CN100396021C - Method for avoiding measurement error accumulation of round trip time in cascade network - Google Patents

Method for avoiding measurement error accumulation of round trip time in cascade network Download PDF

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CN100396021C
CN100396021C CNB2004100848322A CN200410084832A CN100396021C CN 100396021 C CN100396021 C CN 100396021C CN B2004100848322 A CNB2004100848322 A CN B2004100848322A CN 200410084832 A CN200410084832 A CN 200410084832A CN 100396021 C CN100396021 C CN 100396021C
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data
moment
time
timing reference
upstream data
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CN1756203A (en
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夏迎九
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Abstract

The present invention discloses a method for avoiding measurement error accumulation of round trip time in a cascade network, which comprises the following steps: timing references shared by unlink and downlink data are respectively established at an REC side and an RE side, and time t20 that first data which is started by an uplink wireless frame fed back by a mobile at an RE antenna port arrive at an REC multi-path searching unit is specified; an REC adds a time label in the transmitting downlink data and specifies time that the downlink data arrive at the target RE antenna port; the target RE selects an opportunity to transmit the downlink data to make the time that the downlink data arrive at the antenna port coincide to the time label; the target RE estimates time that the uplink data arrive at the antenna port after the uplink data is fed back by a mobile terminal and adds a time label which denotes the estimated time in the uplink data to be sent to the REC; the REC selects an opportunity to put the uplink data in the multi-path searching unit to make time that the uplink data arrive at the multi-path searching unit is the sum of the time t20 and the value of the time label. The proposal of the present invention can avoid the influence of cascade stage number to the measuring accuracy of the RTT.

Description

Avoid the method for measurement error accumulation of round trip time in cascade network
Technical field
The present invention relates to the measuring technique of two-way time in the mobile communication (RTT, Round Trip Time), be meant especially under a kind of cascade network situation, avoid the method for measurement error accumulation of round trip time in cascade network.
Background technology
RTT is meant that wireless signal passes to mobile phone from the antenna for base station of wireless communication system, turns back to the used time of antenna for base station from mobile phone again.The base station needs to consider the time-delay factor of inside of base station usually when measure R TT.Referring to shown in Figure 1, the base station can obtain downlink data from the timing reference point through antenna for base station to mobile phone, after this upstream data of mobile phone feedback arrives time interval T1+T2+T3+T4 between the timing reference point through antenna for base station, but need from this time interval, deduct the time-delay (T1+T4) of inside of base station, the RTT that the final acquisition of ability needs, i.e. RTT=T2+T3.
In wireless communication system, wireless device (RE, Radio Equipment) cascade network is a kind of important networking mode, and its network configuration is referring to shown in Figure 2.
Fig. 2 has provided the base station of being made up of with three RE cascades a radio equipment controller (REC, Radio Equipment Control) REC.In this base station of being made up of REC and RE, each RE inside all is provided with the timing reference point, can obtain the time-delay that data are transmitted by method REC such as design estimation or experimental measurements between each reference point.The timing reference point that is provided with in REC is represented descending transmission start time point and upstream data time of reception point.Search to mobile phone upward signal multi-path location is handled, and the final calculating of RTT is all finished in REC usually.Describe below inserting the RTT measuring process of RE3 mobile phone:
With Tn, n=1,2 ..., 10, the expression data postpone through each section shown in Figure 2, and wherein, T1, T2, T3, T8, T9, T10 are time delay of data transmission between each timing reference point of inside of base station; T4 and T7 are the transfer of data time-delay between RE3 timing reference point and the antenna opening; T5 and T6 are time delay of data transmission between RE3 antenna opening and the mobile phone, T5 and T6 and be exactly the value of needed RTT.REC can obtain the value of T1, T2, T3, T4, T7, T8, T9, T10, and twice value T through REC internal clocking reference point of up-downgoing data Total=T1+T2+T3+T4+T5+T6+T7+T8+T9+T10.Then, by calculating T Total-T1-T2-T3-T4-T7-T8-T9-T10 obtains the RTT value of expecting (T5+T6).
This shows, in the RTT measurement scheme of prior art, the precision of RTT and T Total, T1, T2, T3, T4, T7, T8, T9, T10 precision relevant, the final precision of RTT is the accumulation of numerous delay parameter precision.Because the precision of in wireless communication protocol RTT being measured often has certain requirement, and along with the increase of base station cascade progression, the RTT measure error can be accumulated thereupon, becomes increasing, thereby causes the certainty of measurement of RTT can't satisfy the requirement of agreement.If merely take to improve the method for every grade certainty of measurement the certainty of measurement of RTT is met the demands,, implement and to become more and more difficult, but also will increase the base station construction cost then along with the continuous increase of cascade progression.
