CN109525533B - Carrier phase error extraction system applied to MAPSK modulation - Google Patents

Carrier phase error extraction system applied to MAPSK modulation Download PDF

Info

Publication number
CN109525533B
CN109525533B CN201811505695.3A CN201811505695A CN109525533B CN 109525533 B CN109525533 B CN 109525533B CN 201811505695 A CN201811505695 A CN 201811505695A CN 109525533 B CN109525533 B CN 109525533B
Authority
CN
China
Prior art keywords
carrier
signal
frequency
phase
phase error
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.)
Active
Application number
CN201811505695.3A
Other languages
Chinese (zh)
Other versions
CN109525533A (en
Inventor
范利娜
刘小明
李涛
林金鹏
何京
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Space Star Technology Co Ltd
Original Assignee
Space Star Technology Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Space Star Technology Co Ltd filed Critical Space Star Technology Co Ltd
Priority to CN201811505695.3A priority Critical patent/CN109525533B/en
Publication of CN109525533A publication Critical patent/CN109525533A/en
Application granted granted Critical
Publication of CN109525533B publication Critical patent/CN109525533B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

A carrier phase error extraction system applied to MAPSK modulation relates to the satellite communication field; the digital controlled oscillator comprises a multiplier, a first filter, a frequency discriminator, a digital controlled oscillator, a second filter, a phase discriminator and a clock recovery module; the method can be used for non-data assistance and data assistance scenes, and is also focused on solving the extraction of the residual carrier phase error of fine synchronization; meanwhile, the constellation characteristics of MPSK/MAPSK signals in a satellite communication system are utilized to simplify and divide the constellation diagrams of the signals in different modulation modes respectively, so that the complex calculation of extracting carrier error signals by directly utilizing the original constellation diagrams is avoided, the engineering realization flexibility is greatly increased, and the rapid realization of products is facilitated; the invention realizes the extraction of phase-related components from the received signals of different modes, thereby realizing the carrier tracking and locking.

