CN1925352A - Method for realizing HSUPA external ring power control - Google Patents

Abstract

This invention discloses one mobile communication system HUSPA outer ring power control method, which comprises the following steps: basic station reporting agreement data unit PDU to test small area wide band total power RTWP to RNC by use of PDU or BLER and remaining BLER; then using RNC by use of BLER to adjust power bias displacement and maximum coils number; then sending RRC order to UE of E-DCH power displacement and maximum coils to re-matching assistant UE and TFC selection to fulfill outer ring control.

Description

HSUPA exterior ring power control implementation method

Technical field

The invention belongs to a kind of outer-loop power controlling method of the physical channel that the up ARQ of having retransmits in the mobile communication system, particularly be directed to the exterior ring power control of HSUPA in the WCDMA system (up reinforced channel).

Background technology

In R99, external circule power control carries out in RNC (radio network controller), the user is the different different target BLER (Block Error Rate) of type of service configuration, Node B (base station) does CRC (cyclic redundancy check) verification and the result is reported RNC each TTI (Transmission Time Interval) of DCH (dedicated channel), RNC is by the BLER of reporting information statistics channel, and BLER compares with target.

If BLER is greater than target BLER, then RNC just raises a step-length to SIRtarget (target signal interference ratio); If BLER is less than target BLER, then RNC is just to step-length of SIRtarget downward modulation.

Except that BLER, BER and FER also can be used to carry out exterior ring power control.

HSUPA proposes in R6, and it has used some key technologies: the dispatching technique of Node B control; HARQ (hybrid ARQ) technology in conjunction with soft merging; Shorter TTI technology (2ms TTI).

The transmit power resource that HSUPA can make full use of UE is carried out the maximization transmission of Packet Service since up be interference-limited, if when uplink interference surpasses a thresholding, the performance of up channel will descend greatly.Surpass threshold value for fear of uplink interference, Node B need measure uplink interference, and reporting RNC to carry out RRM (RRM) control, measured value is RTWP (Received total wide band power, a received total wideband power) in HSUPA.

The channel of HSUPA transmit ascending data is E-DCH, because E-DCH and DCH are variant at aspects such as TTI length, target BLER and Active Set sizes, so their external circule power control is different.The different of the TTI length of DCH and E-DCH cause two channels to have the different gains that interweaves, and the long DCH of TTI has the bigger gain that interweaves.

The different needs RNC of target BLER should have the ability of the BLER that controls DCH and E-DCH respectively.In soft handover, the Active Set of E-DCH and DCH size might be different, so when DCH and E-DCH were configured to transmit data, two channels had visibly different macro diversity.

E-DCH and the most tangible difference of DCH are that E-DCH has HARQ to retransmit, and DCH does not have.At external circule power control entity and RLC (Radio Link control) entity, DCH has identical Block Error Rate (BLER conforms to actual channel).After E-DCH was introduced into, owing to adopt the HARQ agreement at the MAC layer, the BLER that sees from external circule power control entity or RLC entity is residual BLER, is the Block Error Rate after soft merging, and was different with the BLER of actual channel.Clearly, residual BLER will be much smaller than channel BLER, and therefore very possible residual BLER keeps a very low level always, and external circule power control can be thought that BLER is fine and can not carry out external circule power control effectively and operate like this.

Exterior ring power control basic thought: the DPCCH (Dedicated Control Channel) that has mentioned E-DCH in the R6 agreement assists E-DCH to carry out power control, and the control of DPCCH power is identical with R99.Under the condition that has DCH to exist,, and guarantee the service quality of E-DCH by the power excursion (PO) of RRC reprovision E-DCH according to the SIRtarget of the outer shroud control DPCCH of the BLER of DCH; Under the situation that does not need DCH, one zero transmission block assists to carry out the exterior ring power control of E-DCH possibly.

Offer in the information of RNC at Node B, comprise each PDU that is transferred to RNC (protocol Data Unit) and be correctly decoded needed the number of transmissions for this PDU.

