CN100420340C - HSDPA call ready to cut-in control method - Google Patents

Abstract

The present invention relates to an HSDPA calling admittance control method which comprises the following steps: a) at the time of system initialization, the maximal data-transmission throughput which can be loaded currently by a high-speed downlink sharing channel of an HSDPA system is estimated, and the throughput threshold is obtained; B) the service quality requirement of a user terminal which requests to be coupled in the HSDPA system and carry out downlink service transmission, and the effective rate of the channel which needs to be occupied by the user terminal is obtained; C) the transmission rates of all the user terminals which are coupled in the high-speed downlink sharing channel of the HSDPA system and carry out service transmission are counted; after the results of B) and C) are added, judgment and comparison are carried out with the throughput threshold of the high-speed downlink sharing channel of the HSDPA system, and the admittance decision to a calling of the user terminal for requesting to be coupled in the HSDPA system to carry out the downlink service transmission is carried out according to the comparison result. The present invention can effectively improve the accuracy of the HSDPA calling admittance decision, and reduce the probability of calling blockage of the system.

Description

A kind of HSDPA call admission control method

Technical field

The present invention relates to wireless communication field, particularly relate to Admission Control field in the RRM (CAC).

Background technology

At mobile radio system, need by RRM (Radio ResourceManagement, RRM) technology distributing radio resource effectively, thereby guarantee the higher system performance.Wherein, (Call Admission Control CAC) is one of the radio resource management techniques of outbalance to Admission Control.The decision method of traditional Admission Control mainly can be categorized as based on number of users, based on equivalent frequency range, based on transmitted power, based on received power, (Signal-to-Interference Ratio SIR) measures, measures and based on methods such as system loading measurements based on system interference based on signal-to-interference ratio (signal interference ratio).

Mobile communication system (Universal Mobile Telecommunications System, UMTS) introduce the descending wireless transmission link of enhancement mode (HighSpeed Downlink Packet Acess in the WCDMA/UTRA-FDD standard R5 version, HSDPA), be desirably in improving Radio Link downlink transfer speed and power system capacity under the minimum prerequisite of changing of WCDMA network configuration.HSDPA adopts Adaptive Modulation and Coding (Adaptive Modulation and Coding, AMC), mix automatic request retransmission (HybirdAutomatic Repeat Request, HARQ), the constant transmissions time interval (TTI, 2ms), fixing spreading factor (SF=16), direct-cut operation (Hard Handover, HHO), fast dispatch (being arranged in NodeB) and fast cell are selected (Fast Cell Selection, FCS) etc. Radio Transmission Technology realizes the high-speed radio transmission link, but do not adopt fast power control (Fast Power Control, FPC), Orthogonal Variable Spreading Factor OVSF (Orthogonal Variable Spreading Factor, OVSF) and soft handover (SoftHandover, SHO) technology makes transmission of radio links speed up to more than the 10Mbps.

HSDPA has added high-speed downlink shared channel (HighSpeed Downlink Shared CHannel on original service transmission channel, HS-DSCH) be used for sharing of high speed grouping service wireless such as Streaming Media, interactive mode and background formula, and interpolation shared control channel (Shared Control Channel, SCCH) and the up link Dedicated Physical Control Channel (Dedicated Physical Control Channel DPCCH) is used to control the transmission of signaling.(Medium Access Control, MAC) in the agreement, (Medium Access Control-high speed MAC-hs) is used to handle business in the HS-DSCH channel to have increased high speed entity at media access control layer.

The MAC-hs entity comprises the scheduling feature of HARQ and HSDPA and to the controlled function of HS-DSCH, the MAC-hs functional entity is arranged in base station (NodeB).

HSDPA has the unique design characteristics, the physical layer transmission technology and the link adaptation techniques that improve the availability of frequency spectrum have been adopted, formed the high-speed wireless link of sign indicating number branch/time division multiplexing coexistence, its high-speed downlink shared channel (HS-DSCH) is mainly used in the transport stream medium, the grouping service wireless that interactive mode and background formula are three types, the principal character of these three types of business is that throughput and time delay all have dynamic characteristic, adopts traditional call admission control method can not be applicable to that the Quality of Service of above business requires and the high-speed wireless link feature of sign indicating number branch/time division multiplexing coexistence.