Description

Carrier phase error extraction system applied to MAPSK modulation
Technical Field
The invention relates to the field of satellite communication, in particular to a carrier phase error extraction system applied to MAPSK modulation.
Background
In the field of broadcast communication, a plurality of code modulation schemes, operation modes, and the like are generally used. Aiming at a newly-increased debugging mode of a satellite communication system, an implementation algorithm needs to be simplified simply and efficiently, so that the method can be finally implemented as a product.
After the digital baseband signal is modulated by a high-frequency carrier and transmitted, a receiving end receives the high-frequency signal and converts the high-frequency signal into a digital signal, and generally, the digital baseband signal includes the following steps that firstly, the high-frequency signal is processed into the baseband signal. However, due to differences and instability of the crystal oscillators, the mixers and the low noise modules at the receiving end and the transmitting end, and accumulation of Doppler frequency deviation introduced during transmission of satellite signals over a long distance, a receiving system of a satellite communication system needs to process a large frequency offset. Because there is a large frequency offset in the initial situation, and only once frequency synchronization is performed, it is impossible to reduce the residual frequency offset to the allowable range of the subsequent phase synchronization module, so the general synchronization will be divided into two parts: coarse synchronization and fine synchronization. In addition, there are two algorithms, data-aided and non-data-aided. The method can be used for non-data assistance and data assistance scenes, and is also focused on solving the extraction of the residual carrier phase error of fine synchronization.
Satellite communication systems have introduced a variety of digital modulation schemes including MPSK and MAPSK. Because the number of signal points of MPSK/MAPSK is large, the distance between constellation points is small, and the MPSK/MAPSK is divided into a plurality of circle layers (MPSK has only an outer circle), great difficulty is brought to the engineering realization of residual carrier phase error extraction, and no good solution to the difficulty of related technical teams exists at present.
Disclosure of Invention
The present invention aims to overcome the above disadvantages of the prior art, and provides a carrier phase error extraction system applied to MAPSK modulation, which realizes extraction of phase-related components from received signals of different modes, thereby realizing carrier tracking and locking.
The above purpose of the invention is realized by the following technical scheme:
a carrier phase error extraction system applied to MAPSK modulation comprises a multiplier, a first filter, a frequency discriminator, a numerical control oscillator, a second filter, a phase discriminator and a clock recovery module;
a multiplier: receiving a baseband signal r (t) transmitted by an external receiver, and performing residual carrier wave elimination processing on the baseband signal r (t) to generate a carrier wave recovery signal; and sending the carrier recovery signal to a clock recovery module; receiving a mixing signal transmitted by a numerical control oscillator; receiving a baseband signal r (t) transmitted by an external receiver at the next moment; performing complex multiplication on the mixing signal and a baseband signal r (t) of the next period to realize compensation on carrier and phase offset of the baseband signal; generating a compensated carrier recovery signal; and sending the compensated carrier recovery signal to a clock recovery module;
a clock recovery module: receiving a carrier recovery signal transmitted by the multiplier, and performing bit synchronization processing on the carrier recovery signal to generate an optimal sampling signal; respectively sending the optimal sampling signals to a frequency discriminator, a phase discriminator and an external demodulator; receiving the compensated carrier recovery signal transmitted from the multiplier, and performing bit synchronization processing to generate an optimal sampling signal of the next period; sending the optimal sampling signal of the next period to an external demodulator;
a frequency discriminator: receiving an optimal sampling signal transmitted by a clock recovery module, carrying out carrier frequency offset estimation processing on the optimal sampling signal to generate a frequency offset estimation signal, and transmitting the frequency offset estimation signal to a first filter;
a phase discriminator: receiving an optimal sampling signal transmitted by a clock recovery module, sequentially carrying out residual small frequency offset and phase tracking extraction processing on the optimal sampling signal to generate a phase error signal, and transmitting the phase error signal to a second filter;
a first filter: receiving a frequency offset estimation signal transmitted by a frequency discriminator, carrying out filtering processing on the frequency offset estimation signal to generate a carrier frequency offset coarse synchronization frequency control word, and transmitting the carrier frequency offset coarse synchronization frequency control word to a numerical control oscillator;
a second filter: receiving a phase error signal transmitted by a phase discriminator, and filtering the phase error signal to generate a residual carrier fine synchronization frequency control word; sending the residual carrier fine synchronization frequency control word to a numerical control oscillator;
a numerically controlled oscillator: receiving a carrier frequency offset coarse synchronization frequency control word transmitted by a first filter; receiving a residual carrier fine synchronization frequency control word transmitted by a second filter; a mixing signal is generated and sent to the multiplier.
In the carrier phase error extraction system applied to MAPSK modulation, the system is circulated, and carrier and phase offset compensation is carried out on the baseband signal in each period; and sends the best sampled signal for each cycle to an external demodulator.
In the above system for extracting carrier phase error applied to MAPSK modulation, the expression of the baseband signal r (t) is:
Figure BDA0001899401310000031
in the formula (f)cIs the residual carrier frequency offset;
Figure BDA0001899401310000032
is the residual carrier phase;
αI(t) is the I-way data amplitude;
αQ(t) is the Q data amplitude; and alpha isQ(t)＝αI(t)。
In the above system for extracting carrier phase error applied to MAPSK modulation, the frequency offset range detected by the frequency discriminator is-10% to 10% of the transmission symbol rate.
In the above-mentioned carrier phase error extraction system applied to MAPSK modulation, the first filter employs a hamming window function of 16 th order.
In the above system for extracting carrier phase error applied to MAPSK modulation, the range of residual frequency offset detected by the phase discriminator is-0.5% to 0.5% of the symbol rate.
