CN110350998A - High-precision time-frequency synchronization between standing under a kind of high dynamic - Google Patents
High-precision time-frequency synchronization between standing under a kind of high dynamic Download PDFInfo
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- CN110350998A CN110350998A CN201910720692.XA CN201910720692A CN110350998A CN 110350998 A CN110350998 A CN 110350998A CN 201910720692 A CN201910720692 A CN 201910720692A CN 110350998 A CN110350998 A CN 110350998A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0644—External master-clock
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0682—Clock or time synchronisation in a network by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/001—Synchronization between nodes
- H04W56/0015—Synchronization between nodes one node acting as a reference for the others
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/004—Synchronisation arrangements compensating for timing error of reception due to propagation delay
- H04W56/005—Synchronisation arrangements compensating for timing error of reception due to propagation delay compensating for timing error by adjustment in the receiver
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
High-precision time-frequency synchronization between standing under a kind of high dynamic moves station to base station and sends information frame and synchronous code, and base station obtains base station arrival time；Base station sends information frame and synchronous code to rover station, and rover station obtains arrival time rover station first time；Base station sends information frame and synchronous code to rover station again, and rover station obtains second of arrival time of rover station；Speed of related movement and Doppler frequency between calculating benchmark station and rover station；Time difference information between calculating benchmark station and rover station, rover station adjust rover station local zone time according to time difference information, so that rover station and base station reach time synchronization；Crystal oscillator frequency difference information between calculating benchmark station and rover station, rover station adjust the crystal oscillator frequency of rover station according to crystal oscillator frequency difference information, so that rover station and base station reach Frequency Synchronization.The present invention obtains time difference information between high-precision station, and by carrier phase rate between measuring station, realizes the Frequency Synchronization of base station and rover station.
Description
Technical field
The present invention relates to High-precision time-frequency synchronizations between standing under digital communicating field more particularly to a kind of high dynamic.
Background technique
Multichip carrier networking detection and Collaborative Control have become the important directions of air defense and anti-missile weapon equipment Development, multichip carrier association
It can effectively improve operating distance and measurement accuracy with Detecting System, the attention by researchers at home and abroad.Between multichip carrier
Group-net communication and co-located are cooperateed with, needs the time of each carrier of network internal and frequency carrying out precise synchronization, Cai Nengshi
Now to the high accuracy positioning of target.The prior art generally passes through navigation satellite signal combined high precision atomic clock to different equipment
Time synchronization is carried out, but this method is on the one hand stronger to navigation satellite signal dependence, be easy by external interference, and started pre-
The hot time is longer, is not suitable for missile borne system.System rejection to disturbance can be improved using the time-frequency synchronization method based on two-way communication
Ability, carrying out certain improvement on original communication link can be obtained Time and Frequency Synchronization function, can not increase hardware cost
In the case where well adapt to bomb-borne application demand.
Existing document studies time-frequency synchronization method.Document 1 (Xie Rongping, Sun Lingfeng, Zhu Feng, time-frequency center
Method for synchronizing time [J] Command Information System and technology, 2016,7 (1): 58-62.) a variety of time-frequency synchronization methods are given, it is right
Synchronization accuracy more attainable than various method institutes, and be described in detail to based on satellite common vision method.When satellite common vision
Frequency synchronous method can achieve nsec synchronization accuracy, but this method is only applicable in and the Time and Frequency Synchronization of ground installation, does not mention
And the net synchronization capability under high dynamic flight progress.Document 2 (epoch method, Liang Tao, Sun Xiyan, Yan Suqing, Lu Weijun pseudo satellite, pseudolite net
Network Time and Frequency Synchronization systematical design idea [J] embedded technology, 2018,6 (44): 39-43) propose pseudo satellite, pseudolite self-organization network
Network time-frequency synchronization method equally uses bidirectional measurement method, but this method is not directed to high dynamic situation and improves, and is not suitable for
High dynamic scene, and this method needs to carry out signal to continue tracking, anti-interference ability is weaker, and function is more single.Patent 1
(Beidou can tame and docile time service method and device, CN201811627948.4,2018), which provides a kind of Beidou, can tame and docile time service method and dress
It sets, this method carries out time synchronization, but and the undeclared attainable timing tracking accuracy of institute by receiving Big Dipper satellite signal.Specially
Benefit 2 (a kind of clock time-frequency one transmission method and device, CN201810916848.7,2018) proposes a kind of based on IRIG-B
Code carries out time and Frequency Transfer method, and this method is transmitted by RS485, multimode fibre, single mode optical fiber etc., is not suitable for nothing
Line transmission mode.