The information that RNC provides according to Node B is kept up-to-date E-DCH power offset, and may determine to transmit the power offset attribute that upgrades to UE.

UE receives the power offset of RNC, with the reference power offset addition that calculates for different E-TFCs (transformat combination) before.

UE just selects E-TFC then, considers the power offset, the dump power of UE and the data total amount that will launch that obtain during selection.

Mentioned and number of retransmissions can have been adjusted SIRtarget as weights at patent WO 2004/091114, to carry out the exterior ring power control of up link.The method that this patent provides is to utilize RTWP, maximum retransmission and the actual number of retransmissions that reports is united and carried out exterior ring power control, can optimize number of retransmissions, improves user throughput.

Because the existence of ARQ mechanism, channel performance is main relevant with residual target BLER with target BLER, and too high residual BLER can cause that RLC retransmits, and therefore will guarantee that at first residual BLER satisfies the requirement of desired value.

Under the prerequisite that guarantees residual BLER, if adopt less number of retransmissions, though reduced the propagation delay time of channel, the Channel Transmission power that increases can produce interference to other user; If adopt bigger number of retransmissions,, increased the propagation delay time of channel though reduced Channel Transmission power.

Adjust channel power and can change residual BLER, can combine them and carry out exterior ring power control with adjustment maximum retransmit number.Simultaneously, can increase uplink interference, so uplink interference also can influence which kind of mode of employing and adjusts residual BLER owing to increase the method for power.

Summary of the invention

In order to overcome the above-mentioned problems in the prior art, the invention provides a kind of being easy to and realize HSUPA outer-loop power controlling method with good throughput performance.

The number of transmissions that HSUPA outer-loop power controlling method of the present invention utilization reports, measure the RTWP report and maximum retransmission and unite and carry out the control of HSUPA exterior ring power.

HSUPA exterior ring power control implementation method of the present invention comprises the steps:

Step 1, initial value is set, comprises target Block Error Rate, object residue Block Error Rate, interference threshold, initial power offset;

Step 2, base station are correctly decoded needed the number of transmissions with protocol Data Unit and report radio network controller with protocol Data Unit, the external circule power control parameter that reports in the radio network controller record certain hour window,

Described external circule power control parameter comprises E-DCH number of retransmissions, received total wideband power;

Step 3, by Block Error Rate and residual Block Error Rate in the number of transmissions window computing time that reports;

Step 4, more residual Block Error Rate and object residue Block Error Rate,

Under the situation of residual Block Error Rate greater than the object residue Block Error Rate, if surpassing, the received total wideband power that reports disturbs decision threshold, then increase the maximum retransmit number, otherwise power excursion (PO) increases step1;

Under the situation of residual Block Error Rate less than the object residue Block Error Rate, if surpassing, the RTWP that reports disturbs decision threshold, power excursion (PO) reduces step2; Otherwise reduce the maximum retransmit number;

Step 5, adjusted power offset values and maximum retransmit number are sent to UE by down order, UE selects to adjust its transmitting power by TFC.

Described step 3 if there is a DCH channel, is then calculated the Block Error Rate of DCH by the cyclic redundancy check indication, according to the Poewr control method of R99 DCH is carried out power control.

Described Block Error Rate and residual Block Error Rate can obtain by following formula:

$\mathrm{BLER}=1-\frac{m-k}{\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{N}_i}$

M is the PDU bag number of handling in the time window in the formula;

N _iWrap the number of times that is transmitted for each PDU;

K reaches the PDU bag number that the maximum retransmit number does not have correct decoding.

Do not have the protocol Data Unit of correct decoding if reach the maximum retransmit number, its residual Block Error Rate is 1, otherwise is 0.

Described step1=k1 * Δ BLER,

K1 can be obtained by emulation for raising coefficient;

Δ BLER=BLER-target BLER;

Described PO=min (PO+step1, MaxPO),

MaxPO is just value of moving of maximum power of system's setting.