Summary of the invention
In view of this, first main purpose of the present invention is to provide a kind of method of avoiding measurement error accumulation of round trip time in cascade network, avoids the influence of cascade progression to the RTT certainty of measurement, and the measurement of RTT under the cascade situation is more prone to, and saves cost.
Based on above-mentioned first main purpose a kind of method of avoiding measurement error accumulation of round trip time in cascade network provided by the invention, comprising:
Set up the timing reference of up-downgoing data sharing in the REC side, and the shared timing reference of relative REC side, according to the maximum preset time delay of data up-downgoing process of estimation, first initial data of up-link wireless frame that regulation is positioned at RE antenna opening position mobile phone feedback arrive the moment t20 of REC Multipath searching unit; Set up the timing reference of up-downgoing data sharing in the RE side;
A) REC adds time tag in the downlink data that sends, and regulation arrives the moment of target RE antenna opening with respect to the timing reference downlink data of target RE side;
B) after target RE receives downlink data, choose the right moment according to the time tag in the current downlink data and to send this downlink data, the moment that makes current downlink data arrive antenna opening conforms to the regulation of time tag;
C) after target RE receives the upstream data of portable terminal feedback, under the timing reference of target RE side, calculate that this upstream data arrives antenna opening constantly, add that in current upstream data the time tag of this reckoning time information of expression is sent to REC;
D) REC chooses the right moment this upstream data is put into the Multipath searching unit according to the time tag in the upstream data, the moment that makes upstream data arrive the Multipath searching unit be described moment t20 value and this upstream data time tag value with.
The timing reference of the described RE side of this method is based on the timing reference that the radio frames of RE antenna opening is regularly set up.
The moment that first initial data of the described downlink radio frame of this method arrive antenna opening is the initial moment of the timing reference of described RE side.
The timing reference of the described RE side of this method is the timing reference of setting up in RE.
Avoid the method for measurement error accumulation of round trip time in cascade network based on above-mentioned first main purpose another kind provided by the invention, comprising:
Set up the timing reference of up-downgoing data sharing in the REC side, and the shared timing reference of relative REC side, according to the maximum preset time delay of data up-downgoing process of estimation, first initial data of up-link wireless frame that regulation is positioned at RE antenna opening position mobile phone feedback arrive the moment t20 of REC Multipath searching unit;
A) REC is sent to target RE with downlink data;
B) after target RE receives downlink data, current downlink data is sent to user terminal through antenna opening, and write down current downlink data and pass through the moment of timing reference point as the initial moment of timing reference;
C) after target RE receives the upstream data of portable terminal feedback, under the timing reference that step b) is set up, according to the time of delay of upstream data from the antenna opening to RE, calculate that this upstream data arrives antenna opening constantly, add that in current upstream data the time tag of this time information of expression is sent to REC;
D) REC chooses the right moment this upstream data is put into the Multipath searching unit according to the time tag in the upstream data, the moment that makes upstream data arrive the Multipath searching unit be described moment t20 value and this upstream data time tag value with.
Second main purpose of the present invention is to provide a kind of cascade network method of measurement of two-way time, makes the measuring process of RTT simpler, and certainty of measurement is not subjected to the influence of cascade progression.
Based on above-mentioned second main purpose a kind of cascade network provided by the invention method of measurement of two-way time, comprising:
Set up the timing reference of up-downgoing data sharing in the REC side, and the shared timing reference of relative REC side, according to the maximum preset time delay of data up-downgoing process of estimation, first initial data of up-link wireless frame that regulation is positioned at RE antenna opening position mobile phone feedback arrive the moment t20 of REC Multipath searching unit; Set up the timing reference of up-downgoing data sharing in the RE side;
A) REC adds time tag in the downlink data that sends, and regulation arrives the moment of target RE antenna opening with respect to the timing reference downlink data of target RE side;
B) after target RE receives downlink data, choose the right moment according to the time tag in the current downlink data and to send this downlink data, the moment that makes current downlink data arrive antenna opening conforms to the regulation of time tag;
C) after target RE receives the upstream data of portable terminal feedback, under the timing reference of target RE side, calculate that this upstream data arrives antenna opening constantly, add that in current upstream data the time tag of this reckoning time information of expression is sent to REC;
D) REC chooses the right moment this upstream data is put into the Multipath searching unit according to the time tag in the upstream data, the moment that makes upstream data arrive the Multipath searching unit be described moment t20 value and this upstream data time tag value with;
What e) value of calculating two-way time was described upstream data moment of putting into the Multipath searching unit with moment t20 is poor.