Document [1] " O.Salent; J.perez; R.Agusti; ' Uplink RRM for conversational andinteractive service in UTRA-FDD " ' and document [2] " Mohamod Moustafa; IbrahimHabib; ' GAME Based Radio Resource Management in Wideband CDMANetworks ', IEEE, 2001 " a kind of WCDMA down link call admission control algorithm based on throughput being disclosed; the access mode decision scheme that this algorithm provides is: be lower than default stressor thresholding as long as new calling inserts the current stressor sum of downstream link overhead factor increment and system that causes; promptly allows new access of calling out, that is:

η _DL+Δη _DL＜η _{DL_threshold}

η in the formula _DLStressor for down link; Δ η _DLThe increment of the downstream link overhead factor that causes for access owing to new user; η _{DL_threshold}Stressor threshold value for systemic presupposition.Provided η in the document respectively _DLWith Δ η _DLComputing formula:

${\mathrm{\η}}_{\mathrm{DL}}=\frac{\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{R}_j}{R_{\max }}=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{R}_j\frac{V_j{(E_b/I_0)}_j}{W}[(1-\stackrel{\‾}{\mathrm{\α}})+\stackrel{\‾}{i}]$

${\mathrm{\Δ\η}}_{\mathrm{DL}}=R_k\frac{V_k{(E_b/I_0)}_k}{W}[(1-\stackrel{\‾}{\mathrm{\α}})+\stackrel{\‾}{i}]$

Wherein, W is a system bandwidth; R _MaxMaximum throughput for the sub-district permission; R _jBit rate for user j; V _jBe activity factor with the j family; α is the average orthogonality of minizone, and i is the average downlink noise power ratio of other sub-district and this sub-district.

But this traditional throughput evaluation method is also inapplicable under the HSDPA system.This is because the HSDPA high-speed wireless link has adopted multiple new technology, as mixes automatic request retransmission (HARQ), Adaptive Modulation and Coding (AMC), high speed scheduling etc., and these technology all exert an influence to the throughput performance of high-speed wireless link.In addition, the throughput characteristic of high-speed link and delay character are also along with the changes in channel conditions of real-time change.Therefore, traditional throughput evaluation method and can not in time, effectively reflect the channel condition that HSDPA is current and service quality (QoS) demand of customer service based on the calling access of this throughput parameter judgement mode, the characteristics that can not reflect HSDPA system high-speed downlink sharied signal channel also can't be guaranteed aspect the accuracy of calculating.

Summary of the invention

The object of the invention is to overcome above-mentioned defective and a kind of HSDPA call admission control method of proposing, it is according to mixing the influence to throughput performance such as automatic request retransmission, Adaptive Modulation and Coding, fast dispatch, estimation HSDPA system high-speed downlink sharied signal channel throughput is carried out access control based on this throughput judgement to user's calling then.This method can effectively be improved the accuracy that HSDPA calls out the access judgement, reduces the probability of call blocking of system.

A kind of HSDPA call admission control method for realizing that the object of the invention provides comprises the following steps:

Steps A) when system initialization, but, draw throughput threshold according to mixing automatic request retransmission and Adaptive Modulation and Coding the current data carried by data transmission of influence estimation HSDPA system high-speed downlink sharied signal channel maximum throughput to the HSDPA link throughput;

Step B) analysis request inserts the quality of service requirement that the HSDPA system carries out the user terminal of downlink traffic transmission, draws the effective data rate of the required busy channel of user terminal;

Step C) statistics has inserted each user terminal transmission rate that HSDPA system high-speed downlink sharied signal channel carries out professional transmission;

Step D) with step B) and step C) results added after, judge comparison with the throughput threshold of HSDPA system high-speed downlink sharied signal channel, according to judging that comparative result carries out the access judgement to the calling that request access HSDPA system carries out the user terminal of downlink traffic transmission.

Described steps A) can comprise the following steps:

Steps A 1) estimation mixes the influence of automatic request retransmission to the HSDPA link throughput;

Steps A 2) the estimation Adaptive Modulation and Coding influences link throughput;

Steps A 3) according to Adaptive Modulation and Coding and the automatic request retransmission of mixing link throughput is influenced estimation link average frequency spectrum utilance, the link maximum throughput when obtaining given bandwidth according to link average frequency spectrum utilance.

Described steps A 2) can comprise the following steps:

Steps A 21) estimates that Adaptive Modulation and Coding is to the influence of link throughput on the small scale fading channel; Or

Steps A 22) estimates that Adaptive Modulation and Coding is to the influence of link throughput on the large scale fading channel.

