CN1764308A - Uplink acceptance controlling method in TD-SCDMA access system - Google Patents

Abstract

The up-acceptance control method TDS-CDMA access system comprises: the system acquires the opposite parameters to decide the call is mixed business or single business and calculate the ratio of per symbol energy to spectral density of interference power by formula; predicting the load increment on every up time slot led by this call according to opposite formula; deciding whether the sum of load increment and accept bandwidth total power exceeds the threshold, if yes, the up acceptance fails; or else, it succeeds. This invention considers different load on every time slot and new business allocation on different time slot, improves network running efficiency, and reduces call loss rate.

Description

Up-admission control method in a kind of TD-SCDMA system

Technical field

The present invention relates to the up-admission control method in a kind of TD-SCDMA system (TD-SCDMA), relate in particular in a kind of TD-SCDMA system up-admission control method based on interference threshold.

Background technology

Cdma system is an a kind of self-interference system, all can produce interference between each user, if the load of air interface allows unlimited increasing, the area coverage of sub-district then can be reduced, and the QoS of institute's link connection (service quality, Quality of service) can not guarantee.Therefore, before admitting a new connection, admit control to need to check whether this admittance can sacrifice the area coverage of the sub-district of planning or build the QoS of connection.Admit control can accept or refuse a request of in wireless access network, setting up a RAB RAB (Radio Access Bear).When carrying is established and revise, need to carry out the admittance control procedure.Accommodating control function is positioned at radio network controller (RNC) (Radio NetworkController), therefrom can obtain the information on load of several sub-districts.Admit control may estimate the load increase that wireless network causes, and this estimation should be carried out respectively in the uplink downlink direction to the foundation of a new bearer.Have only when a request is all admitted in the admittance control of uplink and downlink link, this carrying request just can be admitted, otherwise it can be because of wireless network being produced too many interference and being rejected.

Present acceptance controlling method mainly is divided into based on the scheme of thresholding and the scheme measured based on signal interference ratio SIR (SignalInterference Ratio).For for the control of the up-admission of interference threshold, most important and most critical be the increment of prediction ascending load, its acceptance judging formula is: I _{Total_old}+ Δ I≤I _ThresholdI _{Total_old}Be current total interference level; Δ I increases the increase of the interference that causes for estimating new user; I _ThresholdBe total interference threshold value.The predictor formula of uplink service incremental loading is mainly based on throughput at present, concrete with reference to please the Harri Holma of Nokia Telecommunications etc. people's works " wireless access of UMTS-3G (Third Generation) Moblie ", the formula of the increment of the existing uplink load factor is:

${\mathrm{\η}}_{\mathrm{UL}}=\frac{1}{1+\frac{W}{{v.E}_b/N_0.R}}---\left(1\right)$

Wherein, W is a spreading rate, and R is professional speed, the v voice activation factor, if speech business, v=0.67 is if other business v=1 then.E _b/ N ₀Be the energy per bit of business and the ratio of disturbance spectrum density, relevant with type of service.Business datum is that 15 time slots in a frame are continuous for the CDMAFDD system, sends the reflection business datum ground actual transmissions situation that professional speed R also can be actual fifty-fifty.Can think that the loading condition of all time slots in the frame is identical with subscriber signal power, so the admittance of FDD system control is based on, and the sub-district carries out.Yet for CDMA TDD system, business datum is not continuous transmission of all time slots in a frame, but concentrate on certain several slot transmission, and each time slot institute data carried by data amount also may be different, the loading condition of each time slot, the increment of load all may be different, and therefore the control of the up-admission in the TDD system must be based on that time slot carries out.

Because the present up-admission control overwhelming majority based on interference threshold is based on the sub-district and adjudicates, only be suitable for the FDD system, and the TDD system takes is the mode of time division duplex, loading condition on each time slot of radio frames is all different, institute's loaded service amount also is different on each time slot, and new access service influence to other existing subscriber on each time slot also is different.Because the otherness of FDD system and TDD system, and the complexity of the Consideration of TDD system has determined the existing up-admission control algolithm based on interference threshold that is suitable for the FDD system can not be applicable to the TDD system.

