CN114944974B - Frequency offset estimation method and device and electronic equipment - Google Patents
Frequency offset estimation method and device and electronic equipment Download PDFInfo
- Publication number
- CN114944974B CN114944974B CN202210418672.9A CN202210418672A CN114944974B CN 114944974 B CN114944974 B CN 114944974B CN 202210418672 A CN202210418672 A CN 202210418672A CN 114944974 B CN114944974 B CN 114944974B
- Authority
- CN
- China
- Prior art keywords
- frame
- signal
- dtmb
- reference signal
- frequency offset
- 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
Links
- 238000000034 method Methods 0.000 title claims abstract description 66
- 230000005855 radiation Effects 0.000 claims abstract description 20
- 238000009432 framing Methods 0.000 claims abstract description 18
- 230000001360 synchronised effect Effects 0.000 claims abstract description 8
- 238000010586 diagram Methods 0.000 claims description 17
- 238000005070 sampling Methods 0.000 claims description 16
- 230000004044 response Effects 0.000 claims description 10
- 238000007781 pre-processing Methods 0.000 claims description 4
- 230000009466 transformation Effects 0.000 claims description 4
- 238000013507 mapping Methods 0.000 claims description 3
- 230000008569 process Effects 0.000 description 13
- 238000012545 processing Methods 0.000 description 12
- 238000004590 computer program Methods 0.000 description 11
- 230000006870 function Effects 0.000 description 5
- 238000001914 filtration Methods 0.000 description 4
- 108010076504 Protein Sorting Signals Proteins 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- ODKSFYDXXFIFQN-UHFFFAOYSA-M argininate Chemical compound [O-]C(=O)C(N)CCCNC(N)=N ODKSFYDXXFIFQN-UHFFFAOYSA-M 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000011022 operating instruction Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- 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
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/003—Arrangements for allocating sub-channels of the transmission path
- H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0024—Carrier regulation at the receiver end
- H04L2027/0026—Correction of carrier offset
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The application discloses a frequency offset estimation method, a device and electronic equipment. The frequency offset estimation method comprises the following steps: acquiring a reference signal through a DTMB signal of an external radiation source, and acquiring a reference signal of time domain synchronization according to the time domain correlation of the reference signal and a standard PN sequence, wherein the reference signal comprises a plurality of frames of DTMB signals; according to the frequency deviation rough estimation of the time domain synchronous reference signal, carrying out frequency deviation compensation on each frame of DTMB signal of the reference signal, and demodulating each frame of DTMB signal after the frequency deviation compensation to obtain a data body of each frame of DTMB signal; framing the data body obtained through demodulation in a DTMB signal format to obtain a reconstructed reference signal; and obtaining the frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal.
Description
Technical Field
The present disclosure relates to the field of communication signal processing technologies, and in particular, to a method and an apparatus for frequency offset estimation and an electronic device.
Background
The external radiation source radar realizes target detection in a coverage range by using a third party non-cooperative irradiation source. External radiation source radars have many advantages over conventional radars, such as the elimination of a bulky transmitter, reducing cost; the working mode of not emitting electromagnetic waves has better anti-interference and concealing capabilities; the external radiation source radar is essentially a bistatic radar, and has a certain degree of anti-stealth capability on a target; the third party radiation source is typically a satellite or television signal, the relative position is typically high, and the available area is wide.
Digital television terrestrial broadcast (Digital Television Terrestrial Multimedia Broadcasting, DTMB, abbreviated as DTMB) signals are generally widely covered in cities and are an ideal third party radiation source. The DTMB signal has larger energy and stable power, the bandwidth of the DTMB signal is 7.56MHz, and the larger bandwidth ensures better distance resolution. In external radiation source systems, a reference signal is usually required, on the one hand for direct wave and multipath clutter suppression; and on the other hand, the method is used for carrying out time-frequency two-dimensional correlation calculation with the echo signal.
In order to ensure that the reference signal is not affected by multipath effect, demodulation reconstruction method is generally adopted, however, the reference signal and echo signal under reconstruction have a certain frequency offset because of the phenomena of local oscillation offset and the like of the receiver or the transmitter. In general, the related art adopts autocorrelation of a Pseudo-noise Sequence (PN Sequence) and cyclic composition characteristics of a frame header to estimate frequency offset, however, since the PN Sequence occupies only a small part of a signal frame, errors are large when the sequences are used to estimate frequency offset.
