CN109525533A - A kind of carrier phase error extraction system applied to MAPSK modulation - Google Patents
A kind of carrier phase error extraction system applied to MAPSK modulation Download PDFInfo
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- CN109525533A CN109525533A CN201811505695.3A CN201811505695A CN109525533A CN 109525533 A CN109525533 A CN 109525533A CN 201811505695 A CN201811505695 A CN 201811505695A CN 109525533 A CN109525533 A CN 109525533A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
- H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
- H04L27/38—Demodulator circuits; Receiver circuits
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1851—Systems using a satellite or space-based relay
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Abstract
A kind of carrier phase error extraction system applied to MAPSK modulation, is related to satellite communication field；Including multiplier, first filter, frequency discriminator, numerical control oscillator, second filter, phase discriminator and clock recovery module；The present invention can be used for unbound nucleus, can be used for data-aided scene, in addition concentrates on and solves the synchronous residual carrier phase error extraction of essence；The present invention utilizes the constellation characterization of the MPSK/MAPSK signal in satellite communication system simultaneously, constellation map simplifying, segmentation are carried out to different modulating mode signal respectively, avoid the complicated calculations that carrier error signal extraction is directly carried out using original planisphere, Project Realization flexibility is considerably increased, Product rapid realization is conducive to；The present invention is realized extracts component relevant to phase from the different mode signal received, to realize carrier track and locking.
Description
Technical field
The present invention relates to a kind of satellite communication field, especially a kind of carrier phase error applied to MAPSK modulation is mentioned
Take system.
Background technique
Field of broadcast communication generally will use a variety of code modulation modes and operating mode etc..It is new for satellite communication system
Increased debud mode needs the simplification being simple and efficient to the algorithm of realization, to be finally able to achieve as product.
Digital baseband signal is modulated by high frequency carrier, and after being launched away, receiving end receives high-frequency signal, and converts
After digital signal, following steps are generally had, high-frequency signal first will be processed into baseband signal.But due to receiving end
With the crystal oscillator of transmitting terminal, frequency mixer, low noise block difference and unstability, and be accumulated the transmission through long-distance,
The Doppler frequency departure that satellite-signal introduces in transmission process, the reception system of satellite communication system will handle biggish
Frequency deviation.Since there are biggish frequency deviations under initial situation, only passes through a Frequency Synchronization, be that residual frequency deviation can not be subtracted
In the range of arriving subsequent phase synchronization module less and can permit, so general synchronization can be divided into two parts: thick synchronization and essence are same
Step.In addition, having data auxiliary and two kinds of algorithms of unbound nucleus.The present invention can be used for unbound nucleus, can be used for counting
According to the scene of auxiliary, in addition concentrates on and solve the synchronous residual carrier phase error extraction of essence.
Satellite communication system introduces a variety of digital modulation patterns, including MPSK and MAPSK.Due to MPSK/MAPSK's
Signal points are numerous, and distance is smaller between constellation point, and is divided into multiple ring layers (MPSK only has outer ring), carry in this way to residual
The Project Realization that wave phase error is extracted brings larger difficulty, has very good solution there is no the relevant technologies team difficult point at present
Method.
Summary of the invention
It is an object of the invention to overcome the above-mentioned deficiency of the prior art, a kind of carrier wave applied to MAPSK modulation is provided
Phase error extraction system realizes and extracts component relevant to phase from the different mode signal received, to realize
Carrier track and locking.
