CN110224807A - A kind of carrier synchronization method estimated based on AGC frequency deviation and system - Google Patents
A kind of carrier synchronization method estimated based on AGC frequency deviation and system Download PDFInfo
- Publication number
- CN110224807A CN110224807A CN201910453119.7A CN201910453119A CN110224807A CN 110224807 A CN110224807 A CN 110224807A CN 201910453119 A CN201910453119 A CN 201910453119A CN 110224807 A CN110224807 A CN 110224807A
- Authority
- CN
- China
- Prior art keywords
- signal
- frequency deviation
- agc gain
- agc
- modulation
- 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
- H04L27/0014—Carrier regulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L7/00—Arrangements for synchronising receiver with transmitter
- H04L7/02—Speed or phase control by the received code signals, the signals containing no special synchronisation information
- H04L7/033—Speed or phase control by the received code signals, the signals containing no special synchronisation information using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0024—Carrier regulation at the receiver end
- H04L2027/0026—Correction of carrier offset
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Circuits Of Receivers In General (AREA)
Abstract
The invention discloses a kind of carrier synchronization method estimated based on AGC frequency deviation and systems, specific steps are as follows: the radiofrequency signal for docking receipts is pre-processed to obtain preprocessed signal and simulation AGC gain modulation, and the peak value of preprocessed signal is limited in the first predetermined voltage range；Digital AGC gain modulation is carried out to the modulated signal of simulation AGC gain, the modulated signal of AGC gain will be simulated and be limited in the second predetermined voltage range；The modulated signal of digital AGC gain is subjected to down-converted and obtains down-conversion signal, the corresponding in-phase branch amplitude of tracking down-conversion signal and quadrature branch amplitude obtain the frequency deviation discreet value of receiving end Yu transmitting terminal carrier signal, and then obtain the frequency deviation region of receiving end Yu transmitting terminal carrier signal, it carries out quickly tracking to realize that carrier synchronization demodulates, to improve the carrier synchronization demodulation accuracy and speed of received radiofrequency signal in frequency deviation region using phaselocked loop.
Description
Technical field
The invention belongs to carrier synchronization fields, and in particular to a kind of carrier synchronization method estimated based on AGC frequency deviation and be
System.
Background technique
Carrier synchronization is also known as carrier auxiliary, i.e., generates one in receiving device and receive the carrier wave of signal with frequently with phase
Local oscillations, supply demodulator are used as coherent demodulation.When receiving in signal includes discrete carrier component, needed in receiving end
Signal carrier is isolated from signal as local coherent carrier；The local coherent carrier frequency isolated in this way is inevitable and receives
Signal(-) carrier frequency is identical, but in order to keep phase also identical, it may be necessary to make adjustment appropriate to the carrier phase isolated.
Carrier synchronization is a key technology of any coherent receiver, therefore in order to accurately track carrier wave, it is also necessary to be used
Phaselocked loop or frequency locking ring eliminate frequency difference, accurately to extract data information.Carrier track by Costas ring according to can be reconstructed
Carrier phase coherent demodulation is realized, i.e., the carrier phase of input signal is locked with phase-locked loop pll.
However, simple phase-locked loop pll method, which exists, hangs up phenomenon, i.e. PLL is in biggish phase error shape for a long time
State, simple PLL method are not suitable for the demodulation in burst communication.In spread spectrum system capturing carrier and accurately track spreading code phase
Behind position, the output signal of tracking despreading module is despread signal, this despread signal should be accurate as far as possible, due to input signal
The output of the influence of the factors such as dynamic change, Doppler frequency shift, multi-path jamming, receiver down coversion can generate frequency difference, this can lead
The mistake for causing despread signal, influences system performance.As patent document CN201821350810.X discloses a kind of digital high speed
Parallel Carrier Synchronization device is handled input signal using digital mixer, and utilizes phase discriminator group, loop filter
And carrier wave digitial controller carries out carrier synchronization processes and fails however, it is only the conventional method of digital communication carrier synchronization
The brings signal processing problems such as input signal dynamic change, Doppler frequency shift are considered comprehensively, can cause the hang-up problem of PLL,
To influence the speed and reliability of carrier synchronization process.
Summary of the invention
Aiming at the above defects or improvement requirements of the prior art, the present invention provides a kind of loads estimated based on AGC frequency deviation
Wave synchronous method and system, by carrying out the modulation of simulation AGC gain and digital AGC gain modulation to received radiofrequency signal,
It is estimated again by carrying out frequency deviation to down-conversion signal, carries out quickly tracking in corresponding frequency deviation region to realize carrier synchronization solution
It adjusts, to improve the carrier synchronization demodulation accuracy and speed of the received radiofrequency signal of the system.