Disclosure of Invention
The embodiment of the application provides a frequency offset estimation method, a frequency offset estimation device and electronic equipment, so as to improve the frequency offset estimation precision of a reference signal.
The embodiment of the application adopts the following technical scheme:
in a first aspect, an embodiment of the present application provides a frequency offset estimation method, including:
acquiring a reference signal through a DTMB signal of an external radiation source, and acquiring a reference signal of time domain synchronization according to the time domain correlation of the reference signal and a standard PN sequence, wherein the reference signal comprises a plurality of frames of DTMB signals;
according to the frequency deviation rough estimation of the time domain synchronous reference signal, carrying out frequency deviation compensation on each frame of DTMB signal of the reference signal, and demodulating each frame of DTMB signal after the frequency deviation compensation to obtain a data body of each frame of DTMB signal;
framing the data body obtained through demodulation in a DTMB signal format to obtain a reconstructed reference signal;
and obtaining the frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal.
Optionally, demodulating each frame of DTMB signal after the frequency offset compensation to obtain a data body of each frame of DTMB signal, including:
carrying out channel estimation and equalization on each frame of DTMB signal after frequency offset compensation to obtain a constellation map of a frame body part of each frame of DTMB signal;
and carrying out constellation judgment on the constellation mapping diagram to obtain the data constellation points of the data body.
Optionally, performing channel estimation and equalization on each frame of DTMB signal after frequency offset compensation, including:
carrying out time domain least square channel estimation on each frame of DTMB signal after frequency offset compensation according to the standard PN sequence to obtain channel impulse response;
and carrying out channel equalization on the frame body part of each frame of the DTMB signal by utilizing the channel impulse response to obtain a constellation map of the frame body part of each frame of the DTMB signal.
Optionally, the DTMB signal format includes a frame header portion and a frame body portion, and the frame body portion includes system data and a data body; framing the data body obtained through demodulation in a DTMB signal format to obtain a reconstructed reference signal, wherein the method comprises the following steps:
the system data of the frame body part and the data body are connected in series in the frequency domain, and Fourier transformation is carried out on the frame body part after the series connection to obtain a time domain frame body part after the series connection;
and inserting a frame header part formed by a standard PN sequence in front of the frame bodies of the time domain frame body parts after the concatenation to obtain a reconstructed DTMB signal of each frame.
Optionally, obtaining the frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal, including:
according to the one-to-one correspondence between the frame numbers of the reference signal and the reconstructed reference signal, determining a current frame DTMB signal and an adjacent frame DTMB signal of the reference signal, and determining the current frame DTMB signal and the adjacent frame DTMB signal of the reconstructed reference signal;
and obtaining the frequency offset fine estimation of the current frame DTMB signal of the reference signal according to the current frame DTMB signal and the adjacent frame DTMB signal of the reference signal and the current frame DTMB signal and the adjacent frame DTMB signal of the reconstructed reference signal.
Optionally, obtaining the frequency offset fine estimation of the current frame DTMB signal of the reference signal according to the current frame DTMB signal of the reference signal, the adjacent frame DTMB signal and the current frame DTMB signal of the reconstructed reference signal, including:
according to the formulaObtaining the frequency offset fine estimation of the ith frame DTMB signal of the reference signal;
wherein x (N) is a reference signal, y (N) is a reconstructed reference signal, N is the frequency number of the reference signal, i is a frame number, N is the length of the DTMB signal, T s For sampling interval f i And (5) carrying out frequency offset fine estimation on the ith frame of DTMB signal.
Optionally, the coarse frequency offset estimation of the time domain synchronous reference signal is obtained through the following steps:
according to the formulaObtaining a frequency offset rough estimation of an ith frame DTMB signal of the reference signal;
wherein x (N) is a reference signal, N is a frequency point of the reference signal, i is a frame number, N is a length of the DTMB signal, M is a length of a standard PN sequence, T s For sampling interval f i ' is a coarse estimate of the frequency offset of the ith frame DTMB signal.
Optionally, performing frequency offset compensation on the DTMB signal of each frame of the reference signal includes:
according to formula exp (2 pi nf i 'T s ) And performing frequency offset compensation on the ith frame DTMB signal.