Above-mentioned purpose of the invention is achieved by following technical solution:
A kind of carrier phase error extraction system applied to MAPSK modulation, including multiplier, first filter, frequency discrimination
Device, numerical control oscillator, second filter, phase discriminator and clock recovery module；
Multiplier: receiving the baseband signal r (t) that external receiver transmits, and carries out residual carrier to baseband signal r (t) and disappears
Except processing, carrier recovery signal is generated；And carrier recovery signal is sent to clock recovery module；Digital controlled oscillator is received to transmit
Mixed frequency signal；Receive the baseband signal r (t) that the external receiver of subsequent time transmits；By mixed frequency signal and next period
Baseband signal r (t) is multiplied again, and realization compensates the carrier wave and phase offset of baseband signal；Generate compensated carrier wave
Restore signal；And compensated carrier recovery signal is sent to clock recovery module；
Clock recovery module: the carrier recovery signal that multiplier transmits is received, carrier recovery signal is carried out at bit synchronization
Reason generates optimum sampling signal；And optimum sampling signal is respectively sent to frequency discriminator, phase discriminator and external demodulator；It receives
The compensated carrier recovery signal that multiplier transmits carries out bit synchronization processing, generates next period optimum sampling signal；And it will
Next period optimum sampling signal is sent to external demodulator；
Frequency discriminator: receiving the optimum sampling signal that clock recovery module transmits, and carries out carrier wave frequency deviation to optimum sampling signal
Estimation processing, generates offset estimation signal, and offset estimation signal is sent to first filter；
Phase discriminator: the optimum sampling signal that clock recovery module transmits is received, remnants are successively carried out to optimum sampling signal
Small frequency deviation and Phase Tracking extraction process generate phase error signal, and phase error signal are sent to second filter；
First filter: receiving the offset estimation signal that frequency discriminator transmits, and to being filtered, it is thick to generate carrier wave frequency deviation
Synchronizing frequency control word, and the thick synchronizing frequency control word of carrier wave frequency deviation is sent to digital controlled oscillator；
Second filter: receiving the phase error signal that phase discriminator transmits, be filtered to phase error signal, raw
At residual carrier essence synchronizing frequency control word；And residual carrier essence synchronizing frequency control word is sent to digital controlled oscillator；
Digital controlled oscillator: the thick synchronizing frequency control word of carrier wave frequency deviation that first filter transmits is received；Receive the second filtering
The residual carrier essence synchronizing frequency control word that device transmits；Mixed frequency signal is generated, and mixed frequency signal is sent to multiplier.
In a kind of above-mentioned carrier phase error extraction system applied to MAPSK modulation, system circulation is realized to each
The baseband signal in period carries out carrier wave and phase offset compensation；And the optimum sampling signal in each period is sent to external demodulation
Device.
In a kind of above-mentioned carrier phase error extraction system applied to MAPSK modulation, the baseband signal r (t)
Expression formula are as follows:
In formula, fcFor remaining carrier wave frequency deviation；
For residual carrier phase；
αIIt (t) is I circuit-switched data amplitude；
αQIt (t) is Q circuit-switched data amplitude；And αQ(t)=αI(t)。
In a kind of above-mentioned carrier phase error extraction system applied to MAPSK modulation, the frequency of the frequency discriminator detection
Inclined range is transmit symbol rate -10%~10%.
In a kind of above-mentioned carrier phase error extraction system applied to MAPSK modulation, the first filter is used
The hamming window function of 16 ranks.
In a kind of above-mentioned carrier phase error extraction system applied to MAPSK modulation, the phase discriminator is detected residual
Remaining frequency deviation region is -0.5%~the 0.5% of symbol rate.
In a kind of above-mentioned carrier phase error extraction system applied to MAPSK modulation, the second filter is being caught
The cut-off frequecy of passband for obtaining the stage is 1.5 Δ f；It is 1.1 Δ f in the cut-off frequecy of passband of tracking phase.
In a kind of above-mentioned carrier phase error extraction system applied to MAPSK modulation, the Δ f is 0.5 times steady
Surely symbol rate is transmitted.
The invention has the following advantages over the prior art:
(1) present invention provides a kind of carrier phase error method applied to satellite communication system, utilizes satellite communication system
The constellation characterization of MPSK/MAPSK signal in system carries out constellation map simplifying, segmentation to different modulating mode signal respectively, avoids
The direct complicated calculations that carrier error signal extraction is carried out using original planisphere, considerably increase Project Realization flexibility,
Be conducive to Product rapid realization；
(2) versatility of the present invention is preferable, and the carrier error for extending to the signal of similar modulation mode extracts problem；
(3) the method for the present invention simplifies, is high-efficient, and the signal carrier error of Different Modulations is extracted problem and returned by this method
One changes to the characteristic as QPSK, and the carrier error of different modulating mode is extracted problem normalized, simplifies problem, real
It is now simple.
Detailed description of the invention
Fig. 1 is carrier phase error extraction system schematic diagram of the present invention.
Specific embodiment
The present invention is described in further detail in the following with reference to the drawings and specific embodiments:
The present invention provides a kind of carrier phase error extraction system applied to MAPSK modulation, the phase applied to carrier wave
Capture and tracking.By the constellation characterization using a variety of MPSK/MAPSK modulation system signals in satellite communication system, respectively
Simple multiply-add subtraction process is carried out to different modulating mode signal, the data for being similar to QPSK constellation point is obtained, utilizes
The phase error of QPSK extracts the calculating extraction that feature carries out phase error, realizes that the phase error of satellite communication system signal mentions
It takes.The complexity that previous phase error is extracted is simplified, and the phase error that can be extended to the signal of similar type extracts problem.
