WO2015013930A1 - 一种多波带ofdm接收机、频率偏移补偿方法及系统 - Google Patents

一种多波带ofdm接收机、频率偏移补偿方法及系统 Download PDF

Info

Publication number
WO2015013930A1
WO2015013930A1 PCT/CN2013/080551 CN2013080551W WO2015013930A1 WO 2015013930 A1 WO2015013930 A1 WO 2015013930A1 CN 2013080551 W CN2013080551 W CN 2013080551W WO 2015013930 A1 WO2015013930 A1 WO 2015013930A1
Authority
WO
WIPO (PCT)
Prior art keywords
frequency offset
optical comb
band
mutation
order
Prior art date
Application number
PCT/CN2013/080551
Other languages
English (en)
French (fr)
Other versions
WO2015013930A9 (zh
Inventor
易兴文
洪成
青华平
Original Assignee
华为技术有限公司
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 华为技术有限公司 filed Critical 华为技术有限公司
Priority to CN201380001287.3A priority Critical patent/CN104521206B/zh
Priority to ES13890447.9T priority patent/ES2644734T3/es
Priority to PCT/CN2013/080551 priority patent/WO2015013930A1/zh
Priority to EP13890447.9A priority patent/EP3021543B1/en
Publication of WO2015013930A1 publication Critical patent/WO2015013930A1/zh
Publication of WO2015013930A9 publication Critical patent/WO2015013930A9/zh
Priority to US15/010,248 priority patent/US9628316B2/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2657—Carrier synchronisation
    • H04L27/2659—Coarse or integer frequency offset determination and synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2657—Carrier synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/61—Coherent receivers
    • H04B10/615—Arrangements affecting the optical part of the receiver
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/61—Coherent receivers
    • H04B10/616—Details of the electronic signal processing in coherent optical receivers
    • H04B10/6164—Estimation or correction of the frequency offset between the received optical signal and the optical local oscillator
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/61—Coherent receivers
    • H04B10/64—Heterodyne, i.e. coherent receivers where, after the opto-electronic conversion, an electrical signal at an intermediate frequency [IF] is obtained
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0298—Wavelength-division multiplex systems with sub-carrier multiplexing [SCM]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2697—Multicarrier modulation systems in combination with other modulation techniques
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2668—Details of algorithms
    • H04L27/2681—Details of algorithms characterised by constraints
    • H04L27/2682—Precision

