CN107483380A - A kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture - Google Patents
A kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture Download PDFInfo
- Publication number
- CN107483380A CN107483380A CN201710815903.9A CN201710815903A CN107483380A CN 107483380 A CN107483380 A CN 107483380A CN 201710815903 A CN201710815903 A CN 201710815903A CN 107483380 A CN107483380 A CN 107483380A
- Authority
- CN
- China
- Prior art keywords
- mrow
- msub
- mover
- carrier
- msup
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2657—Carrier synchronisation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
- H04L27/20—Modulator circuits; Transmitter circuits
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2668—Details of algorithms
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The invention provides a kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture, and the rough estimate of carrier frequency is carried out using iteration time delay multiplication forward frequency method of estimation, realizes the quick lock in of carrier wave；The combined estimation method with reference to carrier synchronization and bit synchronization is used to realize carrier phase with estimating while the information of position for residual frequency departure phase, it is proposed goes wound method to eliminate carrier phase 180 degree integral multiple fuzzy problem, and the accurate estimation of carrier phase is realized using automatic sliding window accumulation method.Solve the problems, such as that carrier phase synchronization synchronously interferes with clock in existing OQPSK modulation, while realize the big frequency deviation fast Acquisition of carrier frequency, and have minimum phase jitter after capturing.
Description
Technical field
The present invention relates to OQPSK fields, and in particular to a kind of OQPSK signals high-frequency offset carrier based on multistage architecture is synchronous
Method.
Background technology
OQPSK is a kind of permanent envelope digital modulation technique, and quadrature branch symbol is offset in time with in-phase branch symbol
One bit interval, i.e. half symbols cycle.OQPSK signals eliminate the radian deflection of adjacent-symbol, have in bandwidth
In the practical communication system of limit, envelope fluctuating is small, and obvious power spectrum secondary lobe will not be produced after nonlinear power amplifier
Proliferative effect, there is high spectrum utilization and high power utilization ratio feature.
OQPSK signal generally use coherent demodulation modes, should be as far as possible to obtain good receptivity and communication quality
Realize accurate carrier synchronization.The carrier synchronization of OQPSK signals typically uses the pattern based on phaselocked loop, different by setting
Error function obtains corresponding feedback-type carrier synchronization loop.Carrier synchronization method based on Werner's theory devises optimal loop
Wave filter, although this method error function chooses simple, loop filter implementation complexity height, synchronization accuracy is low.It is based on
The IQ two paths of data after IQ two paths of data and half of symbol is used in combination to complete to estimate in the carrier synchronization method of COSTAS rings
Judgement, there is larger self noise in synchronous ring, very sensitive to clock jitter.Larger clock jitter can cause COSTAS
Ring capture time is very long, and synchronous error is big, and synchronization loop stability is poor, frequently occurs cycle-skipping phenomenon, or even can not restrain.Especially
For big frequency offset signal, it is necessary to which phenomenon is hung up in certain entering to lock the time and exist, it is impossible to realize the quick lock in of carrier wave.Such as figure
1 show based on the OQPSK carrier synchronizations loop of COSTAS rings and the theory diagram of clock synchronizing method.
Traditional OQPSK demodulation methods use the carrier synchronization method estimated respectively synchronous with clock, the essence of carrier synchronization
Degree influences clock and synchronously estimated, causes the clock synchronization acquistion time to grow, and synchronous error is big and stability is poor.Based on maximum likelihood
Although carrier clock phase estimation algorithm can estimate carrier wave and clock simultaneously, its capture range is narrow, and synchronization accuracy is not high, and
Integral multiple phase fuzzy problem be present.
The content of the invention
It is an object of the invention to provide a kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture, solution
The problem of carrier phase synchronization synchronously interferes with clock in certainly existing OQPSK modulation, while realize the big of carrier frequency
Frequency deviation fast Acquisition, and have minimum phase jitter after capturing.