The timing reference of the described RE side of this method is based on the timing reference that the radio frames of RE antenna opening is regularly set up.
The moment that first initial data of the described downlink radio frame of this method arrive antenna opening is the initial moment of the timing reference of described RE side.
The timing reference of the described RE side of this method is the timing reference of setting up in RE.
Based on above-mentioned second main purpose another kind of cascade network provided by the invention method of measurement of two-way time, comprising:
Set up the timing reference of up-downgoing data sharing in the REC side, and the shared timing reference of relative REC side, according to the maximum preset time delay of data up-downgoing process of estimation, first initial data of up-link wireless frame that regulation is positioned at RE antenna opening position mobile phone feedback arrive the moment t20 of REC Multipath searching unit;
A) REC is sent to target RE with downlink data;
B) after target RE receives downlink data, current downlink data is sent to user terminal through antenna opening, and write down current downlink data and pass through the moment of timing reference point as the initial moment of timing reference;
C) after target RE receives the upstream data of portable terminal feedback, under the timing reference that step b) is set up, according to the time of delay of upstream data from the antenna opening to RE, calculate that this upstream data arrives antenna opening constantly, add that in current upstream data the time tag of this time information of expression is sent to REC;
D) REC chooses the right moment this upstream data is put into the Multipath searching unit according to the time tag in the upstream data, the moment that makes upstream data arrive the Multipath searching unit be described moment t20 value and this upstream data time tag value with;
What e) value of calculating two-way time was described upstream data moment of putting into the Multipath searching unit with moment t20 is poor.
From above as can be seen, the method of measurement error accumulation of round trip time in cascade network and the method for measurement of RTT avoided provided by the invention, by setting up timing reference respectively at REC and RE side, and the up-downgoing data were fixed up in the two-way time of base station system inside by the mode of pasting time tag, make the certainty of measurement of every grade of the precision of RTT value and inside of base station irrelevant, thereby when having broken away from the base station system of cascade measure R TT value, must calculated data the thought of time of delay between inside of base station is at different levels confine.Avoided of the influence of cascade progression, when improving the RTT certainty of measurement greatly, simplified the measuring process of RTT again, saved cost the RTT certainty of measurement.
Description of drawings
Fig. 1 carries out the schematic diagram that RTT measures for prior art in the base station of non-cascade structure;
Fig. 2 carries out the schematic diagram that RTT measures for prior art in the base station of adopting the cascade network mode;
Fig. 3 carries out the schematic diagram that RTT measures for the preferred embodiment of the present invention in the base station of adopting the cascade network mode;
Fig. 4 is for adopting the RTT metering system of the preferred embodiment of the present invention, the schematic flow sheet of up-downgoing data in the cascade network base station;
Fig. 5 is for adopting the RTT metering system of the preferred embodiment of the present invention, and the RTT of up-downgoing data calculates and the error analysis schematic diagram in the cascade network base station.
Embodiment
The present invention is further described in more detail below in conjunction with drawings and the specific embodiments.
Referring to shown in Figure 3, because under normal conditions, downlink data is promptly decided the RE design from the reference point of RE to the used time delay T4 of this RE antenna opening and can be known; On the opposite direction, upstream data from antenna opening to this antenna opening place RE the time delay T7 of reference point also fixing and can know.
Therefore the present invention at first need set up the shared timing reference of up-downgoing in the RE side, and in the up-downgoing process data is carried out registration process.
The reference point of RE3 is that the uplink and downlink data are done the place with the timing reference registration process of RE3 in RE3 inside among Fig. 3.Wherein, the physical location of uplink and downlink reference point in RE3 can be different, but time reference must be identical, all will be from public timing reference.
T4 is the time of delay of downlink data from RE3 descending reference point to antenna opening, and T7 is the time of delay of upstream data from antenna opening to up reference point.
Then, when the data up-downgoing, increase the process of data time registration process.
The downlink data time unifying is treated to: RE3 sends downlink data according to the time tag information of downlink data.Wherein, the time tag of downlink data has illustrated the downlink data that RE3 receives needs when to send in antenna opening.
The upstream data time unifying is treated to: RE3 stamps time tag information according to timing reference to the upstream data of receiving.Wherein, the time tag of upstream data refers to the time migration of upstream data with respect to antenna opening.
