CN1394013A - Downlink reception control method for WCDMA system - Google Patents

Abstract

The invention discloses the method for controlling the downward reception used for the wide band code division multiple access (WCDMA). The said method is utilzied in the radio network controller (RNC) of the WCDMA system. The target of the method is to accurately estimate the increment of the calling traffic in order to carry out the reception control. With the common measurement value of the base station being combined with equivalent radius, the increased quanlity of the power of the multiple access interference is calculated. The final transmitting powder and load increment are also calculated. Then, comparing the above value with the allowed load threshold completes the reception control. In the mixed service, the invention provides the features of aculeate evaluation, easy of control and low cost call rate etc.

Description

A kind of downlink reception control method of broadband CDMA system

The invention belongs to 3-G (Generation Three mobile communication system)---Wideband Code Division Multiple Access (WCDMA) (WCDMA) field specifically, relates to WCDMA system descending acceptance controlling method.

Mobile communication development recently is very rapid, become a very important part among the human lives between a few years, under the promotion of Internet fast development, people have greatly promoted the development of 3-G (Generation Three mobile communication system) (IMT-2000) to craving for of mobile Internet (Mobile Internet) simultaneously.The WCDMA technology is the mainstream technology of 3-G (Generation Three mobile communication system), the 3GPP of 3-G (Generation Three mobile communication system) standardization body in March, 99 by and the wireless interface technology standard of having issued Release 99 ' version, later on also among revising.But 3GPP does not work out unified standard to the acceptance controlling method of WCDMA system, and system control method is that each company is that develop on the basis with the standard.

Three big characteristics of 3-G (Generation Three mobile communication system) are to possess characteristics such as broadband high-speed, mixed service and variable bit rate, with the main distinction of second-generation system is that loaded service is different, second-generation system is mainly based on voice service, third generation system then is the multimedia service that voice service and Packet data service are laid equal stress on, and supports the high speed data transfer up to 2Mbps.In IMT-2000, according to the attribute of miscellaneous service and application, carrying out usually it being divided into four major types when Quality of Service is analyzed: conversational service (in real time), interactive service (non real-time), data streaming service (in real time) and backstage business (non real-time) etc.It is speech that the typical case of conversational service uses, and it is the WWW visit that the typical case of interactive service uses, and it is video flowing, file transfer (FTP) etc. that the typical case of dataflow-style business uses, and it is Email (E-mail) that the typical case of background type service uses.

In the WCDMA system,, when making a call the request Radio Resource, the user must admit control because aerial wireless capacity is very limited.The prerequisite of accurately admitting control is accurately to estimate on the basis of cell load, and the load increment that causes after also will inserting call business (comprising new call business and switch call business) is predicted accurately.Admit the accuracy height of control, just can under the prerequisite that system loading allows, admit more user or business as far as possible, thereby can keep the lower percent of call lost and cutting off rate, reach higher service quality.

At present, the method for predictive call traffic load increment is based on the method for throughput.The concrete works of being write with reference to the 3GPP protocol specification with reference to people such as the Harri Holma of Nokia---" WCDMA of UMTS---wireless access of 3G (Third Generation) Moblie ".In the method for prediction downlink business load increment commonly used, professional load increment estimated value Δ η and the relation of information source speed R are non-linear now, and do not consider that multiple access disturbs the power ramp factor that causes; In addition, the downlink load increment of predictive call business is not direct transmitting power increment, and is not corresponding with real system, both impracticable, inaccurate again, causes the false judgment of admitting control easily.

The WCDMA system is a self-interference system, no matter is up or descending, capacity be power at all.Up-link capacity is total interference power-limited, and downlink capacity is a transmit power limited.System for reality, the total interference power of reception of real time dynamic measurement system (sub-district) and descending total transmitting power, call business is carried out the uplink interference power increment to be estimated, call business is carried out the down transmitting power increment to be estimated, the power ramp rule of both direction is not exclusively the same, so should admit control in the uplink and downlink direction respectively, so that adapt to the access of asymmetric traffic.

