demand produced in wlan network, correspond to The QCI (Qos Class Indication, QCI classification logotype) of the TD-LTE network carrying so that TD-LTE can rapidly by WLAN data is assigned to suitably carry be transmitted.In the present invention, TD-LTE is as the access system being relayed to base station Formula, receives user data and carries out QCI coupling and forwarding, the performance of TD-LTE system can be caused to reduce, and is especially applicable to big Scale user accesses environment.Therefore the QCI completing data stream in WLAN side maps, it is possible to reduce the MAC layer of TD-LTE to data The coupling again of stream and filter process.

4, a kind of channel matched based on time delay rule is designed, it is ensured that delay sensitive business.

Use multistage Fast Channel matching mechanisms, it is ensured that the different system needs to Qos, according to different Qos demands, Select optimum resource matched principle.The present invention is directed to the delay requirement in LTE system, propose a kind of channel based on time delay Join rule, it is ensured that delay sensitive business, if real-time voice is with minimum time delay overhead transmission.Present invention contemplates that multi-user field Subchannel matching problem under scape.

Situation one: first when not differentiating between user's service priority, jumps according to different user in difference second The difference of the channel quality in subchannel, selects user's service that channel quality is best in each subchannel, then distinguishes Mate one by one after jumping AC business demand and the second hop channel quality-ordered by first, so can fully obtain multi-user diversity and increase Benefit, maximum system throughput；

Situation two: secondly when distinguishing user's service priority, first service high-priority users, high priority User jumps second that to select the best channel of channel quality be its service, then jumps first and selects with the second hop channel quality Close subchannel matches, and so can ensure the service quality of high-priority users on two-hop link, if last Also have remaining subchannel after having serviced high-priority users, distribute to low priority user according to situation one；Additionally, due to Have employed Adaptive Modulation and Coding (AMC) mechanism on every sub-channels to carry out data transmission, the adaptive power in subchannel divides Add benefit not notable, can simply utilize power averaging to distribute, so greatly reduce algorithm complex.

Owing to have employed such scheme, the invention have the characteristics that:

In the present invention, the relay station in car collects user data and corresponding Qos grade, by virtual map mechanism, really Determining the QCI numerical value of different data streams, and carry out traffic queuing at IP layer, the MAC layer being sent to TD-LTE one by one carries out data Transmission.Owing to WLAN is Tong Bu with the clock of TD-LTE system and has distinguished the up-downlink direction of channel, the WLAN data of collection Can be without waiting for.In like manner, WLAN receives the downlink data come from TD-LTE, it is also ensured that the real-time biography of data stream Defeated.Minimal time delay finally by TD-LTE subchannel and different AC class business mates, reduce under large-scale consumer environment by In the high-priority service time delay occurring traffic collisions to cause.

The present invention is directed to high ferro operating environment, the radio access scheme that design is merged, there is higher practicality and feasible Property.

The present invention is directed to two kinds of concrete wireless standards TD-LTE and WLAN, design the optimum resource between two kinds of standards Join algorithm, by united Qos mapping mechanism, accurate channel synchronization and the WLAN traffic collisions rollback designed for TD-LTE Mechanism, it is ensured that the real time business requirement to time delay.The present invention supports the synchronous signaling mechanism of two kinds of standards, in order to ensure WLAN system Formula effectively reduces TD-LTE propagation delay time, it is necessary to carries out rationalizing scheduling on the basis of synchronization, to ensure two simultaneously Plant the safety issue between standard.Application claims is differentiating uplink and downlink channel in WLAN standard, according to precise synchronization clock Scheduling, exactly corresponds to the up-downgoing channel under TD dual-mode, reduces the frame caused due to lock-out and waits in line.In associating The preferred channels matching mechanisms of Qos grade under two kinds of standards, has 9 kinds of Qos grades, QCI flag bit represents under TD-LTE standard, The most then define four kinds of AC (Access Category).When designing resource mapper, need to consider two kinds of Qos Dividing impact on weighted value, the weighted value of time delay needs to combine Qos grade, channel matched degree, CQI information carry out COMPREHENSIVE CALCULATING. Fallback mechanism during WLAN user collision, owing to having distinguished WLAN up-downgoing, it is possible to corresponding TD-LTE frame format very easily Time proportioning.Therefore the collision Backoff time of WLAN up-downgoing business, also should refer to the up-downgoing time ratio of TD-LTE frame format, Thus reduce the queuing delay of business.