To achieve the above object, according to one aspect of the present invention, it is same to provide a kind of carrier wave estimated based on AGC frequency deviation
One step process, specific steps are as follows:
S1. received radiofrequency signal is pre-processed to obtain preprocessed signal, simulation AGC is carried out to preprocessed signal and is increased
The peak value of preprocessed signal is limited in the first predetermined voltage range by benefit modulation, simulation AGC gain modulation；
S2. digital AGC gain modulation is carried out to the modulated signal of simulation AGC gain, digital AGC gain modulation will simulation
The modulated signal of AGC gain is limited in the second predetermined voltage range；
S3. the modulated signal of digital AGC gain is subjected to down-converted and obtains down-conversion signal, tracking down coversion letter
Number corresponding in-phase branch amplitude and quadrature branch amplitude obtain the frequency deviation discreet value of receiving end Yu transmitting terminal carrier signal, in turn
The frequency deviation region of receiving end Yu transmitting terminal carrier signal is obtained, carries out quickly tracking to realize in frequency deviation region using phaselocked loop
Carrier synchronization demodulation, to improve the carrier synchronization demodulation accuracy and speed of received radiofrequency signal.
As a further improvement of the present invention, received radiofrequency signal is pre-processed specifically: by received radio frequency
Signal becomes intermediate-freuqncy signal after mixing.
As a further improvement of the present invention, the amount of gain adjustment of simulation AGC gain modulation are as follows:
Δ G (n)=20 [log | S (n) |-logE] C
Wherein, E is the threshold voltage for simulating AGC gain modulation, and S (n) is preprocessed signal, and C is representative simulation AGC gain
One variable of the time constant of modulation.
As a further improvement of the present invention, the detailed process of digital AGC gain modulation are as follows: after simulation AGC gain modulation
Signal be X (n), X (n) is multiplied in proportion to obtain output signal Y (n) with gain factor M (n)；
The confirmation process of gain factor M (n) are as follows: with the initial value of gain factor M (n) be multiplied to obtain in proportion by X (n) defeated
Signal Y'(n out), output signal Y'(n) by Hilbert transformation and square root calculation after acquire output signal Y'(n) packet
Network generates an error signal (n) through logarithm operation compared with ideal reference levels R, and error signal (n) is integrated and opposes
Number calculation process obtains gain factor M (n) value.
As a further improvement of the present invention, the frequency deviation discreet value Δ f of receiving end and transmitting terminal carrier signal specifically:
Wherein, Amp_I (t) and Amp_Q (t) are respectively the corresponding in-phase branch amplitude of down-conversion signal and quadrature branch width
Value, Ts are corresponding character rate in downconversion process.
To achieve the above object, other side according to the invention provides a kind of carrier wave estimated based on AGC frequency deviation
Synchronization system, the system include sequentially connected preprocessing module, simulation AGC gain modulation module, digital AGC gain modulation mould
Block, down conversion module, frequency deviation estimate module and phase-locked loop module,
Preprocessing module to received radiofrequency signal for being pre-processed to obtain preprocessed signal；
Simulation AGC gain modulation module is used to carry out preprocessed signal simulation AGC gain modulation, simulates AGC gain tune
The peak value of preprocessed signal is limited in the first predetermined voltage range by system；
Digital AGC gain modulation module is used to carry out digital AGC gain modulation to the modulated signal of simulation AGC gain,
Digital AGC gain modulation will be simulated the modulated signal of AGC gain and is limited in the second predetermined voltage range；
Down conversion module is used to the modulated signal of digital AGC gain carrying out down-converted to obtain down-conversion signal；
Frequency deviation is estimated module and is connect for tracking the corresponding in-phase branch amplitude of down-conversion signal with quadrature branch amplitude
The frequency deviation discreet value of receiving end and transmitting terminal carrier signal, and then obtain the frequency deviation region of receiving end Yu transmitting terminal carrier signal；
Phase-locked loop module is used to carry out quickly tracking in frequency deviation region to realize that carrier synchronization demodulates, to improve this and be
The carrier synchronization demodulation accuracy and speed for received radiofrequency signal of uniting.
As a further improvement of the present invention, received radiofrequency signal is pre-processed specifically: by received radio frequency
Signal becomes intermediate-freuqncy signal after mixing.
As a further improvement of the present invention, the amount of gain adjustment of simulation AGC gain modulation are as follows:
Δ G (n)=20 [log | S (n) |-logE] C
Wherein, E is the threshold voltage for simulating AGC gain modulation, and S (n) is preprocessed signal, and C is representative simulation AGC gain
One variable of the time constant of modulation.
As a further improvement of the present invention, the detailed process of digital AGC gain modulation are as follows: after simulation AGC gain modulation
Signal be X (n), X (n) is multiplied in proportion to obtain output signal Y (n) with gain factor M (n)；
The confirmation process of gain factor M (n) are as follows: with the initial value of gain factor M (n) be multiplied to obtain in proportion by X (n) defeated
Signal Y'(n out), output signal Y'(n) by Hilbert transformation and square root calculation after acquire output signal Y'(n) packet
Network generates an error signal (n) through logarithm operation compared with ideal reference levels R, and error signal (n) is integrated and opposes
Number calculation process obtains gain factor M (n) value.
As a further improvement of the present invention, the frequency deviation discreet value Δ f of receiving end and transmitting terminal carrier signal specifically:
Wherein, Amp_I (t) and Amp_Q (t) are respectively the corresponding in-phase branch amplitude of down-conversion signal and quadrature branch width
Value, Ts are corresponding character rate in downconversion process.