According to the present invention program, the flow process of the up-downgoing data of preferred embodiment of the present invention is referring to shown in Figure 4.
The t axle is represented the time among Fig. 4, and the s axle is represented distance.
At first, set up the shared timing reference of up-downgoing.
Because three position REC, the RE3 that will relate in the following flow process are different with the time reference that the RE3 antenna opening is adopted, and therefore, set up timing reference respectively on three positions, promptly set up three time coordinate systems:
First time coordinate system is to be benchmark with the timing reference among the REC, represent with TB1, the data transmit-receive among the REC all with this time coordinate system as benchmark; Second time coordinate system is benchmark with the total timing reference of the up-downgoing among the RE3, represents with TB2; The benchmark of the 3rd time coordinate system is the radio frames timing of RE3 antenna opening, represents with TB3.TB3 is that RE3 sets up according to TB2, and the skew between the benchmark of TB3 and the benchmark of TB2 is made as T101, and T101 is a numerical value of the very little error of existence known of a RE3.Skew between the benchmark of TB2 and TB1 is T102, and T102 may be the interior numerical value that changes of some bigger scopes, and REC and RE3 know the scope of T102, but do not know its accurate numerical value.
According to the maximum preset time delay of the relative REC data up-downgoing process of estimating, regulation is positioned at first initial data of up-link wireless frame of RE antenna opening position mobile phone feedback, arrives the moment t20 of REC Multipath searching unit with respect to the TB1 coordinate system.
Data up-downgoing process comprises the steps:
Step 401, REC stamps time tag information and sends to RE3 in downlink data.
Here, stipulated in the time tag that described downlink data comprises that this downlink data is sent to the moment of antenna opening, this is to be constantly as time coordinate with TB3.Individual prerequisite is arranged here, and promptly REC knows downlink data in the moment that antenna opening occurs with respect to the TB3 coordinate, and this point is at present mobile communication protocol, as: among WCDMA, the GSM etc. all is to accomplish.Wherein, the moment that identifies in the time tag described here can be concrete moment value, also can be to represent the code that is worth sometime.
Step 402, current downlink data arrives RE3 through RE1 and RE2, after RE3 receives this downlink data, according to the moment that is sent to antenna opening of defined in this downlink data time tag, and the known time-delay that arrives antenna opening from self reference point, select suitable opportunity that this downlink data is sent, so that downlink data arrives antenna opening constantly in the regulation of time tag.
Wherein, the moment that the downlink data of supposing defined in the time tag information here arrives the RE3 antenna opening is t3, and the time coordinate system of t3 is TB3, supposes that here t3 in the current downlink data is 0 with respect to the value of TB3 coordinate system; This downlink data is t1 through the moment of timing reference point among the REC, and the time coordinate system of t1 is TB1; The moment through reference point among the RE3 is t2, and the time coordinate system of t2 is TB2; And the time delay T4 of downlink data from the RE3 reference point to antenna opening is known, then this time delay T4=t3+T101-t2 under correct situation about sending, the moment t2=t3+T101-T4 of downlink data arrival RE3 reference point thus.Thereby under the situation of known T101, RE3 can be t2 by the moment of selecting suitable transmission to make this downlink data arrive its internal reference point the opportunity fully, and this process is called the time unifying processing procedure of downlink data in the present invention.
In addition, also can obtain downlink data and should be T16=t3+T101+T102-t1 from the time delay T16 that REC timing reference point arrives antenna opening.Be not difficult to find out, REC be downlink data beat time tag the time, need leave adequate time and postpone, make T16 more than or equal to downlink data from REC timing reference point to the required shortest time of antenna opening; If the required shortest time is made as T161, then T16-T161 is exactly the time that needs among the RE3 the downlink data buffer memory.
Step 403, downlink data at t3 constantly arrives antenna opening through T4 after the time from the RE3 reference point, and the time coordinate system of t3 is TB3.
Step 404, downlink data arrives mobile phone from antenna opening through T5 after the time.
Step 405, it is T6 that mobile phone sends upstream data to the used time of antenna opening.
Step 406, upstream data is sent to RE3 from antenna opening, and wherein arriving the RE3 used time of reference point from antenna opening is T7, and after this RE3 stamps time tag information and sends to REC in this upstream data.