Described step D) can comprise the following steps:

Step D1) judgment condition does not satisfy, the effective data rate sum that the transmission rate that has added each user terminal of HSDPA system adds the required busy channel of new user terminal is during greater than the maximum throughput thresholding, then refuse the service access request, and the notice relevant terminal;

Step D2) otherwise, satisfy judgment condition, the transmission rate that has added each user terminal of HSDPA system adds when the effective data rate sum of the required busy channel of new user terminal is less than or equal to the maximum throughput thresholding, accept business and insert request, distributing radio resource, and notice relevant terminal.

Described step B) in downlink traffic transmission can for:

High-speed downlink shared channel is to the high-speed downlink shared channel service switchover in the base station;

High-speed downlink shared channel is to the high-speed downlink shared channel service switchover between the base station;

The new call business of Streaming Media;

Interactive new call business;

The new call business of background formula;

One or more than one combination in any in the above-mentioned business.

Described step B) effective data rate obtains for using the successful transmission probability of automatic re-transmission that real time rate is weighted in.

The described automatic re-transmission probability of success calculates by frame error rate.

Described step B) effective data rate obtains for using the average packet throughput that real time rate is weighted in.

Described step B) effective data rate obtains for using successful transmission probability that real time rate is weighted in, and does not consider retransmission version when the described successful transmission probability of estimation.

The invention has the beneficial effects as follows: the estimation HSDPA HS-DSCH of system that the present invention proposes goes up the method for throughput, considered of the influence of each principal element to throughput, the throughput of the grouping service wireless that high-speed wireless link that coexists at the sign indicating number branchs/time division multiplexing of HSDPA and Streaming Media, interactive mode, background formula are three types and the dynamic characteristic of time delay can be estimated HS-DSCH throughput characteristic preferably.On this basis, proposed admittance control method to be carried out in the access request of customer service according to high-speed downlink shared channel throughput index.Like this, can improve the calling access judgement accuracy of HSDPA effectively, reduce the probability that customer call gets clogged.

Description of drawings

Fig. 1 is a HSDPA call admission control method flow chart;

Fig. 2 for be positioned at (r, the user terminal of θ) locating be positioned at (r _i, θ _i) between i base station locating apart from schematic diagram.

Embodiment

Further describe HSDPA call admission control method of the present invention below in conjunction with attached Fig. 1 and 2.

As shown in Figure 1, the present invention considers the characteristics of HSDPA system high-speed downlink sharied signal channel and the multiple technologies of employing, especially mix automatic request retransmission (HARQ), Adaptive Modulation and Coding (AMC), fast dispatch etc. to HSDPA link throughput Effect on Performance, amid all these factors estimate the link throughput performance index.On this basis, according to the throughput index of estimation the access control judgement is made in the call request of customer service again.

A) when system initialization, but the current data carried by data transmission of the estimation HSDPA HS-DSCH of system maximum throughput draws throughput threshold Th.

A1) at first, estimation mixes the influence of automatic request retransmission (HARQ) to link throughput.

Mix automatic request retransmission (HARQ) and be meant that the recipient under the situation of decoding failure, preserves the data that receive, and requires the transmit leg data retransmission, the recipient made up data and the previous data that receive that retransmit before decoding.Mix automatic retransmission technique and can improve systematic function, and can adjust effective code element speed neatly, can also compensate because the error code that adopts link adaptation to bring.

Mixing automatic request retransmission (HARQ) is that (Forward Error Correction, FEC) (Automatic Repeat Request ARQ) forms, and what wherein forward error correction was adopted is Turbo code with re-transmission automatically by forward error correction.

Just require a kind of transmission mechanism of retransmitting when automatically repeat requests (ARQ) is a data transmission fails.Under the wireless transmission environment; interchannel noise and because the decline that brings of mobility and other users' interference make channel transmission quality relatively poor; in order to guarantee communication quality; just must be protected the data grouping; forward error correction coding (FEC) is adopted in this protection usually, i.e. the extra overhead bit of transmission in grouping.Obviously, too much forward error correction coding can make the efficiency of transmission step-down.It is the combined errors controlling schemes that ARQ and FEC combine that rapid mixing retransmits (HARQ) automatically.HARQ not only can adjust efficient coding speed neatly, can also compensate owing to the error code that adopts link adaptation to bring, thereby improve systematic function greatly.HSDPA combines AMC and HARQ technology just can reach better link self adaptation effect.