Embodiment two

What the present invention considered is suitable for scene is in personnel concentrated area from far-off regions or the compartment of following high-speed railway In, owing to optical cable cannot lay so that wireless relay mode can more conveniently realize user's networking, below as a example by high ferro, The heterogeneous network type considered is 802.11e and TD-LTE.

Can produce mass data business when user surfs the Net, the type of service of generation is also varied.Assist according to 802.11e View regulation, there are the 4 class grades of service, are 2 class background business, 1 class video traffic and 1 class speech business respectively；Corresponding Qos etc. Level rises successively from 0 to 3.In pertinent literature and test report it will be seen that when number of users is more than 20, collision probability meeting Significantly promote, and owing to the time delay average that causes of collision can reach more than 200ms, in heterogeneous network environment, this generally Rate and time delay also can be greatly improved.Therefore when there is network congestion, it is within the contemplation of the invention that high-grade business can preferentially be passed through, And by reasonably scheduling heterogeneous network resource, what between minimizing heterogeneous network, operation brought waits in line time delay.

Considering the network insertion scene on bullet train, on compartment, user accesses and is completed by 802.11e, and train is adopted to base station TD-LTE standard, the wireless access point AP that often joint compartment is placed is used all to be connected with TD-LTE terminal by optical cable, due to IP layer Processing speed is determined by CPU, will not impact RRM, when therefore neglecting the process of IP layer in the present invention Prolong.The mass data stream that often joint compartment produces all converges to be transmitted on TD-LTE, has increased the weight of the burden of TD-LTE, has caused relatively Big queuing access delay.And be heterogeneous system between 802.11e and TD-LTE, it is impossible to synchronous working, increase TD-further The queuing time of LTE upstream data.

As a example by user uplink business, the present embodiment is as a example by symmetrical type of service, i.e. up-downgoing business has equally Qos demand, the method for the invention is described in detail, specific implementation process is as follows:

Although the timing synchronization function that IEEE 802.11 agreement is had by oneself meets the timing function of self, but is intended to it Reference clock as other synchronous services also has the biggest defect.First, it uses offset compensation, in the wink being calibrated Between inevitably cause clock saltus step forward or backward；Secondly as there is clock drift, clock synchronization accuracy can be subject to The impact of beacon interval change, is degrading net synchronization capability；Finally, TSF does not have anti-beacon delay and loss ability, and this is further Reduce the reliability of WLAN TSF.In order to solve these problems, the present invention proposes based on TD-on the basis of existing TSF The host-guest architecture formula continuous clock synchronizing process of LTE time register, it can be preferably for setting up the synchronous service on WLAN Reference clock is provided.As in figure 2 it is shown, owing to the network of train system is unique so that synchronizing process is without taking extra nothing Line resource, clock register obtains the clock information in SCH synchronizing channel, is broadcast to all access AP websites and performs Timing Synchronization Function, synchronization between each AP and mobile station.

Corresponding to 4 classes AC, each terminal sets up 4 AC transmit queues.The Frame of miscellaneous service is first mapped to difference AC, put into corresponding transmit queue.Each transmit queue uses DCF (distributed coordination Function) machine-processed independent competitive channel.In competition process, terminal uses respective AIFS (arbitration frame interval), CWmin (minimum competition window), CWmax (maximum contention window) and maximum retransmission value.Race condition has:

1) between multiple transmit queues of same terminal inner because of competitive channel clash time, by a virtual scheduling Device (virtual collision handler) selects the queue that priority is higher to be transmitted, and other Low Priority Queuings Competition window double, number of retransmissions adds 1.

2) will collide when different terminals sends Frame simultaneously, each transmit queue collided will experience Retransmission processes, unrelated with queue priority height.