Summary of the invention
The present invention provides stand under a kind of high dynamic between High-precision time-frequency synchronization, using the improved time synchronization side RTT
Method obtains time difference information between high-precision station, and by carrier phase rate between measuring station, realizes the frequency of base station and rover station
Rate is synchronous.
In order to achieve the above object, the present invention provides stand under a kind of high dynamic between High-precision time-frequency synchronization, comprising with
Lower step:
Base station and rover station are according to fixed slot length Δ T transmission information frame and synchronous code；
Rover station sends information frame and synchronous code to base station, and base station obtains base station arrival time TOAI；
Base station sends information frame and synchronous code to rover station, and rover station obtains rover station first time arrival time TOAR1；
Base station sends information frame and synchronous code to rover station again, and rover station obtains second of arrival time of rover station
TOAR2；
Speed of related movement v and Doppler frequency f between calculating benchmark station and rover stationd；
Wherein, fcFor carrier frequency；
Time difference information ε between calculating benchmark station and rover station, when rover station adjusts rover station local according to time difference information ε
Between, so that rover station and base station reach time synchronization；
Wherein, td1On the basis of station time of the timing initial time to signal emission time, tp1It is that rover station is sent out to base station
Send signal propagation time when information frame and synchronous code, tp2When being that base station sends information frame and synchronous code to rover station for the first time
Signal propagation time；
Crystal oscillator frequency difference information Δ f between calculating benchmark station and rover station, rover station are adjusted according to crystal oscillator frequency difference information Δ f
The crystal oscillator frequency of rover station, so that rover station and base station reach Frequency Synchronization；
Wherein, foFor crystal oscillator frequency, fnFor carrier beat, For carrier wave
Phase,I and q is respectively to obtain after carrying out quadrature frequency conversion to radiofrequency signal
In-phase branch I and quadrature branch Q signal.
The present invention passes through the intercommunication of a base station and other rover stations, so that rover station obtains and base station
Time difference information reaches so as to adjust local zone time and reaches nanosecond level with base station time synchronization, timing tracking accuracy,
Furthermore in communication process, the frequency difference information between rover station and base station can also be obtained, so as to adjust local crystal oscillator frequency,
Reach and reaches 10 with base station Frequency Synchronization, Frequency Synchronization precision-9Magnitude.
Detailed description of the invention
Fig. 1 is the flow chart of High-precision time-frequency synchronization between standing under a kind of high dynamic provided by the invention.
Fig. 2 is the embodiment schematic diagram of High-precision time-frequency synchronization between standing under a kind of high dynamic provided by the invention.
Specific embodiment
Below according to Fig. 1 and Fig. 2, presently preferred embodiments of the present invention is illustrated.
Method for synchronizing time has round-trip timing (RTT, Round Trip Time) method, round-trip timing RTT between common station
Synchronizing is a kind of two-way pumping station method measured based on arrival time (TOA:Time of Arrival).Two-way pumping station
Working principle is, using participating in the two-way to transmitting the error for offsetting wireless signal in path transmission of time synchronization both sides TOA,
By the way that accurate both sides' time difference is calculated.But in high dynamic, due to the relative motion between base station and rover station,
Causing time difference measurement, there are errors, while frequency difference measurement error can be also caused because of Doppler effect.Therefore, the present invention is original
Increase one-shot measurement process on the basis of RTT method, eliminates the time difference under high dynamic and frequency difference.
The present invention uses improved RTT method for synchronizing time, obtains time difference information between high-precision station, and by between measuring station
Carrier phase rate realizes the Frequency Synchronization of base station and rover station.
By wireless radio-frequency link interactive information between base station and rover station, physical layer uses TDMA (time division multiplexing) mode
Work, each base station and rover station send the information frame of corresponding length according to fixed slot length, and information frame is using spread spectrum
Modulation.In addition, also sending the synchronous code for accurately calculating arrival time after each information frame.
