CN104244397B - A method of it is compensated for TD-LTE fiber optic stretch equipment delays - Google Patents
A method of it is compensated for TD-LTE fiber optic stretch equipment delays Download PDFInfo
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Abstract
The invention discloses a kind of method for the compensation of TD-LTE fiber optic stretch equipment delays, including data determination step, delay compensation step, signal exports step and caching output step.The present invention is before normal signal work operation, pass through the delay data of survey calculation digital optical fiber remote equipment, to calculate this time delay of gained, the emission time of the downlink signal of the base stations compensation control TD-LTE and the time of reception of uplink signal, it is allowed in advance in canonical reference time (GPS/1588 or the Big Dipper), so that in the equivalent air interface to radiofrequency signal of time delay of digital optical fiber remote equipment physical presence, the delay compensation of the fiber optic stretch covering of TD-LTE can be preferably solved the problems, such as.This method of the present invention, it can be ensured that the work of whole network synchronizes, and no matter uplink and downlink business or access, switching can work normally.
Description
Technical field
The invention belongs to the radiofrequency signals in forth generation (4G) public wireless communication system to zoom out, cover, networking technology neck
Domain relates in particular to a kind of method for the compensation of TD-LTE fiber optic stretch equipment delays.
Background technology
TD-LTE is forth generation mobile communication system, runs on time-division system, i.e.,：The transmission of uplink and downlink business exists
It is carried out in same frequency.In order to avoid signal interferes with each other in system, it is desirable that the edge of signal radio frames must be aligned.Having
It is Base Transmitter in the downlink working time, the state that mobile terminal receives under body running frequency point, is movement in the uplink working time
The state that terminal transmission, base station receive, this requires all devices clocks having the same in whole network, i.e. work in system
The all devices of work are stringent synchronizations.Outdoor optical fiber remote device accesses signal from the prevention at radio-frequency port of base station equipment, in proximal end
Radiofrequency signal is transformed to digital signal, then distal end is transferred to by fiber optic stretch, (is counted distally carrying out opposite process again
Word signal to radiofrequency signal translation process).Additional signal delay is necessarily introduced in such signal processing,
Since networking can not coexists in the communication system that the presence of these delays would potentially result in remote device and normal work.
Existing technical solution is that mobile communication base station passes through the clock source of external GPS, the Big Dipper or 1588V2, reality
Existing synchronization of the outdoor base station equipment to entire communication system, and in order to avoid interference, the remote termination of each website remote device is sent out
The radio frames edge of signal is alignment.
The signal network connection that outdoor optical fiber remote device is constituted is as shown in Figure 1.
Radiofrequency signal zooms out to transmission loss is larger due to directly, so disposing the close of fiber optic stretch equipment in base station machine room
Terminal is connect with base station equipment with radio-frequency cable, and the downlink radio-frequency signal of base station equipment is converted to downstream digital optical fiber letter
Number it is transmitted to remote termination far through optical fiber, then corresponding downlink radio-frequency signal is transformed to by remote termination, letter is carried out to mobile terminal
Number covering；The upstream radio-frequency signal of mobile terminal is also converted to upstream digital fiber-optic signal and is transmitted to its institute through optical fiber by remote termination
The near-end machine of connection is transformed to corresponding upstream radio-frequency signal access base station equipment by near-end machine, and near-end machine can connect more
Remote termination so that the remote termination that optical fiber and digital signal transmission to multiple spot disposes.
Remote device, near-end machine, remote termination and the optical fiber of connection realize zooming out for radiofrequency signal, and fiber optic stretch is set
It is standby the radiofrequency signal of base station is converted into digital optical signal after transmitted at a distance, the signal transmission distance of maximum positive can be with
Reach 20km.But the data in digital optical signal are transmitted will produce delay in a fiber, in this way, digital optical fiber remote equipment
Radiofrequency signal possibly that remote termination is sent out in its website can not be synchronous with the radiofrequency signal holding that other base station equipments are sent out.Such as figure
The radio frequency covering signal of digital optical fiber remote equipment third remote termination 13 shown in 1 and the radio frequency covering of the second base station equipment 2 are believed
Number signal overlap area is formed, and then form interfering with each other for radiofrequency signal in the signal overlap area, TD-LTE is moved in the area
Dynamic terminal device may can not work normally, and be embodied as access delay and increase, be successfully accessed rate reduction, handover success rate drop
Low, service rate reduces.