Therefore, prior art has yet to be improved and developed.

Summary of the invention

The object of the present invention is to provide the up-admission control method in a kind of TD-SCDMA system, its technical problem that will solve is to provide a kind of up-admission control method based on interference threshold in the TD-SCDMA system, improve network operation efficient, reduce the percent of call lost and cutting off rate.

At above-mentioned technical problem, technical scheme of the present invention is:

Up-admission control method in a kind of TD-SCDMA system, it may further comprise the steps:

A) when terminal made a call request, described system obtained professional relevant parameter;

B) judge that this time call request is mixed service or single business, calculates the ratio of every symbol energy and interference power spectrum density according to professional relevant parameter;

C) according to the ratio and the dynamic sign indicating number resource allocation result of every symbol energy and interference power spectrum density, predict the incremental loading of this time calling at the ascending time slot of this time of carrying calling;

D) judge accepting bandwidth gross power sum and whether can surpassing pre-configured thresholding of the incremental loading of ascending time slot and this ascending time slot, if surpass pre-configured thresholding then the up-admission failure; When all will carry the incremental loading of ascending time slot of this time calling and the bandwidth gross power sum of accepting on the time slot all is no more than pre-configured thresholding, then up-admission success.

Described method, wherein, described step a) also comprises:

A1) described system extracts professional energy per bit and interference power spectrum density ratio from the QoS parameter of this time call request loaded service;

A2) described system obtains the relevant parameter of transmission channel, calculates this time call request loaded service and is adding in a frame and want the loaded information bit numbers before the cyclic redundancy check (CRC) code at most;

A3) carry out dynamically sign indicating number resource allocation, obtain the time slot and the sign indicating number resource allocation result of this time call request, dynamic sign indicating number resource allocation result is the resource units quantity of coded combination transmission channel in the resource units sum of subframe domestic demand carrying and the required carrying of each ascending time slot difference in this subframe;

A4) obtain and will carry the measuring amount of all ascending time slots of this time calling, this measuring amount is that time slot is accepted the bandwidth gross power.

Described method, wherein, under single service conditions, the ratio E of every symbol energy of described new user and interference power spectrum density _Symbol/ N ₀For:

$E_{\mathrm{symbol}}/N_0=\frac{E_b}{N_0}\·\frac{L_{\inf }}{2\·N_{\mathrm{subframe}}\·44}$

Wherein: E _b/ N ₀Be the quality factor of this single business, L _InfFor this business needs the loaded information bit number, N add cyclic redundancy check (CRC) code in a frame before _SubframeBe the resource units number of this user a subframe domestic demand distribution.

Described method, wherein, under the mixed service situation, new user's the every symbol energy and the ratio E of interference power spectrum density _Symbol/ N ₀For:

$E_{\mathrm{symbol}}/N_0=\frac{\underset{i=1}{\overset{K}{\mathrm{\Σ}}}{E}_b^i/N_0\·L_{\inf }^i}{N_{\mathrm{subframe}}\·88}$

Wherein: E _b ⁱ/ N ₀Be the quality factor of i kind business, L ⁱ _NfiBe i kind business loaded information bit number in a frame, N _SubframeBe the resource units number that this user distributes a subframe domestic demand, i is the natural number that is used to count.

Described method, wherein, this user causes to such an extent that the formula of incremental loading is as follows on current time slots:

$\mathrm{\Δ}{L}_i=\frac{1}{1+\frac{W}{v\·E_{\mathrm{symbol}}/N_0\·\frac{{N^i}_{\mathrm{timeslot}}\·44}{T_{\mathrm{timeslot}}}}}$

Wherein, v is the voice activation factor, speech business v value 0.67, data service v value 1; T _TimeslotBe the cycle of a conventional time slot, value 675 μ S; N ⁱ _TimeslotBe the resource units number that new user distributes in current time slots, W is spreading rate 1.28Mchips/s;

Predict that the incremental loading that new user can cause in current time slots is:

${\mathrm{\ΔI}}_i\left(\mathrm{dBm}\right)=\left(\frac{I_{\mathrm{itatal}}}{1-{\mathrm{\η}}_i}\right)\left(\mathrm{dBm}\right)+{\mathrm{\ΔL}}_i\left(\mathrm{dB}\right)$

Wherein, I _ItatalAccept bandwidth gross power, η for current time slots _iThe ascending load factor for current time slots.