Definitions

  • Multi-band OFDM receiver frequency offset compensation method and system
  • the present invention relates to the field of network communication technologies, and in particular, to a multi-band OFDM receiver, a frequency offset compensation method, and a system.
  • OFDM Orthogonal Frequency Division Multiplexing
  • Orthogonal Frequency Division Multiplexing In the process of transmitting information by using Orthogonal Frequency Division Multiplexing (OFDM), it is necessary to modulate information onto a light comb line generated by a transmitter to form a multi-band signal, and at the receiving end, use the optical comb in the receiver. Signal demodulation is achieved with the beat frequency. Since the interval between the optical comb lines in the transmitter and the interval of the optical comb lines in the receiver are not exactly the same, the difference in the interval may degrade the performance of the receiver. In the prior art, frequency offset compensation is generally performed on a radio frequency driving signal for generating an optical comb line, but the accuracy of the existing compensation method is low.
  • OFDM Orthogonal Frequency Division Multiplexing
  • Embodiments of the present invention provide a multi-band OFDM receiver, a frequency offset compensation method, and a system, to solve the problem that the frequency offset compensation accuracy of a multi-band OFDM receiver RF drive signal is not high in the prior art.
  • a frequency offset compensation method is provided.
  • the frequency offset compensation method is used to compensate a frequency offset of a multi-band OFDM receiver optical comb generator radio frequency driving signal, and the method includes the following steps:
  • the optical comb line whose amplitude of the single-band band frequency shift is less than the mutation threshold is divided into a low-mutation optical comb line, which will be single Waveband frequency
  • An optical comb line whose offset time-varying curve mutation level is greater than the mutation threshold is divided into a high-mutation optical comb line;
  • step S4 further includes the following steps:
  • the step S1 includes:
  • the single-band phase estimation is performed by using the beat signals of the respective order optical comb lines and the corresponding signal bands, and phase information of each order of the comb lines is obtained;
  • phase of the training symbols in each phase of the optical comb line information is deduced by time and averaged to obtain a single-band estimated frequency offset of the optical comb lines.
  • the number of mutations of the frequency shift of the optical comb line frequency deviation in each unit time is taken as the single-band frequency of each order optical comb line. Offset curve change level with time;
  • the single-band frequency offset with time curve of the sudden change of the threshold value is greater than half of the number of information symbols contained in one frame.
  • the step S2 includes:
  • the low-mutation optical comb line and the high-mutation optical comb line are divided for the first time, if the single-band frequency shift of each order optical comb line changes with time, the level of the mutation is all greater than the frequency of the single-band frequency of the comb line.
  • the transition threshold of the time-varying curve is shifted, and the 0-order optical comb line and the ⁇ 1st-order optical comb line are divided into low-mutation optical comb lines, and the other-order optical comb lines are divided into high-mutation optical comb lines.
  • the method further includes:
  • the single-band phase obtained by phase unwrapping the single-band estimated frequency offset of each high-order abrupt optical comb line using the low-mutation optical comb phase information as the training symbol phase in the phase information of the corresponding optical comb line The steps S1 to S2 are repeated.
  • the step S3 includes:
  • the weighted average of the single-band estimated frequency offsets of the low-order abrupt optical comb lines includes:
  • the joint estimated frequency offset is obtained by weighted averaging the difference of the single-waveband estimated frequency offsets of the adjacent-order low-order optical comb lines in the respective order low-mutation optical comb lines.
  • the second aspect provides a frequency offset compensation system, including
  • the frequency offset estimation module is configured to perform single-band frequency offset estimation on each order optical comb line, and obtain a single-band estimated frequency offset of each order optical comb line, wherein the optical comb line is a spectral line of the optical frequency comb ;
  • the mutation level estimation dividing module is configured to divide the single-band band frequency offset with a time-varying curve whose mutation level is smaller than the mutation threshold into a low-mutation according to a sudden change threshold of the frequency shift of the single-band frequency shift of the optical comb line
  • the optical comb line divides the single-band frequency offset with a time-varying curve whose mutation level is greater than the mutation threshold into a high-mutation optical comb line;
  • the joint frequency offset estimation module is configured to perform joint frequency offset estimation by using a single-band estimated frequency offset of each order of low-mutation optical comb lines to obtain a joint estimated frequency offset;
  • the RF drive signal frequency offset compensation module is configured to compensate the RF drive signal frequency offset by using the joint estimated frequency offset.
  • the frequency offset estimation module performs single-band phase estimation by using a beat signal of each order optical comb line and a corresponding signal band, and obtains each order optical comb line. Phase information
  • phase of the training symbols in each phase of the optical comb line information is deduced by time and averaged to obtain a single-band estimated frequency offset of the optical comb lines.
  • the mutation level estimation dividing module uses the number of mutations of the frequency shift of the optical comb line frequency deviation per unit time as a single wave band of each order optical comb line Frequency shift curve as a function of time;
  • the single-band frequency offset with time curve of the sudden change of the threshold value is greater than half of the number of information symbols contained in one frame.
  • the mutation level estimation division module performs the first time of the low-mutation optical comb line and the high-mutation optical comb line division, if the single-band frequency of each order optical comb line is biased
  • the transition level of the shifting time curve is all greater than the sudden change of the frequency shift of the single-band frequency shift of the comb line, and the 0-order optical comb line and the ⁇ 1st-order optical comb line are divided into low-mutation optical comb lines, and other steps.
  • the number of optical comb lines is divided into high-mutation optical comb lines.
  • the frequency offset compensation system also includes:
  • phase unwinding module which uses the low-mutation optical comb phase information to phase unwrap the single-waveband estimated frequency offset of each high-order abrupt optical comb line;
  • the single-band phase obtained by phase unwrapping the single-band estimated frequency offset of each high-order abrupt optical comb line using the low-mutation optical comb phase information as the training symbol phase in the phase information of the corresponding optical comb line And sent to the frequency offset estimation module to perform single-band frequency offset estimation.
  • the joint frequency offset estimation module is configured to perform a single wave on the low order abrupt optical comb line A weighted average with an estimated frequency offset results in the joint estimated frequency offset.
  • the joint frequency offset estimation module is configured to the adjacent low order light in the low order abrupt optical comb line
  • the weighted average of the single-band estimated frequency offsets of the comb lines is weighted averaged to obtain the joint estimated frequency offset.
  • a third aspect provides a multi-band OFDM receiver, the multi-band OFDM receiver comprising the frequency offset compensation system.
  • the multi-band OFDM receiver, the frequency offset compensation method and the system according to the embodiment of the present invention divide the optical comb line into a low-mutation optical comb line and a high-mutation optical comb line according to a sudden change threshold of a single-band frequency shift with time curve.
  • Combining the frequency offset estimation of the single-band estimated frequency offset of each order low-mutation optical comb line, using the joint frequency estimation to compensate the RF driving signal increases the number of optical comb lines for joint frequency offset estimation, avoiding high
  • the abrupt optical comb line participates in the performance degradation of the joint frequency offset estimation, improves the accuracy of the frequency offset compensation of the RF driving signal, and the method cyclically compensates the frequency offset frequency of the RF driving signal, gradually reduces the frequency offset, and improves the frequency offset. Reliability and comprehensiveness of RF drive signal frequency offset frequency compensation.
  • FIG. 1 is a flow chart of an embodiment of a frequency offset compensation method according to the present invention.
  • FIG. 2 is a flow chart of another embodiment of a frequency offset compensation method according to the present invention.
  • FIG. 3 is a flow chart of still another embodiment of a frequency offset compensation method according to the present invention.
  • FIG. 4 is a schematic structural diagram of a module of an embodiment of a frequency offset compensation system according to the present invention.
  • FIG. 5 is a structural diagram of an embodiment of a multi-band OFDM receiver according to the present invention.
  • DETAILED DESCRIPTION OF THE INVENTION The following embodiments of the present invention provide a multi-band OFDM receiver, a frequency offset compensation method, and a system to improve the accuracy of RF drive signal compensation.
  • the frequency offset compensation method is used to compensate a frequency offset of a radio frequency driver signal of a multi-band OFDM receiver optical comb generator.
  • FIG. 1 is a flowchart of an embodiment of a frequency offset compensation method according to the present invention, as shown in FIG. 1, the method includes:
  • Step 101 Perform single-band frequency offset estimation on each order optical comb line to obtain a single-band estimated frequency offset of each order optical comb line, where the optical comb line is a spectral line of the optical frequency comb;
  • the single-band estimated frequency offset is an estimated value of the difference between the center frequency of a certain order optical comb and its corresponding signal light band
  • the method for performing single-band frequency offset estimation for each order of the optical comb line includes :
  • the single-band phase estimation is performed by using the beat signals of the respective order optical comb lines and the corresponding signal bands, and phase information of each order of the comb lines is obtained;
  • phase of the training symbols in each phase of the optical comb line information is deduced by time and averaged to obtain a single-band estimated frequency offset of the optical comb lines.
  • the estimated frequency offset of each order optical comb single band can also be obtained by using the following formula:
  • the phase information of the low-order optical comb line is the phase information caused by the frequency offset bias in the beat signal of the corresponding signal band, and the phase information can be obtained by setting the training symbol in the signal band.
  • the frequency signal is separated and obtained, for time, ⁇ / ⁇ is the estimated frequency offset of the m-order optical comb single wave band, and m is the order of the optical comb line;
  • Step 102 According to the sudden change threshold of the single-band frequency shift of the optical comb line with time, the optical comb line whose amplitude of the single-band frequency offset is less than the mutation threshold is divided into low-mutation optical comb lines, and The single-band frequency offset with time curve has a mutation level greater than the abrupt threshold, and the optical comb line is divided into high-mutation optical comb lines.
  • whether the mutation occurs by determining whether the phase change of the corresponding phase of the optical comb line of each order in the unit time exceeds the frequency jump threshold for example, a phase change of 2 11 ⁇ 0.1 or 2 11 ⁇ 0.2 may be taken.
  • the single-band band frequency offset of each order of the optical comb line is abruptly changing with time.
  • the number of times of the frequency shift of each order of the optical comb line per unit time is abrupt.
  • a person skilled in the art can set a single-band band frequency offset curve with a sudden change in time according to the selected device accuracy, the required frequency offset accuracy of the RF driving signal, and the empirical value, and the single-band band frequency offset changes with time.
  • the curve mutation threshold has a value range greater than half of the number of information symbols contained in one frame less than one frame.
  • the low-mutation optical comb line and the high-mutation optical comb line are divided for the first time, if the single-band frequency shift of each order optical comb line changes with time, the level of the mutation is all greater than the frequency of the single-band frequency of the comb line.
  • the transition threshold of the time-varying curve is shifted, and the 0-order optical comb line and the ⁇ 1st-order optical comb line are divided into low-mutation optical comb lines, and the other-order optical comb lines are divided into high-mutation optical comb lines.
  • the frequency offset of the frequency shift of the high-mutation optical comb is estimated to be abruptly changed with time, the frequent mutation may severely distort the signal, thereby affecting the reliability of the frequency offset estimation.
  • Sex By dividing the estimated frequency offset of each order of the optical comb line, it is divided into low-mutation high-order optical comb single-band estimated frequency offset and high-mutation high-order optical comb single-band estimated frequency offset, which makes the low division.
  • the abrupt high-order optical comb single-band estimation reduces the distortion of the frequency offset signal, thereby improving the reliability and accuracy of the frequency offset estimation.
  • Step 103 Perform joint frequency offset estimation by using a single-band estimated frequency offset of each step of the low-mutation optical comb line to obtain a joint estimated frequency offset.