Unidirectional RF analog signal is converted into the transfer process and inverse transformation process of Digital Signal Processing, respectively needs 3
The time of μ s to 4 μ s, so the summation of near-end machine and single remote termination processing delay is about 6 μ s to 8 μ s.If using the light of 20km
Fibre zooms out, then by fibre ribbon Lai delay be 100 μ s (light velocity 3x108, light transmits that there are refraction paths in light, about
1.5 times of air line distance, so the delay of 20Km is about：2x104x1.5/3x108=100 μ s), add up to 106 μ s of total delay extremely
108μs.This time has been more than the protection interval CP (normal CP length be 5.2 μ s) of TD-LTE, thus downlink signal interference compared with
Greatly, the reduction of terminal received signals signal-to-noise ratio will certainly be caused, so that network performance declines, reduces network throughput；When prolonging
When caused interference when increasing again, user data and reference data may be caused to demodulate mistake, cause data receiver to fail, sternly
Weight possibility cause network some areas interrupt, even if mobile terminal can normal searching to TD-LTE signal but
It can not work normally, seriously affect user's use.
By actual test, when the time delay of optical fiber and digital remote device is more than 16 μ s, with TD-LTE standard base stations
Signal overlap area cannot be normally carried out business, when time delay is 5 μ s between the two, downstream rate drop by half.
From above to problem description it is found that in TD-LTE networks with digital optical fiber remote equipment network system with just
Normal TD-LTE network systems cannot normal networking work the reason of be caused by the two signal not exclusively synchronizes, and it is this
It is asynchronous the optimization of itself to be fully solved by digital optical fiber remote equipment.
Invention content
It is an object of the invention to overcome the deficiency of the prior art, provide a kind of for TD-LTE fiber optic stretch equipment delays
The method of compensation, be before normal signal work operation, by the delay data of survey calculation digital optical fiber remote equipment, with
This time delay of gained is calculated, when the reception of the emission time of the downlink signal of compensation control TD-LTE base stations and uplink signal
Carve, be allowed in advance in canonical reference time (GPS/1588 or the Big Dipper) so that digital optical fiber remote equipment physical presence when
Prolong in the equivalent air interface to radiofrequency signal, can preferably solve the problems, such as the delay compensation of the fiber optic stretch covering of TD-LTE.
The technical solution adopted by the present invention to solve the technical problems is：One kind being used for TD-LTE fiber optic stretch equipment delays
The method of compensation, under conditions of being the interface Ir link synchronizations between the remote device being connect with TD-LTE base station equipment radio frequencies,
It includes the following steps：
Data determination step, which is to measure the delay data of itself by optical fiber delay by remote device, and by institute
The delay data obtained is transmitted to TD-LTE base station equipments by message interaction process by the near-end machine of remote device；
Delay compensation step, the step are to measure the delay data of gained according to remote device by TD-LTE base station equipments,
Calculate the equipment of optical fiber at different levels connection when extend to the maximum delay of remote device, and when to internal time relative to canonical reference
Between difference be adjusted, realize the internal consumption time compensated in advance；
Signal exports step, which is that the frame signal of delay compensation is completed by the output of the base stations TD-LTE, and through zooming out
The near-end machine of equipment is transmitted to the remote termination of remote device；
Caching output step, when the remote termination of remote device cascade is except by addition to signal continued access to subordinate's remote termination, also needing
When this website services mobile terminal, this needs cascade remote termination will be according to the optical-fiber time-delay of itself and the base stations TD-LTE
Data and the offset data of TD-LTE base station signals carry out radiofrequency signal and cache transmitting/reception.
The data determination step, further comprises：
A1. base station requests step, the step are to send out latency measurement request to remote device from TD-LTE base station equipments to disappear
Breath；
A2. DATA REASONING step, the step are that the measurement request message of TD-LTE base station equipments is responded by remote device, into
Row delay data measures；
Delay data includes the following contents：
Toffset：Downlink reception CPRI frame heads send the time difference of CPRI frame heads with remote device uplink；
T14：Remote device sends out CPRI frame heads and receives the time difference of CPRI uplink CP RI frame heads；
TBdelayUL：When remote device cascades, CPRI frame heads are from second line of a couplet optical port to the time delay of first line of a couplet optical port；
TBdelayDL：When remote device cascades, CPRI frame heads are from first line of a couplet optical port to the time delay of second line of a couplet optical port；
n：Remote device cascades number
A3. data back step, the step are that the measured value of itself surveyed delay data is passed through response by remote device
Message offers TD-LTE base station equipments.