In general, through the invention it is contemplated above technical scheme is compared with the prior art, have below beneficial to effect
Fruit:
A kind of carrier synchronization method estimated based on AGC frequency deviation of the invention and system, by believing received radio frequency
Number carry out the modulation of simulation AGC gain and digital AGC gain modulation, solve simulation AGC gain modulation bring dynamic range it is big,
The problem that response time is slow, output signal has certain shake and simulation AGC gain modulation bring out-put dynamic range small, then
It is estimated by carrying out frequency deviation to down-conversion signal, carries out quickly tracking in corresponding frequency deviation region to realize carrier synchronization solution
It adjusts, to improve the carrier synchronization demodulation accuracy and speed of the received radiofrequency signal of the system.
A kind of carrier synchronization method estimated based on AGC frequency deviation of the invention and system, according to frequency discrimination algorithm by transporting
Calculation obtains the estimated value of frequency deviation, by the compensation of this estimated value into phaselocked loop NCO, so that it is exactly real that phaselocked loop, which needs the frequency deviation tracked,
The difference of border frequency deviation and this estimated value realizes that phase-locked loop can track under higher precision, and then adjusts and receive baseband signal
Frequency and phase, realize carrier synchronization to give effective frequency and phase compensation, due to only doing limited times offset estimation,
It does not need to do frequency discrimination operation in real time, hardware configuration is relatively easy.
Detailed description of the invention
Fig. 1 is a kind of schematic diagram of carrier synchronization system estimated based on AGC frequency deviation of the embodiment of the present invention；
Fig. 2 is the schematic diagram of the digital AGC gain modulation of the embodiment of the present invention；
Fig. 3 is the emulation schematic diagram that the frequency deviation of the embodiment of the present invention is estimated.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.
In addition, as long as technical characteristic involved in the various embodiments of the present invention described below is each other not
Constituting conflict can be combined with each other.The present invention is described in more detail With reference to embodiment.
Fig. 1 is a kind of schematic diagram of carrier synchronization method estimated based on AGC frequency deviation of the embodiment of the present invention.Such as Fig. 1 institute
Show, the specific steps of this method are as follows:
S1. received radiofrequency signal is pre-processed to obtain preprocessed signal, simulation AGC is carried out to preprocessed signal and is increased
Benefit modulation, wherein the peak value of preprocessed signal is limited in the first predetermined voltage range by simulation AGC gain modulation；
Specifically, received radiofrequency signal becomes intermediate-freuqncy signal after mixing；
E is set by the threshold voltage, that is, delay voltage for simulating AGC gain modulation, preprocessed signal is S (n), simulates AGC
The amplification factor of gain modulation is G (n), amount of gain adjustment (dB) are as follows:
Δ G (n)=20 [log | S (n) |-logE] C
Wherein, C is a variable of the time constant of representative simulation AGC gain modulation；
As S (n) > E, illustrates that the amplification factor for simulating AGC gain modulation is bigger than normal, then need to reduce amplification factor, can pass through
The modulation voltage for increasing simulation AGC gain modulation is equivalent to the charging process of simulation AGC gain modulation；As S (n) < E, say
The amplification factor of bright simulation AGC gain modulation is less than normal, then needs to increase amplification factor, can be by reducing simulation AGC gain modulation
Modulation voltage is equivalent to the charging process of simulation AGC gain modulation；
As an example, the input dynamic range of simulation AGC gain modulation is 60dB, exports 3dB.
S2. digital AGC gain modulation is carried out to the modulated signal of simulation AGC gain, wherein digital AGC gain modulation
The modulated signal of AGC gain will be simulated to be limited in the second predetermined voltage range；
For simulation AGC gain modulation, dynamic range is big, and the response time is slow, and modulated signal has certain
Shake, is extremely difficult to accurately modulate, and therefore, the simulation modulated signal of AGC gain is needed to carry out digital AGC gain tune
System；
The detailed process of digital AGC gain modulation are as follows: the simulation modulated signal of AGC gain is X (n), by X (n) and is increased
Beneficial factor M (n) is multiplied in proportion obtains output signal Y (n)；
Fig. 2 is the schematic diagram of the digital AGC gain modulation of the embodiment of the present invention.As shown in Fig. 2, gain factor M (n) is really
Recognize process are as follows: be multiplied to obtain output signal Y'(n in proportion with the initial value of gain factor M (n) by X (n)), output signal Y'
(n) by Hilbert transformation and square root calculation after acquire output signal Y'(n) envelope, through logarithm operation and desired reference
Level R compares, and generates an error signal (n), and integrated and antilogarithm calculation process obtains exact gain factor M (n)
Value, the too big then gain factor of envelope value is opposite to be reduced, and the too small then gain factor of envelope value is opposite to be increased；
As an example, output signal Y'(n can also be realized using the average energy variation of signal in track window)
Envelope calculates, and refers to the sampling number of setting fixed number in certain time interval in window；The average energy of input signal in window
Computational algorithm are as follows:
Or
Or
Wherein, I is the in-phase component of signal in window, and Q is the quadrature component of signal in window；
As an example, the input dynamic range of digital AGC gain modulation is 10dB, exports 0.5dB.