Each call business be grouped in several Transmission Time Intervals (Transmission Time Interval, TTI) transmission in, promptly traffic packets length is to carry out in several Transmission Time Intervals (TTI) to the mapping of link layer Transmission Time Interval (TTI).

The fast packet scheduling algorithm controls of HSDPA in the MAC-hs functional entity the quick distribution of shared resource, according to the quality condition of wireless channel and etc. data volume and professional factors such as priority level to be launched, realize the optimum allocation of shared resource apace.

Radio multi-user dispatching algorithm on the shared channel makes that the interior mistake that takes place of each Transmission Time Interval (TTI) is separate, so the number of retransmissions of each Transmission Time Interval (TTI) data is independently.According to central-limit theorem, surpass 10 independent same distribution stochastic variables and can be approximately Gaussian Profile.Then the number of transmissions of grouping bag is that an average is N _s, variance is σ ²Gaussian Profile.

A2) according to mixing the influence estimation Adaptive Modulation and Coding (AMC) of automatic request retransmission (HARQ) link throughput is influenced link throughput.

Adaptive Modulation and Coding (AMC) be according to the change of instantaneous channel condition and corresponding change modulation and coded format.Adaptive Modulation and Coding (AMC) is selected best down link modulation and coded system according to the operating position of current wireless quality of channel situation and Internet resources, thereby increases terminal use's data throughout as far as possible, reduces transmission delay.When the user is in favourable communication point, then select the channel coding method of high order modulation and two-forty to transmit user data, for example 16QAM modulates and 3/4 code rate, thereby obtains higher transmission rate; And when the user is in disadvantageous communication point, then choose the channel coding schemes of low-order-modulated mode and low rate, for example QPSK modulates and 1/4 code rate, thereby guarantees communication quality.

Adaptive Modulation and Coding (AMC) can provide adaptive Modulation and Coding Scheme (seven grades of modulation) to adapt to different channels, and it can effectively improve the transmission rate and the availability of frequency spectrum.Adaptive Modulation and Coding (AMC) with the multi-subscriber dispatching technology and the time domain scheduling combine, make terminal be in low decline state.

Adaptive Modulation and Coding (AMC) carries out work in conjunction with mixing automatic request retransmission (HARQ), and target is a maximum data speed, satisfies service quality (QoS) requirement simultaneously.

Small scale decline and large scale decline are small scale decline and the large scale declines that user terminal radio channel is arrived in the base station, and these two kinds of declines are simultaneous, are used to describe the characteristics of radio channels of base station to user terminal.The Modulation and Coding Scheme of Adaptive Modulation and Coding is subjected to the influence of small scale decline and large scale decline, and its different Modulation and Coding Scheme obtains different throughputs.

A21) estimate that Adaptive Modulation and Coding (AMC) is to the influence of link throughput on the small scale fading channel.

For flat fading channel, channel quality can be weighed by signal to noise ratio.Because channel status remains unchanged in a frame, so describe γ with general Nakagami-m channel _bStatistical nature.The received signal to noise ratio γ of every frame _bBe one and obey the stochastic variable that gamma (Gamma) distributes,

$f_{{\mathrm{\γ}}_b}\left({\mathrm{\γ}}_b\right)=\frac{m^m{\mathrm{\γ}}^{m-1}}{{\stackrel{\‾}{\mathrm{\γ}}}^m\mathrm{\Γ}\left(m\right)}\exp (-\frac{\mathrm{m\γ}}{\stackrel{\‾}{\mathrm{\γ}}})$

γ wherein _b:=E{ γ _bBe the average received signal to noise ratio, $\mathrm{\Γ}\left(m\right):={\∫}_0^{\∞}{t}^{m-1}{e}^{-t}\mathrm{dt}$ Be gamma (Gamma) function, m is Na Kajiami (Nakagami) decline index (m 〉=1/2).The Nakagami-m channel model is represented a big class fading channel, is Rayleigh (Rayleigh) channel when m=1.

