CN104994543A - Uplink and downlink scheduling method for LTE (Long Term Evolution)-Advanced system/LTE-Advanced relay system - Google Patents

Abstract

The invention discloses a random access overload control method based on an LTE (Long Term Evolution)-Advanced system. The random access overload control method comprises a downlink scheduling algorithm and an uplink scheduling algorithm, wherein the downlink scheduling algorithm specifically comprises the following process: traversing all radio bearers, performing summation to obtain the total volume D<sum> of data to be transmitted in a base station cache region, performing normalization processing to obtain an uplink scheduling parameter P<up>, and adding the uplink scheduling parameter P<up> into the scheduling algorithm in the form of r<P>, wherein r corresponds to the instantaneous transmission rate of each user; and the uplink scheduling method comprises the following process: performing summation according to BSRs uploaded by users to obtain the total volume D<sum> of data to be uploaded, performing normalization processing to obtain a downlink scheduling parameter P<down>, and adding the downlink scheduling parameter P<down> into the scheduling algorithm in the form of r<P>. The scheduling algorithms can have throughput adaptability. When the volume of the data to be transmitted is small, the influences of the parameters of the data to be transmitted on the algorithms are small, and increase along with the increase of the total volume of the data to be transmitted, so that the throughput adaptability of the system is improved; higher throughput than that of an unimproved scheduling algorithm can be achieved finally; and the performance of a base station is improved.

Description

The up-downgoing dispatching method of LTE-Advanced system/LTE-Advanced relay system

Technical field

The present invention relates to the LTE-Advanced system of moving communicating field, particularly relate to a kind of up-downgoing dispatching algorithm being applicable to LTE-Advanced relay system.

Background technology

LTE-Advanced is the evolution version of LTE (Long Term Evolution) technology, and in March, 2008, in May, 2008 determines demand.For meeting higher demand and the Geng Duo application of wireless communications market in the coming years, LTE-Advanced will reach descending 1Gbit/s, the peak rate of up 500Mbit/s.Relaying is a key characteristic of the LTE-Advanced specified in 3GPP Release10, and it can expand MPS process area, improve cell capacity.LTE-A have employed the key technologies such as carrier aggregation, multiple antennas enhancing, coordinated multipoint transmission, relaying, the enhancing of heterogeneous network interference coordination, greatly can improve the peak data rate of wireless communication system, peak value spectrum efficiency, community mean spectral efficiency and cell boundary users performance, also can improve the networking efficiency of whole network simultaneously.This makes lte-a system become the main flow of Development of Wireless Communications in the coming years.

In existing wireless communication technology, people improve constantly for the requirement of bandwidth rates, but thing the most rare is in a communication network exactly exactly resource and bandwidth.In limited bandwidth sum resource, how to reach and the most effectively utilize, how to carry out dispatching and distributing, this problem be mobile communication from the first generation to forth generation, be also study hotspot and the emphasis of LTE-Advanced.In order to can data rate under Rapid matching different radio channel, fully effectively utilize and distribute the resource of physical layer, the eNB of LTE system introduces scheduling feature in MAC layer.Scheduling is an important component part of LTE, and its functional entity is scheduler.Scheduler is in the core position of MAC layer, is also the core of whole system.Scheduler can call other module, and controls it and play corresponding function.The major function of scheduler module is allocation of radio resources and management, calculates the priority of different user business, HARQ Retransmission control etc.Which determine the priority of user scheduling, the running time-frequency resource of CU, the Modulation and Coding Scheme of employing and MIMO transmission pattern etc.Scheduler must take into full account when dispatched users each user and with the data volume of user side radio bearer and the concrete quality of service requirement of different business, take into account the fairness of whole system scheduling simultaneously, strive for making throughput of system reach maximum.These functions are all the key functions being related to lte-a system performance, and that is, the quality of dispatching algorithm directly affects the performance of lte-a system.

Summary of the invention

Corresponding this problem of adjustment can not be made according to the difference of data buffer storage amount to overcome above-mentioned existing dispatching algorithm, the present invention proposes the up-downgoing dispatching method of a kind of LTE-Advanced system/LTE-Advanced relay system, introduce this concept of data cached total amount, achieve and there is the adaptive dispatching algorithm of data buffer storage amount, meanwhile, the priority of user can be subject to the impact of the data cached total amount of current base station.