The present invention uses following technical scheme：
A kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture, comprises the following steps：
Step 1：Reception signal is sampled, sampling period kTs, then sample after signal be：x(kTs)=s (kTs)
+n(kTs), make z (kTs)=x (kTs)x*((k-D)Ts), wherein, D is time delay, is obtained：
Step 2：Average is taken to formula (1), and carries out section summation, the sequence number of k representative samples, L0It is observed length, N refers to one
The ratio of the number, i.e. code-element period and sampling period of sampling, has in individual code-element period：
Step 3：Argument is taken simultaneously to formula (2) both sides, using and value replace its mathematic expectaion, obtain one kind approximation most
Excellent solution, and solve △ f and obtain：
Because time delay multiplication can amplify noise when itself estimates, hydraulic performance decline is caused, in order to further improve estimated accuracy,
Using increase iterations, and estimated accuracy is improved during each iteration；
Step 4：It is to realize to carry out stable state estimation to residual carrier phase with that after the thick synchronization of carrier frequency is completed,
Realize that carrier synchronization is completely estimated, while consider the particularity of OQPSK modulated signals, it is same when carrier phase estimation is carried out
Shi Jinhang bit synchronizations, avoid different phase estimate between influence each other, improve net synchronization capability；Using based on maximum-likelihood criterion
Derived, row constraint and approximation are entered to likelihood function, propose to slide accumulation length of window Self Adaptive Control to improve estimation essence
Degree；
After time delay multiplication forward frequency method of estimation eliminates frequency deviation, base band OQPSK signals are expressed as：
θ carrier wave skews in formula (3), τ are timing offset, and T is mark space, and g (t) is Pulse shaped filter；
Make a={ aiAnd b={ biRepresent respectively with transmission symbol independent in phase and quadrature component, with distribution, and with etc.
Parameter probability valuing ± 1, then the maximum likelihood equations of measured signal be；
WhereinCarrier wave skew θ, timing offset τ, symbol a and b estimate are represented respectively；
Step 5：In order to realize the Combined estimator of carrier wave skew and timing offset, by above formula for sign estimation valueWith
Be averaging, obtain be on parameter θ and τ maximum likelihood equations：
It is zero to seek local derviation on parameter θ and τ and make it, tries to achieve the carrier phase estimate that formula (4) equation obtains maximum
And timing errorEstimate, it is as follows：
Wherein m and l is arbitrary integer；
Step 6：From formula (5)π integral multiple phase ambiguity be present；Timing error estimate in formula (6)T/2 be present
Integral multiple obscure, asking formula (5) and formula (6) codomain of complex variable function (arg { }) to be (- π, π), soValue limited
System is in the range of (- pi/2, pi/2)；Value be limited in the range of (- T/2, T/2)；Due to carrier frequency shift and adopt
The presence of sample frequency deviation of clock, carrier phase and timing offset value will constantly change, in change procedure, when seeking argument letter
When several output valves changes to the edge of (- π, π) scope, the function-output meeting π of saltus step 2, thus carrier phase estimateIt can jump
Become pi/2；Clock jitter estimateCan saltus step T/2；
Using going wound algorithm to be used to eliminate cycle-skipping and fuzzy problem, go wound algorithm to the π sequence φ (n) of mould 2 plus such as
Lower correction sequence Ck(n)：
Therefore phase or timing sequence φ after deconvolutingu(n) it is：
φu(n)=φ (n)+Ck(n)
Step 7：Carrier wave change is bigger, and the significant maximum length for sliding accumulation window is with regard to smaller.Therefore, carrier frequency
Deviation is bigger, and the significant maximum length for sliding accumulation window is with regard to smaller；
Accumulation window is slided using length of window is adjustable, length of window sets shorter when frequency departure is larger, when frequency
The length of sliding window is set when rate deviation is smaller and longer completes accurately to estimate；Existed using the estimation phase value after wound is removed
The average value of variable quantity in unit intervalAccumulation length of window L is slided to controlw,It is bigger, LwValue it is smaller, control
Process is represented with equation below：
At synchronous initial stage, sliding window is short, can be to carrier phase rough estimate, through controlling after a while, with carrier wave phase
The continuous reduction of position average, adaptive parameter control device can gradually increase sliding window length, and carrier phase estimation can become more
Add accurately, until carrier estimation meets to require.
The invention has the advantages that：
OQPSK signal high-frequency offset carriers synchronous method based on multistage architecture uses multistage open loop structure form, for carrying
Wave frequency rate rough estimate uses iteration time delay multiplication forward frequency method of estimation, this method to the bit synchronizations of OQPSK modulated signals not
It is sensitive, it is not necessary to accurate bit synchronization information, the thick synchronization of big frequency deviation frequency can be completed while improving estimated accuracy.Using knot
The combined estimation method for closing carrier synchronization and bit synchronization carries out residual frequency departure with estimating while the information of position, avoids carrier wave same with position
Influencing each other for step estimation, realizes the accurate estimation of carrier frequency and phase, and the whole of phase estimation is eliminated using wound method is gone
Several times phase fuzzy problem, and the fuzzy problem of bit synchronization estimation is eliminated, avoid the cycle-skipping phenomenon of estimating carrier frequencies.Using
The adjustable accumulation window that slides of length of window improves carrier frequency and bit synchronization estimated accuracy, and the control method is simple and effective,
Accelerate the speed of estimation while estimated accuracy is provided.
Brief description of the drawings
Fig. 1 is based on the OQPSK carrier waves of COSTAS rings and the theory diagram of clock synchronizing method.
Fig. 2 is the theory diagram of the OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture.