  • the joint estimated frequency offset is the interval of the center frequency of the adjacent band of the signal light, that is, the difference between the frequency interval of the optical comb line of the transmitter and the frequency interval of the receiver optical comb line.
  • the joint estimated frequency offset can be obtained by weighted averaging the single-waveband estimated frequency offsets of the various order low-mutation optical comb lines.
  • the combined estimated frequency offset may also be obtained by weighted averaging the difference of the single-waveband estimated frequency offsets of adjacent low-order optical comb lines in the low-order optical comb lines.
  • the joint estimated frequency offset can also be obtained by weighted averaging using the following formula
  • ⁇ is the joint estimated frequency offset, which is a weight value
  • the frequency offset is estimated for the m-th order low-mutation optical comb single-band
  • m is the order of the optical comb.
  • the high-mutation optical comb single-band estimated frequency offset can also be added to the joint frequency offset estimation, and only the corresponding weight value is set to 0.
  • the joint frequency estimation is performed by estimating the frequency offset of the low-mutation optical comb single-band, and the optical comb line for estimating the frequency offset is added to the prior art, which improves the accuracy of the frequency estimation and avoids Lee
  • the instability of the frequency offset estimation is estimated by the high-mutation optical comb, thereby improving the accuracy of the frequency offset estimation and the tolerance to the laser wavelength shift.
  • the frequency offset of the optical comb line is estimated by using the frequency offset difference of the adjacent optical comb lines, the method can avoid the influence of the laser wavelength shift in the frequency offset estimation.
  • Step 104 Compensating for a frequency offset of the RF driving signal by using the joint estimated frequency offset.
  • the shifting of more optical comb lines for frequency offset estimation makes the obtained joint estimation frequency offset more accurate and reliable, it is better to compensate the frequency offset of the RF driving signal by using the joint estimated frequency offset.
  • the weighted average weight value in the joint frequency offset estimation represents the reliability of the frequency offset estimation of each order optical comb.
  • the method further comprises the step 105: repeating the steps 101 to 104.
  • the frequency offset compensation of the RF driving signal during the cycle causes the frequency offset of the optical comb line generated by the beam generator to be more
  • the frequency shift of the single-band frequency shift of the optical comb line is lower and lower with the change of the curve, and the number of low-mutation optical comb lines is more and more.
  • the RF drive signal is applied. The compensation of the frequency offset is more accurate and reliable.
  • the single-band estimated frequency of each of the low-mutation optical comb lines is divided into a low-mutation optical comb line and a high-mutation optical comb line according to the sudden change threshold of the single-band frequency shift with time curve.
  • Offset for joint frequency offset estimation using joint frequency estimation to compensate for RF drive signals increases the number of combs for joint frequency offset estimation, avoiding the performance degradation of high-abruption combs participating in joint frequency offset estimation
  • the accuracy of the frequency offset compensation of the RF driving signal is improved, and the method cyclically compensates the frequency offset frequency of the RF driving signal, gradually reduces the frequency offset, and improves the reliability and comprehensiveness of the frequency offset frequency compensation of the RF driving signal.
  • FIG. 2 it is a flowchart of another embodiment of a frequency offset compensation method according to the present invention. This embodiment is described based on the previous embodiment:
  • the method further includes:
  • Step 201 Perform phase unwrapping on the single-band estimated frequency offset of each high-order abrupt optical comb line by using the low-mutation optical comb line phase information;
  • the low-mutation optical comb phase information includes phase jump information of the low-order optical comb.
  • the high-mutation optical comb line will produce a winding phenomenon when the frequency offset is estimated, the winding phenomenon will frequently cause a large change in the curve of the frequency offset estimation over time, and a large number of frequent mutations occur at a limited digital sampling frequency.
  • the signal is severely distorted, which affects the reliability of the estimation. Therefore, it is necessary to phase unwind the high-mutation optical comb estimation frequency offset.
  • the phase curve of the high-mutation comb is unwound using a low-mutation comb phase curve to eliminate the mutation in the frequency-off curve, thereby making the high-mutation
  • the reliability of the frequency offset estimation provided by the optical comb line is improved to achieve the purpose of participating in the joint estimation.
  • the symbol phase is trained, and the steps S1 to S2 are repeated.
  • the phase curve is unwrapped, and then the frequency offset is estimated in the derivative until the mutation is smaller than the mutation threshold, and then the estimated value is added to the joint estimation. Calculate the frequency offset.
  • the number of estimated frequency offsets of the large-short high-order optical comb single-band is reduced, and more optical single-band estimated frequency offsets are further participated in the joint frequency offset.
  • the accuracy and reliability of the frequency offset estimation of the RF driving signal are improved, and the compensation degree of the frequency offset of the RF driving signal is more comprehensive and accurate.
  • FIG. 3 it is a flowchart of still another embodiment of a method for compensating a frequency offset of a radio frequency driving signal according to the present invention. This embodiment is described based on the previous embodiment:
  • Step 301 Set a 0th-order frequency offset threshold, and obtain a 0-order optical comb line single-band estimated frequency offset obtained in step 101.
  • Step 302 When the 0-order optical comb line single-band estimated frequency offset is greater than the 0-th order frequency offset threshold, adjust the center wavelength of the optical comb generator input laser to be aligned with the transmitting end center wavelength, and repeat step 101. Go to step 105.
  • the center wavelength of the laser is misaligned, so the laser is adjusted, and the RF drive is performed after the laser center wavelength is aligned. Estimation and compensation of signal frequency offset.
  • Step 303 When the 0-order optical comb line single-band estimated frequency offset is smaller than the 0-th order frequency offset threshold, step 104 divides the single-band estimated frequency offset of each order of the low-mutation optical comb line by a corresponding one. The order is summed to obtain the joint estimated frequency offset, that is, the joint estimated frequency offset is obtained by using the following formula:
  • ⁇ is the joint estimated frequency offset
  • ⁇ / TM is the m-order low-mutation optical comb single-band estimated frequency offset
  • m is the order of the optical comb line
  • m ⁇ 0 is the 0-order optical comb line estimate
  • the frequency offset compensation method divides the optical comb line into a low-mutation optical comb line and a high-mutation optical comb line for each order of low-mutation optical comb lines according to the sudden change threshold of the single-band frequency shift with time curve.
  • the band frequency estimation frequency offset is used for joint frequency offset estimation, and the joint frequency estimation is used to compensate the RF driving signal, which increases the number of optical comb lines for joint frequency offset estimation, and avoids the high-mutation optical comb line participating in joint frequency offset estimation.
  • the performance degradation occurs, the accuracy of the frequency offset compensation of the RF driving signal is improved, and the method cyclically compensates the frequency offset frequency of the RF driving signal, gradually reduces the frequency offset, and improves the frequency offset frequency compensation of the RF driving signal.
  • Sexuality and comprehensiveness occurs, the accuracy of the frequency offset compensation of the RF driving signal is improved, and the method cyclically compensates the frequency offset frequency of the RF driving signal, gradually reduces the frequency offset, and improves the frequency offset frequency compensation of the RF driving signal.
  • a block diagram of an embodiment of a frequency offset compensation system includes: a frequency offset estimation module 401, configured to perform single-band frequency offset estimation on each order of optical comb lines to obtain various order lights.
  • a single wave band of the comb line estimates a frequency offset, and the optical comb line is a spectral line of the optical frequency comb;
  • the mutation level estimation dividing module 402 is configured to divide the single-band band frequency offset from the optical comb line whose time-changing curve is less than the abrupt threshold according to the sudden change threshold of the frequency shift of the single-band frequency offset of the optical comb line a mutant optical comb line, wherein the single-band frequency shifting time-varying curve is higher than the abrupt threshold, and the optical comb line is divided into a high-mutation optical comb line;
  • the joint frequency offset estimation module 403 is configured to perform joint frequency offset estimation by using a single-band estimated frequency offset of each order of low-mutation optical comb lines to obtain a joint estimated frequency offset;
  • the RF drive signal frequency offset compensation module 404 is configured to compensate the RF drive signal frequency offset by using the joint estimated frequency offset.
  • the frequency offset estimation module 401 performs single-band phase estimation by using beat signals of respective order optical comb lines and corresponding signal bands to obtain phase information of each order optical comb line;
  • phase of the training symbols in each phase of the optical comb line information is deduced by time and averaged to obtain a single-band estimated frequency offset of the optical comb lines.
  • the mutation level estimation dividing module 402 uses the number of mutations of the frequency-competitive frequency shift curve of each order in a unit time as a single-band frequency offset curve of each order of the optical comb line as a function of a time-varying curve;
  • the single-band frequency offset with time curve of the sudden change of the threshold value is greater than half of the number of information symbols contained in one frame.
  • the mutation level estimation dividing module 402 performs the low-mutation optical comb line and the high-mutation optical comb for the first time.
  • the level of the sudden change of the curve is greater than the sudden change of the frequency shift of the single-band frequency offset of the optical comb line with time
  • the 0-order optical comb line and The ⁇ 1 order optical comb line is divided into low-mutation optical comb lines, and the other order optical comb lines are divided into high-mutation optical comb lines.
  • the frequency offset compensation system further includes:
  • the phase unwinding module 405 is configured to perform phase unwrapping on the single-band estimated frequency offset of each high-order abrupt optical comb line by using the low-mutation optical comb phase information;
  • the single-band phase obtained by phase unwrapping the single-band estimated frequency offset of each high-order abrupt optical comb line using the low-mutation optical comb phase information as the training symbol phase in the phase information of the corresponding optical comb line And sent to the frequency offset estimation module 401 to perform single-band frequency offset estimation.
  • the joint frequency offset estimation module 403 weights the single-band estimated frequency offsets of the low-order abrupt optical comb lines to obtain the joint estimated frequency offset.
  • the joint frequency offset estimation module 403 performs weighted averaging on the difference between the estimated single-band-band frequency offsets of the adjacent-order low-order optical comb lines in each of the low-order abrupt optical comb lines to obtain the joint estimated frequency offset. .
  • the frequency offset estimation module 401 is connected to the mutation level estimation division module mutation level estimation division module 402 and the joint frequency offset estimation module 403, and the joint frequency offset estimation module 403 is connected to the RF drive signal frequency offset compensation module 404.
  • the phase unwinding module 405 is coupled to the mutation level estimation partitioning module 402 and the frequency offset estimation module 401.
  • the frequency offset compensation system provided by the embodiment of the present invention is used for implementing a frequency offset compensation method for a radio frequency driving signal.
  • the specific principle of the RF driving signal frequency offset compensation system is the same as that of the RF driving signal frequency offset compensation method, and thus is not Let me repeat.
  • the multi-band OFDM receiver includes the frequency offset compensation system described in the above embodiment, 501.
  • the RF driving signal frequency offset compensation system 501 to compensate the optical comb generator using the RF driving signal, the interval of the optical comb line in the multi-band OFDM receiver can be effectively adjusted, and the multi-wave is reduced.
  • the residual frequency offset of the optical comb spacing in the OFDM receiver is the same as that of the optical comb line in the transmitter, thus ensuring the normal operation of the coherent reception.
  • the techniques in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on such understanding, the technical solution in the embodiments of the present invention may be embodied in the form of a software product in essence or in the form of a software product, which may be stored in a storage medium such as a ROM/RAM. , a disk, an optical disk, etc., including instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform various embodiments of the present invention The method described in the examples or parts of the examples.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optical Communication System (AREA)