3), when uplink and downlink business collides, worst situation can cause highest priority traffic one-way latency to surpass Cross 200ms.In order to avoid the generation of this situation, it is provided with business rollback strategy as shown in Figure 4, and in PLCP (physical layer Convergence protocol, PHYLayer Convergence Procedure) coverage (service field) in Header is inner increases Plus descending diacritics position sf_LinkDirection, the value arranging sf_LinkDirection is 0 or 1, wherein under 0 expression OK, 1 represents up, as shown in Figure 3.Different rollback strategies is used for up-downgoing business, it is ensured that high precedence industry The two-way connectivity of business.The purpose of rollback strategy is to produce collision in time in order to avoid business, simultaneously in order to reduce WLAN- The queuing delay of TD LTE, the Backoff window of up-downgoing business have to come according to the uplink/downlink frames form proportioning of TD-LTE system Formulate.

The present embodiment supposing, TD-LTE system takes the 4th kind of up-downgoing proportioning, i.e. in the frame length of 10ms, up-downgoing Sub-frame number ratio is 3: 7, and corresponding WLAN up-downgoing service competition window interval time slot is also 3: 7, and total length is also configured as 10ms。

WLAN traffic collisions rollback strategy under technical scheme described in the present embodiment: when uplink service produces, according to same Step clock (i.e. clock register) and zone bit information (i.e. up-downgoing diacritics position), it may be judged whether be in uplink traffic transmission Process；If it is, select to enter transmission queue；Otherwise wait for.In back off procedure, each AC monitor channel, if letter Road is idle, then every a free timeslot, fallback counter subtracts 1；When following two situation, fallback counter is hung up:

1, other AC are had to send data on channel；

2, channel is carrying out downlink data transmission.

The calculating of minimum and maximum contention window size, rollback and number of retransmissions is with reference to agreement regulation in 802.11E.Adjust Later rollback strategy, by the separately transmission of the bi-directional data of symmetrical service, reduces similar AC and competes the probability of same channel, with Time according to the characteristic of low priority traffice, i.e. uplink business data amount is far smaller than downlink business, devises and competes district accordingly Between, also can reduce the access collision time delay of low priority traffice.

For the heterogeneous access system of design in the present invention, using TD-LTE terminal as the via node of car-ground access, need All business that train user to be processed produces, when data rheology is big, can increase the weight of the work load of TD-LTE node M AC layer. In LTE system, in order to ensure the Qos demand of different business, the IP packets need of user is mapped to different EPS Bearer, to obtain corresponding QoS guarantee.Such mapping relations are TFT (the Traffic Flow by MAC layer Template) realize with Packet Filters therein.

In the present invention, the access service of WLAN is classified and in TD-LTE, the QCI grade of regulation carries out virtual map pairing, The idled radio resource of TD-LTE is registered to mapper, and by virtual map, the data stream accessed by WLAN directly corresponds to close On suitable EPS Bearer, so that TD-LTE is without classifying one by one to data stream, it is possible to accelerate the process speed of MAC layer Degree.The relation mapped is as shown in table 1.

Table 1: associating Qos mapping table

Virtual QCI maps the processing speed that can accelerate TD-LTE, and the user for each QCI grade distributes different Dedicated Bearer, Dedicated Bearer needs to distribute certain Radio Resource for it and carries out data biography when setting up Defeated.In order to ensure that Radio Resource is utilized, proposed below is nearest subchannel matching algorithm (Closest Subchannel Matching, CSM), this algorithm preferentially distributes the second hop channel resource to high-priority users, and First jumps selection matches with the second jumping subchannel quality immediate AC business demand, so can first ensure high preferential The service quality of level user, if distributing high-priority users also have remaining subchannel, then according to single service-user above Remaining subchannel is distributed to low priority user, as shown in Figure 5 by the algorithm proposed in situation.

Concrete subchannel matching mechanisms is described as follows:

The first step: determine the service order of user according to the type of service of user and required transfer rate, first service High-priority users.Assume that K user has K1 high-priority users (business such as such as Voice, Video), remaining K-K1 Individual user be the transfer rate needed for low priority user (business such as such as FTP, HTTP), user k be r_k(k∈Ω^K), wherein Ω^KRepresent the set of all users.

