CN100461941C - Up-admission control method for CDMA communication system - Google Patents

Abstract

This invention discloses an up admission control method in the CDMA communication system including: 1, setting a service to be a primary service, a base station pre-configures the equivalent user numbers of the primary service, other services, the maximum numbers of the primary service and an up interference threshold, 2, the base station receives the service call request to find out the configured equivalent and the maximum user numbers of the primary service, the up interference threshold and the current total interference of the local area, 3, if the up total interference of the local area is greater than the threshold, then it enters into step 6, otherwise, step 4, 4, if the sum of the current and the service equivalent user numbers are greater than the maximum of the primary service, then step 6 is done, otherwise step 5 is done, 5, receiving the request and refreshing the current numbers of the area to the sum of the two equivalent user numbers in step 4 then returning to step 2, 6, refusing the request to be fed back to step 2 and the base station asks for releasing said service and refreshes the current equivalent user numbers of the area.

Description

Up-admission control method in the code division multiple address communication system

Technical field

The present invention relates to the up-admission control method in a kind of code division multiple access (CDMA, Code Division Multiple Access) communication system.

Background technology

A distinguishing feature of cdma system is that it is a self-interference system, and at up direction, for a specific user, other user's signal all is to disturb.After a new user inserts, increased interference to existing subscriber in the system, in order to keep speech quality, under the effect of closed power control, all users increase transmitting power, the phenomenon that emergent power is soaring.If the number of users to connecting system is not limited, under extreme case, power ramp will cause all users all to launch with maximum power, but still not reach required signal-noise ratio threshold, all users can't carry out normal talking, system's state that paralyses.For this reason, must limit the total number of users of connecting system, make up total interference of system remain on one below the certain threshold, this thresholding is called admits the control thresholding, and it is normally to move patient maximum uplink interference by the maintenance system.Cdma system must have the function of the control of admitting, admitting the effect of control is when receiving a user's call request, new calling being inserted the interference of back system predicts, and compare with admitting the control thresholding, surpass admittance control thresholding if predict the outcome, then refuse this new call request, to keep the stable of whole system.

Influence to system loading behind different types of service access system is different, Qos (the Quality of service that this is main with professional, service quality) relevant, specifically, relevant with the bit rate of desired Eb/No of business (up quality factor) and business.Professional desired Eb/No is big more, and then user's transmitting power is high more, and when Eb/No was identical, user's speed was big more, and transmitting power is also high more.Admit control will take all factors into consideration the influence of Eb/No and service rate to system loading.

In disclosed various acceptance controlling methods, (WCDMA for UMTS JOHNWILEY ﹠amp such as Harri Holma; SONS, LTD, 2000) proposed a kind ofly to allow control method based on stressor and interference and at the up link call acceptance of single business, in this method, if new total interference level is higher than interference threshold, I even _{Total_old}+ Δ I〉I _Threshold, new user will not admitted by the up link admission control algorithm.Adopted two kinds of methods when Δ I is estimated: first differential method, it two is integration methods.These two kinds of methods have all been considered the load curve of single business, but how mixed service is estimated not relate to.

Number of patent application is that 01101408.3 application documents disclose the technology that is entitled as " method of Admission Control in a kind of cdma communication system ", it has proposed a kind of method of admitting control in cdma system, system loading when this method just will ask to insert simply compares with admitting thresholding, load after new user not being inserted is predicted, number of users is not limited yet, be a kind of very rough admittance control, when system loading is higher, be easy to cause system overload, admit control fails.Application number is that the application documents of 02158074.X disclose the technology that is entitled as " a kind of acceptance controlling method in the CDMA mobile communication systems ", it has proposed a kind of acceptance controlling method based on matrix computations, determines whether admitting by the invertibity of judging power matrix.The operand that significant disadvantages of this method is matrix operation is big, is unsuitable for the real-time requirement of communication system.

Clearly, prior art does not solve this problem that how to control effectively when new user uplink in the cdma communication system inserts well.And in RRM, admitting control is the important leverage of service quality, under the limited resources condition, admits to control can make full use of system resource and the maintenance system stability is being brought into play important effect.

Summary of the invention

At existing problem and shortage in the up-admission control method in the above-mentioned existing code division multiple address communication system, the purpose of this invention is to provide the up-admission control method in a kind of simple and practical, code division multiple address communication system that process user request efficient is high.

The present invention is achieved in that the up-admission control method in a kind of code division multiple address communication system, may further comprise the steps:

1) with a kind of benchmark business that is set in each business in the system, the base station calculates benchmark service-user number and the equivalent user number of other business with respect to this benchmark business according to professional relevant parameter, and then calculates the maximum number of user and the uplink interference thresholding of benchmark business; The maximum number of user and the uplink interference thresholding of the professional equivalent user number of benchmark, other professional equivalent user numbers, benchmark business are stored in this base station data storehouse as configuration parameter; And the current equivalent user number in sub-district is initialized as 0.

