CN1761169A - Method for controlling up going admission based on actual measured quantity in CDMA system - Google Patents

Abstract

The method includes following steps: when no user accesses, periodic pretreatment for admission control is carried out; based on result of pretreatment for admission control, determining upper limit of transmitting power of new user; calculating lower limit of transmitting power of new user; determining whether maximal transmitting power of new user is between upper limit and lower limit; if yes, then up going admission is successful, and the said lower limit is as initial transmitting power of new user at the sub zone; if no, then sending message of failing admission. Not only considering influencing factor by new user on QoS of former users in system as accessing moment, the method also considers influence of power control action in system on QoS after new user is accessed so as to guarantee admission control in real time.

Description

In a kind of cdma system based on the up-admission control method of actual measurement amount

Technical field

The present invention relates to a kind of up-admission control method in code division multiple access access (CDMA) mobile communication system, relate in particular to a kind of up-admission control method based on the actual measurement amount, method operation principle of the present invention is also applicable to all CDMA mobile communication systems.

Technical background

Because cdma system is an a kind of self-interference system, can produces mutually between user and the user and disturb.Particularly at up direction, cdma system is subject to interference.After a new user inserts the sub-district, this user can produce new interference to other user in the sub-district, makes other user's interference increase, and carrier/interface ratio descends, at this moment can make these users' transmitting power soaring by power control, thereby improve carrier/interface ratio.But this part soaring power has caused new interference again between the user, from and need to increase transmitting power and resist newly-increased interference, power ramp that Here it is.When the number of users in the sub-district is within certain limit range, be to reach one by power control to restrain stable status gradually.And in case exceeded this limit, will make the user power sub-district in and user's interference surge.Can cause each user all to use maximum transmitting power emission at last, but still can not reach the service quality that can receive.To avoid the appearance of this situation so admit control as far as possible.

Admit the principle of control to be: at first, a new user's access can not be to sacrifice the Qos (service quality of other user in the current area, Quality of service) is cost, that is to say that this user's access must guarantee that original quality of services for users is not less than a level that can receive in the sub-district.Secondly, under the condition of first prerequisite of assurance, new user's Qos itself also also will reach an acceptable level as far as possible.

This shows that for up direction, each user's that the base station receives in the cdma system signal power and the suffered interference of each user are dynamic change procedures.The present up-admission controlling schemes based on interference threshold provides a fixing threshold value according to worst situation often, if the reception of system disturbs gross power to surpass threshold value, does not then allow new user to insert.Yet, the process of the actual dynamic change of user power and interference in the very difficult reflection system of this up-admission control method based on interference threshold.

Be that its basic thinking of which kind of scheme all is that earlier the new user of hypothesis inserts, and then whether the access of judging new user cause system's situation that oversteps the extreme limit.

The threshold value that receives interference power in traditional acceptance controlling method has reflected a limiting case of system, but because this threshold value is fixed, can only reflect a situation the worst, user's signal power and interfere with dynamic change procedure in the reflection system exactly.And in the present up-admission control method based on signal interference ratio (SIR) measurement, because cdma system allows mixed service to insert, every kind of business all has the requirement of different service quality, therefore tend to relate to complicated matrix operation or interative computation, calculation delay is very big, so just more is difficult to guarantee to admit the real-time of control.

Summary of the invention

The purpose of this invention is to provide in a kind of cdma system up-admission control method based on the actual measurement amount, for cdma communication system designs a kind of up-admission control method based on the actual measurement amount, the access that guarantees new user can make its carrier/interface ratio requirement of assurance of original user in the system, simultaneously also make new user also can satisfy the carrier/interface ratio requirement of oneself, otherwise, refuse this subscriber access system.

Technical scheme of the present invention is such:

Based on the up-admission control method of actual measurement amount, this method may further comprise the steps in a kind of cdma system:

Step 1): when no new user inserts, carry out periodicity and admit the control preliminary treatment, in each cycle, calculate when certain user uses maximum transmission power and signal quality to satisfy the target carrier/interface ratio respectively, the increment of this user's the interference increment and the sub-district received bandwidth total power that will cause, and the increment minimum value of output received bandwidth total power and and the interference increment of respective user;

Step 2): according to and the minimum value of exporting the increment of received bandwidth total power and interference increment determine the upper limit of new user emission power;

Step 3): the lower limit that calculates new user's transmitting power according to current area received bandwidth total power and target carrier/interface ratio;

Step 4): the maximum transmission power of judging new user whether between upper and lower bound, if, then up-admission success, and with described lower limit as the new Initial Trans of user on this sub-district; If not, then send the admittance failure.