The delay compensation step, further comprises：
B1. time-delay calculation step, the step are surveyed according to the time delay for receiving remote device return by TD-LTE base station equipments
Information is measured, segmentation calculates fiber delay time T at different levels12And T34, calculating process is as follows：
The time delay of first order remote device is first calculated,
The time delay of n-th grade of remote device (n > 1) is calculated again,
B2. time delay configuration step, the step are obtained by TD-LTE base station equipments according to remote device metrical information
Optical fiber maximum delay data shift to an earlier date the downlink start time of eating dishes without rice or wine of signal frame when the normal downlink of eating dishes without rice or wine of standard time clock starts
It carves, and the data at moment are to calculate the optical fiber maximum delay data of gained in advance.
A kind of method for the compensation of TD-LTE fiber optic stretch equipment delays of the present invention, in order to ensure in TD-LTE networks
Networking work can normally coexists in the system of system and normal TD-LTE base station equipments with digital optical fiber remote equipment, drawing
The work of remote equipment connection base station equipment will first synchronize pretreatment before starting, to be formed because remote device and optical fiber connect
Time loss is supplemented, it is ensured that the synchronous operation of system work, delay compensation enter back into work startup after the completion.Base station equipment
After starting into work, by onboard clock module, to external GPS or external, other clocks lock, the generation system time
The system digits clock such as TOD information, PP2S realizes the clock distribution to Service Processing Module by the clock bus on backboard,
Clock bus is by the way of point-to-point.Base station equipment according to the requirement of the delay compensation of digital optical-fiber remote system, with TOD,
On the basis of PP2S clocks, signal internal wireless frame edge placement is adjusted so that the signal inter-process end time is in advance in eating dishes without rice or wine
Launch time, and equal to the maximum delay data obtained from digital optical-fiber remote system, that is, ensure the end of signal inter-process
Time lead is eated dishes without rice or wine launch time before not adjusting so that signal practical launch time of eating dishes without rice or wine is advanced, and its leading time etc.
In the summation of measured optical fiber delay time and AD/DA transformation and radio-frequency treatment time.This ensure that digital fiber is drawn
The frame edge for the frame edge radio frames corresponding with GPS clock that remote system sends out signal radio frames is aligned.Base station with remote termination most
Long time delay carries out the time delay adjustment compensation of signal, the remote termination concatenated before farthest remote termination according to itself and base station when
Prolong data to cache the data-signal for having carried out maximum delay compensation, and is carried out at the time of being consistent with self time-delay data
Signal transmitting and receiving.
Compared with prior art, the beneficial effects of the invention are as follows：
The present invention by normal signal work operation survey calculation digital optical fiber remote equipment of coming delay data,
And to calculate this time delay of gained, the emission time of the downlink signal of the base stations compensation control TD-LTE and the reception of uplink signal
Moment is allowed in advance in canonical reference time (GPS/1588 or the Big Dipper) so that digital optical fiber remote equipment physical presence
In the equivalent air interface to radiofrequency signal of time delay, the delay compensation that can preferably solve the fiber optic stretch covering of TD-LTE is asked
Topic；This method of the present invention, it can be ensured that the work of whole network synchronizes, no matter uplink and downlink business or access, switching can
Enough normal works.
Invention is further described in detail with reference to the accompanying drawings and embodiments；But one kind of the present invention being used for TD-LTE
The method of fiber optic stretch equipment delay compensation is not limited to embodiment.
Description of the drawings
Fig. 1 digital optical fiber remote network connection schematic diagrames；
The flow chart of Fig. 2 present invention；
Fig. 3 time delay relation schematic diagrams；
Fig. 4 base station equipments start synchronizing process interaction figure when connecting fiber optic stretch equipment；
Radiofrequency signal interferes schematic diagram before Fig. 5 embodiments do not apply delay compensation；
Radiofrequency signal corresponds to schematic diagram after Fig. 6 embodiments apply delay compensation.
Specific implementation mode
Embodiment, shown in Fig. 1 to Fig. 6.