In the above system for extracting carrier phase error applied to MAPSK modulation, the passband cut-off frequency of the second filter in the capturing phase is 1.5 Δ f; the passband cutoff frequency during the tracking phase is 1.1 Δ f.
In the above system for extracting carrier phase error applied to MAPSK modulation, Δ f is 0.5 times of stable transmission symbol rate.
Compared with the prior art, the invention has the following advantages:
(1) the invention provides a carrier phase error method applied to a satellite communication system, which simplifies and segments constellation diagrams of signals in different modulation modes respectively by using the constellation characteristics of MPSK/MAPSK signals in the satellite communication system, avoids the complex calculation of extracting carrier error signals by directly using the original constellation diagrams, greatly increases the engineering realization flexibility and is beneficial to the quick realization of products;
(2) the invention has better universality and can be expanded to the problem of extracting the carrier error of signals in a similar modulation mode;
(3) the method is simple and high in efficiency, normalizes the signal carrier error extraction problems of various modulation modes to the characteristics same as QPSK, normalizes the carrier error extraction problems of different modulation modes, simplifies the problems and is simple to realize.
Drawings
Fig. 1 is a schematic diagram of a carrier phase error extraction system according to the present invention.
Detailed Description
The invention is described in further detail below with reference to the following figures and specific examples:
the invention provides a carrier phase error extraction system applied to MAPSK modulation, which is applied to phase capture and tracking of a carrier. The method comprises the steps of carrying out simple multiplication-addition-subtraction processing on signals of different modulation modes respectively by using the constellation characteristics of various MPSK/MAPSK modulation mode signals in the satellite communication system to obtain data approximate to QPSK constellation distribution points, and carrying out calculation extraction on phase errors by using the phase error extraction characteristics of QPSK to realize phase error extraction of signals of the satellite communication system. The complexity of the conventional phase error extraction is simplified, and the problem of phase error extraction of signals of similar types can be solved.
As shown in fig. 1, a schematic diagram of a carrier phase error extraction system, it can be known that a carrier phase error extraction system applied to MAPSK modulation includes a multiplier, a first filter, a frequency discriminator, a numerical control oscillator, a second filter, a phase discriminator, and a clock recovery module;
a multiplier: receiving a baseband signal r (t) transmitted by an external receiver; the expression of the baseband signal r (t) is:
Figure BDA0001899401310000041
in the formula (f)cIs the residual carrier frequency offset;
Figure BDA0001899401310000042
is the residual carrier phase;
αI(t) is the I-way data amplitude;
αQ(t) is the Q data amplitude; and alpha isQ(t)＝αI(t)。
Carrying out residual carrier wave elimination processing on the baseband signal r (t) to generate a carrier wave recovery signal; and sending the carrier recovery signal to a clock recovery module; receiving a mixing signal transmitted by a numerical control oscillator; receiving a baseband signal r (t) transmitted by an external receiver at the next moment; performing complex multiplication on the mixing signal and a baseband signal r (t) of the next period to realize compensation on carrier and phase offset of the baseband signal; generating a compensated carrier recovery signal; and sending the compensated carrier recovery signal to a clock recovery module.
A clock recovery module: receiving a carrier recovery signal transmitted by the multiplier, and performing bit synchronization processing on the carrier recovery signal to generate an optimal sampling signal; respectively sending the optimal sampling signals to a frequency discriminator, a phase discriminator and an external demodulator; receiving the compensated carrier recovery signal transmitted from the multiplier, and performing bit synchronization processing to generate an optimal sampling signal of the next period; sending the optimal sampling signal of the next period to an external demodulator;
a frequency discriminator: receiving an optimal sampling signal transmitted by a clock recovery module, carrying out carrier frequency offset estimation processing on the optimal sampling signal to generate a frequency offset estimation signal, and transmitting the frequency offset estimation signal to a first filter; the frequency deviation range detected by the frequency discriminator is-10% of the transmission symbol rate.
A phase discriminator: receiving an optimal sampling signal transmitted by a clock recovery module, sequentially carrying out residual small frequency offset and phase tracking extraction processing on the optimal sampling signal to generate a phase error signal, and transmitting the phase error signal to a second filter; the range of the residual frequency deviation detected by the phase discriminator is-0.5% of the symbol rate.
A first filter: receiving a frequency offset estimation signal transmitted by a frequency discriminator, carrying out filtering processing on the frequency offset estimation signal to generate a carrier frequency offset coarse synchronization frequency control word, and transmitting the carrier frequency offset coarse synchronization frequency control word to a numerical control oscillator; the first filter employs a hamming window function of order 16.
A second filter: receiving a phase error signal transmitted by a phase discriminator, and filtering the phase error signal to generate a residual carrier fine synchronization frequency control word; sending the residual carrier fine synchronization frequency control word to a numerical control oscillator; the passband cutoff frequency of the second filter during the acquisition phase is 1.5 Δ f; the passband cutoff frequency during the tracking phase is 1.1 Δ f; Δ f is 0.5 times the stable transmission symbol rate.
A numerically controlled oscillator: receiving a carrier frequency offset coarse synchronization frequency control word transmitted by a first filter; receiving a residual carrier fine synchronization frequency control word transmitted by a second filter; a mixing signal is generated and sent to the multiplier.
The system is circulated, and the carrier and phase offset compensation is carried out on the baseband signal of each period; and sends the best sampled signal for each cycle to an external demodulator.
The invention has better universality, and can be expanded to the problem of extracting the carrier error of signals in a similar modulation mode; the method is simple and high in efficiency, normalizes the signal carrier error extraction problems of various modulation modes to the characteristic same as QPSK, normalizes the carrier error extraction problems of different modulation modes, simplifies the problems and is simple to realize;
those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.