S3. the modulated signal of digital AGC gain is subjected to down-converted and obtains down-conversion signal, tracking down coversion letter
Number corresponding in-phase branch amplitude and quadrature branch amplitude obtain the frequency deviation discreet value of receiving end Yu transmitting terminal carrier signal, into one
Step obtains the frequency deviation region of receiving end Yu transmitting terminal carrier signal, carries out quickly tracking with reality in frequency deviation region using phaselocked loop
Existing carrier synchronization demodulation, to improve the carrier synchronization demodulation accuracy and speed of received radiofrequency signal.
Signal the problems such as there are Doppler effect, transmitting terminal and receiving end reliabilities in transmission process that transmitting terminal is sent
Cause in down-conversion signal there are the residual carrier of a low frequency, specifically:
The carrier signal of transmitting terminal are as follows:The carrier signal of receiving end are as follows:
Wherein, I (t) is in-phase branch signal, wcFor the IF frequency of the carrier signal of transmitting terminal, wdReceiving end and transmission
The frequency deviation at end, Δ φ are the phase difference of receiving end and transmitting terminal carrier signal；
The signal obtained after mixing and filtering are as follows:Signal after down coversion containsComponent,
Therefore, the phase and frequency of receiving end needs accurate tracking to receive signal spread spectrum code phase and residual carrier is just able to achieve reliably
Demodulation, to restore carrier data；
Further, the corresponding in-phase branch amplitude Amp_I (t) of down-conversion signal and quadrature branch amplitude Amp_Q are acquired
(t) it is respectively as follows:
Amp_I (t)=cos (2 π Δ ft+ Δ φ+φ0)·cos[2πΔf(t-Ts)+Δφ+φ0]
+sin(2πΔft+Δφ+φ0)·sin[2πΔf(t-Ts)+Δφ+φ0]
=cos [2 π Δ ft+ Δ φ+φ0-2πΔf(t-Ts)-Δφ-φ0]
=cos (2 π Δ fTs)
Amp_Q (t)=cos (2 π Δ ft+ Δ φ+φ0)·sin[2πΔf(t-Ts)+Δφ+φ0]
-sin(2πΔft+Δφ+φ0)·cos[2πΔf(t-Ts)+Δφ+φ0]
=-sin [2 π Δ ft+ Δ φ+φ0-2πΔf(t-Ts)-Δφ-φ0]
=-sin (2 π Δ fTs)
Wherein, Δ f is the frequency deviation of receiving end and transmitting terminal carrier signal, and Δ φ is receiving end and transmitting terminal carrier signal
Phase difference, φ0For the original phase of carrier signal, N is the noise that carrier signal introduces in transmission process, and Ts is down coversion mistake
Corresponding character rate in journey；
Acquire the frequency deviation discreet value of receiving end Yu transmitting terminal carrier signal are as follows:
Therefore, the corresponding in-phase branch amplitude of tracking down-conversion signal and quadrature branch amplitude obtain receiving end and transmitting terminal
The frequency deviation region of carrier signal, demodulation phaselocked loop NCO is quickly tracked in the frequency deviation region, to improve received radio frequency
The carrier synchronization demodulation accuracy and speed of signal.
Capture down-conversion signal simultaneously obtains offset estimation value by operation according to frequency discrimination algorithm, by this estimated value compensation to lock
In phase ring NCO, then it is exactly the difference of practical frequency deviation He this estimated value that phaselocked loop, which needs the frequency deviation tracked, this is one relatively small
Frequency deviation, phase-locked loop can track under higher precision.Due to only doing limited times offset estimation, do not need to do frequency discrimination fortune in real time
It calculates, i.e., in the detection-phase of down-conversion signal, frequency deviation is estimated according to frequency discrimination algorithm using the output result of correlator, by phaselocked loop
The frequency deviation for needing to track narrows down in a certain range, can obtain superior performance, increase of the method to hardware design complexity
Seldom.In practical applications, it is contemplated that the estimation of the influence of noise, frequency deviation should take the mean value repeatedly calculated.Theoretically calculate
The more results of number are closer to actual value, but the system for using time-division system, synchronous for system in each frame data
Frame head part cannot be too long, otherwise the effective bandwidth of system will take limited times average value with reality by serious curtailments, therefore
The Fast synchronization of existing system.
Fig. 3 is the emulation schematic diagram that the frequency deviation of the embodiment of the present invention is estimated.As shown in figure 3, simulated conditions are that the time-division is entirely double
Work TDD communication system, QPSK modulation system, using spread-spectrum code rate 2.5Mbps, spreading code uses M sequence, and length 64 is adopted
It is realized with frame structure, the error of offset estimation under different average lengths is emulated, it can be seen that when average length takes 30,
Error is more stable, and mean error is less than 40Hz, and this average length can also receive.Thus, as one
Example, using frequency deviation is estimated with the mean value of 30 points, phaselocked loop only needs to track the frequency deviation of about tens Hz at this time, in this way
The bandwidth of cycle of phase-locked loop can be designed smaller to obtain better tracking accuracy, can faster realize the mistake of carrier synchronization
Journey.