Described method, wherein, admit the control preprocessing process further comprising the steps of in the described step 1):

A) obtain the target carrier/interface ratio of all users in each sub-district, the maximum transmission power parameter;

B) obtain the periodic report measurement result of each sub-district: each user's signal power, disturb the up path loss;

C) if when calculating certain user and use the maximum transmission power emission according to above-mentioned parameter, this user's interference increment ${\mathrm{\ΔI}}_j=(\frac{P_{j\_\max }\·g_j}{{\mathrm{\γ}}_j}-I_j)$ Increment with the received bandwidth total power of correspondence ${\mathrm{\ΔI}}_{\mathrm{total}}=(\frac{P_{j\_\max }\·g_j}{{\mathrm{\γ}}_j}-I_j)+(P_{j\_\max }{\·g}_j-P_j),$ Wherein, P _{J_max}Be the maximum transmission power of user j, g _jBe the path loss of user j, I _jBe the interference of user j, P _jBe the signal power of user j, γ _jBe the target carrier/interface ratio of user j, j is a natural number;

D) select the increment Delta I of received bandwidth total power in this sub-district _TotalValue is hour corresponding user, with this user as current area near the user of limit situation, export the increment Delta I of the received bandwidth total power of this user's correspondence _TotalValue and user's interference increment Δ I _jValue.

Described method, wherein, described method also is included in the new user of n+1 when inserting, judge as follows, the upper limit P of this new user emission power _{T_n+1_max}Determine by following formula:

$P_{T\_n+1\_\max }=\min \{\left(\frac{I_{\mathrm{total}}+{\mathrm{\ΔI}}_{\mathrm{total}\_\min }}{1/{\mathrm{\γ}}_{n+1}+1}\right)/g_{n+1},(\frac{P_{j\_\max }{\·g}_j}{{\mathrm{\γ}}_j}-I_j)/g_{n+1}\};$

If this user n+1 will make its carrier/interface ratio satisfy γ after inserting the sub-district at least _N+1, i.e. the lower limit P of this new user emission power _{T_n+1_min}Determine by following formula:

P _{T_n+1_min}＝γ _n+1·I _total/g _n+1；

Maximum transmission power P as user n+1 _{N+1_max}Satisfy following relational expression:

P _{T_n+1_min}≤P _{n+1_max}·α≤P _{T_n+1_max}

Think that then this user can not cause this cell-overload, can insert safely, otherwise exclude this user;

Wherein α is the transmitting power redundancy factor, I _TotalInsert the reception of current area for user n+1 and disturb gross power, γ _N+1Be the target carrier/interface ratio of user n+1, g _N+1Be the uplink pathloss factor of user n+1, n is a natural number.

In a kind of cdma system provided by the present invention based on the up-admission control method of actual measurement amount, considered that not only there is the influencing factor of user's Qos moment that new user inserts to system Central Plains, but also considered that new user is after access, the power control action is to the influence of Qos in the system, compare with traditional up-admission control method based on interference threshold, the limit situation that the inventive method is determined is along with the type of service of existing subscriber in the system is different and different, the loading condition that has reflected a kind of reality, guaranteed to allow the user who inserts no matter be the moment of just inserting by this method judgement, still after inserting, under the effect of power control, can not cause the user that Qos is the poorest in the system user of limit situation (near) to meet or exceed its limit situation in a period of time, thereby prevent system overload effectively.And compare with the general scheme based on the signal interference ratio sir measurement, the inventive method does not need to compare complicated matrix or interative computation, has reduced operand; And the inventive method is periodically admitted the control preliminary treatment in the free time that no user inserts, in this processing procedure, finish the calculating and the sequencer procedure of relative complex, and when the user inserts, acceptance judging directly uses admits pretreated result, has guaranteed to admit the real-time of control.

Description of drawings

Fig. 1 is the frame diagram of whole acceptance controlling method of the present invention;

Fig. 2 is the concrete implementing procedure figure of the pretreatment module of the inventive method;

Fig. 3 is based on the implementing procedure figure of the up-admission control method of actual measurement amount in the cdma system of the present invention.

Embodiment

Below will be described in detail preferred embodiment of the present invention.

