CN102970757A

CN102970757A - Long-term evolution (LTE) downlink filling resource distribution method based on real-time service

Info

Publication number: CN102970757A
Application number: CN2012104799851A
Authority: CN
Inventors: 付茂豹; 刘圣洁; 张艳凤; 王斌
Original assignee: Nanjing Post and Telecommunication University
Current assignee: Zhong Tong Clothing Consulting And Design Research Institute Co Ltd
Priority date: 2012-11-23
Filing date: 2012-11-23
Publication date: 2013-03-13
Anticipated expiration: 2032-11-23
Also published as: CN102970757B

Abstract

The invention discloses a long-term evolution (LTE) downlink filling resource distribution method based on a real-time service, and belongs to the technical field of wireless network resource distribution. The method comprises the following steps of: classifying users into a voice over Internet protocol (VoIP) group and a file transfer protocol (FTP) group according to quality of service (QoS) information; scheduling the users in the VoIP group, and generating a VoIP group scheduling priority level set; scheduling the users in the FTP group from residual resource blocks, and generating an FTP group scheduling priority level set; distributing the VoIP users and the FTP users with close channel quality information (CQI) values to the same resource block, and updating the VoIP group scheduling priority level set; and combining the FTP group scheduling priority level set and the updated VoIP group scheduling priority level set to obtain a final scheduling priority level set, wherein a base station finishes an encoding and packet sending process according to the final scheduling priority level set. By the method, system resources are used at the maximum extent according to the characteristics of VoIP and FTP data packets; the problem of waste of resources of the conventional scheduling algorithm is solved; and the system performance and the capacity are improved.

Description

Based on the descending filling resource allocation methods of the LTE of real time business

Technical field

The invention discloses the descending filling resource allocation methods based on the LTE of real time business, belong to the technical field that wireless network resource is distributed.

Background technology

Future Ten year, be accompanied by the promotion of using such as new datas such as mobile network page browsing, video download, game on line and social networks, people will still keep rapid growth to the demand of cellular communication service, and this just proposes higher requirement to the performance of wireless communication system.The business development of 3G network technology originates from the UMTS/WCDMA system of the 3GPP of calendar year 2001, the UMTS/HSPA stage of having developed at present.In order to keep the competitiveness of 3GPPUMTS system, and carry out evolution to 4G, LTE(Long Term Evolution, Long Term Evolution steadily fast) the quick upgrading of system seems incomparable urgent.LTE systems technology standard began in 2006 to formulate, and this becomes an of paramount importance step in the evolution process.In December, 2009, commercial LTE network service is started operation in the Scandinavian Peninsula, and plans to carry out system upgrade in short-term and promote.So far, the standards and guidelines of relevant LTE and related versions thereof is also in constantly improving.

The main target of LTE system provides higher message transmission rate, lower data delay, the higher availability of frequency spectrum, lower cost and more succinct operating experience.In the LTE system, each user can dispose its exclusive wireless network identification, and the base station is distinguished the user by user's wireless network identification to authorizing the indicating downlink control channel to carry out mask.For same user's dissimilar authorization message, indication can be authorized by different wireless network identification by system.Transmission block is to form in medium layer (MAC layer) among the LTE, the base station receives each user's feedback information (mainly being CQI), and scheduler calculates the concrete Modulation and Coding Scheme that transmission block is big or small and this transmission block adopts that this TTI will transmit by the feedback information of weighing each user.

Packet scheduling algorithm commonly used can both be applicable to the packet scheduling of LTE system in the radio communication, comprising: max carrier to interference scheduling algorithm, repeating query algorithm, equitable proportion algorithm and improved weight limit time delay priority algorithm.The throughput that max carrier to interference scheduling algorithm has improved system but can not guarantee user's fairness; The Round Robin algorithm has guaranteed the throughput that fairness has but been sacrificed system.The equitable proportion algorithm is the compromise of max carrier to interference algorithm and polling algorithm, and major defect is not consider the qos requirement of different business, particularly delay requirement.Improved weight limit time delay priority algorithm can cause these users' packet in base station side larger time delay to be arranged to the user of bad channel conditions, and the maximum tolerance that surpasses the user when time delay will be abandoned during the time.

