CN100421510C - Access priority queuing method for time division duplex system under multi-frequency point condition - Google Patents

Abstract

The invention relates to a code resource-based access priority queuing method for a TDD system under the condition of multiple frequency points, which is used for RNC to allocate radio resources when UE accesses according to queuing. Including: calculating the total remaining code resources of each frequency point in the multi-frequency point cell, performing frequency point access priority queuing according to the size of the total remaining code resources, and the access priority of the frequency point with the largest total remaining code resources is the highest. In frequency point access priority queuing, the total remaining code resources of each uplink time slot are calculated for each frequency point, and the uplink time slot access priority queuing within the frequency point is performed according to the size, and the total remaining code resources are the largest Uplink time slot access priority is the highest; and for each frequency point, calculate the total remaining code resources of each downlink time slot, and perform downlink time slot access priority queuing within the frequency point according to the size, and the total remaining code resources are the largest The downlink time slot access has the highest priority. In this way, priority queuing of frequency points and access priority queuing of uplink and downlink time slots within each frequency point are obtained.

Description

Access priority queuing method for time division duplex system under multi-frequency point condition

technical field

The invention relates to a resource allocation method under the condition of realizing multi-frequency point cells in a time-division duplex (TDD) cellular mobile communication system, in particular to a method for queuing up access priorities based on code resources.

Background technique

In order to meet the increasing demand of mobile users in the next generation digital cellular mobile communication system, the use of sectorization and multi-carrier technology can reduce the interference within the system and thus increase the capacity of the system.

In the case of a single-carrier cell, a base station can cover several sectors, and each carrier area in the several sectors covered by the base station is regarded as an independent logical cell, and the radio network controller (RNC) In the management (RRM) algorithm, resource allocation can be performed in units of logical cells. For example, if the base station covers 3 sectors and 3 carrier frequencies, it is considered that there are 9 logical cells, and the access control of the radio resource management is to complete an independent access operation for each logical cell. Each logical cell sends its own pilot broadcast information.

The main advantage of cell sectorization is that inter-symbol interference is suppressed. Compared with non-sectorized cells, under the condition of the same number of users, the communication quality of sectorized cells will be improved, or the communication quality of sectorized cells will be improved while maintaining the same system performance. Under certain circumstances, sectorization can increase the number of users accommodated in the cell.

After the multi-carrier cell is adopted, each sector covered by the base station is regarded as an independent logical cell, but this logical cell can include multiple carriers, which can improve the resource utilization and efficiency of the system. However, the wireless resource allocation in the case of multi-carrier cells is more complicated than the resource allocation in the case of single-carrier cells, which brings many changes. Utilization provides better conditions and methods.

Under the system architecture of a multi-carrier cell, for each sector, one of the allocated N frequency points is determined as the main carrier frequency, and in the same sector, only the downlink pilot time slot is sent on the main carrier frequency (DwPTS), uplink pilot time slot (UpPTS) and broadcast information. Therefore, for the development of existing protocol specifications, it is necessary to clearly indicate the main carrier frequency so that the base station (NodeB) can determine on which frequency to send broadcast information, and the existing protocol needs to add frequency point information in the message of channel configuration, so that The terminal and NodeB obtain information about the relevant content.

Resource allocation function is one of the main problems to be solved in wireless resource management. In order to improve the utilization rate of system wireless resources, the access priority queuing problem of resource allocation must be solved first, and then according to resource units such as frequency or time The priority of slots is high and low in order, so as to allocate radio resources reasonably.

Currently, the access priority queuing method for wireless resource allocation is mainly aimed at single-carrier cells, such as the time slot priority queuing method based on resources and loads, but the access priority queuing method for single-carrier cells cannot directly It is applied to the access priority queuing problem in the case of multi-frequency points in the cell. Because in the case of multi-frequency cells, the calculation and statistical methods of access priority queuing based on resources or loads are completely different, and the calculation methods of resources or loads under the conditions of multi-frequency cells will be more complex and diverse. Therefore, for the access priority queuing method of the multi-frequency cell, especially the access priority queuing method of the multi-frequency cell in the TDD mode, there is no relevant implementation technology at present.

Contents of the invention

The purpose of the present invention is to design a method for queuing up the access priority of a time division duplex system under a multi-frequency point condition, which is a queuing method for the access priority under the condition that the cell adopts a multi-frequency point in a TDD mobile communication system, According to the result of priority queuing, the allocation of wireless resources can achieve high resource utilization.