A kind of method for the compensation of TD-LTE fiber optic stretch equipment delays of the present invention is suitable for transmission time domain data feelings
Optical-fiber time-delay under condition measures and compensation, when interface Ir (the RF remote lists between the remote device being connect with base station equipment radio frequency
The interface of first RRU and Base Band Unit BBU) under conditions of link synchronization (control is normally established with management C&M channels), this method packet
Include following steps (as shown in Figure 2)：
Data determination step 21, the step are to measure the delay data of itself by optical fiber delay by remote device, and incite somebody to action
The delay data of gained is transmitted to TD-LTE base station equipments by message interaction process by the near-end machine of remote device；
Delay compensation step 22, the step are to measure the time delay number of gained according to remote device by TD-LTE base station equipments
According to, calculate the equipment of optical fiber at different levels connection when extend to the maximum delay of remote device, and internal time is joined relative to standard
The difference for examining the time is adjusted, and realizes the compensated in advance of internal consumption time；
Signal exports step 23, which is that the frame signal of delay compensation is completed by the output of the base stations TD-LTE, and through drawing
The near-end machine of remote equipment is transmitted to the remote termination of remote device；
Caching output step 24, when the remote termination of remote device cascade is except by addition to signal continued access to subordinate's remote termination, also
It need to be when this website services mobile terminal, when this needs cascade remote termination will be according to the optical fiber of itself and the base stations TD-LTE
The offset data for prolonging data and TD-LTE base station signals carries out radiofrequency signal caching transmitting/reception.
It is shown in Figure 1.The radiofrequency signal drawn from first base station equipment 1 is connected to digital optical fiber remote through radio-frequency cable
The downlink radio-frequency signal of first base station equipment 1 is carried out radio frequency/digital signal conversion by equipment near-end machine 10, the near-end machine 10, point
It is connected to digital optical fiber remote device far end machine through optical fiber for 2 branches, then is changed to downstream digital signal contravariant by each remote termination
Downlink radio-frequency signal；In addition, each digital optical fiber remote device far end machine also by the upstream radio-frequency signal of terminal device carry out radio frequency/
Digital signal conversion is connected to digital optical fiber remote equipment near-end machine through optical fiber, then accesses first base station equipment 1.
Wherein one article of the 4th remote termination 14 of optical fiber and digital signal branch end connection digital optical fiber remote equipment, and assume responsibility for
To the business service of mobile terminal；The digital optical fiber remote equipment third distal end of another optical fiber and digital signal branch end connection
2 grades of remote terminations i.e. the first remote termination of digital optical fiber remote equipment 11 and digital optical fiber remote has been concatenated between machine 13 and near-end machine 10 to set
Standby second remote termination 12, and the first remote termination of digital optical fiber remote equipment 11 and digital optical fiber remote equipment third remote termination 13 are equal
Assume responsibility for the business service to mobile terminal, and the radiofrequency signal of digital optical fiber remote equipment third remote termination 13 and the second base station
There are radiofrequency signal overlapping areas between the radiofrequency signal of equipment 2.
In the present embodiment, the first remote termination of digital optical fiber remote equipment 11 and digital optical fiber remote equipment near-end machine 10
Fiber distance is 10km, the light of the first remote termination of digital optical fiber remote equipment 11 and the second remote termination of digital optical fiber remote equipment 12
Fine distance is 5km, the optical fiber of the second remote termination of digital optical fiber remote equipment 12 and digital optical fiber remote equipment third remote termination 13
Distance is 5km, i.e., the optical fiber total distance of digital optical fiber remote equipment third remote termination 13 to near-end machine 10 is 20km.
The data determination step, further comprises：
A1. base station requests step, the step are to send out latency measurement request to remote device from TD-LTE base station equipments to disappear
Breath；
A2. DATA REASONING step, the step are that the measurement request message of TD-LTE base station equipments is responded by remote device, into
Row delay data as shown in Figure 3 measures；
Delay data includes the following contents：
Toffset：Downlink reception CPRI frame heads send the time difference of CPRI frame heads with remote device uplink；
T14：Remote device sends out CPRI frame heads and receives the time difference of CPRI uplink CP RI frame heads；
TBdelayUL：When remote device cascades, CPRI frame heads are from second line of a couplet optical port to the time delay of first line of a couplet optical port；
TBdelayDL：When remote device cascades, CPRI frame heads are from first line of a couplet optical port to the time delay of second line of a couplet optical port；
n：Remote device cascades number
A3. data back step, the step are that the measured value of itself surveyed delay data is passed through response by remote device
Message offers TD-LTE base station equipments.
The delay compensation step, further comprises：
B1. time-delay calculation step, the step are surveyed according to the time delay for receiving remote device return by TD-LTE base station equipments
Information is measured, segmentation calculates fiber delay time T at different levels12And T34, calculating process is as follows：
The time delay of first order remote device is first calculated,
The time delay of n-th grade of remote device (n > 1) is calculated again,
B2. time delay configuration step, the step are obtained by TD-LTE base station equipments according to remote device metrical information
Optical fiber maximum delay data shift to an earlier date the downlink start time of eating dishes without rice or wine of signal frame when the normal downlink of eating dishes without rice or wine of standard time clock starts
It carves, and the data at moment are to calculate the optical fiber maximum delay data of gained in advance.