The present invention proposes a kind of Stochastic accessing overload controlling method based on LTE-Advanced system, the method comprises row dispatching algorithm and descending scheduling algorithm, wherein:

Described uplink scheduling algorithm, specifically comprises following flow process:

Each subscriber equipment in LTE-Advanced system/LTE-Advanced relay system Zhong Ge community carries out buffer state report and reports;

Data total amount D to be uploaded is obtained according to the BSR summation that subscriber equipment is uploaded _sum, the data to be uploaded of all users then same base station is connected are normalized, and obtain uplink scheduling parameter P _up, join in uplink scheduling algorithm;

Obtain the parameter that this scheduling will be used, at least comprise channel quality information, service quality, user's momentary rate, user's average throughput;

According to the parameter obtained, according to adding scheduling parameter P _upuplink scheduling algorithmic formula, calculate resources for user equipment distribute priority, described uplink scheduling algorithmic formula is as follows:

$p_{iup}=-{\mathrm{lg\&delta;}}_i*\frac{D_{HOLi}}{{\mathrm{\&tau;}}_i}*\frac{r_i{\left(t\right)}^{p_{up}}}{R_i(t-1)};$

Wherein, δ _ithat can bear for data flow i maximumly exceedes threshold value by team's head time delay and the packet loss caused; D _hOLiit is team's head packet delay time of stream i; τ _iit is the patient delay threshold of stream i; r _it () is the momentary rate of stream i in current TTI; R _i(t-1) be the average data transfer rate of stream i in the time window that t-1 is ending; P _idownrepresent the priority of the stream i calculated;

Subscriber equipment priority according to calculating carries out Resourse Distribute from high to low, by first Resource Block, is the user equipment allocation Resource Block resource of limit priority on this Resource Block, until meet required or resource is most;

Perform Adaptive Modulation and Coding, determine the modulation coding mode of scheduled user's equipment, transmission block size parameter;

Build the uplink scheduling information generating this, send to user by PDCCH channel;

Described descending scheduling algorithm, specifically comprises following flow process:

Travel through all radio bearers, summation obtains the data total amount D to be sent in node B cache district _sum, then this data volume to be sent of base station is normalized and obtains scheduling parameter P _down, join in descending scheduling algorithm;

Obtain the parameter that this scheduling will be used, at least comprise channel quality information, service quality, user's momentary rate, user's average throughput;

According to the parameter obtained, according to adding scheduling parameter P _downdescending scheduling algorithmic formula, calculate resources for user equipment distribute priority, described descending scheduling algorithmic formula is as follows:

$p_{idown}=-{\mathrm{lg\&delta;}}_r*\frac{D_{HOLi}}{{\mathrm{\&tau;}}_i}*\frac{r_i{\left(t\right)}^{p_{down}}}{R_i(t-1)};$

Wherein, δ _ithat can bear for data flow i maximumly exceedes threshold value by team's head time delay and the packet loss caused; D _hOLiit is team's head packet delay time of stream i; τ _iit is the patient delay threshold of stream i; r _it () is the momentary rate of stream i in current TTI; R _i(t-1) be the average data transfer rate of stream i in the time window that t-1 is ending; P _idownrepresent the priority of the stream i calculated;

Subscriber equipment priority according to calculating carries out Resourse Distribute from high to low, by first Resource Block, is the user equipment (UE) Resources allocation block resource of limit priority on this Resource Block, until meet required or resource is most;

Determine the modulation coding mode of scheduled user's equipment, transmission block size parameter;

Build the down dispatch information generating this, send to subscriber equipment by PDCCH channel.

Compared with prior art, enforcement of the present invention has following good effect:

The data total amount to be sent that up-downgoing is treated is incorporated in dispatching algorithm as parameter, has made dispatching algorithm have throughput adaptivity; When data volume to be sent is fewer time, the impact of data parameters to be sent on algorithm is smaller, but along with the lifting of data total amount to be sent, data parameters to be sent promotes the impact of algorithm, the adaptive lifting of throughput of drive system, and finally can obtain than improving the higher throughput of front dispatching algorithm, promote the performance of base station.

Accompanying drawing explanation

Fig. 1 is communication system allocation of radio resources schematic diagram;

Fig. 2 is the uplink scheduling algorithm flow chart of standard;

Fig. 3 is the descending scheduling algorithm flow chart of standard;

Fig. 4 is the uplink scheduling algorithm flow chart of improvement of the present invention;

Fig. 5 is the descending scheduling algorithm flow chart of improvement of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in detail, if these execution modes exist exemplary content, should not be construed to limitation of the present invention.

Fig. 1 is the allocation of radio resources schematic diagram of communication system.The first half shows downlink data and receives from base station, carries out Resourse Distribute through downlink scheduler, then sends to the process of user; The latter half shows upstream data and produces from business, carries out Resourse Distribute and is sent to base station from terminal, the process then sent from base station by uplink scheduling device.