Because the 3-G (Generation Three mobile communication system) loaded service can be asymmetric, promptly the transmission rate difference of uplink and downlink direction will divide uplink and downlink to admit control like this.Because the WCDMA system is a self-interference system, up-link capacity is interference-limited.Downlink capacity is a power limited, because the down transmitting power of sub-district (base station) equipment is subjected to the restriction of physical device, and the descending restriction that an emission maximum ability is arranged, generally each sector (sub-district), each carrier frequency maximum transmission power are no more than 20W.Therefore, control for descending acceptance, at first to accurately measure the power load of cell downlink, when service call, the speed in the professional Quality of Service, class of business (real time business or non-real-time service), signal to noise ratio requirement etc. are analyzed, by calculating the descending required transmitting power predicted value Δ P of call business, admit control again.When the enough call business of descending surplus resources use, just admit, otherwise just refuse.Calling comprises the calling and the switch call of new initiation, and certainly, new calling is different with the priority of switch call, and the thresholding of judgement is also just different.

When descending traffic load increment is estimated, may there be the descending circuit loss value of real-time and effective to use, at this moment, because wireless location technology prematurity still, it also not the essential function of standard, so can not accurately know the position and the path loss of travelling carriage, thereby be difficult to estimate professional required transmitting power, promptly Ye Wu downlink load increment is a generally acknowledged difficult problem.Although admit error only to influence once, can not accumulate, evaluated error too conference improves the percent of call lost, and reduces running efficiency of system.

The objective of the invention is to propose a kind of when call business (user) request inserts, the method to call business carries out descending acceptance control to reduce the percent of call lost of system, improves the operational efficiency of system.

The method that the present invention proposes realizes by following technical scheme, may further comprise the steps:

1) the professional information source speed R of extraction, required signal-to-noise ratio Eb/No value, priority level and calling party's identify label from the quality of service of call business;

2) search the descending circuit loss value L that this User Identity reports recently;

3) judge whether descending circuit loss value L is effective, if effectively then change 5); Otherwise to 4);

4) calculate descending path loss intermediate value L _jTo replace descending circuit loss value L;

5) with descending circuit loss value L, information source speed R and the required down transmitting power of required signal-to-noise ratio Eb/No value computing service;

6) calculate the descending soaring power of call business;

7) computing system sub-district (base station) descending soaring power;

8) the descending load increment of computing service;

9) rated load of system cell (base station) is deducted the measured value of cell load, obtain system cell (base station) residual capacity;

10) if the residual capacity of system cell (base station) greater than professional downlink load increment, is then admitted this call business; Otherwise refusal is waited for the next call business;

11) give the call business distributing system resource;

Judge in the described step 3) whether descending circuit loss value L is meant effectively that present time is deducted the time difference of records of values time to be judged, if the time difference is that the several seconds is with interior non-0 value, then effective, otherwise try to achieve the approximation L of descending path loss by evaluation method to step 4 _jAs descending circuit loss value L.

Calculate descending path loss intermediate value L in the described step 4) _jThe propagation distance parameter utilizes following formula to calculate $L_j=80+40(1-4\×{10}^{-3}{\mathrm{\Δh}}_b){\log }_{10}\left(\frac{\sqrt{2}}{2}{r}_{\max }\right)+21\×{\log }_{10}\left(f\right)-18{\log }_{10}\left({\mathrm{\Δh}}_b\right)\mathrm{dB},$

Wherein, Δ h _bBe the cell parameter base station antenna height, r _MaxIt is the maximum covering radius of sub-district.

The required down transmitting power of computing service obtains with following formula in the described step 5): ${\mathrm{\ΔP}}_{\mathrm{dBm}}=L-\{103\mathrm{dBm}+\[P_G-{\left(\frac{E_b}{N_0}\right)}_{\mathrm{dB}}\]\}\mathrm{dBm}$

Wherein: the signal to noise ratio decibels ${\left(\frac{E_b}{N_0}\right)}_{\mathrm{dB}}={10\log }_{10}\left(\frac{E_b}{N_0}\right)$ $P_G=10\×{\log }_{10}\left(\frac{3840\mathrm{kcps}}{R}\right)\mathrm{dB}$

P _GBe processing gain, R is a service rate, and dimension is kbps.