In order to ensure the system for carrying digital optical fiber remote equipment in TD-LTE networks and normal TD-LTE base station equipments
Networking work can normally coexists in system, and pre- place is first synchronized before the work startup that remote device connects base station equipment
Reason, to connecting the time loss to be formed because of remote device and optical fiber and supplementing, it is ensured that the synchronous operation of system work, time delay are mended
Work startup is entered back into after the completion of repaying, the flow that delay compensation starts is shown in Figure 4.After base station equipment enters work startup,
By onboard clock module, to external GPS or external, other clocks lock for it, generation system time TOD information, PP2S etc.
System digits clock realizes by the clock bus on backboard and distributes to the clock of Service Processing Module that clock bus uses point
To the mode of point.Base station equipment is according to the requirement of the delay compensation of digital optical-fiber remote system, on the basis of TOD, PP2S clock,
Adjust signal internal wireless frame edge placement so that the signal inter-process end time is equal in advance in launch time of eating dishes without rice or wine
The maximum delay data obtained from digital optical-fiber remote system ensure that the end time of signal inter-process is ahead of and do not adjust
Preceding eats dishes without rice or wine launch time so that signal practical launch time of eating dishes without rice or wine is advanced, and its leading time prolongs equal to measured optical fiber
The slow time is converted with AD/DA and the summation of radio-frequency treatment time.This ensure that digital optical-fiber remote system send out signal without
The frame edge of the frame edge radio frames corresponding with GPS clock of line frame is aligned.Base station carries out signal with the maximum delay of remote termination
Time delay adjustment compensates, and the remote termination concatenated before farthest remote termination is according to the delay data of itself and base station to having carried out most
The data-signal of long time delay compensation is cached, and is sent and received signals at the time of being consistent with self time-delay data.
Referring to Fig. 5.Not when delay compensation method using the present invention, because first base station equipment 1 and the second base station equipment 2 are equal
GPS standard clock has been accessed, therefore the radiofrequency signal of the two output synchronizes, but since the radiofrequency signal of first base station equipment 1 accesses
Remote device, and the time delay transmitted by remote device radio frequency/digital signal conversion and optical fiber so that digital optical fiber remote equipment the
The radiofrequency signal of three remote terminations 13 certainly exists time delay with the radiofrequency signal of first base station equipment 1 (and second base station equipment 2), i.e.,
The frame head of the radio frames of the two radiofrequency signal is misaligned.Therefore, if the signal of communication system is configured to normal protection interval CP
One subframe of length, signal includes 14 symbols, and first symbol includes 160 CP (5.2 μ s) and 2048 sub-carrier numbers
According to.Signal time delay caused by optical fiber total distance with digital optical fiber remote equipment third remote termination 13 to first base station equipment 1,
In the radiofrequency signal overlapping area of digital optical fiber remote equipment third remote termination 13 and the second base station equipment 2, digital fiber is drawn
Remote 13 radiofrequency signal of equipment third remote termination is formed by a length of 10 μ s when interference, has been more than the length of CP.
Fig. 5 show 2 signal of the second base station equipment and the interference of 13 signal of digital optical fiber remote equipment third remote termination is shown
It is intended to.110 μ s delays caused by 20km optical fiber will generate the offset interference of 1.7 symbols, and at the T1 moment, digital optical fiber remote is set
Standby third remote termination 13 generates interference to the access of the second base station equipment 2, and at the T2 moment, the second base station equipment 2 is to digital fiber
The uplink of remote device third remote termination 13 generates interference.The two radiofrequency signal causes mutual severe jamming so that terminal device
Using effect have a greatly reduced quality.
One embodiment of the present of invention is implemented under these conditions.Since the radiofrequency signal is transmission time domain data,
The delay compensation of optical fiber and digital remote device is carried out using corresponding step.
First, under conditions of interface Ir link synchronizations (C&M is normally established in channel) between remote device, first base station is set
Standby 1 proceeds by synchronous pretreatment.According to the description to data determination step 21 in aforementioned, sends out time delay to remote device and survey
Request message is measured, each remote termination receives the message, measured to the delay data of itself.