Up-admission control method in a kind of TD-SCDMA system provided by the present invention, the up-admission control method that proposes is based on that time slot carries out, considered the current different loading condition on each time slot, the difference of new access service on different time-gap distributed; In addition, the inventive method can not only be applicable to the access of single business but also consider the complex situations that mixed service inserts, be well positioned to meet multi-service in the TDD system, the requirement of asymmetric traffic.The inventive method can accurately be calculated the interference increment of new access user on each time slot, prevented new user's access can cause that overload appears in each time slot in the TDD system, on the basis of fail safe that has guaranteed the time slot in the sub-district and stability and then prevented whole sub-district the situation of overload to occur, network operation efficient is improved, and the percent of call lost and cutting off rate reduce.

Description of drawings

Shown in Fig. 1 is the overall procedure frame diagram of admitting control in the TDSCDMA of the present invention system;

Fig. 2 is the concrete implementing procedure figure of up-admission method of the present invention.

Embodiment

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

Up-admission control method in the TD-SCDMA system of the present invention, as shown in Figure 1, it may further comprise the steps:

The first step, obtain required relevant parameter:

1. from the Qos parameter of call business, extract professional quality factor E _b/ N ₀Parameter.

2. obtain the relevant parameter of transmission channel, calculate pre-access service the most maximum loaded information number L of bits of wanting in a frame _Inf, do not comprise cyclic redundancy check (CRC) code.

3. carry out dynamically sign indicating number resource allocation, obtain new user's time slot and sign indicating number resource allocation result: CCTrCH the total N of RU (resource units, Resource Unit) in subframe domestic demand carrying _SubframeAnd at the RU quantity N of the required carrying of each time slot _Timeslot

4. obtain the measuring amount with all ascending time slots of this time of carrying calling: time slot is accepted bandwidth gross power I _Itatal

Second step, judge that this time calling is mixed service or single business, calculate the ratio E of every symbol energy and interference power spectrum density according to professional relevant parameter and corresponding formulas _Symbol/ N ₀

The 3rd step is according to the ratio of every symbol energy and interference power spectrum density and dynamically sign indicating number resource allocation result and respective formula are predicted the incremental loading that this time calling causes at each ascending time slot.

The 4th step, judge accepting bandwidth gross power sum and whether can surpassing thresholding of incremental loading and time slot on the time slot, if above pre-configured thresholding up-admission fail; When all will carry the incremental loading of ascending time slot of this time calling and the bandwidth gross power sum of accepting on the time slot all is no more than pre-configured thresholding, then up-admission success.

As shown in Figure 2, be the schematic flow sheet of specific embodiments of the invention, in the access control equipment of TD-SCDMA system, taked following up-admission control procedure:

Step 200: obtain relevant parameter, specifically can may further comprise the steps again:

A) described system extracts professional energy per bit and interference power spectrum density ratio from the QoS parameter of this time call request loaded service, at first obtains professional pre-configured parameter E _b/ N ₀

B) secondly obtain the transmission channel relevant parameter: pre-each new business of admitting is maximum loaded information number L of bits in the frame of a 10ms ⁱ _Nfi(before adding CRC);

C) call the resource allocation of dynamic sign indicating number, obtain new user's time slot and sign indicating number resource allocation result: coded combination transmission channel CCTrCH is at RU (resource units, ResourceUnit) the total N of subframe domestic demand carrying _SubframeAnd at the RU quantity N of the required carrying of each time slot ⁱ _Timeslot

D) obtain the measuring amount of each ascending time slot: this measuring amount is the up bandwidth gross power I that accepts _Itatl

Step 201: judge that the pre-user who inserts still is single business for mixed service, if be single business then change step 202 over to; Otherwise, change step 203 over to.