2) after the base station receives certain service call request, inquire about maximum number of user and the uplink interference thresholding that its configuration parameter corresponding obtains its equivalent user number, benchmark business according to type of service; Call the current up total interference in sub-district that the base station records simultaneously;

3) if size of total interference of comparison cell uplink and uplink interference thresholding greater than threshold value, then enters step 6), otherwise enters step 4);

4) maximum number of user of the current equivalent user number in sub-district and this business equivalent user being counted sum and benchmark business compares, if greater than the maximum number of user of benchmark business, then enter step 6), otherwise enter step 5);

5) accept this service call request, and two equivalent user that the current equivalent user number in sub-district is updated in the step 4) counted sum, and return step 2) etc. pending next service call;

6) refuse this service call request, and return step 2) etc. pending next service call.

Further, this method also comprises: the base station discharges this business after receiving professional release request, and the current equivalent user number in the sub-district in the step 5) is updated to the poor of itself and this professional equivalent user number.

Further, the total interference of described cell uplink is drawn by base station periodicity public-measurement and upgrades in time.

Further, described professional relevant parameter comprises the parameters such as the maximum uplink load factor that professional Eb/No, service rate, apread spectrum bandwidth, the professional voice activation factor, Background Noise Power and this sub-district allow.

Further, when described each professional service rate changes along with the service traffics variation, network is then dynamically adjusted according to service traffics and is distributed to each professional corresponding bandwidth, then need to search corresponding professional equivalent user number again, and upgrade the current equivalent user number in sub-district simultaneously according to the pairing speed of adjusted service rate.

Further, professionally in the described system include conversational service such as speech business etc., such as the flow-type business of streamed multimedia business etc., such as the interactive service of databank retrieval business etc. with such as the backstage business of file transfer business etc.

One benchmark business at first is set in variant business in the cdma system of the present invention, and the parameters such as maximum number of user of the equivalent user number of variant business, benchmark business are calculated in advance according to related data be configured well as network parameter, and when admitting control, need not to carry out complicated calculating, only need to obtain the equivalent user number of this service request according to type of service, simply compare, just can judge whether this service request can be access in.Simultaneously, also the real-time interference to each sub-district limits, and has avoided because the situation that the erroneous judgement that the fluctuation of disturbing causes is determined.The present invention is simple and practical and efficient.

Description of drawings

Below in conjunction with accompanying drawing the present invention is illustrated in further detail:

Fig. 1 is a base station public measurement schematic flow sheet in the WCDMA system;

Fig. 2 is that WCDMA of the present invention admits the control flow schematic diagram.

Embodiment

Satisfying certain covering under the condition that requires, cdma system determines the capacity of a certain business, and promptly system's total number of users that can insert this business is determined.Dissimilar business, the maximum number of user that can insert is different, this is mainly relevant with professional Eb/No and service rate.The present invention at first selects a kind of benchmark business, voice service for example, determine the heap(ed) capacity of the system that represents with the maximum number of user of this benchmark business, other business then is mapped as equivalent benchmark service-user number according to Eb/No and service rate, when carrying out the up-admission judgement, only need to judge whether the total equivalent reference user number of system surpasses maximum reference user number and get final product.

In the cdma system, the up quality factor Eb/No of certain professional j can be expressed as:

${(\mathrm{Eb}/\mathrm{No})}_j=\frac{W}{v_j{R}_j}\·\frac{P_j}{I_{\mathrm{total}}-P_j}=\frac{{\mathrm{PG}}_j}{v_j}\·\frac{P_j}{I_{\mathrm{total}}-P_j}---\left(1\right)$

(1) in the formula, W is an apread spectrum bandwidth, R _jBe service rate, v _jBe this professional voice activation factor, P _jBe this professional signal power that receives in the base station, I _TotalBe total interference that the base station receives, equal all users' power and background noise sum, ${\mathrm{PG}}_j=\frac{W}{R_j}$ Be this professional processing gain.The received power that can obtain j class business from (1) formula is:

$P_j=\frac{{(\mathrm{Eb}/\mathrm{No})}_j}{{\mathrm{PG}}_j/v_j+{(\mathrm{Eb}/\mathrm{No})}_j}\·I_{\mathrm{total}}---\left(2\right)$

If redefine ${\mathrm{PG}}_j=\frac{W}{R_j\·v_j},$ Then (2) formula can be expressed as:

$p_j=\frac{1}{\frac{{\mathrm{PG}}_j}{{(\mathrm{Eb}/\mathrm{No})}_j}+1}\·I_{\mathrm{total}}---\left(3\right)$

And the uplink load factor of system is:

${\mathrm{\&eta;}}_{\mathrm{UL}}=\frac{P_{\mathrm{total}}}{I_{\mathrm{total}}}=\frac{\underset{j=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_j}{I_{\mathrm{total}}}=\underset{j=1}{\overset{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="C200510069330E00121.png"\; state="\{\{state\}\}">N</figure-callout>}}{\mathrm{\&Sigma;}}}\frac{1}{\frac{{\mathrm{PG}}_j}{{(\mathrm{Eb}/\mathrm{No})}_j}+1}---\left(4\right)$

(4) in the formula, N is a number of users total in the sub-district.As seen, the uplink load factor of system is that each user's of receiving with the base station signal power is relevant, and power is big more, and is big more to the contribution of stressor.If have only a kind of business in the sub-district, then (4) formula becomes:

${\mathrm{\&eta;}}_{\mathrm{UL}}=\frac{N}{\frac{{\mathrm{PG}}_j}{{(\mathrm{Eb}/\mathrm{No})}_j}+1}---\left(5\right)$

Selected a kind of benchmark business, voice service for example, its Eb/No and PG are expressed as (Eb/No) _NormAnd PG _Norm, the Eb/No and the PG of j class business are expressed as (Eb/No) _jAnd PG _j, the equivalent user that defines j class business is counted n _jFor:

$n_j=\frac{P_j}{P_{\mathrm{norm}}}=\frac{\frac{{\mathrm{PG}}_{\mathrm{norm}}}{{(\mathrm{Eb}/\mathrm{No})}_{\mathrm{norm}}}+1}{\frac{{\mathrm{PG}}_j}{{(\mathrm{Eb}/\mathrm{No})}_j}+1}---\left(6\right)$

(4) the uplink load factor in the formula can be expressed as again:

${\mathrm{\&eta;}}_{\mathrm{UL}}=\frac{P_{\mathrm{total}}}{I_{\mathrm{total}}}=\frac{\underset{j=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_j}{I_{\mathrm{total}}}=\frac{\underset{j=1}{\overset{N}{\mathrm{\&Sigma;}}}{n}_j}{\frac{{\mathrm{PG}}_{\mathrm{norm}}}{{(\mathrm{Eb}/\mathrm{No})}_{\mathrm{norm}}}+1}---\left(7\right)$

The uplink load factor can also be expressed as upstream noise and promote:

${\mathrm{\&eta;}}_{\mathrm{UL}}=1-\frac{1}{\mathrm{Noise}\_\mathrm{rise}}=1-\frac{1}{I_{\mathrm{total}}/P_N}=1-\frac{P_N}{I_{\mathrm{total}}}---\left(8\right)$

(8) P in the formula _NBe Background Noise Power.

The present invention is at first according to the speed R of apread spectrum bandwidth W, every kind of business _jVoice activation factor v with every kind of business _jCome the processing gain PG of computing service _jChoose a kind of business, for example voice service is calculated the equivalent user of every kind of business and is counted n as the benchmark business according to formula (6) _j, result of calculation is rounded up as the network parameter configuration result; According to the covering requirement of the network planning, determine the maximum uplink load factor η that the sub-district allows _UL, the maximum number of user Nmax according to formula (5) calculating benchmark business calculates the uplink interference thresholding I_thresh that the peak load factor pair is answered according to formula (8).Each parameter configuration is arrived corresponding base station.

Be example with the broadband CDMA system in the third generation mobile system (WCDMA) below, technical scheme of the present invention is described in further detail.

The apread spectrum bandwidth W=3.84Mhz of WCDMA.The WCDMA system supports the multiple business that different Q os requires that has, and the Eb/No of every kind of business and speed R are inequality.In this example, only consider that service rate is the voice service of 12.2kbps, the data service of 64kbps and 144kbps, and with the 12.2k voice service as the benchmark business, the Qos configuration parameter of these three kinds of business is as shown in the table:

Table 1

Professional numbering	Service rate R (bps)	Eb/No(dB)	Eb/No (real number)	Voice activation factor v j	Processing gain PG	Equivalent user is counted n j
							1	12.2	7.2	5.2	0.67	469.8	1
2	64	3.4	2.2	1	60	4
							3	144	2.8	1.9	1	26.7	7

In this example, uplink load factor η _UL=75%, up Background Noise Power P _N=-107dBm, other parameter that need dispose is as shown in the table:

Table 2

Uplink load factor η UL	Background noise P N(dBm)	Background noise P N(real number)	Maximum voice user is counted Nmax	Interference threshold I_thresh (dBm)
					0.75	—107	1.9953e-011	68	-100.1

As shown in Figure 1, in the WCDMA system, cell uplink load (RTWP) measures by base station (Node B) and periodic report is given base station controller (RNC).RNC starts public-measurement by Iub message breath message informing Node B, after Node B is ready to, echoes to RNC and to answer message, gives RNC with measurement result by Iub mouth information reporting then.