The descending soaring power of call business is further to realize by following scheme in the described step 6): at first: the decibels of prediction transmitting power original value converts absolute figure to, utilizes following formula to calculate the required original absolute value (mW) of down transmitting power of call business: $\mathrm{\ΔP}={10}^{0.1\mathrm{\Δ}{P}_{\mathrm{dBm}}}\×\mathrm{\υmW}$

Secondly: remedy the signal to noise ratio reduction that nonopiate factor causes, additional power ramp amount, descending power was soaring after computing service inserted on the original absolute value basis of base station down transmitting power is worth: ${\mathrm{\&Delta;P}}_{\mathrm{total}}=(\frac{{\mathrm{<figure-callout\; id="0"\; label="E\; b\; N"\; filenames="A0111327300181.png"\; state="\{\{state\}\}">E</figure-callout>}}_b}{N_{}}{\&times;\mathrm{\&alpha;}}^2+1)\mathrm{\&Delta;PmW}$ Wherein α is the descending nonorthogonal factor of multipath wireless environment, and value 0.1 to 0.4 is relevant with wireless environment.

The descending soaring power of described step 7) system cell (base station) utilizes following formula to calculate:

P ₀＝η×P _max。

Professional descending load increment is further to realize by following scheme in the described step 8):

Total transmitting power estimated value when at first computing service inserts the back power ramp:

ΔP ₀′＝P ₀α ²

Secondly: computing service inserts the load increment that causes: ${\mathrm{\&Delta;\&eta;}}_{\mathrm{DL}}=\frac{{{\mathrm{\&Delta;P}}_0}^{\&prime;}+{\mathrm{\&Delta;P}}_{\mathrm{total}}}{P_{\max }}\%.$

Described step 10) is according to Δ η _DL%≤η _Th%-η % judges: for new call business, and Δ η _DL%≤60%-η admits during %; For the switch call business, as Δ η _DL%≤90%-η admits during %; Otherwise refusal.

The present invention is further illustrated below in conjunction with accompanying drawing:

Fig. 1 is based on prior art load increment predictor formula function curve diagram;

Fig. 2 is the flow chart of the inventive method;

Fig. 3 is the flow chart of the embodiment of the invention;

Fig. 1 is based on prior art load increment predictor formula function curve diagram; Functional relation is formula (1a) as follows. $\mathrm{\&Delta;\&eta;}=\frac{1}{1+\frac{W_c}{\mathrm{\&upsi;}\&CenterDot;E_b/N_o\&CenterDot;R}}----\left(1a\right)$

(1a) in the formula: υ is the voice activation factor, and the voice service unification gets 0.67, and the data service unification gets 1.00; Wc represents spreading rate, is a constant, equals 3840kcps; Eb/No is the absolute number of the professional signal to noise ratio that requires, and can be converted to by decibel (dB) value; R is the source bits speed (dimension is kbps) of call business.When only considering data service (υ=1), under different signal to noise ratios required, the relation curve of information source speed R and load increment Δ η was seen accompanying drawing 1.

As seen find out from Fig. 1, the relation of load increment Δ η and information source speed R is non-linear, and the descending power increment to business does not calculate, can't utilize the real-time measurement parameter of system, in real system, be difficult to operation, therefore the downlink load increment of this Calculation Method predictive call business is unpractical, causes the false judgment of admitting control easily.

In the system applies of reality, the load of system is dynamic change in time, has only the current load of real-time measurement system, correctly the descending residual capacity of judgement system, accurately estimating to admit control accurately under the load and power increment prerequisite of call business.Residual capacity is the difference of rated capacity (capacity thresholding) and real-time measuring capacity.Like this, under the prerequisite that guarantees system stable operation, can admit call business as far as possible, reduce the percent of call lost, improve the operational efficiency of system and the economic benefit of operation.The result who admits control admits, refuses, and needs the required transmitting power of outgoing traffic after the admittance, as the down initial transmitting power of business, is issued to the desired value requirement of signal to noise ratio in the control of closed loop fast power.