The technical solution for realizing the purpose of the present invention is: an access priority queuing method for a time division duplex system under multi-frequency point conditions, which is used for wireless resource allocation when user terminals access, and is characterized in that it includes:

A. According to the formula CR _ft =C-CO _ft calculate the total remaining code resources of each uplink time slot in each frequency point of the multi-frequency point cell, where CR _ft is the total remaining code resources of each uplink time slot in frequency point f The remaining code resource, C is the total code resource of each time slot, CO _ft is the total code resource occupied by each uplink time slot, the uplink time slot t=1,..., Nu, f=1, ..., N; Nu is the number of uplink time slots of each frequency point, and N is the number of frequency points of the multi-frequency point cell;

B. According to the formula CR _ft' = C-CO _ft', calculate the total remaining code resources of each downlink time slot in each frequency point, where CR _ft' is the total remaining code resources of each downlink time slot at frequency point f Code resource, CO _ft' is the total code resource occupied by each downlink time slot, downlink time slot t'=1,..., Nd, f=1,..., N, Nd is each The number of downlink time slots at the frequency point;

C. Calculate the total remaining code resources of all uplink time slots in each frequency point according to the formula CR _fu = C·Nu-CO _fu , where CR _fu is the total remaining code resources of all uplink time slots in each frequency point , CO _fu is the code resource occupied by all uplink time slots counted in each frequency point;

D. Calculate the total remaining code resources of all downlink time slots in each frequency point according to the formula CR _fd = C·Nd-CO _fd , where CR _fd is the total remaining code resources of all downlink time slots in each frequency point , CO _fd is the code resource occupied by all downlink time slots counted in each frequency point;

E. Calculate the total remaining code resources of each frequency point according to the calculation results of step C and step D;

F. Perform frequency point access priority queuing according to the total remaining code resource size of each frequency point calculated in step E, and the frequency point with the largest total remaining code resource is the frequency point with the highest access priority.

The code resource CO _fu occupied by all the uplink time slots counted in each frequency point uses the formula ${\mathrm{CO}}_{\mathrm{fu}}=\underset{t=1}{\overset{\mathrm{Nu}}{\mathrm{\Σ}}}{\mathrm{CO}}_{\mathrm{ft}}$ calculate.

The code resource CO _fd occupied by all the downlink time slots counted in each frequency point uses the formula ${\mathrm{CO}}_{\mathrm{fd}}=\underset{t^{\′}=1}{\overset{\mathrm{Nd}}{\mathrm{\Σ}}}{\mathrm{CO}}_{f{t}^{\′}}$ calculate.

The method also includes: for the frequency point with the highest access priority, according to the total remaining code resource size of each uplink time slot obtained in step A, perform uplink time slot access priority queuing, and the remaining code resources The largest uplink time slot is the uplink time slot with the highest access priority. According to the total remaining code resource size of each downlink time slot obtained in the step B, the downlink time slot access priority queuing is performed, and the remaining code resources are the largest The downlink time slot of is the downlink time slot with the highest access priority.

The method further includes: when receiving the wireless resource request, performing access according to the access priority of the uplink time slot and the downlink time slot in the frequency point with the highest access priority.

If the access at the frequency point with the highest access priority is unsuccessful, then continue to use the method described in claim 4 to start from the frequency point with the second highest access priority according to the order of the access priority of each frequency point. Start to queue the uplink time slots and downlink time slots of each frequency point one by one, and perform access according to the access priority of the uplink time slots and downlink time slots until the access is successful, or all frequency points All uplink and downlink time slots cannot be accessed successfully.

The present invention is an access priority queuing method based on code resources under the condition of multiple frequency points in a TDD system, that is, an access priority queuing method for frequency point resources and time slot resources based on the resource occupancy status of the current cell. Under the condition of multi-frequency point cell, access priority queuing is divided into frequency point priority queuing and time slot priority queuing in two steps. The frequency point priority queuing and time slot priority queuing are all based on the occupancy of code resources or Talk about the situation of remaining code resources.