According to Adaptive Modulation and Coding (AMC) rule, (Modulation andCoding Scheme MCS) depends on received signal to noise ratio γ with real-time frame error rate to Modulation and Coding Scheme _bThe selection probability of every kind of Modulation and Coding Scheme (MCS) is

$\mathrm{Pr}\left(n\right)={\∫}_{{\mathrm{\γ}}_n}^{{\mathrm{\γ}}_{n+1}}{f}_{{\mathrm{\γ}}_b}\left({\mathrm{\γ}}_b\right){\mathrm{d\γ}}_b=\frac{\mathrm{\Γ}(m,\frac{{\mathrm{m\γ}}_n}{{\stackrel{\‾}{\mathrm{\γ}}}_b})-\mathrm{\Γ}(m,\frac{{\mathrm{m\γ}}_{n+1}}{{\stackrel{\‾}{\mathrm{\γ}}}_b})}{\mathrm{\Γ}\left(m\right)}$

Wherein $\mathrm{\Γ}(m,x):={\∫}_x^{\∞}{t}^{m-1}{e}^t\mathrm{dt}$ Be non-complete gamma (Gamma) function that replenishes.Average repeat time under Modulation and Coding Scheme (MCS) the pattern n is simultaneously

${\stackrel{\‾}{N}}_n={\∫}_{{\mathrm{\γ}}_n}^{{\mathrm{\γ}}_{n+1}}{N}_s{\mathrm{d\γ}}_b$

Wherein, N _sAverage for the number of transmissions Gaussian Profile of mixing automatic request retransmission (HARQ) grouping bag.

A22) estimate that Adaptive Modulation and Coding (AMC) is to the influence of link throughput on the large scale fading channel

The large scale decline is meant because the wireless signal decline that the base station causes to the distance between the portable terminal, different distances and geographical environment have in various degree decline to wireless signal, make the signal to noise ratio of received signal vary in size, influence Modulation and Coding Scheme, different Modulation and Coding Scheme obtains different throughputs, usually, can adopt the large scale fading channel expression calculating channel large scale decline of simplification.

The large scale fading channel of simplifying utilizes existing simplification calculating formula to obtain.

For example: (1) considers to have many cell structures of 19 sub-districts, and (2) user terminal location is evenly to distribute, and (3) consider the decline of lognormal large scale, (4) use polar coordinates (r, θ), this cell base station as with initial point, (r, decline θ) is to user terminal in (a 5) i base station

$L_i(r,\mathrm{\θ})=D^{-l}{10}^{\frac{X_i}{10}}=D^{-1}{e}^{Y_i}=D^{-l}{K}_i$

Wherein D is that (l is path loss exponent (representative value is 3 or 4) for r, distance θ) to user terminal in i base station.X _iFor average is zero, standard deviation is

Gauss (Gaussian) distribute K _iBe the lognormal stochastic variable.As Fig. 2, i base station (r _i, θ _i) (r, decline θ) is to user terminal

$L_i(r,\mathrm{\θ})={(r^2+r_i^2-{2r}_{i}r\cos ({\mathrm{\θ}}_i-\mathrm{\θ}))}^{-\frac{l}{2}}{K}_i$

(r, received signal to noise ratio θ) is user terminal

${\mathrm{\γ}}_b=\frac{E_b}{N_t}=\mathrm{SF}\·\frac{{\mathrm{PL}}_0(r,\mathrm{\θ})/W}{N_0+\underset{i=1}{\overset{18}{\mathrm{\Σ}}}{\mathrm{PL}}_i(r,\mathrm{\θ})/W}$

$=\mathrm{SF}\·\frac{{\mathrm{PK}}_0{r}^{-l}/W}{N_0+\underset{i=1}{\overset{18}{\mathrm{\Σ}}}P{(r^2+r_i^2-2r_{i}r\cos ({\mathrm{\θ}}_i-\mathrm{\θ}))}^{-\frac{l}{2}}{K}_i/W}$

N ₀Be thermal noise density, P and W are respectively through-put power and apread spectrum bandwidth.Because high-speed down link uses the full power transmission signals, so the influence of thermal noise can be ignored.Then

${\mathrm{\γ}}_b=\frac{K_0}{\underset{i=1}{\overset{18}{\mathrm{\Σ}}}{J}_i^{-l}{K}_i}=\frac{K_0}{\underset{i=1}{\overset{18}{\mathrm{\Σ}}}{I}_i}=\frac{K_0}{I}$

Whole interference I can remember and does

$I={10}^{\frac{X_i}{10}}$

X wherein _IBe that average is

Variance is

Gauss (Guassian) stochastic variable.

Then

$\frac{E_b}{N_0}=\frac{K_0}{I}={10}^{\frac{X_0-X_i}{10}}={10}^{\frac{X_T}{10}}$

X wherein _T=X ₀-X _IBe that average is m _T, variance is σ _T ²Gauss (Guassian) stochastic variable.