A kind of carrier synchronization system estimated based on AGC frequency deviation, the system include sequentially connected preprocessing module, simulation
AGC gain modulation module, digital AGC gain modulation module, down conversion module, frequency deviation estimate module and phase-locked loop module,
Preprocessing module is for pre-processing received radiofrequency signal to obtain preprocessed signal, specifically, pretreatment
Received radiofrequency signal is become intermediate-freuqncy signal after mixing by module；
Simulation AGC gain modulation module is used to carry out preprocessed signal simulation AGC gain modulation, simulates AGC gain tune
The peak value of preprocessed signal is limited in the first predetermined voltage range by system；
Specifically, E being set by the threshold voltage, that is, delay voltage for simulating AGC gain modulation, preprocessed signal is S (n),
The amplification factor for simulating AGC gain modulation is G (n), amount of gain adjustment (dB) are as follows:
Δ G (n)=20 [log | S (n) |-logE] C
Wherein, C is a variable of the time constant of representative simulation AGC gain modulation；
As S (n) > E, illustrates that the amplification factor for simulating AGC gain modulation is bigger than normal, then need to reduce amplification factor, can pass through
The modulation voltage for increasing simulation AGC gain modulation is equivalent to the charging process of simulation AGC gain modulation；As S (n) < E, say
The amplification factor of bright simulation AGC gain modulation is less than normal, then needs to increase amplification factor, can be by reducing simulation AGC gain modulation
Modulation voltage is equivalent to the charging process of simulation AGC gain modulation；
As an example, the input dynamic range of simulation AGC gain modulation is 60dB, exports 3dB.
Digital AGC gain modulation module is used to carry out digital AGC gain modulation to the modulated signal of simulation AGC gain,
Digital AGC gain modulation will be simulated the modulated signal of AGC gain and is limited in the second predetermined voltage range；
For simulation AGC gain modulation, dynamic range is big, and the response time is slow, and modulated signal has certain
Shake, is extremely difficult to accurately modulate, and therefore, the simulation modulated signal of AGC gain is needed to carry out digital AGC gain tune
System；
The detailed process of digital AGC gain modulation are as follows: the simulation modulated signal of AGC gain is X (n), by X (n) and is increased
Beneficial factor M (n) is multiplied in proportion obtains output signal Y (n)；
The solution procedure of gain factor M (n) are as follows: with the initial value of gain factor M (n) be multiplied to obtain in proportion by X (n) defeated
Signal Y'(n out), output signal Y'(n) by Hilbert transformation and square root calculation after acquire output signal Y'(n) packet
Network generates an error signal (n), integrated and antilogarithm calculation process through logarithm operation compared with ideal reference levels R
Exact gain factor M (n) value is obtained, the too big then gain factor of envelope value is opposite to be reduced, the too small then gain factor phase of envelope value
To increase；
As an example, output signal Y'(n can also be realized using the average energy variation of signal in track window)
Envelope calculates, and refers to the sampling number of setting fixed number in certain time interval in window；The average energy of input signal in window
Computational algorithm are as follows:
Or
Or
Wherein, I is the in-phase component of signal in window, and Q is the quadrature component of signal in window；
As an example, the input dynamic range of digital AGC gain modulation is 10dB, exports 0.5dB.
Down conversion module is used to the modulated signal of digital AGC gain carrying out down-converted to obtain down-conversion signal；
Frequency deviation is estimated module and is connect for tracking the corresponding in-phase branch amplitude of down-conversion signal with quadrature branch amplitude
The frequency deviation discreet value of receiving end and transmitting terminal carrier signal, and then obtain the frequency deviation region of receiving end Yu transmitting terminal carrier signal；
Phase-locked loop module is used to carry out quickly tracking in frequency deviation region to realize that carrier synchronization demodulates, to improve this and be
The carrier synchronization demodulation accuracy and speed for received radiofrequency signal of uniting.
Signal the problems such as there are Doppler effect, transmitting terminal and receiving end reliabilities in transmission process that transmitting terminal is sent
Cause in down-conversion signal there are the residual carrier of a low frequency, specifically:
The carrier signal of transmitting terminal are as follows:The carrier signal of receiving end are as follows:
Wherein, I (t) is in-phase branch signal, wcFor the IF frequency of the carrier signal of transmitting terminal, wdReceiving end and transmission
The frequency deviation at end, Δ φ are the phase difference of receiving end and transmitting terminal carrier signal；
The signal obtained after mixing and filtering are as follows:Signal after down coversion containsPoint
Amount, therefore, the phase and frequency of spread spectrum code phase and residual carrier that receiving end needs accurate tracking to receive signal are just able to achieve
Reliable demodulation despreading, to restore carrier data；
Further, the corresponding in-phase branch amplitude of down-conversion signal is acquired to be respectively as follows: with quadrature branch amplitude
Amp_I (t)=cos (2 π Δ ft+ Δ φ+φ0)·cos[2πΔf(t-Ts)+Δφ+φ0]
+sin(2πΔft+Δφ+φ0)·sin[2πΔf(t-Ts)+Δφ+φ0]
=cos [2 π Δ ft+ Δ φ+φ0-2πΔf(t-Ts)-Δφ-φ0]
=cos (2 π Δ fTs)
Amp_Q (t)=cos (2 π Δ ft+ Δ φ+φ0)·sin[2πΔf(t-Ts)+Δφ+φ0]
-sin(2πΔft+Δφ+φ0)·cos[2πΔf(t-Ts)+Δφ+φ0]
=-sin [2 π Δ ft+ Δ φ+φ0-2πΔf(t-Ts)-Δφ-φ0]
=-sin (2 π Δ fTs)
Wherein, Δ f is the frequency deviation of receiving end and transmitting terminal carrier signal, and Δ φ is receiving end and transmitting terminal carrier signal
Phase difference, φ0For the original phase of carrier signal, N is the noise that carrier signal introduces in transmission process, and Ts is down coversion mistake
Corresponding character rate in journey；
Acquire the frequency deviation of receiving end Yu transmitting terminal carrier signal are as follows:
The corresponding in-phase branch amplitude of tracking down-conversion signal and quadrature branch amplitude can be received end and transmitting terminal
The frequency deviation region of carrier signal, demodulation phaselocked loop NCO is quickly tracked in the frequency deviation region, to improve received radio frequency
The carrier synchronization demodulation accuracy and speed of signal.