Second step: the service order of the user determined according to step one is jumped second and selected son to believe for high-priority users Road, uses Max C/I algorithm and channel to estimate, replaces C/I with SINR in an ofdm system, in conjunction with customer service to BER (error code Rate, Bit Error Rate) demand, concreteIndividual user selects subchannel according to the following formula until meeting its institute The transfer rate needed:

$j\left(k\right)=\arg \underset{j\∈A_j}{\max }{\mathrm{SINR}}_j^k,\underset{j\∈A_j}{\min }{\mathrm{BER}}_j^k$

Wherein, A_jRepresent unassigned sets of sub-channels.

3rd step: set the signal to noise ratio of subchannel j distributing to kth user in the second jumping asIn first jumping not The signal to noise ratio of AC (i) the class business demand of distribution subchannel isCarry out subchannel coupling according to the following formula:

$i\left(j\right)=\underset{i\∈B\left(j\right)}{\min }|{\mathrm{SINR}}_{s,r}^i-{\mathrm{SINR}}_{r,k}^j|$

Wherein, remaining customer service set in the first jumping after j-1 sub-channels before the second jumping has been mated in B (j) expression.

4th step: if also having remaining subchannel after having serviced high-priority users, then according on described in the 3rd step Remaining subchannel is distributed to low priority user to improve system entire throughput by subchannel matching algorithm.

In algorithm, step one and step 2 ensure that the service quality of high-priority users in the second hop link above, step Consider the overall transfer stability of two-hop link in rapid three, select channel quality immediate double bounce subchannel coupling, it is ensured that High-priority users overall transmission rate on two-hop link.

Subchannel matching algorithm can also use the distribution of adaptive optimal power the overall performance of system is entered The raising of one step, but present invention primarily contemplates the matching problem of double bounce subchannel, so have employed power averaging distribution method, phase Algorithm implementation complexity is largely reduced than Optimum Matching algorithm.

Owing to using power averaging distribution subchannel matching mechanisms to mate with use adaptive optimal power distribution subchannel Mechanism is applicable to different customer service scenes, can meet different system requirements in two kinds of different scenes, the first Mechanism has good performance in system entire throughput, and the second mechanism mainly considers the Service Quality of high-priority users Amount requirement.

Description of the invention and application are illustrative, are not wishing to limit the scope of the invention in above-described embodiment. The deformation of embodiments disclosed herein and change are possible, embodiment for those skilled in the art Replace and equivalence various parts be known.It should be appreciated by the person skilled in the art that in the essence without departing from the present invention In the case of god or substitutive characteristics, the present invention can otherwise, structure, layout, ratio, and with other elements, material Realize with parts.

Claims (8)

1. the combined wireless resource dispatching method that a time delay is controlled, it is characterised in that comprise the following steps:

Step one, is used the system clock of the reading TD-LTE network of extra clock register timing, and is deposited by clock The notice wlan network of device timing, makes wlan network keep Tong Bu with TD-LTE network；

Step 2, at the up-downlink direction of the MAC layer differentiated service of wlan network, and arranges up competition window and descending competition Window, window size is with reference to the up-downgoing time proportioning of TD-LTE network；

Step 3, for the business demand produced in wlan network, designs united virtual map mechanism so that TD-LTE can It is assigned to suitably carry by WLAN data rapidly and is transmitted；Described united virtual map mechanism is: by wlan network The business demand of middle generation is mapped to the classification logotype QCI of the TD-LTE network carrying；

Step 4, designs a kind of channel matched based on time delay rule, it is ensured that delay sensitive business；Described channel based on time delay Matched rule is: first when not differentiating between user's service priority, jumps according to different user at different son letters second The difference of the channel quality on road, selects user's service that channel quality is best, the most respectively by the in each subchannel Mate one by one after one jumping AC business demand and the second hop channel quality-ordered；Secondly in the situation distinguishing user's service priority Under, first servicing high-priority users, it is its service that high-priority users jumps, second, the channel selecting channel quality best, so After first jump select match with the second immediate subchannel of hop channel quality；If after having serviced high-priority users Also have remaining subchannel, then distribute to low priority user according to the situation not differentiating between user's service priority.