According to Adaptive Modulation and Coding (AMC) rule, Modulation and Coding Scheme (MCS) and real-time frame error rate depend on received signal to noise ratio γ _bThe selection probability of every kind of Modulation and Coding Scheme (MCS) is

$\mathrm{Pr}\left(n\right)={\∫}_0^R{\∫}_0^{{\mathrm{\θ}}_s}{P}_{n|r,\mathrm{\θ}}r\frac{2}{R^2{\mathrm{\θ}}_s}\mathrm{dxdy}$

$={\∫}_0^R{\∫}_0^{{\mathrm{\θ}}_s}[Q\left(\frac{{\mathrm{SNR}}_{n+1}-m_T}{{\mathrm{\σ}}_T}\right)-Q\left(\frac{{\mathrm{SNR}}_n-m_T}{{\mathrm{\σ}}_T}\right)]\·r\·\frac{2}{R^2{\mathrm{\θ}}_s}\mathrm{dxdy}$

Wherein R is a radius of society, θ _sBe sector angle value at random.

Average repeat time under Modulation and Coding Scheme (MCS) the pattern n is

${\stackrel{\‾}{N}}_n={\∫}_{{\mathrm{\γ}}_n}^{{\mathrm{\γ}}_{n+1}}{N}_s{\mathrm{d\γ}}_b$

Wherein, N _sAverage for the number of transmissions Gaussian Profile of mixing automatic request retransmission (HARQ) grouping bag.

A3) according to Adaptive Modulation and Coding (AMC) link throughput is influenced estimation link average frequency spectrum utilance, the link maximum throughput when obtaining given bandwidth according to link average frequency spectrum utilance then.

When adopting MCS _nDuring pattern, modulation system is M _n-QAM, code rate is R _cEach transmission symbol carries R _n=R _cLog ₂(M _n) individual information bit.For coding transmission pattern not, R _c=1.Adopting a bandwidth is B=1/T _sNai Shi (Nyquist) pulse shaping filter, T wherein _sBe character rate.So average frequency spectrum utilance (bit rate of per unit bandwidth) is

${\stackrel{\‾}{S}}_e=\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\·\frac{N_{\mathrm{code}}{R}_n(1-{\mathrm{FER}}_r\left(n\right))\mathrm{Pr}\left(n\right)}{{\stackrel{\‾}{N}}_n}$

${\mathrm{FER}}_r\left(n\right)={\∫}_{{\mathrm{\γ}}_n}^{{\mathrm{\γ}}_{n+1}}{\mathrm{FER}}_r\·{\mathrm{d\γ}}_b$

N wherein _CodeFor adopting MCS _nCode channel number during pattern, FER _r(n) be MCS _nRemaining frame error rate under the pattern.System is to FER _rCertain requirement is arranged, must be no more than P _Loss, i.e. FER _r≤ P _Loss

For given bandwidth W, the average throughput of link is Th=WS _e

Behind the maximum throughput Th according to said method estimation HSDPA high-speed downlink shared channel, service request from user is made the access judgement.

B) analysis request access HSDPA system carries out service quality (QoS) requirement of the user terminal K+1 of downlink traffic transmission, draws the effective speed R of the required busy channel of user terminal K+1 _Eff(k+1).

Usually, the business that can transmit of HSDPA is:

The interior HS-DSCH in base station (NodeB) is to the HS-DSCH service switchover;

HS-DSCH is to the HS-DSCH service switchover between the base station (NodeB);

The new call business of Streaming Media;

Interactive new call business;

The new call business of background formula.

High-speed packet data service is provided by shared down channel, is one and adopts time-multiplexed cdma system.Based on the channel condition information that feedback channel transmits, dispatching algorithm is carried out the timeslice configuration to user terminal.Throughput and scheduler are closely related directly to have influence on the throughput that the user can reach because interior which user data of each scheduling interval is transmitted.

Owing to do not consider frame error rate and retransmission information, real time rate can not the perfect representation transmission rate.At first, it only represents the transmission rate when grouping is bundled into the merit reception.When the packet transmissions mistake took place, actual transfer rate was zero, and the grouping bag retransmits or abandons.This mistake is more obvious in multi-user system.Secondly, mix automatic request retransmission (HARQ) mechanism for great majority, based on soft merging, re-transmission has high success rate.For any dispatching algorithm, use effective speed R _Eff(k) replace real time rate R _{MCS (k)}, adjust dispatching algorithm like this and make it consider actual retransmission mechanism.