Abstract

多波带OFDM接收机、频率偏移补偿方法及系统，该方法包括：对各阶光梳线进行单波带频率偏移估计；将光梳线划分为低突变光梳线和高突变光梳线；对低突变光梳线进行联合频率偏移估计；利用联合估计频率偏移对射频驱动信号频率偏移进行补偿。本发明提高了射频驱动信号频率偏移估计的准确性和可靠性，使得补偿度更加全面准确。

Description

一种多波带 OFDM接收机、 频率偏移补偿方法及系统
技术领域 本发明涉及网络通信技术领域， 特别涉及一种多波带 OFDM接收机、 频率偏移 补偿方法及系统。 背景技术 正交频分复用技术 (Orthogonal Frequency Division Multiplexing, OFDM)将信道 分成若干正交子信道，将高速数据信号转换成并行的低速子数据流， 调制到在每个子 信道上进行传输。 目前 OFDM技术已经被广泛应用于广播式的音频和视频领域以及 民用通信系统中， 主要的应用包括： 非对称的数字用户环路 （ADSL)、 ETSI标准的 数字音频广播 （DAB)、 数字视频广播 （DVB )、 高清晰度电视 （HDTV)、 无线局域 网 （WLAN) 等。
在利用正交频分复用（Orthogonal Frequency Division Multiplexing, OFDM)传输 信息过程中， 需要将信息调制到发射机产生的光梳线上形成多波带信号，在接收端利 用接收机中的光梳与之拍频实现信号解调。由于发射机中的光梳线间隔与接收机中的 光梳线间隔存在偏差并不完全相同， 而这种间隔的不同， 会劣化接收机的性能。现有 技术中一般会对用于生成光梳线的射频驱动信号进行频率偏移补偿，然而现有的补偿 方法的准确性较低。 发明内容 本发明实施例提供多波带 OFDM接收机、 频率偏移补偿方法及系统， 以解决现 有技术中多波带 OFDM接收机射频驱动信号频率偏移补偿准确性不高的问题。
为了解决上述技术问题， 本发明实施例公开了如下技术方案：
第一方面， 提供一种频率偏移补偿方法， 所述频率偏移补偿方法用于对多波带 OFDM接收机光梳生成器射频驱动信号的频率偏移进行补偿， 所述方法包括步骤：
51.对各阶光梳线进行单波带频率偏移估计， 得到各阶光梳线的单波带估计频率 偏移， 所述光梳线为光频率梳的谱线；
52.根据光梳线单波带频率偏移随时间变化曲线突变阈值将单波带频率偏移随时 间变化曲线突变水平小于所述突变阈值的光梳线划分为低突变光梳线，将单波带频率 偏移随时间变化曲线突变水平大于所述突变阈值的光梳线划分为高突变光梳线；
53.利用各阶低突变光梳线的单波带估计频率偏移进行联合频率偏移估计， 得到 联合估计频率偏移；
54.利用所述联合估计频率偏移对射频驱动信号频率偏移进行补偿.
在第一方面的第一种可能的实现方式中， 所述步骤 S4之后还包括步骤：
55.重复所述步骤 S1至 S4。
在第一方面的第二种可能的实现方式中， 所述步骤 S1包括：
利用各阶光梳线和对应的信号波带的拍频信号进行单波带相位估计，得到各阶光 梳线相位信息；
分别将各阶光梳线相位信息中的训练符号的相位对时间求导并做时间平均得到 所述各阶光梳线的单波带估计频率偏移。
在第一方面的第三种可能的实现方式中， 所述步骤 S2中， 将单位时间内各阶光 梳线频率偏移随时间变化曲线的突变次数作为各阶光梳线的单波带频率偏移随时间 变化曲线突变水平；
所述单波带频率偏移随时间变化曲线突变阈值的取值范围大于一帧中存在两次 突变小于一帧中所含信息符号数量的一半。
在第一方面的第四种可能的实现方式中， 所述步骤 S2包括：
在第一次进行低突变光梳线和高突变光梳线划分时，如果各阶光梳线的单波带频 率偏移随时间变化曲线突变水平全部大于所述光梳线单波带频率偏移随时间变化曲 线突变阈值， 将 0阶光梳线和 ± 1阶光梳线划分为低突变光梳线， 其他阶数的光梳线 划分为高突变光梳线。
结合第一方面的第二种可能实现方式， 在第一方面的第五种可能的实现方式中， 所述步骤 S2之后， 还包括：
利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计频率偏移进 行相位解卷绕；
将利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计频率偏移 进行相位解卷绕得到的单波带相位作为对应光梳线相位信息中的训练符号相位，重复 所述步骤 S1至 S2。
结合第一方面至第一方面的第五种可能实现方式，在第一方面的第六种可能的实 现方式中， 所述步骤 S3包括：
对所述各阶低突变光梳线的单波带估计频率偏移进行加权平均得到所述联合估 计频率偏移。
结合第一方面的第六种可能实现方式， 在第一方面的第七种可能的实现方式中， 所述对所述各阶低突变光梳线的单波带估计频率偏移进行加权平均得到所述联合估 计频率偏移， 包括：
对所述各阶低突变光梳线中相邻阶低阶光梳线的单波带估计频率偏移之差进行 加权平均得到所述联合估计频率偏移。
第二方面提供一种频率偏移补偿系统， 包括
频率偏移估计模块，用于对各阶光梳线进行单波带频率偏移估计，得到各阶光梳 线的单波带估计频率偏移， 所述光梳线为光频率梳的谱线；
突变水平估计划分模块，用于根据光梳线单波带频率偏移随时间变化曲线突变阈 值将单波带频率偏移随时间变化曲线突变水平小于所述突变阈值的光梳线划分为低 突变光梳线，将单波带频率偏移随时间变化曲线突变水平大于所述突变阈值的光梳线 划分为高突变光梳线；
联合频率偏移估计模块，用于利用各阶低突变光梳线的单波带估计频率偏移进行 联合频率偏移估计， 得到联合估计频率偏移；
射频驱动信号频率偏移补偿模块，用于利用所述联合估计频率偏移对射频驱动信 号频率偏移进行补偿。
在第二方面的第一种可能的实现方式中，所述频率偏移估计模块利用各阶光梳线 和对应的信号波带的拍频信号进行单波带相位估计， 得到各阶光梳线相位信息；
分别将各阶光梳线相位信息中的训练符号的相位对时间求导并做时间平均得到 所述各阶光梳线的单波带估计频率偏移。
在第二方面的第二种可能的实现方式中，所述突变水平估计划分模块将单位时间 内各阶光梳线频率偏移随时间变化曲线的突变次数作为各阶光梳线的单波带频率偏 移随时间变化曲线突变水平；
所述单波带频率偏移随时间变化曲线突变阈值的取值范围大于一帧中存在两次 突变小于一帧中所含信息符号数量的一半。
在第二方面的第三种可能的实现方式中，突变水平估计划分模块在第一次进行低 突变光梳线和高突变光梳线划分时，如果各阶光梳线的单波带频率偏移随时间变化曲 线突变水平全部大于所述光梳线单波带频率偏移随时间变化曲线突变阈值，将 0阶光 梳线和 ± 1阶光梳线划分为低突变光梳线， 其他阶数的光梳线划分为高突变光梳线。
结合第二方面的第一种可能的实现方式，在第二方面的第四种可能的实现方式中， 频率偏移补偿系统还包括：
相位解卷绕模块，利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带 估计频率偏移进行相位解卷绕；
将利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计频率偏移 进行相位解卷绕得到的单波带相位作为对应光梳线相位信息中的训练符号相位，发送 给频率偏移估计模块， 进行单波带频率偏移估计。
结合第二方面至第二方面的第四种可能的实现方式，在第二方面的第五种可能的 实现方式中，联合频率偏移估计模块对所述各阶低突变光梳线的单波带估计频率偏移 进行加权平均得到所述联合估计频率偏移。
结合第二方面的第五种可能的实现方式，在第二方面的第六种可能的实现方式中， 联合频率偏移估计模块对所述各阶低突变光梳线中相邻阶低阶光梳线的单波带估计 频率偏移之差进行加权平均得到所述联合估计频率偏移。