Described step2=k2 * Δ BLER,

K2 can be obtained by emulation for the downward modulation coefficient;

Δ BLER=BLER-target BLER;

Described PO=max (PO-step2, MinPO),

MinPO is the minimum power deviant that system is provided with.

Described interference decision threshold is set to be less than or equal to interference threshold.

Adopt method of the present invention, not only method is easy to realize having good throughput performance.

Description of drawings

Fig. 1 is the overview flow chart of HSUPA power control of the present invention;

Fig. 2 is an outer-loop power controlling method flow chart of the present invention.

Embodiment

Below in conjunction with accompanying drawing and HSUPA exterior ring power control embodiment the present invention is described in further detail.

Accompanying drawing 1 has illustrated that HSUPA carries out the overview flow chart of power control.

In this example, UE transmission DCH and E-DCH, DCH carries out power control according to Release 1999: Node B utilizes the SIR of DPCCH to carry out inner-loop power control, and RNC utilizes the BLER of DCH to carry out external circule power control.

Node B reports the PDU the number of transmissions to give RNC, also the sub-district RTWP that records is reported RNC simultaneously, and RNC utilizes PDU and retransmission information to calculate target BLER and the object residue BLER of E-DCH; RNC utilizes target BLER, object residue BLER and RTWP to adjust power offset and maximum retransmit number then; Last RNC orders power excursion and maximum retransmit number to UE reprovision E-DCH, reprovision data to assist UE to carry out TFC to select by sending RRC, and UE is applied to physical channel with E-TFC and the power excursion of selecting, thereby finishes external circule power control.

Wherein, the power excursion of reprovision is E-DCH power demand skew and difference with reference to the E-TFC power excursion, and this reference power skew is that RNC is that the E-TFC of appointment is provided with.

Accompanying drawing 2 has illustrated HSUPA outer-loop power controlling method flow chart, and this figure has specifically described RNC processing procedure among Fig. 1:

Step 20 is provided with target BLER, object residue BLER, interference threshold, initial power offset, and being provided with of object residue BLER can influence the RLC re-transmission; Being provided with of target BLER will embody the preceding link performance of HARQ re-transmission; Interference threshold has embodied the limiting case of uplink interference, can leave certain allowance under actual conditions, if the interference threshold that is provided with is I _Max, then disturbing decision threshold is I _Max-Δ I.Δ I 〉=0 can determine by emulation; Initial power offset is that RNC is provided with for each MAC-d stream, and initial power offset is the power offset values with respect to reference E-TFC power excursion.Above parameter can be provided with and optimizes according to emulation and actual measurement.

The number of retransmissions of using about each E-DCH PDU bag in the step 201 record certain hour window and the CRCI (CRC indication) of DCH channel, and from Node B measurement reports, obtain RTWP, the RTWP value is a periodic report.

Step 202 is calculated BLER, the residual BLER of E-DCH.If there is the DCH channel, calculates the BLER of DCH by CRCI, and carry out the inner and outer ring power control of DCH by the power control algorithm of R99.

The BLER of E-DCH and residual BLER can obtain by following formula:

$\mathrm{BLER}=1-\frac{m-k}{\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{N}_i},$

M is the PDU bag number of handling in the time window in the formula;

N _iFor each PDU bag is correctly decoded required the number of transmissions;

K reaches the PDU bag number that the maximum retransmit number does not have correct decoding.

Whether step 203 judges residual BLER greater than object residue BLER, if residual BLER greater than object residue BLER, then enters step 204; Otherwise enter step 207.

Step 204 judges that whether RTWP is more than or equal to disturbing decision threshold, if RTWP then enters step 206 more than or equal to disturbing decision threshold; Otherwise enter step 205.

Step-length step1 is raised in step 205 rated output skew, and make PO=min (PO+step1, MaxPO), MaxPO is the maximum power offset values that system is provided with, min is a function of getting minimum value.Step1 can be calculated as follows:

step1＝k1×ΔBLER

K1 can be obtained by emulation for raising coefficient in the formula;

Δ BLER=BLER-target BLER.