Effective data rate is following the two ratio:

1) transmits the average information that to carry next time;

2) carry needed average time of amount of information like this or resource.

The effective data rate of user k when the L time transmission is

$R_{\mathrm{eff}}\left(k\right)={\mathrm{\μ}}_L(\mathrm{\η},{\stackrel{\‾}{\mathrm{\φ}}}_{L-1},\mathrm{MCS}\left(k\right))=\frac{E\left(S\right|\mathrm{\η},{\stackrel{\‾}{\mathrm{\φ}}}_{L-1},\mathrm{MCS}\left(k\right))}{E\left(T\right|\mathrm{\η},{\stackrel{\‾}{\mathrm{\φ}}}_{L-1},\mathrm{MCS}\left(k\right))}$

Φ wherein _L-1Expression transmission log in the past comprises the through-put power operating position, modulation and coded system MCS etc.Employed modulation of terminal k of MCS (k) representative of consumer and coded system, η represents the prediction signal to noise ratio SINR of user terminal k.E (S| η, Φ _L-1, MCS (k)) and for considering the average successful transmission information bit number of transmission in the past, E (T| η Φ _L-1, MCS (k)) and consider the average transmission time of transmission in the past.

The described high speed dispatching algorithm of using at HSDPA has poll (Round Robin) algorithm, max carrier to interference (Max.C/I) algorithm and equitable proportion (Proportional Fair) algorithm.

Use automatic re-transmission (ARQ) successful transmission probability that real time rate is weighted and to obtain R _Eff(k).F _{MCS (k)}(η) for using MCS (k), the frame error rate when input signal-to-noise ratio is η.R _MCSReal time data speed when Modulation and Coding Scheme (MCS) is adopted in expression as modulation coding mode.The success transmission probability depends on whether be retransmission version.When being retransmission version, successful transmission probability depends on the HARQ retransmission mechanism of employing.

Mix automatic request retransmission (HARQ) retransmission mechanism have stop-waiting for (Stop-and-Wait) mechanism, order retransmits (Go back N) mechanism and selects to retransmit (Selected retransmission) mechanism.

Then

$R_{\mathrm{eff}}\left(k\right)=R_{\mathrm{MCS}\left(k\right)}\·(1-F_{\mathrm{MCS}\left(k\right)}(\mathrm{\η}+{\widehat{\mathrm{\η}}}_L))$

Wherein,

Prediction signal to noise ratio SINR for preceding L-1 transmission accumulation.For simple retransmit automatically (ARQ), ${\widehat{\mathrm{\η}}}_L=0,$ For Chase combining, ${\widehat{\mathrm{\η}}}_L={\mathrm{\Σ}}_{k=1}^{L-1}\mathrm{\η}\left(t_k\right),{\widehat{\mathrm{\η}}}_1=0.$ This mechanism provides high priority to re-transmission, because Chase combining makes that retransmitting the probability of success increases greatly.

Effective speed R the estimation user _Eff(k) time, can adopt different methods of weighting, as, can also use average packet throughput based on effective throughput, consider that not only current transmission also has the following influence that retransmits, the calculating of throughput depends on HARQ mechanism and channel characteristics; Or use successful transmission probability that real time rate is weighted, promptly

R _eff(k)＝R _MCS(k)·(1-F _MCS(k)(η))

Promptly when the successful transmission probability of estimation, do not consider whether be retransmission version.

C) statistics has inserted each user terminal transmission rate that HSDPA high-speed downlink shared channel (HS-DSCH) carries out professional transmission.

$\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{R}_{\mathrm{eff}}\left(i\right)$

D) with B) and C) result of addition and the throughput threshold of the HS-DSCH of HSDPA system judge comparison, according to judging that comparative result carries out the access judgement to the calling of this user terminal.

$\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{R}_{\mathrm{eff}}\left(i\right)+R_{\mathrm{eff}}(k+1)\≤\mathrm{TH}$

When D1) judgment condition does not satisfy, the effective speed sum that the transmission rate that has promptly added each user's user terminal of HSDPA system adds the required busy channel of new customer service is during greater than the maximum throughput thresholding, then refuse the service access request, and notice relevant user terminals (UE);

D2) otherwise, satisfy judgment condition, the transmission rate that has promptly added each user terminal of HSDPA system adds when the effective speed sum of the required busy channel of new customer service is less than or equal to the maximum throughput thresholding, accept business and insert request, distributing radio resource, and notice relevant user terminals (UE).