As shown in Figure 1, the present invention provides High-precision time-frequency synchronization between standing under a kind of high dynamic comprising the steps of:
Step S1, rover station sends information frame and synchronous code to base station, and base station obtains base station arrival time；
Rover station sends information frame and synchronous code to base station, and base station receives information frame, and being calculated using synchronous code should
The arrival time of information frame is denoted as base station arrival time；
Step S2, base station sends information frame and synchronous code to rover station, when rover station obtains rover station arrival for the first time
Between；
Base station sends information frame and synchronous code to rover station, contains calculated benchmark in step S1 in the information frame
It stands arrival time, rover station receives information frame and obtains base station arrival time, while calculating the information frame using synchronous code
Arrival time is denoted as rover station arrival time first time；
Step S3, base station sends information frame and synchronous code to rover station again, and rover station obtains rover station and arrives for the second time
Up to the time；
Base station sends information frame and synchronous code to rover station again, and rover station receives information frame, and utilizes synchronous code meter
The arrival time for calculating the information frame is denoted as second of arrival time of rover station；
Step S4, the speed of related movement and Doppler frequency between calculating benchmark station and rover station；
Current base station and stream is calculated by second of arrival time of rover station arrival time first time and rover station
Speed of related movement and Doppler frequency between dynamic station；
Step S5, the time difference information between calculating benchmark station and rover station；
Benchmark is calculated by speed of related movement information, base station arrival time, rover station arrival time first time
The time difference information stood between rover station, it is same that adjustment rover station local zone time may make that rover station with base station reaches the time
Step；
Step S6, the crystal oscillator frequency difference information between calculating benchmark station and rover station；
Rover station is during carrying out despread-and-demodulation to information frame, by the IQ of AD (analog-to-digital conversion) chip acquisition (to radio frequency
Signal carries out the signal of in-phase branch I and quadrature branch Q obtained after quadrature frequency conversion) signal and the spreading code that is locally stored into
The operation of row related progressive, finally respectively obtains the integrated value of IQ, calculates current carrier phase information by the integrated value；
Rover station calculates carrier phase information at interval of certain time, is changed with time rate according to carrier phase, calculates
Carrier beat information out, the carrier beat subtract the doppler information as caused by speed and divided by frequency multiplication value (carrier frequency and crystalline substances
Vibration frequency ratio) obtain crystal oscillator frequency difference between base station and rover station；
It is same to may make that rover station with base station reaches frequency according to the crystal oscillator frequency that crystal oscillator frequency difference information adjusts rover station
Step.
As shown in Fig. 2, illustrating calculating process of the invention, practical feelings by taking 2 stations (1 base station, 1 rover station) as an example
It can be promoted to 1 base station and multiple rover stations under condition.Each rover station and base station are believed with fixing the time slot of 3ms and sending
Frame is ceased, rover station and the base station initial time difference are denoted as ε.
Step S1, information frame and synchronous code are sent from rover station to base station first, the base station that base station measures reaches
Time is TOAI, wherein signal propagation time is denoted as tp1。
Step S2, base station sends information frame and synchronous code to rover station, and the rover station that rover station measures reaches for the first time
Time is TOAR1, wherein signal propagation time is denoted as tp2。
Step S3, base station sends information frame and synchronous code to rover station again, and the rover station that rover station measures is for the second time
Arrival time is TOAR2, wherein signal propagation time is denoted as tp3。
Step S4, the speed of related movement and Doppler frequency between calculating benchmark station and rover station；
As can be seen from Figure 2:
TOAR2-TOAR1=td2-td1-tp2+tp3 (1)
Wherein, td1On the basis of station time of the timing initial time to signal emission time, td2On the basis of station timing starting when
It carves to the time of second of signal emission time, td2-td1=3ms, when base station sends the propagation of information frame to rover station twice
Between tp2、tp3Difference mainly influenced by a relative motion of standing, it is assumed that speed of related movement v, then signal transmission distance twice
Variation be v*3ms, then have:
tp3-tp2=(v*3ms)/c (2)
Wherein c is the light velocity, can calculate speed of related movement in conjunction with formula (1), (2):
Doppler frequency between then standing are as follows:
Wherein fcFor carrier frequency.