Capture down-conversion signal simultaneously obtains offset estimation value by operation according to frequency discrimination algorithm, by this estimated value compensation to lock
In phase ring NCO, then it is exactly the difference of practical frequency deviation He this estimated value that phaselocked loop, which needs the frequency deviation tracked, this is one relatively small
Frequency deviation, phase-locked loop can track under higher precision.Due to only doing limited times offset estimation, do not need to do frequency discrimination fortune in real time
It calculates, i.e., in the detection-phase of down-conversion signal, frequency deviation is estimated according to frequency discrimination algorithm using the output result of correlator, by phaselocked loop
The frequency deviation for needing to track narrows down in a certain range, can obtain superior performance, increase of the method to hardware design complexity
Seldom.In practical applications, it is contemplated that the estimation of the influence of noise, frequency deviation should take the mean value repeatedly calculated.Theoretically calculate
The more results of number are closer to actual value, but the system for using time-division system, synchronous for system in each frame data
Frame head part cannot be too long, otherwise the effective bandwidth of system will take limited times average value with reality by serious curtailments, therefore
The Fast synchronization of existing system.
As it will be easily appreciated by one skilled in the art that the foregoing is merely illustrative of the preferred embodiments of the present invention, not to
The limitation present invention, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should all include
Within protection scope of the present invention.
Claims (10)
1. a kind of carrier synchronization method estimated based on AGC frequency deviation, which is characterized in that specific steps are as follows:
S1. received radiofrequency signal is pre-processed to obtain preprocessed signal, simulation AGC gain tune is carried out to preprocessed signal
The peak value of preprocessed signal is limited in the first predetermined voltage range by system, simulation AGC gain modulation；
S2. digital AGC gain modulation is carried out to the modulated signal of simulation AGC gain, digital AGC gain modulation will simulate AGC
Signal after gain modulation is limited in the second predetermined voltage range；
S3. the modulated signal of digital AGC gain is subjected to down-converted and obtains down-conversion signal, track down-conversion signal pair
The in-phase branch amplitude and quadrature branch amplitude answered obtain the frequency deviation discreet value of receiving end Yu transmitting terminal carrier signal, and then obtain
The frequency deviation region of receiving end and transmitting terminal carrier signal carries out quickly tracking to realize carrier wave in frequency deviation region using phaselocked loop
Synchronous demodulation, to improve the carrier synchronization demodulation accuracy and speed of received radiofrequency signal.
2. a kind of carrier synchronization method estimated based on AGC frequency deviation according to claim 1, which is characterized in that described right
Received radiofrequency signal is pre-processed specifically: received radiofrequency signal is become intermediate-freuqncy signal after mixing.
3. a kind of carrier synchronization method estimated based on AGC frequency deviation according to claim 1 or 2, which is characterized in that described
Simulate the amount of gain adjustment of AGC gain modulation are as follows:
Δ G (n)=20 [log | S (n) |-logE] C
Wherein, E is the threshold voltage for simulating AGC gain modulation, and S (n) is preprocessed signal, and C is the modulation of representative simulation AGC gain
Time constant a variable.
4. a kind of carrier synchronization method estimated based on AGC frequency deviation according to any one of claim 1-3, feature are existed
In the detailed process of digital AGC gain modulation are as follows: the simulation modulated signal of AGC gain is X (n), by X (n) and gain factor
M (n) is multiplied in proportion obtains output signal Y (n)；
The confirmation process of gain factor M (n) are as follows: be multiplied X (n) in proportion with the initial value of gain factor M (n) to obtain output letter
Number Y'(n), output signal Y'(n) by acquiring output signal Y'(n after Hilbert transformation and square root calculation) and envelope, warp
Logarithm operation generates an error signal (n) compared with ideal reference levels R, and error signal (n) is integrated and antilogarithm is transported
Calculation handles to obtain gain factor M (n) value.
5. a kind of carrier synchronization method estimated based on AGC frequency deviation, feature described in any one of -4 are existed according to claim 1
In the frequency deviation discreet value Δ f of receiving end and transmitting terminal carrier signal specifically:
Wherein, Amp_I (t) and Amp_Q (t) are respectively the corresponding in-phase branch amplitude of down-conversion signal and quadrature branch amplitude,
Ts is corresponding character rate in downconversion process.