The time difference T of CPRI frame heads and downlink reception CPRI frame heads is sent for remote device uplinkoffset, shown in Fig. 3
The data of the first order to third level remote termination are respectively：
The first order：14.0μs
The second level：6.5μs
The third level：0.5μs
First order distance 10km, second level distance 5km, third level distance 5km, then：
T14=201.1 μ s
Toffset1=101.4 μ s
Toffset2=51.7 μ s
Toffset3=2 μ s
When being cascaded for remote device, time delay T of the CPRI frame heads from second line of a couplet optical port to first line of a couplet optical portBdelayUL, such as Fig. 1 institutes
The data of the first order shown to third level remote termination are：It is cascade to increase level-one due to needing number combining for 0.3 μ s, uplink
About 1 μ s of time delay；
When being cascaded for remote device, time delay T of the CPRI frame heads from first line of a couplet optical port to second line of a couplet optical portBdelayDL, such as Fig. 1 institutes
The data of the first order shown to third level remote termination are：0.3 μ s are down forwarded and are increased about 0.7 μ s of level-one；
The data of each measurement are sent to first base station equipment by remote terminations at different levels respectively by near-end machine connected to it
1。
According to the description to time delay compensation process 22 in aforementioned, first base station equipment 1 receives the time delay of remote device return
Metrical information, segmentation calculate fiber delay time T at different levels12And T34It is as follows：
First order T12=T34：
(T14–Toffset1- 0.7+1)/2=(201.1-101.4+0.3)/2=50 μ s
Second level T12=T34：
(Toffset1–Toffset2- 0.7+1)/2=(101.4-51.7+0.3)/2=25 μ s
Third level T12=T34：
(Toffset2–Toffset3- 0.7+1)/2=(51.7-2+0.3)/2=25 μ s
The latency measurement data that first base station equipment 1 is provided according to remote device, after completing preset time data in advance,
Optical-fiber time-delay is calibrated and compensated for work completion, and first base station equipment 1, which is started to work, to be started, into normal communication state.Signal
Synchronized relation is as shown in Figure 6.
Referring to Fig. 6, the GPS time corresponding t0 moment eats dishes without rice or wine to carve at the beginning of downlink for the second base station equipment 2, and herein
At the preceding t0a moment, the signal a of delay compensation is just completed in first base station equipment 1, and the data of time bias are that (t00 is extremely by Δ t
T0), and in advance in the t0c moment of 2 signal b of the second base station equipment, exported at the t0a moment, through optical fiber transmission delay Δ t, until number
When word fiber optic stretch equipment third remote termination 13, signal c is synchronous with the signal b of base station 2 consistent, i.e., in t0 moment, the second base
The downlink moment of eating dishes without rice or wine of station equipment 2 is aligned with the downlink moment of eating dishes without rice or wine of digital optical fiber remote equipment third remote termination 13, and
The downlink start time of eating dishes without rice or wine of the lower mobile terminal of two base station equipments 2 service takes in digital optical fiber remote equipment third remote termination 13
The downlink start time of eating dishes without rice or wine of the lower mobile terminal of business is consistent；
Since the signal a of first base station equipment 1 is in advance in the signal b of the second base station equipment 2, for signal a, thereon
Downlink space interface switching instant must also shift to an earlier date, that is, be advanced to t1b moment (Δ t), and the t1a moment before t1b, (2 Δ t) were
Eating dishes without rice or wine uplink start time for digital optical fiber remote equipment third remote termination 13, through optical fiber transmission delay, just can guarantee in t1b
It is carved into and reaches first base station equipment 1, is i.e. the uplink of eating dishes without rice or wine of the lower mobile terminal of the service of digital optical fiber remote equipment third remote termination 13 is opened
Moment beginning is the t1a moment, and the uplink start time of eating dishes without rice or wine of the lower mobile terminal of the second base station equipment 2 service is t1, and the two exists
Difference.
In the present embodiment, the 4th remote termination 14 of digital optical fiber remote equipment has the business of service our station mobile terminal,
The first remote termination of digital optical fiber remote equipment 11 also has service our station mobile terminal in addition to continued access signal to next stage remote termination
Business, because the fiber path that two website is connect with near-end machine is shorter, and first base station equipment 1 is with digital optical fiber remote equipment
The maximum delay of third remote termination 13 carries out time delay adjustment compensation, the signal a that first base station equipment 1 exported at the t0a moment compared with
Digital optical fiber remote equipment third remote termination 13 before just have reached 11/ digital light of the first remote termination of digital optical fiber remote equipment
The 4th remote termination 14 of fine remote device, t0b moment as shown in Figure 6,11/ number of the first remote termination of digital optical fiber remote equipment
The 4th remote termination 14 of fiber optic stretch equipment is cached signal a, and at the corresponding t1c moment emit/receive.Although two
The radiofrequency signal of the radiofrequency signal of person and the second base station equipment 2 and no signal overlapping area, but the time delay of first base station equipment 1
Cachings of the signal a of compensation through the 4th remote termination 14 of 11/ digital optical fiber remote equipment of the first remote termination of digital optical fiber remote equipment
Transmitting/reception remains to synchronous with the signal b of the second base station equipment 2 consistent.