As shown in Figure 1 be carrier phase error extraction system schematic diagram, as seen from the figure, it is a kind of applied to MAPSK modulation
Carrier phase error extraction system, including multiplier, first filter, frequency discriminator, numerical control oscillator, second filter, phase demodulation
Device and clock recovery module；
Multiplier: the baseband signal r (t) that external receiver transmits is received；The expression formula of the baseband signal r (t) are as follows:
In formula, fcFor remaining carrier wave frequency deviation；
For residual carrier phase；
αIIt (t) is I circuit-switched data amplitude；
αQIt (t) is Q circuit-switched data amplitude；And αQ(t)=αI(t)。
Residual carrier Processing for removing is carried out to baseband signal r (t), generates carrier recovery signal；And by carrier recovery signal
It is sent to clock recovery module；Receive the mixed frequency signal that digital controlled oscillator transmits；The external receiver for receiving subsequent time transmits
Baseband signal r (t)；Mixed frequency signal and the baseband signal r (t) in next period are multiplied again, realize the load to baseband signal
Wave and phase offset compensate；Generate compensated carrier recovery signal；And compensated carrier recovery signal is sent to
Clock recovery module.
Clock recovery module: the carrier recovery signal that multiplier transmits is received, carrier recovery signal is carried out at bit synchronization
Reason generates optimum sampling signal；And optimum sampling signal is respectively sent to frequency discriminator, phase discriminator and external demodulator；It receives
The compensated carrier recovery signal that multiplier transmits carries out bit synchronization processing, generates next period optimum sampling signal；And it will
Next period optimum sampling signal is sent to external demodulator；
Frequency discriminator: receiving the optimum sampling signal that clock recovery module transmits, and carries out carrier wave frequency deviation to optimum sampling signal
Estimation processing, generates offset estimation signal, and offset estimation signal is sent to first filter；The frequency deviation model of frequency discriminator detection
It encloses to transmit -10%~the 10% of symbol rate.
Phase discriminator: the optimum sampling signal that clock recovery module transmits is received, remnants are successively carried out to optimum sampling signal
Small frequency deviation and Phase Tracking extraction process generate phase error signal, and phase error signal are sent to second filter；Mirror
The residual frequency deviation range of phase device detection is -0.5%~the 0.5% of symbol rate.
First filter: receiving the offset estimation signal that frequency discriminator transmits, and to being filtered, it is thick to generate carrier wave frequency deviation
Synchronizing frequency control word, and the thick synchronizing frequency control word of carrier wave frequency deviation is sent to digital controlled oscillator；First filter uses 16
The hamming window function of rank.
Second filter: receiving the phase error signal that phase discriminator transmits, be filtered to phase error signal, raw
At residual carrier essence synchronizing frequency control word；And residual carrier essence synchronizing frequency control word is sent to digital controlled oscillator；It is described
Second filter is 1.5 Δ f in the cut-off frequecy of passband of acquisition phase；It is 1.1 Δ f in the cut-off frequecy of passband of tracking phase；
Δ f is that 0.5 times stablize transmits symbol rate.
Digital controlled oscillator: the thick synchronizing frequency control word of carrier wave frequency deviation that first filter transmits is received；Receive the second filtering
The residual carrier essence synchronizing frequency control word that device transmits；Mixed frequency signal is generated, and mixed frequency signal is sent to multiplier.
System circulation is realized and carries out carrier wave and phase offset compensation to the baseband signal in each period；And by each period
Optimum sampling signal be sent to external demodulator.
Versatility of the present invention is preferable, and the carrier error that the present invention extends to the signal of similar modulation mode extracts problem；
The present invention simplifies, is high-efficient, and the signal carrier error of Different Modulations is extracted problem and normalized to and QPSK mono- by this method
The carrier error of different modulating mode is extracted problem normalized, simplifies problem by the characteristic of sample, is realized simple；
The content that description in the present invention is not described in detail belongs to the well-known technique of those skilled in the art.