The priority queuing of the present invention fully considers the characteristics of multi-frequency point cells, and is the priority queuing of frequency points and time slots during wireless resource access, and then wireless resource allocation can be performed according to the priorities of frequency points and time slots . Compared with the radio resource allocation method of a single carrier cell, the radio resource allocation of a multi-carrier cell is more flexible. In the TDD mobile communication system proposed by the present invention, the radio resource allocation solution under the multi-carrier cell condition can be used to improve the radio resource utilization rate of the system.

The method of the invention can be directly applied to the TD-SCDMA mobile communication system of multi-frequency point cells.

Description of drawings

Fig. 1 is a block diagram of access priority queuing process based on code resources.

Detailed ways

The present invention mainly solves the priority queuing method of frequency points and time slots before the access operation in the case of multi-frequency point cells. The access priority queuing is carried out in two steps, and the first step is to perform frequency point priority Queuing, the second step is to queue up the time slot priority.

When carrying out the frequency point priority queuing of the first step, be to carry out priority queuing to all frequency point resources of each subdistrict, calculate the access priority level of each frequency point resource in the subdistrict by the algorithm proposed by the present invention, then Queue up according to access priority.

When performing the time slot priority queuing in the second step, based on the frequency point priority queuing completed in the first step, first perform time slot priority queuing on the highest priority frequency point, and then queue according to the time slot priority , select each time slot in the queue in turn to access until the access is successful, if the time slot with the lowest priority still cannot be successfully accessed, select the second highest priority frequency point from the frequency point priority queue, And perform time slot priority queuing on the second high priority frequency point, and select each time slot in the queue in turn according to the order of time slot priority queuing for access, and so on until the access is successful.

When selecting time slots on the selected frequency points, each frequency point is performed independently of each other, and access priority queuing is performed on uplink (UL) and downlink (DL) time slots of a frequency point respectively.

Wherein, the calculation of the access priority of each frequency point resource in the cell is based on the code resource occupancy of each frequency point in the current cell. Sorting is performed according to the total code resources currently used by each frequency point, that is, according to the amount of remaining code resources for each frequency point. Priority queuing of frequency points is performed according to the size of available code resources of each frequency point. The remaining code resources of the frequency point reflect the access priority of the frequency point during resource allocation.

In the present invention, the prioritization of the uplink and downlink time slots of each frequency point is also based on the code resource occupancy of the uplink and downlink time slots, and the access priority queues are respectively performed on the uplink and downlink time slots.

The technical solution of the present invention will be further described below in conjunction with the accompanying drawing 1 of the embodiment.

For the convenience of description, it is assumed that the cell has N frequency points, and the ratio of uplink and downlink time slots of each frequency point can be the same or different (the same purpose is to reduce cell interference); the number of uplink time slots of each frequency point Be Nu, the number of downlink time slots is Nd, Nu+Nd=constant, as in TD-SCDMA mobile communication system, this constant is 6;

The code resource occupied by each time slot is denoted by CO, the remaining code resource of each time slot is denoted by CR, and the total code resource CO+CR=C of each time slot is also fixed.

Step 11, the radio network controller counts the code resources occupied by each uplink and downlink time slot on each frequency point according to the records in the resource database, expressed as CO _ft , and counts the remaining code resources of each uplink and downlink time slot on each frequency point code resources, denoted as CR _ft , for uplink time slots, t=1,...,Nu, for downlink time slots, t=1,...,Nd, if it is known that the code resource occupied by a time slot is CO _ft , then the remaining code resource of the time slot is: CR _ft =C-CO _ft , and vice versa: CO _ft =C-CR _ft . There are Nu uplink time slots of each frequency point, there are remaining code resource values of Nu uplink time slots; Nd downlink time slots of each frequency point, there are Nd downlink time slots remaining code resource values.

Step 12, calculate the code resources occupied by each frequency point and each direction and the remaining code resources, f=1, ..., N, including calculating the frequency point f according to the formula 1 The uplink direction occupies the code resource CO _fu (formula 1 The CO _ft in the formula represents the code resource occupied by each uplink time slot counted in step 11), and the code resource CO _fd in the downlink direction of frequency point f is calculated according to formula 2 (the CO _ft in the formula 2 represents each code resource occupied in the step 11 counted The code resource occupied by the downlink time slot), and according to the calculation results of formulas 1 and 2, calculate the remaining code resource CR _fu of frequency point f in the uplink direction according to formula 3, and calculate the remaining code resource CR _fd of frequency point f in the downlink direction according to formula 4.