When service-user existed simultaneously as the real time business user and when non-, real time business user's priority will be higher than non-real-time service, and the real time business user obtains first resource under normal circumstances.Because the packet of real time business is smaller, has caused the throughput of whole system lower, can not bring into play the advantage of LTE system fully, causes the great wasting of resources.

Summary of the invention

Technical problem to be solved by this invention is the deficiency for the above-mentioned background technology, and the descending filling resource allocation methods based on the LTE of real time business is provided.

The present invention adopts following technical scheme for achieving the above object:

Based on the descending filling resource allocation methods of the LTE of real time business, comprise the steps:

Step 1, base station receive each user's feedback information, and described feedback information comprises: QoS information, CQI value;

Step 2, scheduler is divided into VoIP group and FTP group according to the QoS information described in the step 1 with the user;

Step 3 is dispatched each user of VoIP group, for each user resource allocation piece and generate the set of VoIP group scheduling priority, removes the user who repeats in the set of VoIP group scheduling; Wherein: described VoIP group scheduling priority set is combined into the form tabulation corresponding with Resource Block;

Step 4 is dispatched FTP group user on remaining Resource Block, for each user resource allocation piece and generate the set of FTP group scheduling priority;

Step 5 arranges the threshold values of FTP user CQI value according to the type of service of user request, the difference of searching CQI value and FTP user CQI value 1 with interior voip user:

When FTP user CQI value was greater than or equal to threshold value, the resource block assignments that described voip user is taken was given described FTP user, and described FTP user's title is filled into the set of the described VoIP group scheduling of step 3 priority, obtained the dispatching priority set;

Otherwise, be not FTP user's distributes resource blocks;

Step 6, combination step 4 described FTP group scheduling priority set and the described dispatching priority set of step 5 obtain final dispatching priority set;

Step 7, gather according to final dispatching priority the base station, and user data is finished the modulating-coding process, sends the packet after encoding, and wherein: the voip user in the same Resource Block and FTP user adopt identical modulation coding mode.

In the descending filling resource allocation methods of described LTE based on real time business, the preferred fair scheduling algorithm dispatched users of step 3 and step 4.

The present invention adopts technique scheme, has following beneficial effect: utilize VoIP, FTP packet characteristics, maximally utilised system resource, overcome the problem of the traditional scheduler algorithm wasting of resources, improved systematic function and capacity.

Description of drawings

Fig. 1 is the schematic diagram of embodiment.

Fig. 2 is the schematic diagram that VoIP group scheduling priority set A generates.

Fig. 3 is the schematic diagram that FTP group scheduling priority set B generates.

Fig. 4 is the schematic diagram that fills into the VoIP group scheduling priority set C generation of FTP user's title.

Fig. 5 is the schematic diagram that final dispatching priority set D generates.

Fig. 6 is the flow chart based on the descending filling resource allocation methods of real time business LTE.

Embodiment

Be elaborated below in conjunction with the technical scheme of accompanying drawing to invention:

As shown in Figure 1.Supposing that residential quarter S spectral bandwidth is 2.7MHZ, can the scheduling resource number of blocks be 15, and we come the identifying resource piece with Rn, n ∈ (1 ~ 15).The base unit of this TTI(time that RRM is administered equals 1ms, is equivalent to a subframe size) the scheduling moment, suppose that the residential quarter has 20 users and accepts service.Other establishes wherein VoIP(Voice over Internet Protocol, the speech network host-host protocol) number of users and FTP user's number all are 10, identify respectively VoIP and FTP (File TransferProtocol, file transfer protocol (FTP)) user with Vn, Fn equally.Because voip user's QoS grade is higher than the FTP user, voip user's priority allocation resource under normal circumstances, the FTP user then can accept scheduling again after the voip user finishes distribution.Resource that the FTP user obtains is the remaining Resource Block of institute after the distribution, and the channel quality status of its resource can not guarantee fully.Under this rule, can discharge the dispatching priority set.Suppose that the professional voice packet size of VoIP is 16bit, the ftp business packet is 500bit, and can calculating at this moment by the dispatching priority set, throughput of system is 2660bit.If only there is the FTP user in the system, then the throughput of system of this moment is limiting value 7500bit.This shows, dispatch iff each professional QoS priority of consideration, can cause the larger wasting of resources.