Step 202: calculate under the single service conditions new user's the every symbol energy and the ratio E of interference power spectrum density _Symbol/ N ₀, concrete formula is as follows:

$E_{\mathrm{symbol}}/N_0=\frac{E_b}{N_0}\·\frac{L_{\inf }}{2\·N_{\mathrm{subframe}}\·44}---\left(2\right)$

Wherein: E _b/ N ₀Be the quality factor of this single business, L _InfBe this business loaded information bit number in a frame, N _SubframeBe the RU number of this user a subframe domestic demand distribution.

Step 203: calculate under the mixed service situation new user's the every symbol energy and the ratio E of interference power spectrum density _Symbol/ N ₀, concrete formula is as follows:

$E_{\mathrm{symbol}}/N_0=\frac{\underset{i=1}{\overset{K}{\mathrm{\Σ}}}{E}_b^i/N_0\·L_{\inf }^i}{N_{\mathrm{subframe}}\·88}---\left(3\right)$

Wherein: E _b ⁱ/ N ₀Be the quality factor of i kind business, L ⁱ _InfIt is i kind business loaded information bit number in a frame.

Step 204: in a subframe, travel through all ascending time slots that new user will insert.

Step 205: judge whether time slot has traveled through.If, then up-admission success; If not, then change step 206 over to.

Step 206: calculate on current time slots this user cause incremental loading, it is as follows specifically to implement formula:

${\mathrm{\ΔL}}_i=\frac{1}{1+\frac{W}{v\·E_{\mathrm{symbol}}/N_0\·\frac{{N^i}_{\mathrm{timeslot}}\·44}{T_{\mathrm{timeslot}}}}}---\left(4\right)$

Wherein, v is the voice activation factor, speech business v value 0.67, the professional v value 1 of PS; T _TimeslotBe the cycles 675 μ S of a conventional time slot; N ⁱ _TimeslotBe the RU number that new user distributes in current time slots, W is spreading rate 1.28Mchips/s.

Step 207: predict the incremental loading that new user can cause in current time slots, concrete formula is as follows:

${\mathrm{\ΔI}}_i\left(\mathrm{dBm}\right)=\left(\frac{I_{\mathrm{itatal}}}{1-{\mathrm{\η}}_i}\right)\left(\mathrm{dBm}\right)+{\mathrm{\ΔL}}_i\left(\mathrm{dB}\right)---\left(5\right)$

Wherein, I _ItatlAccept bandwidth gross power, η for current time slots _iThe ascending load factor for current time slots.

Step 208: judge current time slots accept the bandwidth gross power and whether the incremental loading sum can be greater than pre-configured thresholding.If then admit failure; If not, then change step 205 over to.

So, the up-admission control method that proposes by said process is based on that time slot carries out, and the inventive method has been considered the current different loading condition on each time slot, and the difference of new access service on different time-gap distributed; In addition, the inventive method can not only be applicable to the access of single business but also consider the complex situations that mixed service inserts, be well positioned to meet multi-service in the TDD tdd systems, the requirement of asymmetric traffic.The inventive method can accurately be calculated to make new advances and insert the interference increment of user on each time slot, prevented new user's access can cause that overload appears in each time slot in the TDD system, on the basis of fail safe that has guaranteed the time slot in the sub-district and stability and then prevented whole sub-district the situation of overload to occur, network operation efficient is improved, has reduced the percent of call lost and cutting off rate.

Should be understood that above-mentioned description at specific embodiment of the present invention is too detailed, can not therefore be interpreted as the restriction of scope that the present invention is asked for protection, scope of patent protection of the present invention should be as the criterion with claims.