The code resources occupied by the up and down directions of the frequency point f are respectively:

uplink: ${\mathrm{CO}}_{\mathrm{fu}}=\underset{t=1}{\overset{\mathrm{Nu}}{\mathrm{\Σ}}}{\mathrm{CO}}_{\mathrm{ft}}$ (Formula 1)

downlink: ${\mathrm{CO}}_{\mathrm{fd}}=\underset{t=\mathrm{Nu}+1}{\overset{\mathrm{Nu}+\mathrm{Nd}}{\mathrm{\Σ}}}{\mathrm{CO}}_{\mathrm{ft}}$ (Formula 2)

The remaining code resources in the uplink and downlink directions of frequency point f are:

Uplink: CR _fu = C·Nu-CO _fu (Formula 3)

Downlink: CR _fd =C·Nd-CO _fd (Formula 4)

Step 13, according to the calculation result of step 12, calculate each frequency point f=1, ..., N including the total remaining code resources CR _f in the uplink and downlink directions according to formula 5:

The total remaining code resource of frequency point f is:

CR _f =CR _fu +CR _fd (Equation 5)

Step 14, line up according to the size of the total remaining code resource CR _f of each frequency point calculated in step 13. The larger the total remaining code resource CR _f , the higher the priority of the corresponding frequency point f, so as to obtain the total remaining code resource CR f The highest priority frequency point f with the largest resource CR _f .

The above steps 11 to 14 complete the first step of the solution of the present invention: performing frequency point priority queuing for the access priority of the multi-frequency point cell.

Step 15, for the access priority queuing of the frequency point obtained by the operation of steps 11 to 14, first select the frequency point f with the highest priority, and proceed according to the size of the remaining code resources of each uplink time slot of the frequency point counted in step 11 The access priority queuing of the uplink time slots, and the size of the remaining code resources of each downlink time slot at the frequency point according to the statistics in step 11 are performed for the access priority queuing of the downlink time slots. The time slot with the most remaining code resources is Access the time slot with the highest priority.

The operation of step 15 completes the second step of the method of the present invention: queue the priority of uplink and downlink time slots for the access priority of the multi-frequency cell.

Step 16, according to the queuing result of step 15, for the resource request, first use the highest priority uplink and downlink time slots discharged by the highest priority frequency point to access, if the access is unsuccessful, select the frequency point with the second highest priority When all uplink and downlink time slots cannot be successfully accessed, select the frequency point with the second highest priority in the frequency point priority queue, and queue up according to the priority of the uplink and downlink time slots Perform uplink and downlink time slot access. In this way, until the access is successful, or all frequency points and all uplink and downlink time slots fail to be accessed, the access operation ends. The scheme of the present invention is only for queuing, and does not involve the radio resource allocation scheme at the time of access.

To sum up, the first step of the method of the present invention is to perform priority queuing for each frequency point of the multi-frequency point cell: by calculating the remaining total code resource CR _f of each frequency point respectively, and then according to the remaining total The size of the code resource CR _f is used for queuing. The larger the CR _f is, the higher the access priority of the corresponding frequency is, otherwise the lower the priority. The second step of the method of the present invention is to perform access priority queuing for the uplink and downlink time slots in each frequency point: for the time slots in the uplink direction, the remaining code resources of each uplink time slot calculated according to each frequency point The size of CR _ft queues the time slots in the uplink direction in turn. The larger the CR _ft, the higher the priority of the uplink time slots; also for the downlink time slots, the queuing method is the same as the uplink, calculated according to each frequency point The size CR _ft of the remaining resources of each downlink time slot queues the time slots in the downlink direction sequentially, and the larger the CR _ft is, the higher the priority of the downlink time slot is.

Since the calculation of the remaining total code resources CR _f of each frequency point in the first step is based on the calculation of the remaining total code resources in the uplink direction and the remaining total code resources in the downlink direction of each frequency point, When calculating the remaining total code resources in the uplink direction and the remaining total code resources in the downlink direction of each frequency point, the basis is the total code resources occupied by each frequency point in the uplink direction and the total code resources occupied in the downlink direction , and the total code resources occupied by the uplink direction and the total code resources occupied by the downlink direction are the remaining code resources of each uplink time slot and the number of each downlink time slot calculated according to the uplink and downlink directions of each frequency point respectively The remaining code resources, so when completing the second step of this embodiment, only the Nd downlink time slot remaining code resources and Nu uplink time slot remaining code resources of the highest priority frequency point calculated in the first step are calculated according to the size By performing queuing, the uplink time slot and downlink time slot with the highest access priority can be determined.