6. a kind of carrier synchronization system estimated based on AGC frequency deviation, the system include sequentially connected preprocessing module, simulation
AGC gain modulation module, digital AGC gain modulation module, down conversion module, frequency deviation estimate module and phase-locked loop module, special
Sign is,
The preprocessing module to received radiofrequency signal for being pre-processed to obtain preprocessed signal；
The simulation AGC gain modulation module is used to carry out preprocessed signal simulation AGC gain modulation, simulates AGC gain tune
The peak value of preprocessed signal is limited in the first predetermined voltage range by system；
The digital AGC gain modulation module is used to carry out digital AGC gain modulation to the modulated signal of simulation AGC gain,
Digital AGC gain modulation will be simulated the modulated signal of AGC gain and is limited in the second predetermined voltage range；
The down conversion module is used to the modulated signal of digital AGC gain carrying out down-converted to obtain down-conversion signal；
The frequency deviation is estimated module and is connect for tracking the corresponding in-phase branch amplitude of down-conversion signal with quadrature branch amplitude
The frequency deviation discreet value of receiving end and transmitting terminal carrier signal, and then obtain the frequency deviation region of receiving end Yu transmitting terminal carrier signal；
The phase-locked loop module is used to carry out quickly tracking in frequency deviation region to realize that carrier synchronization demodulates, to improve this and be
The carrier synchronization demodulation accuracy and speed for received radiofrequency signal of uniting.
7. a kind of carrier synchronization system estimated based on AGC frequency deviation according to claim 6, which is characterized in that described right
Received radiofrequency signal is pre-processed specifically: received radiofrequency signal is become intermediate-freuqncy signal after mixing.
8. a kind of carrier synchronization system estimated based on AGC frequency deviation according to claim 6 or 7, which is characterized in that described
Simulate the amount of gain adjustment of AGC gain modulation are as follows:
Δ G (n)=20 [log | S (n) |-logE] C
Wherein, E is the threshold voltage for simulating AGC gain modulation, and S (n) is preprocessed signal, and C is the modulation of representative simulation AGC gain
Time constant a variable.
9. a kind of carrier synchronization system estimated based on AGC frequency deviation a method according to any one of claims 6-8, feature are existed
In the detailed process of digital AGC gain modulation are as follows: the simulation modulated signal of AGC gain is X (n), by X (n) and gain factor
M (n) is multiplied in proportion obtains output signal Y (n)；
The confirmation process of gain factor M (n) are as follows: be multiplied X (n) in proportion with the initial value of gain factor M (n) to obtain output letter
Number Y'(n), output signal Y'(n) by acquiring output signal Y'(n after Hilbert transformation and square root calculation) and envelope, warp
Logarithm operation generates an error signal (n) compared with ideal reference levels R, and error signal (n) is integrated and antilogarithm is transported
Calculation handles to obtain gain factor M (n) value.
10. a kind of carrier synchronization system estimated based on AGC frequency deviation, feature according to any one of claim 6-9
It is, the frequency deviation discreet value Δ f of receiving end and transmitting terminal carrier signal specifically:
Wherein, Amp_I (t) and Amp_Q (t) are respectively the corresponding in-phase branch amplitude of down-conversion signal and quadrature branch amplitude,
Ts is corresponding character rate in downconversion process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910453119.7A CN110224807A (en) | 2019-05-28 | 2019-05-28 | A kind of carrier synchronization method estimated based on AGC frequency deviation and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910453119.7A CN110224807A (en) | 2019-05-28 | 2019-05-28 | A kind of carrier synchronization method estimated based on AGC frequency deviation and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110224807A true CN110224807A (en) | 2019-09-10 |
Family
ID=67818336
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910453119.7A Pending CN110224807A (en) | 2019-05-28 | 2019-05-28 | A kind of carrier synchronization method estimated based on AGC frequency deviation and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110224807A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112787610A (en) * | 2020-12-22 | 2021-05-11 | 湖南艾科诺维科技有限公司 | Parallel implementation device and method for constantly establishing time digital AGC loop |
| CN113922887A (en) * | 2021-10-22 | 2022-01-11 | 中国科学院西安光学精密机械研究所 | Carrier synchronization method and system for spatial coherent optical communication 2PSK modulation signal |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040137851A1 (en) * | 2002-10-29 | 2004-07-15 | Akhter Mohammad Shahanshah | Frequency offset controller |
| CN1642156A (en) * | 2004-01-14 | 2005-07-20 | 北京大学 | Carrier wave catching device and method for large dynamic signal under condition of large frequency deviation |