If downlink data sends with the forms of broadcasting here, because the position difference of each mobile phone, the moment of the upstream data that is therefore fed back arrival antenna opening is also different, and the upstream data that RE3 need send for these different mobile phones be stamped time tag respectively.Having identified this upstream data in the time tag information of described upstream data is the temporal information of TB3 with respect to time coordinate, and promptly this upstream data is with respect to the moment of TB3 coordinate system in the antenna opening appearance.The moment of supposing upstream data arrival RE3 antenna opening is t4, and the time coordinate of t4 is TB3; The moment that arrives the RE3 reference point from antenna opening is t5, and the time coordinate of t5 is TB2, then time tag t4=t5-T101-T7.If be in the signal that the mobile phone of RE3 antenna opening position returns, time tag t4=t3=0 then, the t5 of this moment is exactly the t10=T101+T7 shown in Fig. 4.
In addition, also has simpler labeling method, be exactly to respect to the TB2 referential, the time tag that the data of constantly being received at T101+T7 add is 0, the time tag that the data of constantly being received at T101+T7+1 add is 1 ..., by that analogy, the time tag that the data of constantly being received at T101+T7+30 add is 30, or the like.This is because the data of being received in the T101+T7 moment, its RTT value is 0, must be from being positioned at the data that RE3 antenna opening position mobile phone returns like this, referring to the signal of representing with thick-line arrow among Fig. 4, therefore first upstream data of returning of this mobile phone moment of arriving the RE3 antenna opening is with respect to the TB3 referential should to leave moment of antenna opening identical with downlink data, be 0, thereby its time label should be 0; T101+T7+1 receives that constantly the time tag of data is 1; Other situation by that analogy.
RE3 is the process of RE3 to the upstream data alignment to being called again among the labelled process the present invention of upstream data.
Step 407, upstream data arrives REC, and REC selects suitable opportunity that this upstream data is put into the Multipath searching unit according to the temporal information that identifies in the upstream data time tag.
The implementation of this step can have a variety of, and a kind of method is REC with moment of time tag sign is 0 data, and TB1 time coordinate system sends into the Multipath searching unit constantly at the t20 that predesignates relatively; With moment of time tag sign is 1 data, sends into the Multipath searching unit constantly at t20+1; By that analogy, be 30 data with moment of time tag sign, send into the Multipath searching unit constantly at t20+30, or the like.Constantly value 1,2 described in this step and the step 406 ..., 30 ... unit can be actual chronomere such as millisecond (ms), or other can represent the unit of time.And, just for example, also can represent described moment value in the reality here with other numeral or symbol.In this way, can guarantee that upstream data fixes to the used time-delay in REC Multipath searching unit from the RE3 antenna opening.
Because downlink data is fixed to the delay of RE3 antenna opening from REC, and the delay of upstream data from the RE3 antenna opening to REC also fixed, so just avoided the precision influence of the data transmission procedure of intermediate node.Based on said process, being calculated as follows of RTT value:
Here, suppose that certain is t6 away from the moment that RE3 antenna opening mobile phone returns the upstream data arrival REC timing reference point of feedback, the time coordinate of t6 is TB1.From the RE3 antenna opening to the used time of RE3 reference point is T7; Being admitted to the used time of REC Multipath searching unit from the RE3 reference point up to these data is T17, can obtain in the data up-downgoing process, at the inner used time delay T140=T17+T7+T101+T102 of base station system.
REC should consider to arrive from antenna opening the time delay of REC Multipath searching unit when upstream data is sent into the Multipath searching unit, promptly T170=T17+T7 should arrive the shortest time of REC timing reference point more than or equal to upstream data from antenna opening.If this shortest time is T171, T170-T171 is exactly that REC needs time to the upstream data buffer memory before upstream data is put into the Multipath searching unit.In principle, the cache-time of upstream data should be short more good more, and the cache-time of data is long more on the one hand, and the metadata cache space that then needs also will be big more, and cache-time is long on the other hand also will influence treatment effeciency, and then may influence speech quality.But, if the cache-time of upstream data is too short, then may be when needs to be sent certain data into multipath, these data also do not have ready.Therefore, the actual conditions that concrete cache-time should coupling system in actual design think over, study, and can determine.
After REC Multipath searching unit receives the mobile phone upstream data, utilize himself function can search out from REC send data to the Multipath searching unit receive feedback data the delay of process, be made as T150.If the RTT=0 of mobile phone, promptly mobile phone is positioned at the situation of the antenna opening of RE3 antenna, then obvious T150=T140; If mobile phone is in antenna opening, i.e. RTT=T5+T6, then upstream data postpones T150=T140+T5+T6, thereby can obtain RTT=T150-T140, because the initial moment of T150 and T140 is identical, therefore obtains RTT=t6-t20 again.As can be seen, by the registration process of up-downgoing data, the value of T140 is actually and has been fixed from above-mentioned steps, and promptly therefore T140=t20-0 is the given value that provides in advance.Thereby as can be seen in the ideal case, RTT is only relevant with the certainty of measurement of T150, and irrelevant with the other factorses such as progression in the base station.