In a kind of cdma system of the present invention based on the up-admission control method of actual measurement amount, suppose behind new user's the access sub-district that transmitting power reaches convergence under the effect of power control, just can cause in the sub-district this moment among original user user to reach criticality, calculate the upper and lower bound value of the user's that makes new advances transmitting power according to this critical condition near limit situation; And whether the maximum transmission power of judging new user satisfy power discriminant, thereby whether decision allows this new user's access.

For solving above-mentioned existent technique problem, now being example in the WCDMA system, the inventive method may further comprise the steps as shown in Figure 1:

Step 1): when no new user asks to insert, carry out periodicity and admit the control preprocessing process:

A) obtain the target carrier/interface ratio of all users in each sub-district, the maximum transmission power parameter;

B) obtain the periodic report measurement result of each sub-district: each user's signal power, disturb the up path loss;

C) if when calculating each user and use the maximum transmission power emission according to above-mentioned parameter, this user's interference increment ${\mathrm{\ΔI}}_j=(\frac{P_{j\_\max }\·g_j}{{\mathrm{\γ}}_j}-I_j)$ Increment with the received bandwidth total power of correspondence ${\mathrm{\ΔI}}_{\mathrm{total}}=(\frac{P_{j\_\max }\·g_j}{{\mathrm{\γ}}_j}-I_j)+(P_{j\_\max }{\·g}_j-P_j),$ Wherein, P _{J_max}Be the maximum transmission power of user j, g _jBe the path loss of user j, I _jBe the interference of user j, P _jBe the signal power of user j, j is the natural number for counting;

D) select Δ I in the sub-district _TotalValue is hour corresponding user, with this user as current area near the user of limit situation, export the Δ I of this user's correspondence _TotalValue and Δ I _jValue.

Step 2): according to admitting the pretreated result of control to determine the upper limit of new user emission power.

Step 3): the lower limit that calculates new user's transmitting power.

Step 4): whether the maximum transmission power of judging this user is between upper and lower bound; If, then up-admission success, and with lower limit as the new Initial Trans of user on this sub-district; If not, then send the admittance failure.

Admittance of the present invention control we can say to a certain extent be exactly to determine cdma communication system accurately limit point where.From the principle of admitting control as can be known, on the sub-district in the cdma system, if new user's access can cause the transmitting power of the some users in this sub-district to reach maximum, and its actual sir value just equals the target SIR value, so when the interference of this sub-district increases again, this user's SIR will be lower than this desired value, and can't control transmitting power that promotes him and then the Qos that improves service quality (because this user's transmitting power has reached the upper limit, can't raise) this moment by power.This kind situation is exactly the limit point of this sub-district.This shows that the limit situation in sub-district is different and different with the state of affairs that has inserted of current area, is not to take a fixing value, this is and thresholding access method difference.

After the limit situation of having determined the user, what next defines is near the user of limit situation, that is to say the easiest user who satisfies maximum conditions.

Supposing has had n user in the sub-district, when n+1 user inserted, the increment of the received bandwidth total power of sub-district can be represented by following equation:

${\mathrm{\ΔI}}_{\mathrm{total}}=\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\ΔP}}_k+{\·P}_{n+1}---\left(1\right)$

Wherein, Δ P _k(k=1,2...... n) are the power ramp amount of original user in this sub-district, P _N+1After user n+1 access, the final convergency value (supposing that presence of intercell interference is constant) of power under the effect of power control.

After user n+1 inserted, the interference increment of the user j in the sub-district can be by following formulate:

${\mathrm{\ΔI}}_j=\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\ΔP}}_k+{\·P}_{n+1}$ (wherein, k ≠ j) (2)

Hence one can see that, and after user n+1 inserted, the increment of the received bandwidth total power in the sub-district can be expressed as again:

ΔI _total＝ΔP _j+·ΔI _j (3)

According to the principle of admitting control as can be known, if its carrier/interface ratio also will reach its target value gamma after user n+1 inserted the sub-district _N+1:

$P_{n+1}=\frac{I_{\mathrm{total}}+{\mathrm{\ΔI}}_{\mathrm{total}}}{1/{\mathrm{\γ}}_{n+1}+1}---\left(4\right)$

Wherein, I _TotalThe time current area received bandwidth total power, by equation (4) as seen as Δ I _TotalFor hour, P _N+1Be minimum.