Fig. 2 is a flow chart of the present invention.Functional module of the present invention is embodied in the radio network controller (RNC) with software, controls and manage many base stations (sub-district) by RNC.In conjunction with step of the present invention, be described in further detail below with an embodiment:

1) from the request of call business (user's) RAB (RAB) with the Quality of Service parameter, extract information source speed R, required signal-to-noise ratio Eb/No value, priority level and the calling party's of call business identify label (ID);

2) the descending circuit loss value L (dB) that relative users reports is recently searched in this user's identify label (ID) in database, generally when initial call connected, travelling carriage can be measured descending circuit loss value and report radio network controller (RNC); The measured value that this value must be nearest hundreds of millisecond in the several seconds, otherwise invalid, can move 6.67 meters with 120km/h in the time of 200ms (millisecond) such as travelling carriage, the mobile distance accuracy that just lost too far away does not have practical significance.

3) judge whether descending circuit loss value L is effective, be about to present time and deduct the records of values time,, use this real-time measurement values, forward the 5th to as circuit loss value even if the time difference is effective with interior non-0 value in the several seconds) go on foot and proceed to calculate; Otherwise to 4) go on foot and try to achieve descending path loss intermediate value L by evaluation method _j(approximation of descending path loss L) replaces descending circuit loss value L;

4) when the no longer effective property of descending circuit loss value of actual measurement, with cell parameter (base station antenna height Δ h _bWith the maximum covering radius r in sub-district _Max) the following computing formula of substitution obtains descending path loss intermediate value L _j, with L _jReplace descending circuit loss value L: $L_j=80+40(1-4\&times;{10}^{-3}{\mathrm{\&Delta;h}}_b){\log }_{10}\left(\frac{\sqrt{2}}{2}{r}_{\max }\right)+21\&times;{\log }_{10}\left(f\right)-18{\log }_{10}\left(\mathrm{\&Delta;}{h}_b\right)\mathrm{dB}$ (1)

5) by the 3rd) or the 4th) after the step obtains descending circuit loss value L, utilize professional speed R, following (2) formula of signal to noise ratio required value Eb/No substitution, can calculate the power load increment original value of call business: ${\mathrm{\&Delta;P}}_{\mathrm{dBm}}=L-\{103\mathrm{dBm}+\&lsqb;P_G-{\left(\frac{E_b}{N_0}\right)}_{\mathrm{dB}}\&rsqb;\}\mathrm{dBm}----\left(2\right)$

Wherein: the signal to noise ratio decibels ${\left(\frac{E_b}{N_0}\right)}_{\mathrm{dB}}=10{\log }_{10}\left(\frac{E_b}{N_0}\right)----\left(3\right)$ $P_G=10\&times;{\log }_{10}\left(\frac{3840\mathrm{kcps}}{R}\right)\mathrm{dB}----\left(4\right)$

P _GBe processing gain, R is a service rate, and dimension is kbps.

6) decibels at prediction transmitting power original value converts absolute figure to, and the statistic multiplexing factor in the time of need considering voice service when conversion utilizes following formula to calculate the required original absolute value (mW) of down transmitting power of call business: $\mathrm{\&Delta;P}={10}^{0.1{\mathrm{\&Delta;P}}_{\mathrm{dBm}}}\&times;\mathrm{\&upsi;mW}-----\left(5\right)$

Wherein υ is the voice activation factor, and data service (non-speech service) gets 1.00, and voice service (symmetrical session service) gets 0.67.

7) because the WCDMA system is a self-interference system, the multipath transmission of down wireless link has caused the nonopiate of physics sign indicating number channel, cause physics sign indicating number interchannel to separate not exclusively, there is interactive composition, be that nonopiate meeting causes that the multiple access of physics sign indicating number interchannel disturbs or noise, the signal to noise ratio of each bar physics sign indicating number channel is reduced.Physics sign indicating number channel is many more, disturbs just big more.In order to remedy the signal to noise ratio reduction that nonopiate factor causes, necessary additional power ramp amount is the 6th) basic upward computing service access back soaring value of descending power in step: ${\mathrm{\&Delta;P}}_{\mathrm{total}}=(\frac{{\mathrm{<figure-callout\; id="0"\; label="E\; b\; N"\; filenames="A0111327300181.png"\; state="\{\{state\}\}">E</figure-callout>}}_b}{N_{}}{\&times;\mathrm{\&alpha;}}^2+1)\mathrm{\&Delta;PmW}----\left(6\right)$

Wherein α is the descending nonorthogonal factor of multipath wireless environment, and value 0.1 to 0.4 is relevant with wireless environment.