The estimation HSDPA HS-DSCH of system that the present invention proposes goes up the method for throughput, considered of the influence of each principal element to throughput, the throughput of the grouping service wireless that high-speed wireless link that coexists at the sign indicating number branchs/time division multiplexing of HSDPA and Streaming Media, interactive mode, background formula are three types and the dynamic characteristic of time delay can be estimated HS-DSCH throughput characteristic preferably.On this basis, proposed the access request of customer service to be carried out the process of access control according to high-speed downlink shared channel throughput index.Like this, can improve the calling access judgement accuracy of HSDPA effectively, reduce the probability that customer call gets clogged.

Present embodiment is to make those of ordinary skills understand the present invention; and to detailed description that the present invention carried out; but can expect; in the scope that does not break away from claim of the present invention and contained, can also make other variation and modification, these variations and revising all in protection scope of the present invention.

Claims (9)

1. a HSDPA call admission control method is characterized in that, comprises the following steps:

Steps A) when system initialization, but, draw throughput threshold according to mixing automatic request retransmission and Adaptive Modulation and Coding the current data carried by data transmission of influence estimation HSDPA system high-speed downlink sharied signal channel maximum throughput to the HSDPA link throughput;

Step B) analysis request inserts the quality of service requirement that the HSDPA system carries out the user terminal of downlink traffic transmission, draws the effective data rate of the required busy channel of user terminal;

Step C) statistics has inserted each user terminal transmission rate that HSDPA system high-speed downlink sharied signal channel carries out professional transmission;

Step D) with step B) and step C) results added after, judge comparison with the throughput threshold of HSDPA system high-speed downlink sharied signal channel, according to judging that comparative result carries out the access judgement to the calling that request access HSDPA system carries out the user terminal of downlink traffic transmission.

2. HSDPA call admission control method according to claim 1 is characterized in that, described steps A) comprise the following steps:

Steps A 1) estimation mixes the influence of automatic request retransmission to the HSDPA link throughput;

Steps A 2) the estimation Adaptive Modulation and Coding influences link throughput;

Steps A 3) according to Adaptive Modulation and Coding and the automatic request retransmission of mixing link throughput is influenced estimation link average frequency spectrum utilance, the link maximum throughput when obtaining given bandwidth according to link average frequency spectrum utilance.

3. HSDPA call admission control method according to claim 2 is characterized in that, described steps A 2) comprise the following steps:

Steps A 21) estimates that Adaptive Modulation and Coding is to the influence of link throughput on the small scale fading channel; Or

Steps A 22) estimates that Adaptive Modulation and Coding is to the influence of link throughput on the large scale fading channel.

4. according to each described HSDPA call admission control method of claim 1 to 3, it is characterized in that described step D) comprise the following steps:

Step D1) judgment condition does not satisfy, the effective data rate sum that the transmission rate that has added each user terminal of HSDPA system adds the required busy channel of new user terminal is during greater than the maximum throughput thresholding, then refuse the service access request, and the notice relevant terminal;

D2) otherwise, satisfy judgment condition, the transmission rate that has added each user terminal of HSDPA system adds when the effective data rate sum of the required busy channel of new user terminal is less than or equal to the maximum throughput thresholding, accept business and insert request, distributing radio resource, and notice relevant terminal.

5. HSDPA call admission control method according to claim 1 is characterized in that, described step B) in downlink traffic transmission be:

High-speed downlink shared channel is to the high-speed downlink shared channel service switchover in the base station;

High-speed downlink shared channel is to the high-speed downlink shared channel service switchover between the base station;

The new call business of Streaming Media;

Interactive new call business;

The new call business of background formula;

One or more than one combination in any in the above-mentioned business.

6. HSDPA call admission control method according to claim 1 or 5 is characterized in that described step B) in effective data rate retransmit successful transmission probability automatically and real time rate is weighted obtains for using.

7. HSDPA call admission control method according to claim 6 is characterized in that, described automatic re-transmission success transmission probability calculates by frame error rate.

8. HSDPA call admission control method according to claim 1 or 5 is characterized in that described step B) in effective data rate obtain for using the average packet throughput that real time rate is weighted.

9. HSDPA call admission control method according to claim 1 or 5, it is characterized in that, described step B) effective data rate obtains for using successful transmission probability that real time rate is weighted in, and does not consider retransmission version when the described successful transmission probability of estimation.

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