Step S5, the time difference information ε between calculating benchmark station and rover station；
As can be seen from Figure 2:
ε+TOAR1=td1+tp2 (5)
ε+tp1=TOAI (6)
It can then be obtained by formula (5), (6):
Can first carry out primary thick synchronizing process usually before carrying out RTT, between base station and rover station, synchronization accuracy according to
Transmission range is different and changes, and the usually signal propagation distance error caused by us magnitude, the time can be ignored, because
This, it is believed that tp3-tp2≈ (v*3ms)/c, wherein v can be calculated by formula (3).
Time difference ε adjustment rover station time counting may make base station and rover station time pair between station obtained by calculation
Together.
Step S6, the crystal oscillator frequency difference information between calculating benchmark station and rover station；
Rover station carries out phase with the spreading code being locally stored during information frame despread-and-demodulation, by the I/Q signal of AD acquisition
Cumulative operation is closed, the integrated value of IQ is finally respectively obtained, current carrier phase information is calculated by the integrated value.
Carrier phase are as follows:
Rover station calculates carrier phase information by formula (8) at interval of certain time (being denoted as T), is denoted asThe carrier beat then measured are as follows:
Wherein, n is pendulous frequency, then the crystal oscillator frequency difference between rover station and base station are as follows:
Wherein, foFor crystal oscillator frequency.
Crystal oscillator frequency difference Δ f adjusts rover station crystal oscillator (generally voltage controlled crystal oscillator) frequency and may make between station obtained by calculation
Base station and the alignment of rover station frequency.
The present invention passes through the intercommunication of a base station and other rover stations, so that rover station obtains and base station
Time difference information reaches so as to adjust local zone time and reaches nanosecond level with base station time synchronization, timing tracking accuracy,
Furthermore in communication process, the frequency difference information between rover station and base station can also be obtained, so as to adjust local crystal oscillator frequency,
Reach and reaches 10 with base station Frequency Synchronization, Frequency Synchronization precision-9Magnitude.
It is discussed in detail although the contents of the present invention have passed through above preferred embodiment, but it should be appreciated that above-mentioned
Description is not considered as limitation of the present invention.After those skilled in the art have read above content, for of the invention
A variety of modifications and substitutions all will be apparent.Therefore, protection scope of the present invention should be limited to the appended claims.
Claims (1)
1. High-precision time-frequency synchronization between standing under a kind of high dynamic, which is characterized in that comprise the steps of:
Base station and rover station are according to fixed slot length Δ T transmission information frame and synchronous code；
Rover station sends information frame and synchronous code to base station, and base station obtains base station arrival time TOAI；
Base station sends information frame and synchronous code to rover station, and rover station obtains rover station first time arrival time TOAR1；
Base station sends information frame and synchronous code to rover station again, and rover station obtains second of arrival time TOA of rover stationR2；
Speed of related movement v and Doppler frequency f between calculating benchmark station and rover stationd；
Wherein, fcFor carrier frequency；
Time difference information ε between calculating benchmark station and rover station, rover station adjust rover station local zone time according to time difference information ε,
So that rover station and base station reach time synchronization；
Wherein, td1On the basis of station time of the timing initial time to signal emission time, tp1It is that rover station is believed to base station transmission
Cease signal propagation time when frame and synchronous code, tp2It is letter when base station sends information frame and synchronous code to rover station for the first time
Number propagation time；
Crystal oscillator frequency difference information Δ f between calculating benchmark station and rover station, rover station is adjusted according to crystal oscillator frequency difference information Δ f to be flowed
The crystal oscillator frequency stood, so that rover station and base station reach Frequency Synchronization；
Wherein, foFor crystal oscillator frequency, fnFor carrier beat, For carrier phase,I and q is respectively same to obtaining after radiofrequency signal progress quadrature frequency conversion
The signal of phase branch I and quadrature branch Q.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110752877A (en) * | 2019-11-04 | 2020-02-04 | 深圳市慧宇系统有限公司 | System and method for transmitting time frequency signal in optical fiber |
| CN111447674A (en) * | 2020-04-03 | 2020-07-24 | 南京大鱼半导体有限公司 | Node synchronization method, device, storage medium and node |
| CN112188609A (en) * | 2019-07-04 | 2021-01-05 | 华为技术有限公司 | Method and device for determining Timing Advance (TA) reference time |
| CN113422638A (en) * | 2021-07-02 | 2021-09-21 | 东方红卫星移动通信有限公司 | Low-earth-orbit satellite system whole-network time synchronization method and system |
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