第三方面提供一种多波带 OFDM接收机， 所述多波带 OFDM接收机包括所述的 频率偏移补偿系统。
本发明实施例的多波带 OFDM接收机、 频率偏移补偿方法及系统， 根据单波带 频率偏移随时间变化曲线突变阈值将光梳线分为低突变光梳线和高突变光梳线对各 阶低突变光梳线的单波带估计频率偏移进行联合频率偏移估计，利用联合频率估计对 射频驱动信号进行补偿增加了进行联合频率偏移估计的光梳线数量，避免了高突变光 梳线参与联合频率偏移估计出现的性能劣化，提高了射频驱动信号频率偏移补偿的准 确性， 并且该方法循环进行射频驱动信号频率偏移频率补偿， 逐步减少频率偏移， 提 高了射频驱动信号频率偏移频率补偿的可靠性和全面性。 附图说明 为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现 有技术描述中所需要使用的附图作简单地介绍， 显而易见地， 下面描述中的附图仅仅 是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前 提下， 还可以根据这些附图获得其他的附图。
图 1为本发明频率偏移补偿方法的一个实施例流程图；
图 2为本发明频率偏移补偿方法的另一个实施例流程图；
图 3为本发明频率偏移补偿方法的又一个实施例流程图；
图 4为本发明频率偏移补偿系统的一个实施例模块结构示意图；
图 5为本发明一种多波带 OFDM接收机一个实施例的结构图。 具体实施方式 本发明如下实施例提供了多波带 OFDM接收机、 频率偏移补偿方法及系统， 以 便提高射频驱动信号补偿的准确性。
为了使本技术领域的人员更好地理解本发明实施例中的技术方案，并使本发明实 施例的上述目的、特征和优点能够更加明显易懂， 下面结合附图对本发明实施例中技 术方案作进一步详细的说明。
本发明实施例的一种频率偏移补偿方法， 所述频率偏移补偿方法用于对多波带 OFDM接收机光梳生成器射频驱动信号的频率偏移进行补偿。
参见图 1， 为本发明频率偏移补偿方法的一个实施例流程图， 如图 1所示， 该方 法包括：
步骤 101， 对各阶光梳线进行单波带频率偏移估计， 得到各阶光梳线的单波带估 计频率偏移， 所述光梳线为光频率梳的谱线；
其中，单波带估计频率偏移是某一阶光梳和其对应的信号光波带的中心频率之间 的差异的估计值， 对各阶光梳线进行单波带频率偏移估计的方法包括：
利用各阶光梳线和对应的信号波带的拍频信号进行单波带相位估计，得到各阶光 梳线相位信息；
分别将各阶光梳线相位信息中的训练符号的相位对时间求导并做时间平均得到 所述各阶光梳线的单波带估计频率偏移。
也可以利用下式得到各阶光梳单波带估计频率偏移：
E[^] = Afm
dt
其中， 为低阶光梳线相位信息， 它是对应的信号波带的拍频信号中由频率偏 移偏导致的相位信息， 可以通过在信号波带中设置训练符号，将该相位信息从拍频信 号中分离出来而得到， 为时间， Δ/Μ为所述 m阶光梳单波带估计频率偏移， m为光 梳线阶数；
步骤 102: 根据光梳线单波带频率偏移随时间变化曲线突变阈值将单波带频率偏 移随时间变化曲线突变水平小于所述突变阈值的光梳线划分为低突变光梳线，将单波 带频率偏移随时间变化曲线突变水平大于所述突变阈值的光梳线划分为高突变光梳 线。
其中，通过计算的单位时间中各阶光梳线对应信号相位的变化量是否超过频率跳 变阈值来确定是否产生突变， 例如， 可取 2 11 ±0.1， 或者 2 11 ±0.2以上的相位变化 量来界定是否产生突变。各阶光梳线的单波带频率偏移随时间变化曲线突变水平为将 单位时间内各阶光梳线频率偏移随时间变化曲线的突变次数。本领域技术人员可以根 据选取的器件精度、要求的射频驱动信号的频率偏移精度以及经验值设定单波带频率 偏移随时间变化曲线突变阈值，所述单波带频率偏移随时间变化曲线突变阈值的取值 范围大于一帧中存在两次突变小于一帧中所含信息符号数量的一半。
在第一次进行低突变光梳线和高突变光梳线划分时，如果各阶光梳线的单波带频 率偏移随时间变化曲线突变水平全部大于所述光梳线单波带频率偏移随时间变化曲 线突变阈值， 将 0阶光梳线和 ± 1阶光梳线划分为低突变光梳线， 其他阶数的光梳线 划分为高突变光梳线。
本实施例中，由于高突变光梳单波带估计频率偏移的频率偏移随时间变化曲线存 在突变较大的情况， 且频繁产生突变会使信号严重失真， 从而影响频率偏移估计的可 靠性。通过对各阶光梳线单波带估计频率偏移进行划分，将其划分为低突变高阶光梳 单波带估计频率偏移和高突变高阶光梳单波带估计频率偏移，使得划分出的低突变高 阶光梳单波带估计频率偏移信号失真现象降低，从而提高频率偏移估计的可靠性和准 确性。
步骤 103: 利用各阶低突变光梳线的单波带估计频率偏移进行联合频率偏移估计， 得到联合估计频率偏移。
其中， 联合估计频率偏移为信号光相邻波带中心频率的间隔， 即发射机的光梳线 频率间隔和接收机光梳线频率间隔的差异。可以通过对所述各阶低突变光梳线的单波 带估计频率偏移进行加权平均得到所述联合估计频率偏移。也可以对对所述各阶低突 变光梳线中相邻阶低阶光梳线的单波带估计频率偏移之差进行加权平均得到所述联 合估计频率偏移。
还可以利用下式进行加权平均得到所述联合估计频率偏移；
其中， ^为所述联合估计频率偏移， 为权重值， 为所述 m阶低突变光 梳单波带估计频率偏移， m为光梳线阶数。
在进行联合频率偏移估计过程中，也可以将高突变光梳单波带估计频率偏移加入 到联合频率偏移估计， 只需将其对应的权重值设置为 0即可。
本实施例中， 通过将低突变光梳单波带估计频率偏移进行联合频率估计， 相对于 现有技术增加了进行频率偏移估计的光梳线，既提高了频率估计的准确性又避免了利 用高突变光梳线频率偏移估计的不稳定性，从而提高了频率偏移估计的准确性和对激 光器波长偏移的容忍性。而且， 由于利用相邻光梳线的频率偏移差来估计光梳线的频 率偏移， 该方法可以避免频偏估计中激光器波长偏移的影响。
步骤 104: 利用所述联合估计频率偏移对射频驱动信号频率偏移进行补偿。 其中， 由于移采用了更多的光梳线进行频率偏移估计，使得得到的联合估计频率 偏更加准确和可靠，因此通过采用联合估计频率偏移对射频驱动信号频率偏移进行补 偿能够更好的实现信号的正交频分复用接收。联合频率偏移估计中加权平均的权重值 代表各阶光梳线的频率偏移估计的可靠性。
优选的， 该方法还包括步骤 105: 重复所述步骤 101至 104。
本实施例中，通过重复所述步骤 101至 104进行循环的射频驱动信号频率偏移补 偿，在循环过程中射频驱动信号的频率偏移补偿使得光束生成器产生的光梳线的频率 偏移越来越小，光梳线单波带频率偏移随时间变化曲线突变水平越来越低，低突变光 梳线的个数越来越多，在进行联合频率偏移估计后，对射频驱动信号频率偏移的补偿 更加准确和可靠。
由上述实施例可见，根据单波带频率偏移随时间变化曲线突变阈值将光梳线分为 低突变光梳线和高突变光梳线对各阶低突变光梳线的单波带估计频率偏移进行联合 频率偏移估计，利用联合频率估计对射频驱动信号进行补偿增加了进行联合频率偏移 估计的光梳线数量，避免了高突变光梳线参与联合频率偏移估计出现的性能劣化，提 高了射频驱动信号频率偏移补偿的准确性，并且该方法循环进行射频驱动信号频率偏 移频率补偿，逐步减少频率偏移，提高了射频驱动信号频率偏移频率补偿的可靠性和 全面性。
参见图 2， 为本发明频率偏移补偿方法的另一个实施例流程图， 本实施例基于上 一实施例进行描述：
在所述步骤 102之后， 还包括：
步骤 201 : 利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计频 率偏移进行相位解卷绕；
其中， 低突变光梳线相位信息包括低阶光梳线的相位跳变信息。