As shown in Figure 2, admit control in RNC, to carry out in the WCDMA of the present invention system, among the figure 1. expression return step 202.The present invention specifically may further comprise the steps:

201, RNC starts Node B public-measurement in initial condition, and report manner is a periodic report.Sub-district current equivalent user counter Nuser zero clearing.Enter step 202 then.

202, wait state.

203,204, RNC receives the public-measurement report of Node B periodic report, upgrades cell uplink load Itotal according to measurement result, returns step 202.

205, RNC receives user's call request, execution in step 206.

206, according to the type of service of call request, obtain this professional equivalent user from table 1 and count n _j, obtain the maximum voice user in sub-district from table 2 and count Nmax, interference threshold I_thresh.

If 207 Itotal〉I_thresh, execution in step 210.Otherwise, execution in step 208.

If 208 Nuser+n _jNmax, execution in step 210, otherwise, execution in step 209.

209, accept this call request, make Nuser=Nuser+n _j, return step 202.

210, refuse this calling, return step 202.

211,212, the base station receives that user's business discharges request, discharges this business, and the current equivalent user number in the sub-district in the step 209 is updated to the poor of itself and this professional equivalent user number, even Nuser=Nuser-n _j, return step 202.

The method of the invention described above is that all professional speed of supposition all are constant situations, and promptly professional speed is constant in whole calling activation.In fact, for Packet Service, its speed changes along with service traffics, and network can dynamically be adjusted the bandwidth of distributing to Packet Service according to the service traffics situation.In this case, should search corresponding professional equivalent user number again according to the pairing speed of adjusted service rate, and revise the current equivalent user number in sub-district.Therefore, for the situation of rate variation, method of the present invention also is suitable for.

Certainly; the present invention also can have other various embodiments; under the situation that does not deviate from spirit of the present invention and essence thereof; those skilled in the art work as can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Claims (6)

1. the up-admission control method in the code division multiple address communication system is characterized in that this method may further comprise the steps:

1) with a kind of benchmark business that is set in each business in the system, the base station calculates professional equivalent user number of benchmark and the equivalent user number of other business with respect to this benchmark business according to professional relevant parameter, and then calculates the maximum number of user and the uplink interference thresholding of benchmark business; The maximum number of user and the uplink interference thresholding of the professional equivalent user number of benchmark, other professional equivalent user numbers, benchmark business are stored in this base station data storehouse as configuration parameter; And the current equivalent user number in sub-district is initialized as 0;

2) after the base station receives certain service call request, inquire about maximum number of user and the uplink interference thresholding that its configuration parameter corresponding obtains its equivalent user number, benchmark business according to type of service; Call the current up total interference in sub-district that the base station records simultaneously;

3) if size of comparison current up total interference in sub-district and uplink interference threshold value greater than the uplink interference threshold value, then enters step 6), otherwise enters step 4);

4) maximum number of user of the current equivalent user number in sub-district and this business equivalent user being counted sum and benchmark business compares, if greater than the maximum number of user of benchmark business, then enter step 6), otherwise enter step 5);

5) accept this service call request, and two equivalent user that the current equivalent user number in sub-district is updated in the step 4) counted sum, and return step 2) etc. pending next service call;

6) refuse this service call request, and return step 2) etc. pending next service call.

2. the up-admission control method in the code division multiple address communication system according to claim 1 is characterized in that, this method also comprises:

The base station discharges this business after receiving professional release request, and the current equivalent user number in the sub-district in the step 5) is updated to the poor of itself and this professional equivalent user number.

3. the up-admission control method in the code division multiple address communication system according to claim 1 and 2 is characterized in that, the current up total interference in described sub-district is drawn by base station periodicity public-measurement and upgrades in time.

4. the up-admission control method in the code division multiple address communication system according to claim 1 and 2, it is characterized in that described professional relevant parameter comprises the maximum uplink load factor that professional Eb/No, service rate, apread spectrum bandwidth, the professional voice activation factor, Background Noise Power and this sub-district allow.

5. the up-admission control method in the code division multiple address communication system according to claim 1 and 2, it is characterized in that, when described each professional service rate changes along with the service traffics variation, network is then dynamically adjusted according to service traffics and is distributed to each professional corresponding bandwidth, then need to search corresponding professional equivalent user number again, and upgrade the current equivalent user number in sub-district simultaneously according to the pairing speed of adjusted service rate.

6. the up-admission control method in the code division multiple address communication system according to claim 1 and 2, it is characterized in that the professional file transfer business that includes interactive speech business, streamed multimedia business, interactive database retrieval service and backstage in the described system.

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