Embodiment
The embodiment of the present invention is described further with specific embodiment below in conjunction with the accompanying drawings：
With reference to Fig. 2, a kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture, during using iteration
Prolong the rough estimate that multiplication forward frequency method of estimation carries out carrier frequency, realize the quick lock in of carrier wave；For residual frequency departure phase
Realize that carrier phase with estimating while the information of position, proposes using the combined estimation method with reference to carrier synchronization and bit synchronization in position
Wound method is carried to eliminate carrier phase 180 degree integral multiple fuzzy problem using automatic sliding window accumulation method to realize
The accurate estimation of wave phase.
Specifically include following steps：
Step 1：In OQPSK modulated signal carrier frequency rough estimates, to avoid carrier synchronization method and the phase of bit synchronization
Mutual sensitiveness, the rough estimate of carrier frequency is carried out using iteration time delay multiplication forward frequency method of estimation, and this method is adjusted to OQPSK
The bit synchronization of signal processed is insensitive, it is not necessary to accurate bit synchronization information, can complete the thick synchronization of frequency.
Reception signal is sampled, sampling period kTs, then sample after signal be：x(kTs)=s (kTs)+n
(kTs), make z (kTs)=x (kTs)x*((k-D)Ts), wherein, D is time delay, is obtained：
Step 2：Average is taken to formula (1), and carries out section summation, the sequence number of k representative samples, L0It is observed length, N refers to one
The ratio of the number, i.e. code-element period and sampling period of sampling, has in individual code-element period：
Step 3：Argument is taken simultaneously to formula (2) both sides, using and value replace its mathematic expectaion, obtain one kind approximation most
Excellent solution, and solve △ f and obtain：
Because time delay multiplication can amplify noise when itself estimates, hydraulic performance decline is caused, in order to further improve estimated accuracy,
Using increase iterations, and estimated accuracy is improved during each iteration.
Step 4：It is to realize to carry out stable state estimation to residual carrier phase with that after the thick synchronization of carrier frequency is completed,
Realize that carrier synchronization is completely estimated, while consider the particularity of OQPSK modulated signals, it is same when carrier phase estimation is carried out
Shi Jinhang bit synchronizations, avoid different phase estimate between influence each other, improve net synchronization capability.
Derived using based on maximum-likelihood criterion, row constraint and approximation are entered to likelihood function, propose to slide accumulation window
Mouthful length Self Adaptive Control improves estimated accuracy；
After time delay multiplication forward frequency method of estimation eliminates frequency deviation, base band OQPSK signals are expressed as：
θ carrier wave skews in formula (3), τ are timing offset, and T is mark space, and g (t) is Pulse shaped filter；
Make a={ aiAnd b={ biRepresent respectively with transmission symbol independent in phase and quadrature component, with distribution, and with etc.
Parameter probability valuing ± 1, then the maximum likelihood equations of measured signal be；
WhereinCarrier wave skew θ, timing offset τ, symbol a and b estimate are represented respectively；
Step 5：In order to realize the Combined estimator of carrier wave skew and timing offset, by above formula for sign estimation valueWith
Be averaging, obtain be on parameter θ and τ maximum likelihood equations：
It is zero to seek local derviation on parameter θ and τ and make it, tries to achieve the carrier phase estimate that formula (4) equation obtains maximum
And timing errorEstimate, it is as follows：
Wherein m and l is arbitrary integer.
According to derivation, as shown in Figure 2.OQPSK input signals are carried out by the estimation of iteration time delay multiplication forward frequency
Signal delay, conjugation is taken, is multiplied and sums, then carrying out obtaining thick frequency deviation after taking argument and iterative estimate.After best rough estimate
OQPSK signals pass through enters line delay and shaping respectively with reference to the combined estimation method of carrier synchronization and bit synchronization progress I roads with Q roads
Filtering, slide accumulation and ask argument to operate, finally obtain phase deviation and clock jitter estimation.
Step 6：From formula (5)π integral multiple phase ambiguity be present；Timing error estimate in formula (6)T/2 be present
Integral multiple obscure, asking formula (5) and formula (6) codomain of complex variable function (arg { }) to be (- π, π), soValue limited
System is in the range of (- pi/2, pi/2)；Value be limited in the range of (- T/2, T/2).
Due to the presence of carrier frequency shift and sample clock frequency deviation, carrier phase and timing offset value will be continuous
Change, in change procedure, when the output valve for seeking argument function changes to the edge of (- π, π) scope, function-output can saltus step
2 π, thus carrier phase estimateCan saltus step pi/2；Clock jitter estimateCan saltus step T/2；
Using going wound algorithm to be used to eliminate cycle-skipping and fuzzy problem, go wound algorithm to the π sequence φ (n) of mould 2 plus such as
Lower correction sequence Ck(n)：
Therefore phase or timing sequence φ after deconvolutingu(n) it is：
φu(n)=φ (n)+Ck(n)；
The phase estimation value of the consecutive variations gone after wound easily can be used for completing frequency offset estimation with recovering.