But, The above results is not considered the influence of some delay parameter errors to the RTT measurement result, and following surface analysis has the error of which delay parameter influential to the RTT measurement result.
According to the present invention program, it is only relevant with the factor of two aspects to influence the RTT certainty of measurement, and factor on the one hand is the accuracy of Multipath searching unit searches mobile phone upward signal, the i.e. certainty of measurement of T150; Factor on the other hand is the accuracy of the time tag that among the RE3 mobile phone upward signal data pasted.Wherein, the accuracy of upward signal data post time tag is made up of following two factors again:
(1) accuracy of T4, because the downstream signal that the upward signal that mobile phone sends is synchronous mobile phone to be received, therefore whether the T4 that estimates in the downlink data process of transmitting is consistent with actual conditions, whether decision downlink data reality is consistent with the moment of regulation in the moment that antenna opening occurs, and then determined upstream data to go out now in antenna opening, i.e. the accuracy of the initial moment t3 of T7.
(2) the label influence of accuracy is conspicuous to upstream data for the accuracy of T7, the accuracy of T7, because RE3 need deduct the time tag that the time of T7 sticks line data.
In general, it is influential that the error of skew T101 between two time coordinates of TB3 and TB2 system also can be pasted the accuracy of time tag to upstream data, but owing to the time reference of TB3 is also set up by RE3, computing formula t2=t3+T101-T4 according to the delivery time of above-mentioned downlink data, T101 can be fixed as an accurate value fully, offset error between TB3 and the TB2 has been embodied in the error of T4 at this moment, when considering the RTT measuring accuracy, just do not need additionally to have considered the error of T101 again.
From above-mentioned analytic process, as can be seen, the RTT measurement result of the mobile phone that inserts RE3 is had nothing to do with the accuracy of data through tandem node RE1 and RE2 delay parameter.
In the said process, since RE3 antenna opening position timing reference is to calculate out according to the timing reference on the RE3 fully, so also can not set up RE3 antenna opening position timing reference, the various time values based on RE3 antenna opening position timing reference that said process relates to can be represented by the timing reference on the RE3.
In the above-mentioned data up-downgoing process, to the further analysis of RTT calculating and error, referring to shown in Figure 5.Rectangular lines is represented downlink data among Fig. 5; The semiellipse curve is represented upstream data.Wherein, less semiellipse curve representation be to be the upstream data that 0 mobile phone sends with respect to RE3 antenna opening radio frames timing offset, promptly RTT is 0 upstream data, the mobile phone that sends this upstream data is in the antenna opening position; Bigger elliptic curve is represented is not to be the upstream data that 0 mobile phone sends with respect to RE3 antenna opening radio frames timing offset, and promptly RTT is not 0 upstream data, and mobile phone and the antenna opening of sending this upstream data have certain distance.What all dotted is digital signal, and solid line is an analog signal.
T1 among Fig. 5 is the RTT numerical value of the mobile phone of the access RE3 that will obtain.T140 as can be seen from Figure 5 is actually REC first data that the antenna opening up-link wireless frame of corresponding RE3 is initial and puts into the deviation (TB1 coordinate system) of the Multipath searching unit moment with respect to the initial moment of REC timing reference.Wherein, first initial data of described antenna opening up-link wireless frame are defined as: suppose mobile phone just when the position of antenna opening, the sampled value of the digital form of first data of radio frames that mobile phone is sent out.Because the free label of upstream data, therefore by suitable buffer memory with leave suitable processing time surplus, REC can put into the Multipath searching unit with first initial data of corresponding RE3 antenna opening radio frames in the specific moment fully, be the initial moment of distance R EC timing reference to postpone T140 during the time, first data that the antenna opening up-link wireless frame of RE3 is initial are put into the Multipath searching unit, and it is error free that T140 is accomplished substantially.T150 is with top described the same, is the length of delay of the upward signal of a mobile phone obtaining of the Multipath searching unit searches of REC with respect to the TB1 coordinate system.T101 is the deviation of the timing reference of RE3 with respect to the timing reference of REC.