The queuing of each frequency point in the frequency point access priority queuing and the uplink and downlink time slots of each frequency point can be performed periodically or triggered by an event. For example, it can be performed when a user terminal accesses and allocates wireless resources, or Queuing can be done before the user terminal accesses.

Claims (6)

1. the access priority queuing strategy of tdd systems under the multifrequency point condition, the allocation of radio resources when being used for user terminal and inserting is characterized in that comprising:

A. according to formula CR _Ft=C-CO _FtCalculate total residue code resource of each ascending time slot in each frequency of multi-frequency-point community, wherein CR _FtBe total residue code resource of each ascending time slot in the frequency f, C is a total yard resource of each time slot, CO _FtBe total sign indicating number resource that each ascending time slot of being added up takies, ascending time slot t=1 ..., Nu, f=1 ..., N; Nu is the number of each frequency ascending time slot, and N is the frequency points of this multi-frequency-point community;

B. according to formula CR _{Ft '}=C-CO _{Ft '}Calculate total residue code resource of each descending time slot in each frequency, wherein, CR _{Ft '}Be total residue code resource of each descending time slot of frequency f, CO _{Ft '}Be total sign indicating number resource that each descending time slot of being added up takies, descending time slot t '=1 ..., Nd, f=1 ..., N, Nd are the numbers of each frequency descending time slot;

C. according to formula CR _Fu=CNu-CO _FuCalculate total residue code resource of all ascending time slots in each frequency, wherein, CR _FuBe total residue code resource of all ascending time slots in each frequency, CO _FuIt is the sign indicating number resource that interior all ascending time slots added up of each frequency take;

D. according to formula CR _Fd=CNd-CO _FdCalculate total residue code resource of all descending time slots in each frequency, wherein, CR _FdBe total residue code resource of all descending time slots in each frequency, CO _FdIt is the sign indicating number resource that interior all descending time slots added up of each frequency take;

E. according to the result of calculation of step C and step D, calculate total residue code resource of each frequency;

F. total residue code resource size of each frequency that calculates according to step e is carried out the queuing of frequency access priority, and the frequency of total residue code resource maximum is the highest frequency of access priority.

2. method according to claim 1 is characterized in that the sign indicating number resource CO that interior all ascending time slots added up of described each frequency take _FuUse formula ${\mathrm{CO}}_{\mathrm{fu}}=\underset{t=1}{\overset{\mathrm{Nu}}{\mathrm{\Σ}}}{\mathrm{CO}}_{\mathrm{ft}}$ Calculate.

3. method according to claim 1 is characterized in that the sign indicating number resource CO that interior all descending time slots added up of described each frequency take _FdUse formula ${\mathrm{CO}}_{\mathrm{fd}}=\underset{t^{\′}=1}{\overset{\mathrm{Nd}}{\mathrm{\Σ}}}{\mathrm{CO}}_{f{t}^{\′}}$ Calculate.

4. method according to claim 1, it is characterized in that, this method also comprises: at the highest frequency of described access priority, according to the total residue code resource size of each ascending time slot that obtains in the described steps A, carry out the queuing of ascending time slot access priority, the ascending time slot of residue code resource maximum is the highest ascending time slot of access priority, according to the total residue code resource size of each descending time slot that obtains among the described step B, carry out the queuing of descending time slot access priority, the descending time slot of residue code resource maximum is the highest descending time slot of access priority.

5. method according to claim 4 is characterized in that, this method also comprises: when receiving radio resource request, in the highest frequency of described access priority, insert according to the size of the access priority of ascending time slot and descending time slot.

6. method according to claim 5, it is characterized in that, if on the highest frequency of described access priority, insert unsuccessful, then the access priority according to each frequency continues to adopt the method described in the claim 4 in proper order, begin one by one the ascending time slot and the descending time slot of each frequency are carried out the access priority queuing from access priority time high frequency, and insert according to the access priority size of ascending time slot and descending time slot, until inserting successfully, perhaps all whole uplink and downlink time slots of frequency all can not insert success.

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