Similarly, when sampling clock has frequency departure, the consecutive variations clock jitter estimate gone after wound is used for judging whether
Need to deduct or add sampled data, data are adopted so as to correct to adopt data more caused by the frequency deviation of sampling clock or leak.
Step 7：Although the length that accumulation window is slided in increase can improve estimated accuracy, carrier phase is not in practice
Disconnected to change, the correlation of front and rear data phase is very poor in longer signal data section.Carrier wave change is bigger, and significant maximum is sliding
The length of dynamic accumulation window is with regard to smaller.Therefore, carrier frequency offset is bigger, and the significant maximum length for sliding accumulation window is just
It is smaller.
Accumulation window is slided using length of window is adjustable, length of window sets shorter when frequency departure is larger, when frequency
The length of sliding window is set when rate deviation is smaller and longer completes accurately to estimate；Existed using the estimation phase value after wound is removed
The average value of variable quantity in unit intervalAccumulation length of window L is slided to controlw,It is bigger, LwValue it is smaller, control
Process is represented with equation below：
At synchronous initial stage, sliding window is short, can be to carrier phase rough estimate, through controlling after a while, with carrier wave phase
The continuous reduction of position average, adaptive parameter control device can gradually increase sliding window length, and carrier phase estimation can become more
Add accurately, until carrier estimation meets to require.
Certainly, described above is not limitation of the present invention, and the present invention is also not limited to the example above, this technology neck
The variations, modifications, additions or substitutions that the technical staff in domain is made in the essential scope of the present invention, it should also belong to the present invention's
Protection domain.
Claims (1)
1. a kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture, it is characterised in that comprise the following steps：
Step 1：Reception signal is sampled, sampling period kTs, then sample after signal be：x(kTs)=s (kTs)+n
(kTs), make z (kTs)=x (kTs)x*((k-D)Ts), wherein, D is time delay, is obtained：
<mrow>
<mi>z</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>kT</mi>
<mi>s</mi>
</msub>
<mo>)</mo>
</mrow>
<mo>=</mo>
<msup>
<mi>Ae</mi>
<mrow>
<mi>j</mi>
<mn>2</mn>
<msub>
<mi>&pi;&Delta;fDT</mi>
<mi>s</mi>
</msub>
</mrow>
</msup>
<mo>+</mo>
<mi>n</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>kT</mi>
<mi>s</mi>
</msub>
<mo>)</mo>
</mrow>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>)</mo>
</mrow>
</mrow>
Step 2：Average is taken to formula (1), and carries out section summation, the sequence number of k representative samples, L0It is observed length, N refers to a code
The ratio of the number, i.e. code-element period and sampling period of sampling, has in first cycle：
<mrow>
<mi>E</mi>
<mo>{</mo>
<munderover>
<mo>&Sigma;</mo>
<mrow>
<mi>k</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow>
<msub>
<mi>NL</mi>
<mn>0</mn>
</msub>
<mo>-</mo>
<mn>1</mn>
</mrow>
</munderover>
<mi>z</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>kT</mi>
<mi>s</mi>
</msub>
<mo>)</mo>
</mrow>
<mo>}</mo>
<mo>=</mo>
<msub>
<mi>NL</mi>
<mn>0</mn>
</msub>
<msup>
<mi>Ae</mi>
<mrow>
<mi>j</mi>
<mn>2</mn>
<msub>
<mi>&pi;&Delta;fDT</mi>
<mi>s</mi>
</msub>
</mrow>
</msup>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>2</mn>
<mo>)</mo>
</mrow>
</mrow>
Step 3：Argument is taken simultaneously to formula (2) both sides, using and value replace its mathematic expectaion, obtain a kind of near-optimization
Solution, and solve △ f and obtain：
<mrow>
<mi>&Delta;</mi>
<mi>f</mi>
<mo>=</mo>
<mfrac>
<mn>1</mn>
<mrow>
<mn>2</mn>
<msub>
<mi>&pi;DT</mi>
<mi>s</mi>
</msub>
</mrow>
</mfrac>
<mi>arg</mi>
<mo>{</mo>
<munderover>