Characteristics according to upstream data can not change in transmission course relatively constantly can obtain target RTT value, T1=T150-T140.
The above just for example, when specific implementation, the timing of RE3 not necessarily leaves no choice but equal the time delay T4 of data from the RE3 reference point to antenna opening with reference to the difference between the initial moment of the initial moment and RE3 antenna opening timing reference, this difference also can be got other value, suppose that this difference equals Tx, as long as Tx is a determined value that RE3 knows.Like this, RE3 always can be designated the up-link wireless frame of RE3 first data in antenna opening with the upstream data of receiving this moment in the moment that postpones Tx+T7 with respect to the up-downgoing common timing with reference to TB3.Like this, target RTT value still equals T150-T140.
In addition, in upstream data registration process process, the up-link wireless frame neither be necessary in first data of antenna opening.If do not receive up-link wireless frame first data in antenna opening, by the cooperation of Several Parameters, the up-link wireless frame also is fine at first Data Position of antenna opening in the upstream of deriving.For example: identified data with respect to deviation Ty of the initial moment of up-link wireless frame, these data are designated as Dy, sampling time interval in upstream between each sampled data is Ts, and first data that then can know the initial moment of up-link wireless frame are with respect to the position of the skew Ty/Ts data of Dy in upstream.
Recited above only is one of them preferred embodiment, and its mode that adopts is to choose an independently time reference, and the up-downgoing data are all carried out registration process with this time reference.The operational processes of aliging with timing reference in the up-downgoing data of RE3 inside can also have multiple implementation, can choose according to actual conditions during realization, as:
Downlink data is not done the operation of special time unifying, upstream data with downlink data at the time point at certain some place of RE3 internal processes as time reference, with this time with reference to carrying out the processing of labelling of upstream data; The prerequisite of this scheme is: do not do special processing, downlink data sends and can satisfy the requirement regularly of antenna port downlink data.
For this mode T140=T17+T7+T101+T102, wherein T17+T7 can fix by the mode of handling of labelling, and still, T101+T102 seemingly can't fix, because REC timing reference point can't be determined to the time delay of RE3 reference point.That need fix is T140.T17 is variable in fact.The difference of choosing according to T140, and upstream data different through the delay of RE1 and RE2 etc., REC can be different to the time of upstream data buffer memory, thus the numerical value of T17 can change.
In addition, also can the downgoing time reference select with certain point in the upstream data processing procedure.Carry out the registration process of downlink data with this time reference; Because time reference is selected with the upstream data processing procedure, the registration process of upstream data can be finished naturally.
The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, not all under the spirit and principles in the present invention, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. a method of avoiding measurement error accumulation of round trip time in cascade network is characterized in that, comprising:
Set up the timing reference of up-downgoing data sharing in the radio equipment controller side, and the shared timing reference of relative radio equipment controller side, according to the maximum preset time delay of data up-downgoing process of estimation, first initial data of up-link wireless frame that regulation is positioned at wireless equipment antenna mouth position mobile phone feedback arrive the moment t20 of radio equipment controller Multipath searching unit; Set up the timing reference of up-downgoing data sharing in the wireless device side;
A) radio equipment controller adds time tag in the downlink data that sends, and regulation arrives the moment of targeted wireless device antenna opening with respect to the timing reference downlink data of targeted wireless device side;
B) after targeted wireless device receives downlink data, choose the right moment according to the time tag in the current downlink data and to send this downlink data, the moment that makes current downlink data arrive antenna opening conforms to the regulation of time tag;
C) after targeted wireless device is received the upstream data of portable terminal feedback, under the timing reference of targeted wireless device side, calculate that this upstream data arrives antenna opening constantly, add that in current upstream data the time tag of this reckoning time information of expression is sent to radio equipment controller;
D) radio equipment controller chooses the right moment this upstream data is put into the Multipath searching unit according to the time tag in the upstream data, the moment that makes upstream data arrive the Multipath searching unit be described moment t20 value and this upstream data time tag value with.
2. method according to claim 1 is characterized in that, the timing reference of described wireless device side is based on the timing reference that the radio frames of wireless equipment antenna mouth is regularly set up.
3. method according to claim 2 is characterized in that, the moment that first initial data of downlink radio frame arrive antenna opening is the initial moment of the timing reference of described wireless device side.
4. method according to claim 1 is characterized in that, the timing reference of described wireless device side is the timing reference of setting up in wireless device.