Claims (7)

1. A carrier phase error extraction system applied to MAPSK modulation is characterized in that: the digital controlled oscillator comprises a multiplier, a first filter, a frequency discriminator, a digital controlled oscillator, a second filter, a phase discriminator and a clock recovery module;
a multiplier: receiving a baseband signal r (t) transmitted by an external receiver, and performing residual carrier wave elimination processing on the baseband signal r (t) to generate a carrier wave recovery signal; and sending the carrier recovery signal to a clock recovery module; receiving a mixing signal transmitted by a numerical control oscillator; receiving a baseband signal r (t) transmitted by an external receiver at the next moment; performing complex multiplication on the mixing signal and a baseband signal r (t) of the next period to realize compensation on carrier and phase offset of the baseband signal; generating a compensated carrier recovery signal; and sending the compensated carrier recovery signal to a clock recovery module;
a clock recovery module: receiving a carrier recovery signal transmitted by the multiplier, and performing bit synchronization processing on the carrier recovery signal to generate an optimal sampling signal; respectively sending the optimal sampling signals to a frequency discriminator, a phase discriminator and an external demodulator; receiving the compensated carrier recovery signal transmitted from the multiplier, and performing bit synchronization processing to generate an optimal sampling signal of the next period; sending the optimal sampling signal of the next period to an external demodulator;
a frequency discriminator: receiving an optimal sampling signal transmitted by a clock recovery module, carrying out carrier frequency offset estimation processing on the optimal sampling signal to generate a frequency offset estimation signal, and transmitting the frequency offset estimation signal to a first filter;
a phase discriminator: receiving an optimal sampling signal transmitted by a clock recovery module, sequentially carrying out residual small frequency offset and phase tracking extraction processing on the optimal sampling signal to generate a phase error signal, and transmitting the phase error signal to a second filter;
a first filter: receiving a frequency deviation estimation signal transmitted by a frequency discriminator, carrying out filtering processing on the frequency deviation estimation signal to generate a carrier frequency deviation coarse synchronization frequency control word, and transmitting the carrier frequency deviation coarse synchronization frequency control word to a numerical control oscillator;
a second filter: receiving a phase error signal transmitted by a phase discriminator, and filtering the phase error signal to generate a residual carrier fine synchronization frequency control word; sending the residual carrier fine synchronization frequency control word to a numerical control oscillator;
a numerically controlled oscillator: receiving a carrier frequency offset coarse synchronization frequency control word transmitted by a first filter; receiving a residual carrier fine synchronization frequency control word transmitted by a second filter; a mixing signal is generated and sent to the multiplier.
2. The system according to claim 1, wherein the carrier phase error extraction system applied to MAPSK modulation is characterized in that: the system is circulated, and the carrier and phase offset compensation is carried out on the baseband signal of each period; and sends the best sampled signal for each cycle to an external demodulator.
3. The system according to claim 2, wherein the carrier phase error extraction system applied to MAPSK modulation is characterized in that: the expression of the baseband signal r (t) is:
Figure FDA0002872883590000021
in the formula (f)cIs the residual carrier frequency offset;
Figure FDA0002872883590000022
is the residual carrier phase;
αI(t) is the I-way data amplitude;
αQ(t) is the Q data amplitude; and alpha isQ(t)＝αI(t)。
4. A carrier phase error extraction system applied to MAPSK modulation according to claim 3, wherein: the frequency deviation range detected by the frequency discriminator is-10% of the transmission symbol rate.
5. The carrier phase error extraction system applied to MAPSK modulation according to claim 4, wherein: the first filter employs a hamming window function of order 16.
6. The system according to claim 5, wherein the carrier phase error extraction system applied to MAPSK modulation is characterized in that: the range of the residual frequency offset detected by the phase discriminator is-0.5% of the symbol rate.
7. The carrier phase error extraction system applied to MAPSK modulation according to claim 6, wherein: the passband cutoff frequency of the second filter during the acquisition phase is 1.5 Δ f; the passband cutoff frequency during the tracking phase is 1.1 Δ f; the Δ f is 0.5 times the stable transmission symbol rate.
CN201811505695.3A 2018-12-10 2018-12-10 Carrier phase error extraction system applied to MAPSK modulation Active CN109525533B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811505695.3A CN109525533B (en) 2018-12-10 2018-12-10 Carrier phase error extraction system applied to MAPSK modulation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811505695.3A CN109525533B (en) 2018-12-10 2018-12-10 Carrier phase error extraction system applied to MAPSK modulation