<mo>&Sigma;</mo>
<mrow>
<mi>k</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow>
<msub>
<mi>NL</mi>
<mn>0</mn>
</msub>
<mo>-</mo>
<mn>1</mn>
</mrow>
</munderover>
<mi>z</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>kT</mi>
<mi>s</mi>
</msub>
<mo>)</mo>
</mrow>
<mo>}</mo>
</mrow>
Because time delay multiplication can amplify noise when itself estimates, hydraulic performance decline is caused, in order to further improve estimated accuracy, is used
Increase iterations, and improve estimated accuracy during each iteration；
Step 4：After the thick synchronization of carrier frequency is completed, it is to realize to carry out stable state estimation to residual carrier phase with that, realizes
Carrier synchronization is completely estimated, while considers the particularity of OQPSK modulated signals, enters simultaneously when carrier phase estimation is carried out
Line position is synchronous, avoid different phase estimate between influence each other, improve net synchronization capability；Carried out using based on maximum-likelihood criterion
Derive, row constraint and approximation are entered to likelihood function, propose to slide accumulation length of window Self Adaptive Control to improve estimated accuracy；
After time delay multiplication forward frequency method of estimation eliminates frequency deviation, base band OQPSK signals are expressed as：
<mrow>
<mi>s</mi>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mi>&theta;</mi>
</mrow>
</msup>
<mo>{</mo>
<munder>
<mo>&Sigma;</mo>
<mi>i</mi>
</munder>
<msub>
<mi>a</mi>
<mi>i</mi>
</msub>
<mi>g</mi>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>-</mo>
<mi>i</mi>
<mi>T</mi>
<mo>-</mo>
<mi>&tau;</mi>
<mo>)</mo>
</mrow>
<mo>+</mo>
<mi>j</mi>
<munder>
<mo>&Sigma;</mo>
<mi>i</mi>
</munder>
<msub>
<mi>b</mi>
<mi>i</mi>
</msub>
<mi>g</mi>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>-</mo>
<mi>i</mi>
<mi>T</mi>
<mo>-</mo>
<mi>T</mi>
<mo>/</mo>
<mn>2</mn>
<mo>-</mo>
<mi>&tau;</mi>
<mo>)</mo>
</mrow>
<mo>}</mo>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>3</mn>
<mo>)</mo>
</mrow>
</mrow>
θ carrier wave skews in formula (3), τ are timing offset, and T is mark space, and g (t) is Pulse shaped filter；
Make a={ aiAnd b={ biRepresent respectively with transmission symbol independent in phase and quadrature component, with distribution, and with equiprobability
Value ± 1, then the maximum likelihood equations of measured signal be；
<mrow>
<mi>&Lambda;</mi>
<mrow>
<mo>(</mo>
<mi>x</mi>
<mo>|</mo>
<mover>
<mi>&tau;</mi>
<mo>~</mo>
</mover>
<mo>,</mo>
<mover>
<mi>&theta;</mi>
<mo>~</mo>
</mover>
<mo>,</mo>
<mover>
<mi>a</mi>
<mo>~</mo>
</mover>
<mo>,</mo>
<mover>
<mi>b</mi>
<mo>~</mo>
</mover>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mi>exp</mi>
<mo>{</mo>
<mfrac>
<msub>
<mi>T</mi>
<mi>s</mi>
</msub>
<msub>
<mi>N</mi>
<mn>0</mn>
</msub>
</mfrac>
<munderover>
<mo>&Sigma;</mo>
<mrow>
<mi>k</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mrow>
<msub>
<mi>NL</mi>
<mn>0</mn>
</msub>
<mo>-</mo>
<mn>1</mn>
</mrow>
</munderover>
<mi>Re</mi>
<mo>&lsqb;</mo>
<mi>x</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>kT</mi>
<mi>s</mi>
</msub>
<mo>)</mo>
</mrow>
<msup>
<mover>
<mi>s</mi>
<mo>~</mo>
</mover>
<mo>*</mo>
</msup>
<mrow>
<mo>(</mo>
<msub>
<mi>kT</mi>
<mi>s</mi>
</msub>
<mo>)</mo>
</mrow>
<mo>&rsqb;</mo>
<mo>-</mo>
<mfrac>
<msub>
<mi>T</mi>
<mi>s</mi>
</msub>
<mrow>
<mn>2</mn>
<msub>
<mi>N</mi>
<mn>0</mn>
</msub>
</mrow>
</mfrac>
<munderover>
<mo>&Sigma;</mo>
<mi>k</mi>
<mrow>
<msub>
<mi>NL</mi>
<mn>0</mn>
</msub>
<mo>-</mo>
<mn>1</mn>
</mrow>
</munderover>
<mo>|</mo>
<mover>
<mi>s</mi>
<mo>~</mo>
</mover>
<mrow>
<mo>(</mo>
<msub>
<mi>kT</mi>
<mi>s</mi>
</msub>
<mo>)</mo>
</mrow>
<msup>
<mo>|</mo>
<mn>2</mn>
</msup>
<mo>}</mo>
</mrow>
WhereinCarrier wave skew θ, timing offset τ, symbol a and b estimate are represented respectively；
Step 5：In order to realize the Combined estimator of carrier wave skew and timing offset, by above formula for sign estimation valueWithAsk flat