User's limit situation expression formula is defined as in the sub-district:

$\frac{P_j+{\mathrm{\ΔP}}_j}{I_j+{\mathrm{\ΔI}}_j}=\frac{P_{j\_\max }{\·g}_j}{I_j+{\mathrm{\ΔI}}_j}={\mathrm{\γ}}_j---\left(5\right)$

Wherein, P _jThe expression base station receives the signal power of user j, I _jBe the interference power that user j is subjected to, P _{J_max}Be the maximum transmission power of user j, g _jBe the uplink pathloss factor of user j, γ _jTarget carrier/interface ratio for user j.

After user n+1 inserted the sub-district, if user j satisfies limit situation, the increment that can draw the received bandwidth total power on the sub-district according to equation (5) and equation (3) was:

${\mathrm{\ΔI}}_{\mathrm{total}}=(\frac{P_{j\_\max }\·g_j}{{\mathrm{\γ}}_j}-I_j)+(P_{j\_\max }{\·g}_j-P_j)---\left(6\right)$

When each user on the uplink cells satisfies the described limit situation of equation (5), increment Delta I of a corresponding received bandwidth total power all _TotalSuppose to have user j to satisfy limit situation, can make Δ I _TotalMinimum is worked as Δ I as can be known by equation (4) _TotalHour, P _N+1Also minimum.By reverse thinking as can be known, as user n+1 signal power P _N+1For hour, can make user j reach its limit situation.

Therefore, user j is exactly that the inventive method is defined near the user of limit situation, then the upper limit expression formula of new user emission power:

$P_{T\_n+1}<\left(\frac{I_{\mathrm{total}}+{\mathrm{\&Delta;I}}_{\mathrm{total}\_\min }}{1/{\mathrm{\&gamma;}}_{n+1}+1}\right)/g_{n+1}---\left(7\right)$

By equation (2) as can be known, the another expression formula of new user's upper limit of emission power is:

$P_{T\_n+1}{<\mathrm{\&Delta;I}}_j/g_{n+1}=(\frac{P_{j\_\max }{\&CenterDot;g}_j}{{\mathrm{\&gamma;}}_j}-I_j)/g_{n+1}---\left(8\right)$

The upper limit of therefore new user emission power is determined by following formula:

$P_{T\_n+1\_\max }=\min \{\left(\frac{I_{\mathrm{total}}+{\mathrm{\&Delta;I}}_{\mathrm{total}\_\min }}{1/{\mathrm{\&gamma;}}_{n+1}+1}\right)/g_{n+1},(\frac{P_{j\_\max }{\&CenterDot;g}_j}{{\mathrm{\&gamma;}}_j}-I_j)/g_{n+1}\}---\left(9\right)$

Wherein, I _TotalInsert the reception of preceding current area for user n+1 and disturb gross power, the interference that user n+1 is subjected to after inserting can not be lower than I at least _Total, so the inventive method is with I _TotalMinimum value as user n+1 interference.If user n+1 will make its carrier/interface ratio satisfy γ after inserting the sub-district at least _N+1, following formula is promptly arranged:

P _{T_n+1_min}＝γ _n+1·I _total/g _n+1 (10)

When the maximum transmission power of user n+1 satisfies following relational expression:

P _{T_n+1_min}≤P _{n+1_max}·α≤P _{T_n+1_max} (11)

Think that then this user can not cause this cell-overload, can insert safely, otherwise exclude this user that wherein α is the transmitting power redundancy factor.

And make this new user's Initial Trans be in this sub-district:

P _{n+1_min_Initial}＝γ _n+1·I _total/g _n+1 (12)

It is as follows that pretreated concrete implementation step is controlled in admittance as shown in Figure 2:

Step 200: obtain the target carrier/interface ratio of all users in the sub-district, the parameter of maximum transmission power.

Step 201: obtain the periodic measurement result in the sub-district: each user's signal power, disturb the up path loss.

Step 202: the increment Delta I that calculates the received bandwidth total power of each user's correspondence by formula (6) _TotalValue and user's interference increment Δ I _jValue.

Step 203: find out the Δ I that makes among all users in the sub-district _TotalThe user that value is minimum, with this user as near the user of limit situation, export the Δ I of this user's correspondence _TotalValue and Δ I _jValue.

The concrete implementation step of the up-admission control method in the inventive method as shown in Figure 3 is as follows:

Step 300: obtain new user's maximum transmission power, target carrier/interface ratio, parameters such as up path loss.

Step 301: the measuring amount of obtaining current area: received bandwidth total power I _Total

Step 302: utilize formula (9) to calculate the upper limit of new user's maximum transmission power.