由于高突变光梳线在频率偏移估计时会产生卷绕现象，卷绕现象会使频偏估计随 时间变化的曲线频繁产生很大突变，在有限的数字采样频率下，频繁产生很大突变会 使信号严重失真， 从而影响估计的可靠性， 因此需要对高突变光梳估计频率偏移进行 相位解卷绕。 由于各级光梳线的相位变化存在整数倍关系，因此对高突变光梳相位曲线卷绕利 用低突变光梳相位曲线进行解卷绕， 以消除频偏变化曲线中的突变， 从而使高突变光 梳线提供的频率偏移估计可靠性得到提升， 达到参与联合估计的目的。
步骤： 202将利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计 频率偏移进行相位解卷绕得到的单波带相位作为对应光梳线相位信息中的训练符号 相位， 重复所述步骤 S1至 S2。
其中，利用低突变光梳线相位信息和高突变光梳线相位关系，对相位曲线解卷绕， 然后在求导作频偏估计， 直到突变小于突变阈值， 再将其估计值加入到联合估计中计 算频偏。
本实施例在不断的相位解卷绕过程中，减少了大突变高阶光梳单波带估计频率偏 移的个数，进一步使更多的光梳单波带估计频率偏移参加到联合频率偏移估计中， 从 而提高了射频驱动信号频率偏移估计的准确性和可靠性，使得射频驱动信号频率偏移 的补偿度更加全面准确。
参见图 3， 为本发明射频驱动信号频率偏移补偿方法的又一个实施例流程图， 本 实施例基于上一实施例进行描述：
步骤 301 : 设置 0阶频率偏移阈值， 获取步骤 101得到的 0阶光梳线单波带估计频率 偏移。
步骤 302: 当 0阶光梳线单波带估计频率偏移大于所述 0阶频率偏移阈值时， 调整 光梳生成器输入激光器的中心波长， 使其对准发射端中心波长， 重复步骤 101至步骤 105。
其中， 0阶光梳线单波带估计频率偏移大于所述 0阶频率偏移阈值时， 说明激光器 中心波长未对准， 因此对激光器进行调整，在激光器中心波长对准后重新进行射频驱 动信号频率偏移的估计和补偿。
步骤 303:: 当 0阶光梳线单波带估计频率偏移小于所述 0阶频率偏移阈值时，步 骤 104将各阶低突变光梳线的单波带估计频率偏移除以对应的阶数进行求和得到所 述联合估计频率偏移， 即利用下式得到所述联合估计频率偏移，
△ =∑
其中， ^为所述联合估计频率偏移， Δ/™为所述 m阶低突变光梳单波带估计频 率偏移， m为光梳线阶数， m≠0即 0阶光梳线估计频率偏移不再参与联合频率估计。 本实施例中，通过设置 0阶频率偏移阈值，根据 0阶光梳单波带估计频率偏移确 定激光器中心波长是否对准，从而有效的避免了因激光器中心波长未对准二造成的误 差。
本发明实施例的频率偏移补偿方法根据单波带频率偏移随时间变化曲线突变阈 值将光梳线分为低突变光梳线和高突变光梳线对各阶低突变光梳线的单波带估计频 率偏移进行联合频率偏移估计，利用联合频率估计对射频驱动信号进行补偿增加了进 行联合频率偏移估计的光梳线数量，避免了高突变光梳线参与联合频率偏移估计出现 的性能劣化，提高了射频驱动信号频率偏移补偿的准确性， 并且该方法循环进行射频 驱动信号频率偏移频率补偿，逐步减少频率偏移，提高了射频驱动信号频率偏移频率 补偿的可靠性和全面性。
参见图 4， 为本发明频率偏移补偿系统的一个实施例模块结构示意图， 包括： 频率偏移估计模块 401， 用于对各阶光梳线进行单波带频率偏移估计， 得到各阶 光梳线的单波带估计频率偏移， 所述光梳线为光频率梳的谱线；
突变水平估计划分模块 402， 用于根据光梳线单波带频率偏移随时间变化曲线突 变阈值将单波带频率偏移随时间变化曲线突变水平小于所述突变阈值的光梳线划分 为低突变光梳线，将单波带频率偏移随时间变化曲线突变水平大于所述突变阈值的光 梳线划分为高突变光梳线；
联合频率偏移估计模块 403， 用于利用各阶低突变光梳线的单波带估计频率偏移 进行联合频率偏移估计， 得到联合估计频率偏移；
射频驱动信号频率偏移补偿模块 404， 用于利用所述联合估计频率偏移对射频驱 动信号频率偏移进行补偿。
进一步的，所述频率偏移估计模块 401利用各阶光梳线和对应的信号波带的拍频 信号进行单波带相位估计， 得到各阶光梳线相位信息；
分别将各阶光梳线相位信息中的训练符号的相位对时间求导并做时间平均得到 所述各阶光梳线的单波带估计频率偏移。
进一步的，所述突变水平估计划分模块 402将单位时间内各阶光梳线频率偏移随 时间变化曲线的突变次数作为各阶光梳线的单波带频率偏移随时间变化曲线突变水 平；
所述单波带频率偏移随时间变化曲线突变阈值的取值范围大于一帧中存在两次 突变小于一帧中所含信息符号数量的一半。
进一步的，突变水平估计划分模块 402在第一次进行低突变光梳线和高突变光梳 线划分时，如果各阶光梳线的单波带频率偏移随时间变化曲线突变水平全部大于所述 光梳线单波带频率偏移随时间变化曲线突变阈值， 将 0阶光梳线和 ± 1阶光梳线划分 为低突变光梳线， 其他阶数的光梳线划分为高突变光梳线。
进一步的， 频率偏移补偿系统还包括：
相位解卷绕模块 405， 利用所述低突变光梳线相位信息对各阶高突变光梳线的单 波带估计频率偏移进行相位解卷绕；
将利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计频率偏移 进行相位解卷绕得到的单波带相位作为对应光梳线相位信息中的训练符号相位，发送 给频率偏移估计模块 401， 进行单波带频率偏移估计。
进一步的，联合频率偏移估计模块 403对所述各阶低突变光梳线的单波带估计频 率偏移进行加权平均得到所述联合估计频率偏移。
进一步的，联合频率偏移估计模块 403对所述各阶低突变光梳线中相邻阶低阶光 梳线的单波带估计频率偏移之差进行加权平均得到所述联合估计频率偏移。
图 4中，频率偏移估计模块 401与突变水平估计划分模块突变水平估计划分模块 402与联合频率偏移估计模块 403连接， 联合频率偏移估计模块 403与射频驱动信号 频率偏移补偿模块 404连接， 相位解卷绕模块 405与所述突变水平估计划分模块 402 和频率偏移估计模块 401连接。
本发明实施例提供的频率偏移补偿系统，用于实现射频驱动信号频率偏移补偿方 法，射频驱动信号频率偏移补偿系统的具体原理与射频驱动信号频率偏移补偿方法的 原理相同， 因此不再赘述。
参见图 5， 本发明一种多波带 OFDM接收机一个实施例的结构图， 所述多波带 正交频分复用接收机包以上实施例所述的频率偏移补偿系统, 501。
本实施例中，通过采用射频驱动信号频率偏移补偿系统 501对利用射频驱动信号 的光梳生成器进行补偿， 能够有效地调节多波带 OFDM接收机中光梳线的间隔， 减 小多波带 OFDM接收机中光梳间距的残余频偏，使其与发射机中光梳线的间隔相同， 从而保证了相干接收的正常工作。
本领域的技术人员可以清楚地了解到本发明实施例中的技术可借助软件加必需 的通用硬件平台的方式来实现。基于这样的理解，本发明实施例中的技术方案本质上 或者说对现有技术做出贡献的部分可以以软件产品的形式体现出来，该计算机软件产 品可以存储在存储介质中， 如 ROM/RAM、磁碟、光盘等， 包括若干指令用以使得一 台计算机设备（可以是个人计算机， 服务器， 或者网络设备等）执行本发明各个实施 例或者实施例的某些部分所述的方法。
本说明书中的各个实施例均采用递进的方式描述，各个实施例之间相同相似的部 分互相参见即可， 每个实施例重点说明的都是与其他实施例的不同之处。尤其， 对于 系统实施例而言， 由于其基本相似于方法实施例， 所以描述的比较简单， 相关之处参 见方法实施例的部分说明即可。
以上所述的本发明实施方式， 并不构成对本发明保护范围的限定。任何在本发明 的精神和原则之内所作的修改、等同替换和改进等，均应包含在本发明的保护范围之 内。