The combined wireless resource dispatching method that time delay the most according to claim 1 is controlled, it is characterised in that: in step 2, Wlan network utilizes GP protection interval to carry out synchronization.

The combined wireless resource dispatching method that time delay the most according to claim 1 is controlled, it is characterised in that: in step 2, Wlan network is provided with the fallback mechanism avoiding user to occur collision in competition window；Described fallback mechanism is according to 802.11e's MAC layer type of service is divided into 4 kinds of AC, and the corresponding different channel competition parameter of every class AC carries out channel competition and back off procedure；Right Should be in 4 classes AC, each terminal sets up 4 AC transmit queues, and the Frame of miscellaneous service is first mapped to different AC, Jin Erfang Enter corresponding transmit queue；Each transmit queue uses the DCF independent competitive channel of mechanism.

The combined wireless resource dispatching method that time delay the most according to claim 3 is controlled, it is characterised in that at channel competition During, race condition has:

1) between multiple transmit queues of same terminal inner because of competitive channel clash time, by the choosing of virtual scheduling device The queue selecting priority higher is transmitted, and the competition window of other Low Priority Queuings doubles, and number of retransmissions adds 1；

2) when different terminals send simultaneously Frame collide time, each transmit queue collided will experience and retransmit Journey, unrelated with queue priority height.

The combined wireless resource dispatching method that time delay the most according to claim 3 is controlled, it is characterised in that described rollback mistake The particular content of journey is: increase up-downgoing diacritics position sf_ in the coverage in PLCP Header LinkDirection, if the value of sf_LinkDirection is 0 or 1, wherein 0 represents descending, and 1 represents up；Up-downgoing business Backoff window formulate according to the uplink/downlink frames form proportioning of described TD-LTE network.

The combined wireless resource dispatching method that time delay the most according to claim 5 is controlled, it is characterised in that: described TD-LTE The ascending-descending subframes quantity of network is than for 3:7, and the up-downgoing service competition window interval time slot of corresponding wlan network is also 3: 7。

The combined wireless resource dispatching method that time delay the most according to claim 5 is controlled, it is characterised in that: described WLAN net In network, when uplink service produces, judge whether to be in up according to described clock register and described up-downgoing diacritics position Business transmitting procedure；If it is, select to enter transmission queue；Otherwise wait for；In back off procedure, each AC monitors letter Road, if channel idle, then every a free timeslot, fallback counter subtracts 1；When following two situation, fallback counter Hang up: on a, channel, have other AC to send data；B, channel are carrying out downlink data transmission.

The combined wireless resource dispatching method that time delay the most according to claim 1 is controlled, it is characterised in that: concrete son letter Road matching mechanisms is:

The first step: determine the service order of user according to the type of service of user and required transfer rate, first service Gao You First level user；Assuming to have in K user K1 high-priority users, remaining K-K1 user is low priority user, user k institute The transfer rate needed is r_k(k∈Ω^K), wherein Ω^KRepresent the set of all users；

Second step: the service order of the user determined according to step one is jumped as high-priority users selection subchannel second, adopts Estimate with Max C/I algorithm and channel, replace C/I with SINR in an ofdm system, in conjunction with the customer service demand to the bit error rate, Kth user selects subchannel according to the following formula until meeting its required transfer rate:

$j\left(k\right)=\arg \underset{j\∈A_j}{max}{\mathrm{SINR}}_j^k,\underset{j\∈A_j}{min}{\mathrm{BER}}_j^k$

Wherein,A_jRepresent unassigned sets of sub-channels；

3rd step: set the signal to noise ratio of subchannel j distributing to kth user in the second jumping asUnallocated son in first jumping The signal to noise ratio of AC (i) the class business demand of channel isCarry out subchannel coupling according to the following formula:

$i\left(j\right)=\underset{i\∈B\left(j\right)}{min}\left|{\mathrm{SINR}}_{s,r}^i-{\mathrm{SINR}}_{r,k}^j\right|$

Wherein, remaining customer service set in the first jumping after j-1 sub-channels before the second jumping has been mated in B (j) expression；

4th step: if also having remaining subchannel after having serviced high-priority users, then according to the subchannel described in the 3rd step Remaining subchannel is distributed to low priority user by matching algorithm.