Step 303: utilize formula (10) to calculate the lower limit of new user's maximum transmission power.

Step 304: whether the maximum transmission power of judging new user satisfies power deterministic (11), if then up-admission success forwards step 305 to; If not, then acceptance judging failure.

Step 305: utilize formula (12) to determine new user's Initial Trans.

A kind of up-admission control method based on the actual measurement amount of the present invention not only is suitable for the CDMAFDD system, and is suitable for CDMA TDD system.During for application this method in CDMA TDD system, only need carry out acceptance judging based on time slot.

Should be understood that foregoing description of the present invention is too concrete, can not therefore be interpreted as the restriction of scope that patent of the present invention is asked for protection, scope of patent protection should be as the criterion with claims.

Claims (3)

1, in a kind of cdma system based on the up-admission control method of actual measurement amount, this method may further comprise the steps:

Step 1): when no new user inserts, carry out periodicity and admit the control preliminary treatment, in each cycle, calculate when certain user uses maximum transmission power and signal quality to satisfy the target carrier/interface ratio respectively, the increment of this user's the interference increment and the sub-district received bandwidth total power that will cause, and the increment minimum value of output received bandwidth total power and and the interference increment of respective user;

Step 2): according to and the minimum value of exporting the increment of received bandwidth total power and interference increment determine the upper limit of new user emission power;

Step 3): the lower limit that calculates new user's transmitting power according to current area received bandwidth total power and target carrier/interface ratio;

Step 4): the maximum transmission power of judging new user whether between upper and lower bound, if, then up-admission success, and with described lower limit as the new Initial Trans of user on this sub-district; If not, then send the admittance failure.

2, method according to claim 1 is characterized in that, admits the control preprocessing process further comprising the steps of in the described step 1):

A) obtain the target carrier/interface ratio of all users in each sub-district, the maximum transmission power parameter;

B) obtain the periodic report measurement result of each sub-district: each user's signal power, disturb the up path loss;

C) if when calculating certain user and use the maximum transmission power emission according to above-mentioned parameter, this user's interference increment ${\mathrm{\&Delta;I}}_j=(\frac{P_{j\_\max }\&CenterDot;g_j}{{\mathrm{\&gamma;}}_j}-I_j)$ Increment with the received bandwidth total power of correspondence ${\mathrm{\&Delta;I}}_{\mathrm{total}}=(\frac{P_{j\_\max }\&CenterDot;g_j}{{\mathrm{\&gamma;}}_j}-I_j)+(P_{j\_\max }\&CenterDot;g_j-P_j),$ Wherein, P _{J_max}Be the maximum transmission power of user j, g _jBe the path loss of user j, I _jBe the interference of user j, P _jBe the signal power of user j, γ _jBe the target carrier/interface ratio of user j, j is a natural number;

D) select the increment Delta I that accepts the bandwidth gross power in this sub-district _TotalValue is hour corresponding user, with this user as current area near the user of limit situation, export the increment Delta I of the received bandwidth total power of this user's correspondence _TotalValue and user's interference increment Δ I _jValue.

3, method according to claim 2 is characterized in that, described method also is included in the new user of n+1 when inserting, judge as follows, the upper limit P of this new user emission power _{T_n+1_max}Determine by following formula:

$P_{T\_n+1\_\max }=\min \{\left(\frac{I_{\mathrm{total}}+\mathrm{\&Delta;}{I}_{\mathrm{total}\_\min }}{1/{\mathrm{\&gamma;}}_{n+1}+1}\right)/g_{n+1},(\frac{P_{j\_\max }\&CenterDot;g_j}{{\mathrm{\&gamma;}}_j}-I_j)/g_{n+1}\};$

If this user n+1 will make its carrier/interface ratio satisfy γ after inserting the sub-district at least _N+1, i.e. the lower limit P of this new user emission power _{T_n+1_min}Determine by following formula:

P _{T_n+1_min}＝γ _n+1·Itotal/g _n+1；

Maximum transmission power P as user n+1 _{N+1_max}Satisfy following relational expression:

P _{T_n+1_min}≤P _{n+1+1_max}·α≤P _{T_n+1_max}

Think that then this user can not cause this cell-overload, can insert safely, otherwise exclude this user;

Wherein α is the transmitting power redundancy factor, I _TotalInsert the reception of current area for user n+1 and disturb gross power, γ _N+1Be the target carrier/interface ratio of user n+1, g _N+1Be the uplink pathloss factor of user n+1, n is a natural number.

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