8) in the real system, reporting system base-station (sub-district) downlink load of RNC is a percentage number, the load value η (%) and base station (sub-district) the maximum transmission power P that utilize actual measurement to report like this _Max(mW) instead push capable total emission power P ₀, so that the power ramp amount of further calculation base station (sub-district);

P ₀＝η×P _max mW (7)

9) because the influence of the nonopiate factor of WCDMA system descending, physics sign indicating number interchannel exists multiple access to disturb, when having reached balance, a power inserts a user (business), this user's transmitting power can make the signal to noise ratio of other physics sign indicating number channel decrease, cause other channel transmitting power that rising is arranged slightly, total transmitting power estimated value is calculated with following formula when considering after the service access power ramp;

ΔP ₀′＝P ₀α ² mW (8)

More than considered the power ramp situation that causes after call business (user) inserts, the load increment that causes of service access can be predicted by following formula so; ${\mathrm{\&Delta;\&eta;}}_{\mathrm{DL}}=\frac{{{\mathrm{\&Delta;P}}_0}^{\&prime;}+{\mathrm{\&Delta;P}}_{\mathrm{total}}}{P_{\max }}\%----\left(9\right)$

10) receivability when preload adds that the load increment of call business is lower than threshold value is then to the 11st) step, the further required system resource of distribution service, otherwise refusal wait for that calling next time arrives;

Δη _DL％≤η _th％-η％ (10)

Call business for different priorities has different threshold values, such as, for new call business, Δ η _DL%≤60%-η admits during %; For the switch call business, its priority height, threshold value is also high, as Δ η _DL%≤90%-η admits during %; Otherwise refusal.

11) after admittance is called out, be necessary for all required system resources of traffic assignments, turn to yard resource allocation subprocess to finish the distribution of resource;

After calling is rejected, wait for that next service call request inserts, when receiving once more when calling out, from the 1st) step carries out the process more than a time again.When a business made a call, the Call Admission Control process was carried out once.

Fig. 3 is the flow chart of the embodiment of the invention.The WCDMA system is that a same frequency is worked simultaneously, the self-interference system of code division multiple access, the uplink interference gross power is limited, and the downlink gross power is limited, and power system capacity is power in essence, the load that is system (sub-district) represents that with power the load increment of call business also shows with wattmeter.

In order to predict the power increment and the load increment of downlink business when the service call, adopted the Forecasting Methodology of downlink path loss measurement in conjunction with equivalent covering radius.If system is set to insert the measurement amount of reporting the downlink path loss value is arranged, then use measured value, because measured value is more accurate than equivalent redius estimated value, but must be noted that, actual measured value is just effective in certain hour (200ms), when being 120km/h such as motion velocity of mobile station, 200ms displacement is 6.7m, if the time is oversize just inaccurate.Calling comprises calling that UE initiates from idle condition, be in and increase the calling that professional calling, switch call and cable network side are come the connection newly, the measurement parameter that the RRM that RNC is the 3rd layer must report to the base station from the RRC signaling, can obtain the Quality of Service parameter from the Iu interface signaling, promptly Ye Wu type (speech or data), downlink business speed, the error rate require (signal to noise ratio Eb/No requirement) and priority or the like; Can obtain current load value of system and downlink path loss value from measurement parameter, thus power increment Δ P that can predictive call _Total(mW) and load increment Δ η (%).Under the situation that accurately the judgement system loads at present, can carry out correct admittance control.When admitting control,, when judging the system loading thresholding, be divided into two thresholding η of height at the situation of call business priority _Th1And η _Th2, establish η here _Th1The=60%, the admittance thresholding of new call business, η _Th2The=90%, the admittance thresholding of switch call; The difference of these two thresholdings 30% is exactly that capacity is reserved, and uses for soft handover, and lower cutting off rate is arranged when guaranteeing direct-cut operation simultaneously.This is equivalent to load is 90% o'clock, and the soft handover traffic carrying capacity reaches more than 50% (0.3/0.6=0.5) with the ratio of new call business amount.Switch call and high-priority call and η _Th1Correspondence is fixed, and is prerequisite with the system stable operation; The new calling and the η of low priority _Th2Correspondence, thresholding are fixing or variable, and variable threshold can reduce the percent of call lost, improve the operational efficiency (benefit) and the service quality of system.