Through first base station equipment 1 carry out delay compensation signal processing after, digital optical fiber remote equipment third remote termination 13 with
Interference between second base station equipment, 2 signal is eliminated.
Delay compensation adjustment after, correspond to remote device terminal with corresponding to the second base station equipment 2 terminal when
It is different in sequence, it may between remote device and the comparable signal junctional area of 2 signal strength of the second base station equipment, two Terminal Types
It interferes with each other, but many is reduced compared with the interference effect between remote device and the second base station equipment 2.
One kind that above-described embodiment only is used for further illustrating the present invention is compensated for TD-LTE fiber optic stretch equipment delays
Method, it is every according to the technical essence of the invention to appointing made by above example but the invention is not limited in embodiment
What simple modification, equivalent change and modification, each falls in the protection domain of technical solution of the present invention.
Claims (3)
1. a kind of method for the compensation of TD-LTE fiber optic stretch equipment delays, it is characterised in that：It is to be set with the base stations TD-LTE
Under conditions of interface link between the remote device of standby radio frequency connection synchronizes comprising following steps：
Data determination step, which is to measure the delay data of itself by optical fiber delay by remote device, and by gained
Delay data is transmitted to TD-LTE base station equipments by message interaction process by the near-end machine of remote device；
Delay compensation step, the step are to measure the delay data of gained according to remote device by TD-LTE base station equipments, are calculated
The equipment of optical fiber at different levels connection when extend to the maximum delay of remote device, and to internal time relative to the canonical reference time
Difference is adjusted, and realizes the compensated in advance of internal consumption time；
Signal exports step, which is that the frame signal of delay compensation is completed by the output of the base stations TD-LTE, and through remote device
Near-end machine be transmitted to the remote termination of remote device；
Caching output step need to also be at this when the remote termination of remote device cascade is except by addition to signal continued access to subordinate's remote termination
When website services mobile terminal, this needs cascade remote termination will be according to the optical-fiber time-delay data of itself and the base stations TD-LTE
And the offset data of TD-LTE base station signals carries out radiofrequency signal and caches transmitting/reception.
2. the method according to claim 1 for the compensation of TD-LTE fiber optic stretch equipment delays, it is characterised in that：It is described
Data determination step, further comprises：
A1. base station requests step, the step are to send out latency measurement request message from TD-LTE base station equipments to remote device；
A2. DATA REASONING step, which is that the measurement request message of TD-LTE base station equipments is responded by remote device, when progress
Prolong DATA REASONING；
Delay data includes the following contents：
Toffset：Downlink reception CPRI frame heads send the time difference of CPRI frame heads with remote device uplink；
T14：Remote device sends out CPRI frame heads and receives the time difference of CPRI uplink CP RI frame heads；
TBdelayUL：When remote device cascades, CPRI frame heads are from second line of a couplet optical port to the time delay of first line of a couplet optical port；
TBdelayDL：When remote device cascades, CPRI frame heads are from first line of a couplet optical port to the time delay of second line of a couplet optical port；
n：Remote device cascades number
A3. data back step, the step are that the measured value of itself surveyed delay data is passed through response message by remote device
Offer TD-LTE base station equipments.
3. the method according to claim 2 for the compensation of TD-LTE fiber optic stretch equipment delays, it is characterised in that：It is described
Delay compensation step, further comprises：
B1. time-delay calculation step, the step are believed according to the latency measurement for receiving remote device return by TD-LTE base station equipments
Breath, segmentation calculate fiber delay time T at different levels12And T34, calculating process is as follows：
The time delay of first order remote device is first calculated,
The time delay of n-th grade of remote device (n > 1) is calculated again,
T12For near-end machine to remote termination optical fiber transmission delay；
T34For remote termination to near-end machine optical fiber transmission delay；
B2. time delay configuration step, the step are the optical fiber obtained according to remote device metrical information by TD-LTE base station equipments
The downlink start time of eating dishes without rice or wine of signal frame is shifted to an earlier date and is eated dishes without rice or wine downlink start time in the normal of standard time clock by maximum delay data,
And the data at moment are to calculate the optical fiber maximum delay data of gained in advance.