, obtain be on parameter θ and τ maximum likelihood equations：
<mrow>
<mi>&Lambda;</mi>
<mrow>
<mo>(</mo>
<mi>x</mi>
<mo>|</mo>
<mover>
<mi>&tau;</mi>
<mo>~</mo>
</mover>
<mo>,</mo>
<mover>
<mi>&theta;</mi>
<mo>~</mo>
</mover>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mi>Re</mi>
<mo>{</mo>
<msup>
<mi>e</mi>
<mrow>
<mo>-</mo>
<mi>j</mi>
<mn>2</mn>
<mover>
<mi>&theta;</mi>
<mo>~</mo>
</mover>
</mrow>
</msup>
<mrow>
<mo>(</mo>
<msup>
<mi>Xe</mi>
<mrow>
<mo>-</mo>
<mi>j</mi>
<mn>2</mn>
<mi>&pi;</mi>
<mover>
<mi>&tau;</mi>
<mo>~</mo>
</mover>
<mo>/</mo>
<mi>T</mi>
</mrow>
</msup>
<mo>+</mo>
<msup>
<mi>Ye</mi>
<mrow>
<mo>-</mo>
<mi>j</mi>
<mn>2</mn>
<mi>&pi;</mi>
<mover>
<mi>&tau;</mi>
<mo>~</mo>
</mover>
<mo>/</mo>
<mi>T</mi>
</mrow>
</msup>
<mo>)</mo>
</mrow>
<mo>}</mo>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>4</mn>
<mo>)</mo>
</mrow>
</mrow>
It is zero to seek local derviation on parameter θ and τ and make it, tries to achieve the carrier phase estimate that formula (4) equation obtains maximumWith it is fixed
When errorEstimate, it is as follows：
<mrow>
<mover>
<mi>&theta;</mi>
<mo>^</mo>
</mover>
<mo>=</mo>
<mfrac>
<mn>1</mn>
<mn>4</mn>
</mfrac>
<mo>&lsqb;</mo>
<mi>arg</mi>
<mrow>
<mo>(</mo>
<mi>X</mi>
<mo>)</mo>
</mrow>
<mo>+</mo>
<mi>arg</mi>
<mrow>
<mo>(</mo>
<mi>Y</mi>
<mo>)</mo>
</mrow>
<mo>&rsqb;</mo>
<mo>+</mo>
<mi>m</mi>
<mfrac>
<mi>&pi;</mi>
<mn>2</mn>
</mfrac>
<mo>-</mo>
<mi>l</mi>
<mi>&pi;</mi>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>5</mn>
<mo>)</mo>
</mrow>
</mrow>
<mrow>
<mover>
<mi>&tau;</mi>
<mo>^</mo>
</mover>
<mo>=</mo>
<mfrac>
<mi>T</mi>
<mrow>
<mn>4</mn>
<mi>&pi;</mi>
</mrow>
</mfrac>
<mo>&lsqb;</mo>
<mo>-</mo>
<mi>arg</mi>
<mrow>
<mo>(</mo>
<mi>X</mi>
<mo>)</mo>
</mrow>
<mo>+</mo>
<mi>arg</mi>
<mrow>
<mo>(</mo>
<mi>Y</mi>
<mo>)</mo>
</mrow>
<mo>&rsqb;</mo>
<mo>+</mo>
<mi>m</mi>
<mfrac>
<mi>T</mi>
<mn>2</mn>
</mfrac>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>6</mn>
<mo>)</mo>
</mrow>
</mrow>
Wherein m and l is arbitrary integer；
Step 6：From formula (5)π integral multiple phase ambiguity be present；Timing error estimate in formula (6)T/2 integer be present
It is times fuzzy, asking formula (5) and formula (6) codomain of complex variable function (arg { }) to be (- π, π), soValue be limited in (-
Pi/2, pi/2) in the range of；Value be limited in the range of (- T/2, T/2)；Due to carrier frequency shift and sampling clock frequency
The presence of rate deviation, carrier phase and timing offset value will constantly change, in change procedure, when the output for seeking argument function
When value changes to the edge of (- π, π) scope, the function-output meeting π of saltus step 2, thus carrier phase estimateCan saltus step pi/2；Clock
Estimation of deviation valueCan saltus step T/2；
Using going wound algorithm to be used to eliminate cycle-skipping and fuzzy problem, wound algorithm is gone to add following school to the π sequence φ (n) of mould 2
Positive sequence Ck(n)：
Therefore phase or timing sequence φ after deconvolutingu(n) it is：
φu(n)=φ (n)+Ck(n)
Step 7：Carrier wave change is bigger, and the significant maximum length for sliding accumulation window is with regard to smaller.Therefore, carrier frequency offset
Bigger, the significant maximum length for sliding accumulation window is with regard to smaller；
Accumulation window is slided using length of window is adjustable, length of window sets shorter when frequency departure is larger, when frequency is inclined
The length of sliding window is set when difference is smaller and longer completes accurately to estimate；Using removing the estimation phase value after wound in unit
The average value of variable quantity in timeAccumulation length of window L is slided to controlw,It is bigger, LwValue it is smaller, control process use
Equation below represents：
<mrow>
<mover>
<mrow>
<mi>&Delta;</mi>
<mi>&theta;</mi>
</mrow>
<mo>&OverBar;</mo>
</mover>
<mrow>
<mo>(</mo>
<mi>k</mi>
<mi>T</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<munderover>
<mo>&Sigma;</mo>
<mrow>
<mi>i</mi>
<mo>=</mo>