Claims

权 利 要 求
1、 一种频率偏移补偿方法， 其特征在于， 所述频率偏移补偿方法用于对多 波带 OFDM接收机光梳生成器射频驱动信号的频率偏移进行补偿， 所述方法包 括步骤：
S1.对各阶光梳线进行单波带频率偏移估计， 得到各阶光梳线的单波带估计 频率偏移， 所述光梳线为光频率梳的谱线；
52.根据光梳线单波带频率偏移随时间变化曲线突变阈值将单波带频率偏移 随时间变化曲线突变水平小于所述突变阈值的光梳线划分为低突变光梳线，将单 波带频率偏移随时间变化曲线突变水平大于所述突变阈值的光梳线划分为高突 变光梳线；
53.利用各阶低突变光梳线的单波带估计频率偏移进行联合频率偏移估计， 得到联合估计频率偏移；
54.利用所述联合估计频率偏移对射频驱动信号频率偏移进行补偿。 2、根据权利要求 1所述的方法，其特征在于，所述步骤 S4之后还包括步骤：
55.重复所述步骤 S1至 S4。
3、 根据权利要求 1所述的方法， 其特征在于， 所述步骤 S1包括： 利用各阶光梳线和对应的信号波带的拍频信号进行单波带相位估计，得到各 阶光梳线相位信息；
分别将各阶光梳线相位信息中的训练符号的相位对时间求导并做时间平均 得到所述各阶光梳线的单波带估计频率偏移。
4、根据权利要求 1所述的方法， 其特征在于， 所述步骤 S2中， 各阶光梳线 的单波带频率偏移随时间变化曲线突变水平是指，单位时间内各阶光梳线频率偏 移随时间变化曲线的突变次数；
所述单波带频率偏移随时间变化曲线突变阈值的取值范围大于一帧中存在 两次突变小于一帧中所含信息符号数量的一半。 5、 根据权利要求 1所述的方法， 其特征在于， 所述步骤 S2包括： 在第一次进行低突变光梳线和高突变光梳线划分时，如果各阶光梳线的单波 带频率偏移随时间变化曲线突变水平全部大于所述光梳线单波带频率偏移随时 间变化曲线突变阈值， 将 0阶光梳线和 ± 1阶光梳线划分为低突变光梳线， 其他 阶数的光梳线划分为高突变光梳线。
6、 根据权利要求 3所述的方法， 其特征在于， 所述步骤 S2之后， 还包括: 利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计频率偏 移进行相位解卷绕；
将利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计频率 偏移进行相位解卷绕得到的单波带相位作为对应光梳线相位信息中的训练符号 相位， 重复所述步骤 S1至 S2。
7、 根据权利要求 1 至 6任意一项所述的方法， 其特征在于， 所述步骤 S3 包括：
对所述各阶低突变光梳线的单波带估计频率偏移进行加权平均得到所述联 合估计频率偏移。
8、 根据权利要求 7所述的方法， 其特征在于， 所述对所述各阶低突变光梳 线的单波带估计频率偏移进行加权平均得到所述联合估计频率偏移， 包括： 对所述各阶低突变光梳线中相邻阶低阶光梳线的单波带估计频率偏移之差 进行加权平均得到所述联合估计频率偏移。
9、 一种频率偏移补偿系统， 其特征在于， 包括
频率偏移估计模块，用于对各阶光梳线进行单波带频率偏移估计， 得到各阶 光梳线的单波带估计频率偏移， 所述光梳线为光频率梳的谱线；
突变水平估计划分模块，用于根据光梳线单波带频率偏移随时间变化曲线突 变阈值将单波带频率偏移随时间变化曲线突变水平小于所述突变阈值的光梳线 划分为低突变光梳线，将单波带频率偏移随时间变化曲线突变水平大于所述突变 阈值的光梳线划分为高突变光梳线；
联合频率偏移估计模块，用于利用各阶低突变光梳线的单波带估计频率偏移 进行联合频率偏移估计， 得到联合估计频率偏移；
射频驱动信号频率偏移补偿模块，用于利用所述联合估计频率偏移对射频驱 动信号频率偏移进行补偿。
10、根据权利要求 9所述的系统， 其特征在于， 所述频率偏移估计模块利用 各阶光梳线和对应的信号波带的拍频信号进行单波带相位估计，得到各阶光梳线 相位信息；
分别将各阶光梳线相位信息中的训练符号的相位对时间求导并做时间平均 得到所述各阶光梳线的单波带估计频率偏移。
11、根据权利要求 9所述的系统， 其特征在于， 所述突变水平估计划分模块 将单位时间内各阶光梳线频率偏移随时间变化曲线的突变次数作为各阶光梳线 的单波带频率偏移随时间变化曲线突变水平；
所述单波带频率偏移随时间变化曲线突变阈值的取值范围大于一帧中存在 两次突变小于一帧中所含信息符号数量的一半。
12、根据权利要求 9所述的系统， 其特征在于， 突变水平估计划分模块在第 一次进行低突变光梳线和高突变光梳线划分时，如果各阶光梳线的单波带频率偏 移随时间变化曲线突变水平全部大于所述光梳线单波带频率偏移随时间变化曲 线突变阈值， 将 0阶光梳线和 ± 1阶光梳线划分为低突变光梳线， 其他阶数的光 梳线划分为高突变光梳线。
13、根据权利要求 10所述的系统，其特征在于，频率偏移补偿系统还包括： 相位解卷绕模块，利用所述低突变光梳线相位信息对各阶高突变光梳线的单 波带估计频率偏移进行相位解卷绕；
将利用所述低突变光梳线相位信息对各阶高突变光梳线的单波带估计频率 偏移进行相位解卷绕得到的单波带相位作为对应光梳线相位信息中的训练符号 相位， 发送给频率偏移估计模块， 进行单波带频率偏移估计。
14、 根据权利要求 9或 13任意一项所述的系统， 其特征在于， 联合频率偏 移估计模块对所述各阶低突变光梳线的单波带估计频率偏移进行加权平均得到 所述联合估计频率偏移。
15、 根据权利要求 14所述的系统， 其特征在于， 联合频率偏移估计模块对 所述各阶低突变光梳线中相邻阶低阶光梳线的单波带估计频率偏移之差进行加 权平均得到所述联合估计频率偏移。
16、 一种多波带 OFDM接收机， 其特征在于， 所述多波带 OFDM接收机包 括权利要求 9-15任意一项所述的射频驱动信号频率偏移补偿系统。
PCT/CN2013/080551 2013-07-31 2013-07-31 一种多波带ofdm接收机、频率偏移补偿方法及系统 WO2015013930A1 (zh)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CN201380001287.3A CN104521206B (zh) 2013-07-31 2013-07-31 一种多波带ofdm接收机、频率偏移补偿方法及系统
ES13890447.9T ES2644734T3 (es) 2013-07-31 2013-07-31 Receptor OFDM multi-longitud de onda, método de compensación del desplazamiento de frecuencia y sistema
PCT/CN2013/080551 WO2015013930A1 (zh) 2013-07-31 2013-07-31 一种多波带ofdm接收机、频率偏移补偿方法及系统
EP13890447.9A EP3021543B1 (en) 2013-07-31 2013-07-31 Multi-waveband ofdm receiver, frequency offset compensation method and system
US15/010,248 US9628316B2 (en) 2013-07-31 2016-01-29 Multi-waveband OFDM receiver, and frequency offset compensation method and system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2013/080551 WO2015013930A1 (zh) 2013-07-31 2013-07-31 一种多波带ofdm接收机、频率偏移补偿方法及系统