5. a method of avoiding measurement error accumulation of round trip time in cascade network is characterized in that, comprising:
Set up the timing reference of up-downgoing data sharing in the radio equipment controller side, and the shared timing reference of relative radio equipment controller side, according to the maximum preset time delay of data up-downgoing process of estimation, first initial data of up-link wireless frame that regulation is positioned at wireless equipment antenna mouth position mobile phone feedback arrive the moment t20 of radio equipment controller Multipath searching unit;
A) radio equipment controller is sent to targeted wireless device with downlink data;
B) after targeted wireless device receives downlink data, current downlink data is sent to user terminal through antenna opening, and write down current downlink data and pass through the moment of timing reference point as the initial moment of timing reference;
C) after targeted wireless device is received the upstream data of portable terminal feedback, under the timing reference that step b) is set up, according to the time of delay of upstream data from the antenna opening to the wireless device, calculate that this upstream data arrives antenna opening constantly, add that in current upstream data the time tag of this time information of expression is sent to radio equipment controller;
D) radio equipment controller chooses the right moment this upstream data is put into the Multipath searching unit according to the time tag in the upstream data, the moment that makes upstream data arrive the Multipath searching unit be described moment t20 value and this upstream data time tag value with.
6. the method for measurement of cascade network two-way time is characterized in that, comprising:
Set up the timing reference of up-downgoing data sharing in the radio equipment controller side, and the shared timing reference of relative radio equipment controller side, according to the maximum preset time delay of data up-downgoing process of estimation, first initial data of up-link wireless frame that regulation is positioned at wireless equipment antenna mouth position mobile phone feedback arrive the moment t20 of radio equipment controller Multipath searching unit; Set up the timing reference of up-downgoing data sharing in the wireless device side;
A) radio equipment controller adds time tag in the downlink data that sends, and regulation arrives the moment of targeted wireless device antenna opening with respect to the timing reference downlink data of targeted wireless device side;
B) after targeted wireless device receives downlink data, choose the right moment according to the time tag in the current downlink data and to send this downlink data, the moment that makes current downlink data arrive antenna opening conforms to the regulation of time tag;
C) after targeted wireless device is received the upstream data of portable terminal feedback, under the timing reference of targeted wireless device side, calculate that this upstream data arrives antenna opening constantly, add that in current upstream data the time tag of this reckoning time information of expression is sent to radio equipment controller;
D) radio equipment controller chooses the right moment this upstream data is put into the Multipath searching unit according to the time tag in the upstream data, the moment that makes upstream data arrive the Multipath searching unit be described moment t20 value and this upstream data time tag value with;
What e) value of calculating two-way time was described upstream data moment of putting into the Multipath searching unit with moment t20 is poor.
7. method according to claim 6 is characterized in that, the timing reference of described wireless device side is based on the timing reference that the radio frames of wireless equipment antenna mouth is regularly set up.
8. method according to claim 7 is characterized in that, the moment that first initial data of downlink radio frame arrive antenna opening is the initial moment of the timing reference of described wireless device side.
9. method according to claim 6 is characterized in that, the timing reference of described wireless device side is the timing reference of setting up in wireless device.
10. the method for measurement of cascade network two-way time is characterized in that, comprising:
Set up the timing reference of up-downgoing data sharing in the radio equipment controller side, and the shared timing reference of relative radio equipment controller side, according to the maximum preset time delay of data up-downgoing process of estimation, first initial data of up-link wireless frame that regulation is positioned at wireless equipment antenna mouth position mobile phone feedback arrive the moment t20 of radio equipment controller Multipath searching unit;
A) radio equipment controller is sent to targeted wireless device with downlink data;
B) after targeted wireless device receives downlink data, current downlink data is sent to user terminal through antenna opening, and write down current downlink data and pass through the moment of timing reference point as the initial moment of timing reference;
C) after targeted wireless device is received the upstream data of portable terminal feedback, under the timing reference that step b) is set up, according to the time of delay of upstream data from the antenna opening to the wireless device, calculate that this upstream data arrives antenna opening constantly, add that in current upstream data the time tag of this time information of expression is sent to radio equipment controller;
D) radio equipment controller chooses the right moment this upstream data is put into the Multipath searching unit according to the time tag in the upstream data, the moment that makes upstream data arrive the Multipath searching unit be described moment t20 value and this upstream data time tag value with;
What e) value of calculating two-way time was described upstream data moment of putting into the Multipath searching unit with moment t20 is poor.
CNB2004100848322A 2004-09-30 2004-09-30 Method for avoiding measurement error accumulation of round trip time in cascade network Expired - Fee Related CN100396021C (en)

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