Fig. 2 is the uplink scheduling algorithm flow chart of the LTE-Advanced system/LTE-Advanced relay system of standard, comprises the following steps:

In step 201:LTE-Advanced system/LTE-Advanced relay system Zhong Ge community, each user carries out BSR buffer state and reports;

Step 202: obtain the parameter that this scheduling will be used, comprise CQI, QoS, user's momentary rate, user's average throughput etc.;

Step 203: according to the scheduling parameter obtained, carry out priority calculating by dispatching algorithm formula;

Step 204: the User Priority according to calculating carries out Resourse Distribute from high to low, by first RB, is that the UE of limit priority this RB on distributes RB resource, until needed for meeting or resource most;

Step 205: perform AMC, the parameter such as MCS, transmission block TB size of the UE that determines to be scheduled;

Step 206: the schedule information building this generates, and sends to user by PDCCH channel.

Fig. 3 is the descending scheduling algorithm flow chart of the LTE-Advanced system/LTE-Advanced relay system of standard, comprises the following steps:

Step 301: obtain the parameter that this scheduling will be used, comprise CQI, QoS, user's momentary rate, user's average throughput etc.;

Step 302: according to the scheduling parameter obtained, carry out priority calculating by dispatching algorithm formula;

Step 303: the User Priority according to calculating carries out Resourse Distribute from high to low, by first RB, is that the UE of limit priority this RB on distributes RB resource, until needed for meeting or resource most;

Step 304: the parameter such as MCS, transmission block TB size of the UE that determines to be scheduled;

Step 305: the schedule information building this generates, and sends to user by PDCCH channel.

Up-downgoing standard dispatching algorithm flow process has many common ground, also has some different: first, does not need buffer state to report (descending buffer state in base station side, up in user side) time descending; Secondly, although schedule information all can send to user by PDCCH channel, time descending, schedule information sends to user together with user data, and now sends to user scheduling information time up, and next TTI user sends upstream data.

Fig. 4 is the uplink scheduling algorithm flow chart of the LTE-Advanced system/LTE-Advanced relay system after improvement of the present invention, comprises the following steps:

In step 401:LTE-Advanced system/LTE-Advanced relay system Zhong Ge community, each user carries out BSR buffer state and reports;

Step 402: obtain data total amount D to be uploaded according to the BSR summation that user uploads _sum, be then normalized and obtain uplink scheduling parameter P _up, and it is joined in uplink scheduling algorithm as a scheduling parameter;

Step 403: obtain the parameter that this scheduling will be used, comprise CQI, QoS, user's momentary rate, user's average throughput etc.;

Step 404: according to the scheduling parameter obtained, by adding parameter P _updispatching algorithm formula carries out priority calculating;

Step 405: the User Priority according to calculating carries out Resourse Distribute from high to low, by first RB, is that the UE of limit priority this RB on distributes RB resource, until needed for meeting or resource most;

Step 406: perform AMC, the parameter such as MCS, transmission block TB size of the UE that determines to be scheduled;

Step 407: the schedule information building this generates, and sends to user by PDCCH channel.

Fig. 5 is the descending scheduling algorithm flow chart of the LTE-Advanced system/LTE-Advanced relay system after improvement of the present invention, comprises the following steps:

Step 501: travel through all radio bearers, summation obtains the data total amount D to be sent in node B cache district _sum, be then normalized and obtain scheduling parameter P _down, and it is joined in dispatching algorithm as a scheduling parameter;

Step 502: obtain the parameter that this scheduling will be used, comprises CQI, QoS, user's momentary rate, user's average throughput etc.;

Step 503: according to the scheduling parameter P obtained _down, by adding scheduling parameter P _downdispatching algorithm formula carries out priority calculating;

Step 504: the User Priority according to calculating carries out Resourse Distribute from high to low, by first RB, is that the UE of limit priority this RB on distributes RB resource, until needed for meeting or resource most;

Step 505: the parameter such as MCS, transmission block TB size of the UE that determines to be scheduled;

Step 506: the schedule information building this generates, and sends to user by PDCCH channel.

For descending scheduling algorithm, using this data volume to be sent of base station as a scheduling parameter, join in dispatching algorithm.Be specially: travel through all radio bearers, summation obtains the data total amount D to be sent in node B cache district _sum, be then normalized and obtain P, and it is joined in dispatching algorithm as a scheduling parameter.The parameter obtained can be that exponential form or non-exponential form add, and joins in algorithm with the form of index, can with r ^pform add, the wherein instantaneous transmission speed of the corresponding each user of r.