In order accurately to predict the load increment of call business in the WCDMA system, adopt the initial required down transmitting power of measuring amount report method and equivalent redius method computing service, emphasis is a power ramp factor of having considered that descending nonorthogonal factor causes, obtained the transmitting power of professional reality, load to system after the service access is estimated, can carry out descending admittance control so more accurately judges, lower call loss (obstruction) rate is arranged under the prerequisite of system stability, improved resource utilization ratio and service quality rating.

The nonopiate of downlink physical sign indicating number interchannel produced the multiple access interference, if do not consider that the power ramp problem just may lose authenticity.All users of WCDMA system are simultaneously in same frequency range work, and resembling has many people in talk the room, and two Cantoneses talk with the Cantonese; two Hok-los talk with the south of Fujian Province language; two Shanghai people talk with Shanghai native language, as long as voice is not too big, can accomplish to be independent of each other.As the people who adds an intercommunication Hakka again, others is interfered so, and spoken sounds will inevitably improve some and just can catch.Perhaps, have a pair of people to quarrel suddenly and improved sound, influenced other people's talk, force other people to improve sound and just can catch, like this, yours is loud, and my sound is higher, power ramp that Here it is; So go down, everybody tears throat and also can not hear clearly at last, has been equivalent to the WCDMA system crash.The different language here is exactly the numeral among the WCDMA, distinguishes different physical channels with sign indicating number.

In sum, the present invention is used for the descending acceptance control of the 3-G (Generation Three mobile communication system) network design and the network operation, measuring amount and equivalent redius method are combined, consider the nonopiate factor of descending wireless multi-path environment, consider that promptly multiple access disturbs the power ramp factor that causes, transmitting power that computing service is final and load increment, can reach predictive call traffic load increment accurately, admit that control is simple, wireless resource utility efficiency is high, the network operation is stable, the effect of the percent of call lost and the reduction of switching cutting off rate.It is the acceptance controlling method of a practicality.

The present invention has proposed the path loss method of estimation of equivalent mean radius first, in the time can not utilizing metrical information, still can estimate the transmitting power of downlink business, thereby can estimate professional load increment value, simultaneously, considered under the environment of wireless multipath channel, the multiple access interference effect that descending nonopiate factor causes has promptly proposed the soaring computational methods of descending power.Like this, can under the mixed service situation, accurately carry out descending acceptance control, the contradiction of the system's operation stability and the percent of call lost when solving higher load.The present invention is a kind of acceptance controlling method of practicality, be used for the network design and the network operation of WCDMA system, can reach to the downlink load increment of call business estimate accurately, admit control easily, network operation efficient height, the percent of call lost and the low effect of cutting off rate.The shielded scope of patent is methods such as definite, the professional power increment estimation of equivalent redius, load increment calculating, power ramp calculating, and range of application comprises moving communicating field.

Claims (8)

1, a kind of method of descending acceptance control in broadband CDMA system is characterized in that may further comprise the steps:

Step 1: the identify label of from the quality of service of call business, extracting professional information source speed R, required signal-to-noise ratio Eb/No value, priority level and calling party;

Step 2: search the descending circuit loss value L that this User Identity reports recently;

Step 3: judge whether descending circuit loss value L is effective, if effectively then change step 5; Otherwise to step 4;

Step 4: calculate descending path loss intermediate value Lj to replace descending circuit loss value L;

Step 5: with descending circuit loss value L, information source speed R and the required down transmitting power of required signal-to-noise ratio Eb/No value computing service;

Step 6: calculate the descending soaring power of call business;

Step 7: the soaring power that computing system sub-district (base station) is descending;

Step 8: the load increment that computing service is descending;

Step 9: the rated load of system cell (base station) is deducted the measured value of cell load, obtain system cell (base station) residual capacity;

Step 10: if the residual capacity of system cell (base station) is then admitted this call business greater than professional downlink load increment, otherwise refusal is waited for the next call business.