| US20080260069A1 (en) * | 1999-01-19 | 2008-10-23 | Matsushita Electric Industrial Co., Ltd. | Apparatus and method for digital wireless communication |
| CN104734788A (en) * | 2015-03-27 | 2015-06-24 | 北京理工大学 | Frequency offset correction device and correction method used for multi-channel amplitude and phase test system |
| CN109412635A (en) * | 2018-12-24 | 2019-03-01 | 南京屹信航天科技有限公司 | A kind of spaceborne measuring and controlling equipment |
| CN109547375A (en) * | 2018-11-28 | 2019-03-29 | 深圳市太赫兹科技创新研究院 | A kind of parallel carriers restoration methods, device and terminal device |
-
2019
- 2019-05-28 CN CN201910453119.7A patent/CN110224807A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080260069A1 (en) * | 1999-01-19 | 2008-10-23 | Matsushita Electric Industrial Co., Ltd. | Apparatus and method for digital wireless communication |
| US20040137851A1 (en) * | 2002-10-29 | 2004-07-15 | Akhter Mohammad Shahanshah | Frequency offset controller |
| CN1642156A (en) * | 2004-01-14 | 2005-07-20 | 北京大学 | Carrier wave catching device and method for large dynamic signal under condition of large frequency deviation |
| CN104734788A (en) * | 2015-03-27 | 2015-06-24 | 北京理工大学 | Frequency offset correction device and correction method used for multi-channel amplitude and phase test system |
| CN109547375A (en) * | 2018-11-28 | 2019-03-29 | 深圳市太赫兹科技创新研究院 | A kind of parallel carriers restoration methods, device and terminal device |
| CN109412635A (en) * | 2018-12-24 | 2019-03-01 | 南京屹信航天科技有限公司 | A kind of spaceborne measuring and controlling equipment |
Non-Patent Citations (5)
| Title |
|---|
| HLAING MINN等: ""In-Phase and Quadrature Timing Mismatch"", 《IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS》 * |
| 喻斌等: ""数字AGC的分析和设计"", 《桂林电子工业学院学报》 * |
| 居行波: ""基于FPGA的邻近空间自适应传输关键技术研究与实现"", 《中国优秀硕士学位论文全文数据库》 * |
| 胡景明: ""高阶调制APSK信号载波同步算法研究"", 《计算机科学》 * |
| 鲁铖: ""基于雷达一体化体制下的调制解调分析"", 《中国优秀硕士学位论文全文数据库》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112787610A (en) * | 2020-12-22 | 2021-05-11 | 湖南艾科诺维科技有限公司 | Parallel implementation device and method for constantly establishing time digital AGC loop |
| CN113922887A (en) * | 2021-10-22 | 2022-01-11 | 中国科学院西安光学精密机械研究所 | Carrier synchronization method and system for spatial coherent optical communication 2PSK modulation signal |
| CN113922887B (en) * | 2021-10-22 | 2023-01-06 | 中国科学院西安光学精密机械研究所 | Carrier synchronization method and system for spatial coherent optical communication 2PSK modulation signal |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4896336A (en) | Differential phase-shift keying demodulator | |
| EP0966819B1 (en) | Phase-locked loop with continuously adjustable bandwith | |
| CA2461336C (en) | Automatic frequency correction method and apparatus for time division duplex modes of 3g wireless communications | |
| US20020122505A1 (en) | Frequency and phase estimation for MPSK signals | |
| CN110071738A (en) | Spread-spectrum signal based on more pseudo-code branch receivers de-spreads tracking | |
| CN108270715A (en) | It is suitble to the carrier recovery system and method for high-order 4096-QAM | |
| US6160838A (en) | Spread spectrum transmitter, spread spectrum receiver and spread spectrum communication method and automatic gain control circuit for spread spectrum receiver | |
| US20220416896A1 (en) | Method and apparatus for satellite laser broadband demodulation | |
| CN110300079B (en) | MSK signal coherent demodulation method and system | |
| CN104104493A (en) | Carrier synchronization method and device for deep space communication | |
| US6021157A (en) | Fast phase estimation in digital communication systems | |
| US5313493A (en) | Plural-differential, phase-shift-keyed modulation, communication system | |
| CN110224807A (en) | A kind of carrier synchronization method estimated based on AGC frequency deviation and system | |
| CN104601506A (en) | Non-data aided OQPSK (Offset Quadra Phase Shift Keying) signal closed loop carrier synchronization method | |
| US6301311B1 (en) | Non-coherent, non-data-aided pseudo-noise synchronization and carrier synchronization for QPSK or OQPSK modulated CDMA system | |
| CN108650203B (en) | Modulation mode identification method based on reconnaissance receiver | |
| CN112803968B (en) | Airborne measurement and control method for unmanned aerial vehicle | |
| CN107528805B (en) | PSK signal synchronization method and device suitable for signal analyzer | |
| CN112839001A (en) | Airborne measurement and control terminal of unmanned aerial vehicle | |
| CN107733824A (en) | A kind of carrier synchronization method based on AFC loops | |
| US20010004377A1 (en) | High-speed cell searching apparatus and method using DPSK-based distributed sample acquisition | |
| CN105471470A (en) | Spread spectrum signal frequency offset estimation method based on decision feedback | |
| Xia et al. | An Improved Digital Carrier Synchronization Method for UQPSK | |
| Gorantla et al. | Synchronization in IEEE 802.15. 4 Zigbee transceiver using MATLAB Simulink | |
| CN111131113B (en) | PM system downlink ranging signal modulation degree control system |
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 |
Application publication date: 20190910 |
|
| RJ01 | Rejection of invention patent application after publication |