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| CN201410389967.3A CN104244397B (en) | 2014-08-08 | 2014-08-08 | A method of it is compensated for TD-LTE fiber optic stretch equipment delays |
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Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105743570B (en) * | 2016-01-27 | 2019-05-24 | 南京典格通信科技有限公司 | A kind of method and device of measurement and the digital optical fiber distribution system time delay of correction |
| CN107979421B (en) * | 2016-10-24 | 2020-03-27 | 中兴通讯股份有限公司 | Method and device for time delay compensation on RRU side |
| CN107437950A (en) * | 2017-08-04 | 2017-12-05 | 杭州长泽科技有限公司 | A kind of tunnel fm broadcast signal numeral covering scheme and implementation method |
| CN107528628B (en) * | 2017-09-28 | 2020-01-10 | 中国电子科技集团公司第七研究所 | Signal synchronization method, device and system of satellite communication system |
| CN109640334A (en) * | 2017-10-09 | 2019-04-16 | 大唐移动通信设备有限公司 | A kind of method for transmitting signals and equipment |
| CN108809416B (en) * | 2018-05-28 | 2019-10-18 | 电子科技大学 | A remote base station delay measurement system and method based on short optical fiber calibration |
| CN112235860B (en) * | 2019-07-15 | 2024-08-27 | 南京中兴新软件有限责任公司 | Active antenna unit time delay alignment method and device and active antenna unit |
| CN113573401B (en) * | 2020-04-28 | 2022-12-06 | 华为技术有限公司 | Communication method, device and system |
| CN111756467B (en) * | 2020-06-22 | 2022-03-11 | 河北远东通信系统工程有限公司 | TD-LTE system clock synchronization method based on universal platform |
| EP4213416A4 (en) * | 2020-09-30 | 2023-11-08 | Guangdong Oppo Mobile Telecommunications Corp., Ltd. | WIRELESS COMMUNICATION METHOD, TERMINAL DEVICE AND NETWORK DEVICE |
| CN112910596B (en) * | 2021-03-26 | 2022-06-21 | 河北远东通信系统工程有限公司 | TD-LTE private network system clock period synchronous calibration method |
| CN113660717A (en) * | 2021-07-07 | 2021-11-16 | 北京高信达通信科技股份有限公司 | Time delay compensation method and system for GPS (global positioning system) synchronization signal of 5G small base station |
| CN113490269A (en) * | 2021-08-09 | 2021-10-08 | 上海瀚讯信息技术股份有限公司 | Method for synchronizing forward interface of wireless transmission system |
| CN114125934A (en) * | 2021-11-10 | 2022-03-01 | 新华三技术有限公司成都分公司 | A time delay compensation method, device and electronic device |
| CN117177352B (en) * | 2023-11-03 | 2024-01-30 | 深圳市佳贤通信科技股份有限公司 | Timing advance compensation system and method for uplink transmission |
| CN117615412B (en) * | 2024-01-23 | 2024-04-19 | 南京典格通信科技有限公司 | Time delay self-adjusting method of 5G repeater system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101039134A (en) * | 2007-04-19 | 2007-09-19 | 中兴通讯股份有限公司 | Method for realizing transmitter diversity using two remote RF units |
| CN101399599A (en) * | 2007-09-25 | 2009-04-01 | 京信通信系统（中国）有限公司 | Digital remote system and time delay calibrating method for optical fiber |
| CN103516423A (en) * | 2012-06-20 | 2014-01-15 | 中兴通讯股份有限公司 | Method and apparatus used for optical fiber clock remote transmission |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040057543A1 (en) * | 2002-09-24 | 2004-03-25 | Arie Huijgen | Synchronizing radio units in a main-remote radio base station and in a hybrid radio base station |
-
2014
- 2014-08-08 CN CN201410389967.3A patent/CN104244397B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101039134A (en) * | 2007-04-19 | 2007-09-19 | 中兴通讯股份有限公司 | Method for realizing transmitter diversity using two remote RF units |
| CN101399599A (en) * | 2007-09-25 | 2009-04-01 | 京信通信系统（中国）有限公司 | Digital remote system and time delay calibrating method for optical fiber |
| CN103516423A (en) * | 2012-06-20 | 2014-01-15 | 中兴通讯股份有限公司 | Method and apparatus used for optical fiber clock remote transmission |
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