Step 11: give the call business distributing system resource.

2, downlink system acceptance controlling method in the broadband CDMA system according to claim 1, it is characterized in that: judge in the described step 3 whether descending circuit loss value L is meant effectively that present time is deducted the time difference of records of values time to be judged, if the time difference is that the several seconds is with interior non-0 value, then effective, otherwise try to achieve the approximation L of descending path loss by evaluation method to step 4 _jAs descending circuit loss value L.

3, downlink system acceptance controlling method in the broadband CDMA system according to claim 1 is characterized in that: calculate descending path loss intermediate value L in the described step 4 _jThe propagation distance parameter utilizes following formula to calculate $L_j=80+40(1-4\&times;{10}^{-3}\mathrm{\&Delta;}{h}_b){\log }_{10}\left(\frac{\sqrt{2}}{2}{r}_{\max }\right)+21{\&times;\log }_{10}\left(f\right)-{18\log }_{10}\left({\mathrm{\&Delta;h}}_b\right)\mathrm{dB},$ Wherein, Δ h _bBe the cell parameter base station antenna height, r _MaxIt is the maximum covering radius of sub-district.

4, downlink system acceptance controlling method in the broadband CDMA system according to claim 1 is characterized in that: the required down transmitting power of computing service obtains with following formula in the described step 5: ${\mathrm{\&Delta;P}}_{\mathrm{dBm}}=L-\{103\mathrm{dBm}+[P_G-{\left(\frac{E_b}{N_0}\right)}_{\mathrm{dB}}\left]\right\}\mathrm{dBm}$

Wherein: the signal to noise ratio decibels ${\left(\frac{E_b}{N_0}\right)}_{\mathrm{dB}}=10{\log }_{10}\left(\frac{E_b}{N_0}\right)$ $P_G=10\&times;{\log }_{10}\left(\frac{3840\mathrm{kcps}}{R}\right)\mathrm{dB}$

P _GBe processing gain, R is a service rate, and dimension is kbps.

5, downlink system acceptance controlling method in the broadband CDMA system according to claim 1 is characterized in that the descending soaring power of call business is further to realize by following scheme in the described step 6:

At first: the decibels of prediction transmitting power original value converts absolute figure to, utilizes following formula to calculate call business

The absolute value (mW) that required down transmitting power is original: $\mathrm{\&Delta;P}={10}^{0.1\mathrm{\&Delta;}{P}_{\mathrm{dBm}}}\&times;\mathrm{\&upsi;mW}$

Secondly: remedy the signal to noise ratio reduction that nonopiate factor causes, additional power ramp amount, descending power was soaring after computing service inserted on the original absolute value basis of base station down transmitting power is worth: $\mathrm{\&Delta;}{P}_{\mathrm{total}}=(\frac{E_b}{N_0}\&times;{\mathrm{\&alpha;}}^2+1)\mathrm{\&Delta;PmW}$

Wherein α is the descending nonorthogonal factor of multipath wireless environment, and value 0.1 to 0.4 is relevant with wireless environment.

6, downlink system acceptance controlling method in the broadband CDMA system according to claim 1 is characterized in that the descending soaring power of described step 7 system cell (base station) utilizes following formula to calculate:

P ₀＝η×P _max。

7, downlink system acceptance controlling method in the broadband CDMA system according to claim 1 is characterized in that professional descending load increment is further to realize by following scheme in the described step 8:

Total transmitting power estimated value when at first computing service inserts the back power ramp:

ΔP ₀′＝P ₀α ²

Secondly: computing service inserts the load increment that causes: $\mathrm{\&Delta;}{\mathrm{\&eta;}}_{\mathrm{DL}}=\frac{{{\mathrm{\&Delta;P}}_0}^{\&prime;}+{\mathrm{\&Delta;P}}_{\mathrm{total}}}{P_{\max }}\%.$

8, downlink system acceptance controlling method in the broadband CDMA system according to claim 1 is characterized in that described step 10 is according to Δ η _DL%≤η _Th%-η % judges: for new call business, and Δ η _DL%≤60%-η admits during %; For the switch call business, as Δ η _DL%≤90%-η admits during %; Otherwise refusal.

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