Publications (2)

Publication Number Publication Date
CN109525533A CN109525533A (en) 2019-03-26
CN109525533B true CN109525533B (en) 2021-03-26

Family

ID=65795405

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811505695.3A Active CN109525533B (en) 2018-12-10 2018-12-10 Carrier phase error extraction system applied to MAPSK modulation

Country Status (1)

Country Link
CN (1) CN109525533B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111901005B (en) * 2019-05-06 2023-02-28 阿里巴巴集团控股有限公司 Data transmission system, method and equipment
CN111147415B (en) * 2019-12-23 2022-05-31 东方红卫星移动通信有限公司 Phase tracking method of low-orbit satellite MAPSK communication system
CN112468421B (en) * 2020-11-27 2021-08-31 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

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102025672A (en) * 2009-09-09 2011-04-20 中国科学院微电子研究所 Pilot frequency-based method for performing OFDM residual phase tracking
CN107241286A (en) * 2017-04-20 2017-10-10 西安电子科技大学 A kind of combination frequency domain and the carrier synchronization method of time domain estimation
CN107733832A (en) * 2017-09-29 2018-02-23 深圳市统先科技股份有限公司 APSK receivers and its method for extracting local carrier-phase error

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8233568B2 (en) * 2008-09-05 2012-07-31 Rajendra Kumar Adaptive receiver for high-order modulated signals over fading channels

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102025672A (en) * 2009-09-09 2011-04-20 中国科学院微电子研究所 Pilot frequency-based method for performing OFDM residual phase tracking
CN107241286A (en) * 2017-04-20 2017-10-10 西安电子科技大学 A kind of combination frequency domain and the carrier synchronization method of time domain estimation
CN107733832A (en) * 2017-09-29 2018-02-23 深圳市统先科技股份有限公司 APSK receivers and its method for extracting local carrier-phase error

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
并行高速通信解调***中同步技术的研究与实现;肖磊;《万方》;20180208;全文 *

Also Published As

Publication number Publication date
CN109525533A (en) 2019-03-26

Similar Documents

Publication Publication Date Title
CN109525533B (en) Carrier phase error extraction system applied to MAPSK modulation
CN111343125B (en) 32APSK modulation system receiver synchronization method
CN101005480B (en) Demodulation circuit and demodulation method
US6714608B1 (en) Multi-mode variable rate digital satellite receiver
WO2018072448A1 (en) Frequency shift key modulation signal demodulation method and system
JPH0775359B2 (en) TDMA signal carrier reproduction system
CN112671446B (en) Demodulation device suitable for high-orbit inter-satellite link
WO2022036489A1 (en) Satellite laser broad band demodulation method, and apparatus
CN106656168B (en) Clock data recovery device and method
CN110636022A (en) Signal receiving method and device for reducing data demodulation threshold
JPH11136597A (en) Symbol timing recovery device and method
CN108337206B (en) Carrier synchronization method and device for satellite communication
CN112468421B (en) Carrier phase recovery method and system based on Q power polarity judgment
US8165259B2 (en) Method and device for processing the frequency shift of the carrier frequency of a signal modulated with a quadrature continuous single-carrier modulation
CN102316058B (en) Coherent demodulation device of non-geostationary orbit satellite DQPSK (Differential Quadrature Phase Shift Keying) communication
US7110475B2 (en) Digital TV receiver
CN114374590B (en) Symbol timing synchronization optimization method based on single-channel pilot frequency
CN1157943C (en) Selective gain adjustement to aid carrier acquisition in a high definition television receiver
CN108111459A (en) A kind of carrier synchronization method of the high speed 16apsk signals based on FPGA
KR20040070567A (en) Digital tv receiver
US7463692B2 (en) Device and method for symbol clock recovery in digital television
Paik et al. Implementation of Wide band Satellite Telemetry Data Receiver using SDR and Matlab
CN111801920A (en) Method and apparatus for signal demodulation
KR19990003694A (en) The phase and frequency detection device of a digital communication system
KR20040046316A (en) Digital tv receiver

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
GR01 Patent grant
GR01 Patent grant