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US15/010,248 Continuation US9628316B2 (en) 2013-07-31 2016-01-29 Multi-waveband OFDM receiver, and frequency offset compensation method and system

Publications (2)

Publication Number Publication Date
WO2015013930A1 true WO2015013930A1 (zh) 2015-02-05
WO2015013930A9 WO2015013930A9 (zh) 2015-05-21

Family

ID=52430866

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2013/080551 WO2015013930A1 (zh) 2013-07-31 2013-07-31 一种多波带ofdm接收机、频率偏移补偿方法及系统

Country Status (5)

Country Link
US (1) US9628316B2 (zh)
EP (1) EP3021543B1 (zh)
CN (1) CN104521206B (zh)
ES (1) ES2644734T3 (zh)
WO (1) WO2015013930A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108353049A (zh) * 2015-09-25 2018-07-31 索尼移动通讯有限公司 频率偏移的基于广播信道的估计

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107409000B (zh) * 2015-04-10 2019-05-28 华为技术有限公司 一种相干光源频偏估计和补偿的相干接收机、方法和系统
US10651820B2 (en) * 2016-09-16 2020-05-12 Ecole Polytechnique Federale De Lausanne (Epfl) Signal processing apparatus and method for transmitting and receiving coherent parallel optical signals
US10979167B2 (en) * 2018-10-01 2021-04-13 Huawei Technologies Co., Ltd. Systems and method of multi-laser wavelength control

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110170873A1 (en) * 2010-01-11 2011-07-14 Xiang Liu Apparatus and Method For Generating Frequency-Locked Optical Comb Sources
CN102223340A (zh) * 2011-06-20 2011-10-19 电子科技大学 基于光梳的太比特传输速率相干光正交频分复用系统
CN102934378A (zh) * 2010-06-17 2013-02-13 日本电信电话株式会社 频率偏移估计装置、接收装置、频率偏移估计方法及接收方法
WO2013105649A1 (ja) * 2012-01-13 2013-07-18 住友大阪セメント株式会社 光パルス発生装置

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5748047A (en) * 1996-08-15 1998-05-05 Northrop Grumman Corporation Microwave frequency generator and method of generating a desired microwave frequency signal
WO2001076026A1 (en) * 2000-03-30 2001-10-11 National Institute Of Standards And Technology ('nist') Mode-locked pulsed laser system and method
WO2003043178A2 (en) * 2001-11-15 2003-05-22 Hrl Laboratories, Llc Frequency agile spread waveform generator and method and pre-processor apparatus and method
US7373088B2 (en) * 2001-11-15 2008-05-13 Hrl Laboratories Agile spread waveform generator
US7881620B2 (en) * 2005-05-04 2011-02-01 Ofs Fitel, Llc Stabilized optical fiber continuum frequency combs using post-processed highly nonlinear fibers
US7561807B2 (en) * 2006-01-17 2009-07-14 Alcatel-Lucent Usa Inc. Use of beacons in a WDM communication system
KR100785473B1 (ko) 2006-10-18 2007-12-13 삼성전자주식회사 멀티-밴드 ｏｆｄｍ 스킴에서 수신 신호의 주파수 옵셋을보상하는 수신기 및 방법
KR100890182B1 (ko) 2007-12-18 2009-03-25 인하대학교 산학협력단 Ｍｂ－ｏｆｄｍ 시스템 기반 채널 및 주파수 옵셋결합추정장치 및 방법
US8705956B2 (en) 2010-04-14 2014-04-22 Nec Laboratories America, Inc. Carrier frequency offset (CFO) estimator with low complexity and high accuracy for orthogonal-frequency-division-multiplexing (CO-OFDM) systems
EP2705622B1 (en) * 2011-04-30 2014-12-24 RWTH Aachen Wdm telecommunications link with coherent detection and optical frequency comb sources

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110170873A1 (en) * 2010-01-11 2011-07-14 Xiang Liu Apparatus and Method For Generating Frequency-Locked Optical Comb Sources
CN102934378A (zh) * 2010-06-17 2013-02-13 日本电信电话株式会社 频率偏移估计装置、接收装置、频率偏移估计方法及接收方法
CN102223340A (zh) * 2011-06-20 2011-10-19 电子科技大学 基于光梳的太比特传输速率相干光正交频分复用系统
WO2013105649A1 (ja) * 2012-01-13 2013-07-18 住友大阪セメント株式会社 光パルス発生装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3021543A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108353049A (zh) * 2015-09-25 2018-07-31 索尼移动通讯有限公司 频率偏移的基于广播信道的估计

Also Published As

Publication number Publication date
US9628316B2 (en) 2017-04-18
CN104521206B (zh) 2017-11-24
ES2644734T3 (es) 2017-11-30
EP3021543A4 (en) 2016-08-10
US20160149742A1 (en) 2016-05-26
EP3021543A1 (en) 2016-05-18
CN104521206A (zh) 2015-04-15
EP3021543B1 (en) 2017-09-13
WO2015013930A9 (zh) 2015-05-21

Similar Documents

Publication Publication Date Title
CA2721415C (en) Apparatus and method for reducing papr of preamble signal in digital broadcasting system
USRE44622E1 (en) Coarse carrier frequency offset estimation for a receiver
EP1555785A2 (en) Course frequency synchronization in a multicarrier receiver
US10171278B2 (en) Methods and apparatus for frequency offset estimation
US20100284478A1 (en) Channel Estimating Apparatus and Method Thereof
JP5108940B2 (ja) 無線通信システムにおけるタイミング調整方法、受信局、送信局及び無線通信システム
JP2002217865A (ja) Ｏｆｄｍシステムに適用される周波数オフセット推定システム及びその方法
CN108605304B (zh) 采用降低的采样率的NB-IoT装置中的下行链路时间跟踪
WO2015013930A1 (zh) 一种多波带ofdm接收机、频率偏移补偿方法及系统
US20090185630A1 (en) Method and apparatus for estimating the channel impulse response of multi-carrier communicating systems
US7821916B2 (en) Timing and frequency acquisition for mediaflo systems
US20120243648A1 (en) Characterization and assessment of communication channel average group delay variation
US8107545B2 (en) Method and system for phase tracking in wireless communication systems
US20080273646A1 (en) Sampling clock offset tracking and symbol re-timing
JP2022084808A (ja) 受信装置、受信方法、送信装置及び送信方法
US9350587B1 (en) System and method for timing error estimation
KR100797470B1 (ko) Ｏｆｄｍ 변조신호 수신장치의 보호구간 검출기
US11343066B2 (en) OFDMA baseband clock synchronization
US20090268829A1 (en) Systems and Methods for Sampling Frequency Offset Estimation
US20090097597A1 (en) Methods For Coarse Frequency Offset Estimation For Orthogonal Frequency Division Multiplexing Schemes
US7864664B2 (en) Delay profile generator
KR101080671B1 (ko) 기저대역의 ｏｆｄｍ 수신기 및 방법
JP5536936B2 (ja) Ｏｆｄｍ信号生成方法、ｏｆｄｍ信号生成装置、ｏｆｄｍ信号受信方法、及びｏｆｄｍ信号受信装置
US9071392B2 (en) Device for generating ranging signal of wireless communication system and method of generating ranging signal of wireless terminal
CN103905362A (zh) 多载波通信系统中载波与取样频率偏移的估计方法与装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13890447

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

REEP Request for entry into the european phase

Ref document number: 2013890447

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 2013890447

Country of ref document: EP