For uplink scheduling algorithm, the data to be uploaded of all users that same base station is connected as scheduling parameter, in the dispatching algorithm added.Be specially: obtain data total amount D to be uploaded according to the BSR summation that user uploads _sum, be then normalized and obtain P, and it is joined in dispatching algorithm as a scheduling parameter.The parameter obtained can be that exponential form or non-exponential form add, and joins in algorithm with the form of index, can with r ^pform add, the wherein instantaneous transmission speed of the corresponding each user of r.

The above, merely illustrate concept of the present invention, and in the process adding dispatching algorithm, form is varied, but make the throughput of base station adaptive change thereupon essential idea be unified by data total amount to be sent.This description for one of ordinary skill in the art, according to thought of the present invention, all will change in specific embodiments and applications, so should not be construed as limitation of the present invention.

Claims (1)

1. based on a Stochastic accessing overload controlling method for LTE-Advanced system, it is characterized in that, the method comprises row dispatching algorithm and descending scheduling algorithm, wherein:

Described uplink scheduling algorithm, specifically comprises following flow process:

Each subscriber equipment in LTE-Advanced system/LTE-Advanced relay system Zhong Ge community carries out buffer state report and reports;

Data total amount D to be uploaded is obtained according to the BSR summation that subscriber equipment is uploaded _sum, the data to be uploaded of all users then same base station is connected are normalized, and obtain uplink scheduling parameter P _up, join in uplink scheduling algorithm;

Obtain the parameter that this scheduling will be used, at least comprise channel quality information, service quality, user's momentary rate, user's average throughput;

According to the parameter obtained, according to adding scheduling parameter P _upuplink scheduling algorithmic formula, calculate resources for user equipment distribute priority, described uplink scheduling algorithmic formula is as follows:

$p_{iup}=-{\mathrm{lg\&delta;}}_i*\frac{D_{HOLi}}{{\mathrm{\&tau;}}_i}*\frac{r_i{\left(t\right)}^{p_{up}}}{R_i\left(t-1\right)};$

Wherein, δ _ithat can bear for data flow i maximumly exceedes threshold value by team's head time delay and the packet loss caused; D _{hOL i}it is team's head packet delay time of stream i; τ _iit is the patient delay threshold of stream i; r _it () is the momentary rate of stream i in current TTI; R _i(t-1) be the average data transfer rate of stream i in the time window that t-1 is ending; P _{i down}represent the priority of the stream i calculated;

Subscriber equipment priority according to calculating carries out Resourse Distribute from high to low, by first Resource Block, is the user equipment allocation Resource Block resource of limit priority on this Resource Block, until meet required or resource is most;

Perform Adaptive Modulation and Coding, determine the modulation coding mode of scheduled user's equipment, transmission block size parameter;

Build the uplink scheduling information generating this, send to user by PDCCH channel;

Described descending scheduling algorithm, specifically comprises following flow process:

Travel through all radio bearers, summation obtains the data total amount D to be sent in node B cache district _sum, then this data volume to be sent of base station is normalized and obtains scheduling parameter P _down, join in descending scheduling algorithm;

Obtain the parameter that this scheduling will be used, at least comprise channel quality information, service quality, user's momentary rate, user's average throughput;

According to the parameter obtained, according to adding scheduling parameter P _downdescending scheduling algorithmic formula, calculate resources for user equipment distribute priority, described descending scheduling algorithmic formula is as follows:

$p_{idown}=-{\mathrm{lg\&delta;}}_i*\frac{D_{HOLi}}{{\mathrm{\&tau;}}_i}*\frac{r_i{\left(t\right)}^{p_{down}}}{R_i(t-1)};$

Wherein, δ _ithat can bear for data flow i maximumly exceedes threshold value by team's head time delay and the packet loss caused; D _{hOL i}it is team's head packet delay time of stream i; τ _iit is the patient delay threshold of stream i; r _it () is the momentary rate of stream i in current TTI; R _i(t-1) be the average data transfer rate of stream i in the time window that t-1 is ending; P _{i down}represent the priority of the stream i calculated;

Subscriber equipment priority according to calculating carries out Resourse Distribute from high to low, by first Resource Block, is the user equipment (UE) Resources allocation block resource of limit priority on this Resource Block, until meet required or resource is most;

Determine the modulation coding mode of scheduled user's equipment, transmission block size parameter;

Build the down dispatch information generating this, send to subscriber equipment by PDCCH channel.