<mn>0</mn>
</mrow>
<mi>n</mi>
</munderover>
<mi>&Delta;</mi>
<mi>&theta;</mi>
<mo>&lsqb;</mo>
<mrow>
<mo>(</mo>
<mi>k</mi>
<mo>-</mo>
<mi>i</mi>
<mo>)</mo>
</mrow>
<mi>T</mi>
<mo>&rsqb;</mo>
</mrow>
<mrow>
<msub>
<mi>L</mi>
<mi>w</mi>
</msub>
<mo>&Proportional;</mo>
<mn>1</mn>
<mo>/</mo>
<mover>
<mrow>
<mi>&Delta;</mi>
<mi>&theta;</mi>
</mrow>
<mo>&OverBar;</mo>
</mover>
</mrow>
At synchronous initial stage, sliding window is short, can be to carrier phase rough estimate, through controlling after a while, as carrier phase is equal
The continuous reduction of value, adaptive parameter control device can gradually increase sliding window length, and carrier phase estimation can become more smart
Really, until carrier estimation meets to require.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710815903.9A CN107483380A (en) | 2017-09-12 | 2017-09-12 | A kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710815903.9A CN107483380A (en) | 2017-09-12 | 2017-09-12 | A kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107483380A true CN107483380A (en) | 2017-12-15 |
Family
ID=60584230
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710815903.9A Pending CN107483380A (en) | 2017-09-12 | 2017-09-12 | A kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107483380A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108965194A (en) * | 2018-08-16 | 2018-12-07 | 北京邮电大学 | A kind of method and device that signal phase restores |
| CN109768823A (en) * | 2018-12-28 | 2019-05-17 | 长沙天仪空间科技研究院有限公司 | A kind of narrowband multichannel satellite communication system |
| CN111294195A (en) * | 2020-01-09 | 2020-06-16 | 杭州华冲科技有限公司 | Clock synchronization module based on CFO adaptive technology |
| CN112543162A (en) * | 2020-11-12 | 2021-03-23 | 重庆邮电大学 | Short wave communication time-frequency joint synchronization method based on Costas sequence |
| CN113098812A (en) * | 2021-03-22 | 2021-07-09 | 青岛农业大学 | 4PSK related demodulation and clock rectification method |
| CN114071695A (en) * | 2021-12-13 | 2022-02-18 | 西南科技大学 | Time synchronization hop convergence method and system |
| CN115348000A (en) * | 2022-10-19 | 2022-11-15 | 北京航空航天大学 | Symbol synchronization method and device of single sampling point per symbol based on wiener coefficient solution |
| CN115603863A (en) * | 2022-11-30 | 2023-01-13 | 紫光同芯微电子有限公司（Cn） | Input signal reading method and device |
| CN115632923A (en) * | 2022-10-10 | 2023-01-20 | 北京睿信丰科技有限公司 | OQPSK (offset quadrature phase shift keying) -based unmanned aerial vehicle and satellite ultra-wideband communication method and related equipment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070253512A1 (en) * | 2006-04-27 | 2007-11-01 | Jennic Limited | Method for acquiring timing and carrier synchronization of offset-QPSK modulated signals |
| CN101394198A (en) * | 2008-10-27 | 2009-03-25 | 北京韦加航通科技有限责任公司 | Frequency bias capture method for block signal with relatively large frequency bias |
| CN105049174A (en) * | 2015-07-16 | 2015-11-11 | 中国电子科技集团公司第四十一研究所 | Carrier and clock combined synchronization method for OQPSK modulation |
-
2017
- 2017-09-12 CN CN201710815903.9A patent/CN107483380A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070253512A1 (en) * | 2006-04-27 | 2007-11-01 | Jennic Limited | Method for acquiring timing and carrier synchronization of offset-QPSK modulated signals |
| CN101394198A (en) * | 2008-10-27 | 2009-03-25 | 北京韦加航通科技有限责任公司 | Frequency bias capture method for block signal with relatively large frequency bias |
| CN105049174A (en) * | 2015-07-16 | 2015-11-11 | 中国电子科技集团公司第四十一研究所 | Carrier and clock combined synchronization method for OQPSK modulation |
Non-Patent Citations (3)
| Title |
|---|
| ANTONIO A. D’AMICO等: ""Feedforward joint phase and timing estimation with OQPSK modulation"", 《IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY》 * |
| 李阳光等: ""循环PN相关时域同步正交频分复用频偏估计算法 "", 《计算机应用》 * |
| 阙隆树等: ""数字调制信号识别中的相位去卷叠门限研究"", 《信号处理》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108965194A (en) * | 2018-08-16 | 2018-12-07 | 北京邮电大学 | A kind of method and device that signal phase restores |