As shown in Figure 6, utilize method of the present invention to carry out distributing based on the descending filling resource of real time business LTE, specifically comprise the steps:

Step 1, base station receive each user's feedback information, and described feedback information comprises: QoS information, CQI (Channel Quality Indicator, quality of wireless channel) value, throughput, interference parameter, fairness, the dry ratio of letter.

Step 2, scheduler calculates the TB(transmission block that this TTI will transmit by the feedback information of weighing each user) the concrete Modulation and Coding Scheme that adopts of size and this TB: according to the QoS information described in the step 1 user is divided into VoIP group and FTP group;

Step 3, proportion of utilization fair algorithm (PF algorithm) is dispatched each user of VoIP group, for each user resource allocation piece and generate VoIP group scheduling priority set A(as shown in Figure 2), remove the user who repeats among the VoIP group scheduling priority set A; Wherein: described dispatching priority set is the form tabulation corresponding with Resource Block.

The formula of equitable proportion algorithm is:

R wherein _Ik(t) be the instant speed of user i on k Resource Block, the letter that User reports is dry than being converted to the indication of CQI(channel quality) value, namely represented the current maximum data rate that can transmit of this user.R _Ik(t) throughput for producing in the last time window of this user has represented this user and has accepted number of times and the quality of serving in the certain hour section.By the PF algorithm, 10 voip users have been assigned to 15 positions that Resource Block is corresponding, guarantee that by cycle detection all voip users are assigned to Resource Block, generate VoIP group scheduling priority set A.Consider that the VoIP data volume is less, remove the voip user who repeats among the VoIP group scheduling priority set A, guarantee that all VoIP can both be assigned with and can only be assigned to a Resource Block in this user's group.

Step 4 is dispatched FTP group user by the PF algorithm on remaining Resource Block, is each user resource allocation piece, and generates FTP group scheduling priority set B(as shown in Figure 3);

Step 5, the threshold values of FTP user CQI value is set according to the type of service of user's request, seek the voip user of close with FTP user CQI value (close difference can require concrete the setting according to obstructed system applies, for example sets the difference of FTP user, voip user CQI value in 1):

When FTP user CQI value is greater than or equal to threshold value, the resource block assignments that described voip user is taken is given described FTP user, described FTP user's title is filled into the described VoIP group scheduling of step 3 priority set A, obtain dispatching priority set C(as shown in Figure 4); Otherwise, be not FTP user's distributes resource blocks.

Step 6, combination step 4 described FTP group scheduling priority set B and the described dispatching priority set of step 5 C obtain final dispatching priority set D(as shown in Figure 5)

Step 7, base station MAC layer are determined the modulation coding mode of user profile in each Resource Block and the filling mode of transmission block, and the voip user in the same Resource Block and FTP user adopt identical modulation coding mode; The base station physical layer is finished the modulating-coding process of real data according to final dispatching priority set; The packet that decode-regulating obtains finally is mapped to transmitting antenna and sends.

In sum, the present invention utilizes VoIP, FTP packet characteristics, has maximally utilised system resource, has overcome the problem of the traditional scheduler algorithm wasting of resources, has improved systematic function and capacity.Above-described embodiment only is a specific embodiment of the present invention, and the method for the invention is equally applicable to other types of service in the LTE system.

Claims

1. based on the descending filling resource allocation methods of the LTE of real time business, it is characterized in that comprising the steps:

Otherwise, be not FTP user's distributes resource blocks;

2. the descending filling resource allocation methods of the LTE based on real time business according to claim 1 is characterized in that the preferred fair scheduling algorithm dispatched users of described step 3 and step 4.