Claims (5)

1, the up-admission control method in a kind of TD-SCDMA system, it may further comprise the steps:

A) when terminal made a call request, described system obtained professional relevant parameter;

B) judge that this time call request is mixed service or single business, calculates the ratio of every symbol energy and interference power spectrum density according to professional relevant parameter;

C) according to the ratio and the dynamic sign indicating number resource allocation result of every symbol energy and interference power spectrum density, predict the incremental loading of this time calling at the ascending time slot of this time of carrying calling;

D) judge accepting bandwidth gross power sum and whether can surpassing pre-configured thresholding of the incremental loading of ascending time slot and this ascending time slot, if surpass pre-configured thresholding then the up-admission failure; When all will carry the incremental loading of ascending time slot of this time calling and the bandwidth gross power sum of accepting on the time slot all is no more than pre-configured thresholding, then up-admission success.

2, method according to claim 1 is characterized in that, described step a) also comprises:

A1) described system extracts professional energy per bit and interference power spectrum density ratio from the QoS parameter of this time call request loaded service;

A2) described system obtains the relevant parameter of transmission channel, calculates this time call request loaded service and is adding in a frame and want the loaded information bit numbers before the cyclic redundancy check (CRC) code at most;

A3) carry out dynamically sign indicating number resource allocation, obtain the time slot and the sign indicating number resource allocation result of this time call request, dynamic sign indicating number resource allocation result is the resource units quantity of coded combination transmission channel in the resource units sum of subframe domestic demand carrying and the required carrying of each ascending time slot difference in this subframe;

A4) obtain and will carry the measuring amount of all ascending time slots of this time calling, this measuring amount is that time slot is accepted the bandwidth gross power.

3, method according to claim 2 is characterized in that, under single service conditions, and the ratio E of every symbol energy of described new user and interference power spectrum density _Symbol/ N ₀For:

$E_{\mathrm{symbol}}/N_0=\frac{E_b}{N_0}\·\frac{L_{\inf }}{2{\·N}_{\mathrm{subframe}}\·44}$

Wherein: E _b/ N ₀Be the quality factor of this single business, L _InfFor this business needs the loaded information bit number, N add cyclic redundancy check (CRC) code in a frame before _SubframeBe the resource units number of this user a subframe domestic demand distribution.

4, method according to claim 2 is characterized in that, under the mixed service situation, and new user's the every symbol energy and the ratio E of interference power spectrum density _Symbol/ N ₀For:

$E_{\mathrm{symbol}}/N_0=\frac{\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{E}_b^i/N_0\·L_{\inf }^i}{N_{\mathrm{subframe}}\·88}$

Wherein: E _b ⁱ/ N ₀Be the quality factor of i kind business, L _Inf ⁱBe i kind business loaded information bit number in a frame, N _SubframeBe the resource units number that this user distributes a subframe domestic demand, i is the natural number that is used to count.

According to claim 3 or 4 described methods, it is characterized in that 5, this user causes to such an extent that the formula of incremental loading is as follows on current time slots:

$\mathrm{\Δ}{L}_i=\frac{1}{1+\frac{W}{v{\·E}_{\mathrm{symbol}}/N_0\·\frac{N_{\mathrm{timeslot}}^i\·44}{T_{\mathrm{timeslot}}}}}$

Wherein, v is the voice activation factor, speech business v value 0.67, data service v value 1; T _TimeslotBe the cycle of a conventional time slot, value 675 μ S; N ⁱ _TimeslotBe the resource units number that new user distributes in current time slots, W is spreading rate 1.28Mchips/s;

Predict that the incremental loading that new user can cause in current time slots is:

${\mathrm{\ΔI}}_i\left(\mathrm{dBm}\right)=\left(\frac{I_{\mathrm{itatal}}}{1-{\mathrm{\η}}_1}\right)\left(\mathrm{dBm}\right)+{\mathrm{\ΔL}}_i\left(\mathrm{dB}\right)$

Wherein, I _ItatalAccept bandwidth gross power, η for current time slots _iThe ascending load factor for current time slots.

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