| CN109768823A (en) * | 2018-12-28 | 2019-05-17 | 长沙天仪空间科技研究院有限公司 | A kind of narrowband multichannel satellite communication system |
| CN111294195A (en) * | 2020-01-09 | 2020-06-16 | 杭州华冲科技有限公司 | Clock synchronization module based on CFO adaptive technology |
| CN112543162A (en) * | 2020-11-12 | 2021-03-23 | 重庆邮电大学 | Short wave communication time-frequency joint synchronization method based on Costas sequence |
| CN113098812A (en) * | 2021-03-22 | 2021-07-09 | 青岛农业大学 | 4PSK related demodulation and clock rectification method |
| CN114071695A (en) * | 2021-12-13 | 2022-02-18 | 西南科技大学 | Time synchronization hop convergence method and system |
| CN114071695B (en) * | 2021-12-13 | 2023-04-28 | 西南科技大学 | Time synchronization hop count convergence method and system |
| CN115632923A (en) * | 2022-10-10 | 2023-01-20 | 北京睿信丰科技有限公司 | OQPSK (offset quadrature phase shift keying) -based unmanned aerial vehicle and satellite ultra-wideband communication method and related equipment |
| CN115348000A (en) * | 2022-10-19 | 2022-11-15 | 北京航空航天大学 | Symbol synchronization method and device of single sampling point per symbol based on wiener coefficient solution |
| CN115603863A (en) * | 2022-11-30 | 2023-01-13 | 紫光同芯微电子有限公司（Cn） | Input signal reading method and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107483380A (en) | A kind of OQPSK signal high-frequency offset carrier synchronous method based on multistage architecture | |
| CN105245303B (en) | A kind of high-speed burst demodulation synchronization system | |
| CN103929394B (en) | High-precision frequency offset estimation method based on iteration algorithm | |
| CN105812303B (en) | A kind of GFSK base-band digital receiver and its baseband synchronization and demodulation method | |
| US6768780B1 (en) | Non-data aided maximum likelihood based feedforward timing synchronization method | |
| CN103023831B (en) | A kind of carrier frequency bias estimation being applicable to burst waveform | |
| CA2306917A1 (en) | Synchronization techniques and systems for radiocommunication | |
| US6415004B1 (en) | Phase detector, timing recovery device using the same, and a demodulator using the timing recovery device | |
| CN111600823B (en) | Parallel OQPSK offset quadriphase shift keying demodulator | |
| CN110300079B (en) | MSK signal coherent demodulation method and system | |
| CN105763500A (en) | Frequency deviation, time delay and phase deviation combined synchronization method of continuous phase modulation signals | |
| CN103428153A (en) | Gaussian minimum shift keying (GMSK) signal receiving method in satellite mobile communication | |
| US8571139B2 (en) | Method for tracking the phase of a signal modulated by continuous phase modulation and synchronization device implementing said method | |
| CN110278169A (en) | A kind of time domain frequency excursion algorithm | |
| CN107342960A (en) | A kind of unbound nucleus frequency deviation estimating method of suitable Amplitude phase shift keying | |
| CN105049174A (en) | Carrier and clock combined synchronization method for OQPSK modulation | |
| CN113037671A (en) | Low-complexity efficient SOQPSK symbol timing and phase joint synchronization algorithm | |
| CN102833204A (en) | Frequency offset estimation implementation method | |
| CN107623647B (en) | Carrier synchronization method based on scattered pilot frequency assistance | |
| CN109714286B (en) | Carrier frequency offset estimation method for Pi/8D8PSK demodulation | |
| CN109462421B (en) | Signal timing recovery method and recovery device, signal demodulation method and demodulation system | |
| CN109756435B (en) | Method for estimating frequency offset of signal | |
| US11962443B2 (en) | Frequency offset estimation | |
| CN114465691A (en) | Low-complexity constant envelope phase modulation signal sampling deviation estimation and compensation method and system | |
| CN115118564A (en) | Carrier frequency deviation estimation method and device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20171215 |