Claims (8)
1. a kind of carrier phase error extraction system applied to MAPSK modulation, it is characterised in that: including multiplier, the first filter
Wave device, frequency discriminator, numerical control oscillator, second filter, phase discriminator and clock recovery module；
Multiplier: the baseband signal r (t) that external receiver transmits is received, baseband signal r (t) is carried out at residual carrier elimination
Reason generates carrier recovery signal；And carrier recovery signal is sent to clock recovery module；Reception digital controlled oscillator transmits mixed
Frequency signal；Receive the baseband signal r (t) that the external receiver of subsequent time transmits；By the base band of mixed frequency signal and next period
Signal r (t) is multiplied again, and realization compensates the carrier wave and phase offset of baseband signal；Generate compensated carrier auxiliary
Signal；And compensated carrier recovery signal is sent to clock recovery module；
Clock recovery module: receiving the carrier recovery signal that multiplier transmits, and carries out bit synchronization processing to carrier recovery signal, raw
At optimum sampling signal；And optimum sampling signal is respectively sent to frequency discriminator, phase discriminator and external demodulator；Receive multiplier
The compensated carrier recovery signal transmitted carries out bit synchronization processing, generates next period optimum sampling signal；And by next week
Phase optimum sampling signal is sent to external demodulator；
Frequency discriminator: receiving the optimum sampling signal that clock recovery module transmits, and carries out Nonlinear Transformation in Frequency Offset Estimation to optimum sampling signal
Processing generates offset estimation signal, and offset estimation signal is sent to first filter；
Phase discriminator: receiving the optimum sampling signal that clock recovery module transmits, and remaining small frequency is successively carried out to optimum sampling signal
Inclined and Phase Tracking extraction process generates phase error signal, and phase error signal is sent to second filter；
First filter: receiving the offset estimation signal that frequency discriminator transmits, and to being filtered, generates carrier wave frequency deviation and slightly synchronizes
Frequency control word, and the thick synchronizing frequency control word of carrier wave frequency deviation is sent to digital controlled oscillator；
Second filter: the phase error signal that phase discriminator transmits is received, phase error signal is filtered, is generated residual
Over-carriage wave essence synchronizing frequency control word；And residual carrier essence synchronizing frequency control word is sent to digital controlled oscillator；
Digital controlled oscillator: the thick synchronizing frequency control word of carrier wave frequency deviation that first filter transmits is received；Second filter is received to pass
The residual carrier essence synchronizing frequency control word come；Mixed frequency signal is generated, and mixed frequency signal is sent to multiplier.
2. a kind of carrier phase error extraction system applied to MAPSK modulation according to claim 1, feature exist
In: system circulation is realized and carries out carrier wave and phase offset compensation to the baseband signal in each period；And it is best by each period
Sampled signal is sent to external demodulator.
3. a kind of carrier phase error extraction system applied to MAPSK modulation according to claim 2, feature exist
In: the expression formula of the baseband signal r (t) are as follows:
In formula, fcFor remaining carrier wave frequency deviation；
For residual carrier phase；
αIIt (t) is I circuit-switched data amplitude；
αQIt (t) is Q circuit-switched data amplitude；And αQ(t)=αI(t)。
4. a kind of carrier phase error extraction system applied to MAPSK modulation according to claim 3, feature exist
In: the frequency deviation region of the frequency discriminator detection is transmit symbol rate -10%~10%.
5. a kind of carrier phase error extraction system applied to MAPSK modulation according to claim 4, feature exist
In: the first filter uses the hamming window function of 16 ranks.
6. a kind of carrier phase error extraction system applied to MAPSK modulation according to claim 5, feature exist
In: the residual frequency deviation range of the phase discriminator detection is -0.5%~the 0.5% of symbol rate.
7. a kind of carrier phase error extraction system applied to MAPSK modulation according to claim 6, feature exist
In: the second filter is 1.5 Δ f in the cut-off frequecy of passband of acquisition phase；It is in the cut-off frequecy of passband of tracking phase
1.1Δf。
8. a kind of carrier phase error extraction system applied to MAPSK modulation according to claim 7, feature exist
In: the Δ f is that 0.5 times stablize transmits symbol rate.
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Cited By (3)
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| CN111147415A (en) * | 2019-12-23 | 2020-05-12 | 东方红卫星移动通信有限公司 | Phase tracking method of low-orbit satellite MAPSK communication system |
| CN111901005A (en) * | 2019-05-06 | 2020-11-06 | 阿里巴巴集团控股有限公司 | Data transmission system, method and equipment |
| CN112468421A (en) * | 2020-11-27 | 2021-03-09 | 中国科学院国家空间科学中心 | Carrier phase recovery method and system based on Q power polarity judgment |
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