Step 206 is adjusted the maximum retransmit number.If the maximum retransmit number is not more than 15 (the HSUPA maximum retransmit is counted the upper limit), then maximum retransmit number+1.Obtain higher residual BLER by increasing number of retransmissions.

Step 207 judges that whether RTWP is more than or equal to disturbing decision threshold, if RTWP then enters step 208 more than or equal to disturbing decision threshold; Otherwise enter step 209.

The long step2 of step 208 rated output skew downward modulation pacing, and make PO=max (PO-step2, MinPO), MinPO is the minimum power deviant of system's setting, max is for getting peaked function.Step2 can be calculated as follows:

step2＝k2×ΔBLER

K2 can be obtained by emulation for the downward modulation coefficient in the formula;

Δ BLER=target BLER-BLER.

Step 206 is adjusted the maximum retransmit number.If the maximum retransmit number is not equal to 0, maximum retransmit number-1 then.Do like this and reduced propagation delay time.

Last RNC issues UE with the power excursion and the maximum retransmit number that calculate by downlink signaling.

Claims (7)

1, a kind of HSUPA exterior ring power control implementation method is characterized in that, comprises as follows:

Step 1, initial value is set, comprises target Block Error Rate, object residue Block Error Rate, interference threshold, initial power offset;

Step 2, base station are correctly decoded needed the number of transmissions with protocol Data Unit and report radio network controller with protocol Data Unit, the external circule power control parameter that reports in the radio network controller record certain hour window, described external circule power control parameter comprises E-DCH number of retransmissions, received total wideband power;

Step 3, by Block Error Rate and residual Block Error Rate in the number of transmissions window computing time that reports;

Step 4, more residual Block Error Rate and object residue Block Error Rate, under the situation of residual Block Error Rate greater than the object residue Block Error Rate, disturb decision threshold if the received total wideband power that reports surpasses, then increase the maximum retransmit number, otherwise power excursion PO increases step1; Under the situation of residual Block Error Rate,, the RTWP that reports disturb decision threshold, power excursion to subtract the few step2 of PO if surpassing less than the object residue Block Error Rate; Otherwise reduce the maximum retransmit number;

Step 5, adjusted power offset values and maximum retransmit number are sent UE by down order, UE selects to adjust its transmitting power by TFC.

2, HSUPA exterior ring power control implementation method as claimed in claim 1 is characterized in that:

In the described step 3,, then calculate the Block Error Rate of DCH, DCH is carried out power control according to the Poewr control method of R99 by the cyclic redundancy check indication if there is a DCH channel.

3, HSUPA exterior ring power control implementation method as claimed in claim 1 is characterized in that:

Described Block Error Rate and residual Block Error Rate can obtain by following formula:

$\mathrm{BLER}=1-\frac{m-k}{\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{N}_i}$

Residual $\mathrm{BLER}=\frac{k}{m}$

M is the PDU bag number of handling in the time window in the formula;

N _iWrap the number of times that is transmitted for each PDU;

K reaches the PDU bag number that the maximum retransmit number does not have correct decoding.

4, HSUPA exterior ring power control implementation method as claimed in claim 3 is characterized in that:

Do not have the protocol Data Unit of correct decoding if reach the maximum retransmit number, its residual Block Error Rate is 1, otherwise is 0.

5, HSUPA exterior ring power control implementation method as claimed in claim 1 is characterized in that:

Described step1=k1 * Δ BLER,

K1 is for raising coefficient; Δ BLER=BLER-target BLER;

Described PO=min (PO+step1, MaxPO),

MaxPO is just value of moving of maximum power of system's setting.

6, HSUPA exterior ring power control implementation method as claimed in claim 1 is characterized in that:

Described step2=k2 * Δ BLER,

K2 is the downward modulation coefficient; Δ BLER=BLER-target BLER;

Described PO=max (PO-step2, MinPO),

MinPO is the minimum power deviant that system is provided with.

7, as claim 1 or 5 or 6 described HSUPA exterior ring power control implementation methods, it is characterized in that:

Described interference decision threshold is set to be less than or equal to interference threshold.

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