In a second aspect, an embodiment of the present application further provides a frequency offset estimation apparatus, including:
the preprocessing unit is used for acquiring a reference signal through a DTMB signal of the external radiation source and obtaining a reference signal of time domain synchronization according to the time domain correlation between the reference signal and a standard PN sequence, wherein the reference signal comprises a plurality of frames of DTMB signals;
the demodulation unit is used for carrying out frequency offset compensation on each frame of DTMB signal of the reference signal according to the frequency offset rough estimation of the reference signal in the time domain synchronization, and demodulating each frame of DTMB signal after the frequency offset compensation to obtain a data body of each frame of DTMB signal;
a reconstruction unit, configured to perform framing in DTMB signal format on the data body obtained by demodulation, so as to obtain a reconstructed reference signal;
and the estimation unit is used for obtaining the frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal.
In a third aspect, embodiments of the present application further provide an electronic device, including:
a processor; and
a memory arranged to store computer executable instructions that, when executed, cause the processor to perform the aforementioned frequency offset estimation method.
In a fourth aspect, embodiments of the present application also provide a computer-readable storage medium storing one or more programs that, when executed by an electronic device comprising a plurality of application programs, cause the electronic device to perform the aforementioned frequency offset estimation method.
The above-mentioned at least one technical scheme that this application embodiment adopted can reach following beneficial effect: according to the frequency offset estimation method, the device, the electronic equipment and the computer readable storage medium, a reference signal is obtained through a DTMB signal, the frequency offset rough estimation of each frame of the DTMB signal in the reference signal is obtained according to the autocorrelation characteristics of each frame of the DTMB signal in the reference signal and a standard PN sequence, the frequency offset rough estimation is utilized to carry out frequency offset compensation on corresponding DTMB signal frames in the reference signal, the compensated DTMB signal frames can be demodulated, the framing processing of the DTMB signal is carried out on a demodulated data body based on the signal format of the DTMB signal, the reconstructed reference signal is obtained, and the frequency offset fine estimation of each frame of the DTMB signal in the reference signal is obtained by utilizing the time domain correlation characteristics between the reconstructed reference signal and the reference signal.
According to the embodiment of the application, the frequency offset with higher precision can be estimated only by demodulating and reconstructing the received reference signal, the problem of large frequency offset estimation error in the existing scheme is solved, and the method is simple and feasible and has higher practicability.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:
fig. 1 is a schematic flow chart of a frequency offset estimation method in an embodiment of the present application;
fig. 2 is a flowchart of frequency offset estimation of a radar reference signal of a DTMB external radiation source in an embodiment of the present application;
fig. 3 is a schematic diagram of a processing flow for converting a DTMB signal into a digital baseband signal according to an embodiment of the present application;
fig. 4 is a schematic diagram of a DTMB signal format according to an embodiment of the present application;
fig. 5 is a schematic diagram of a frame number correspondence between a reference signal and a reconstructed reference signal in an embodiment of the present application;
fig. 6 is a schematic structural diagram of a frequency offset estimation device in an embodiment of the present application;
fig. 7 is a schematic structural diagram of an electronic device in an embodiment of the present application.
Detailed Description
For the purposes, technical solutions and advantages of the present application, the technical solutions of the present application will be clearly and completely described below with reference to specific embodiments of the present application and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
For the foregoing, the DTMB radiation source is a relatively ideal external radiation source, and when the reference signal is reconstructed by the DTMB signal, the prior art estimates the frequency offset of the reference signal by using the autocorrelation between the standard PN sequence and the frame header portion of the DTMB signal, but since the standard PN sequence is only a small portion of the DTMB signal frame, the frequency offset estimation error obtained by using the sequence of the standard PN sequence is relatively large, which results in deterioration of the subsequent direct wave, multipath clutter suppression and time-frequency two-dimensional correlation.
Aiming at the problems, according to the embodiment of the application, a reference signal received by a direct wave channel generates a local standard PN sequence according to the broadcasting standard of the DTMB, and the reference signal and the PN sequence are subjected to time domain correlation to obtain the starting position of a signal frame; further, according to the characteristic that each signal frame head is the same, frequency offset coarse estimation of the reference signal is carried out, and frequency offset compensation is carried out on the DTMB signal by utilizing the frequency offset coarse estimation, so that the DTMB signal after the frequency offset compensation is demodulated; reconstructing the data frame obtained by demodulation according to the signal format of the DTMB, and carrying out fine estimation on the frequency offset according to the time domain correlation of the reconstructed reference signal and the original reference signal.
The following describes in detail the technical solutions provided by the embodiments of the present application with reference to the accompanying drawings.
The embodiment of the application provides a frequency offset estimation method, as shown in fig. 1, and provides a flow diagram of the frequency offset method in the embodiment of the application, where the method at least includes the following steps S110 to S140:
step S110, a reference signal is obtained through the DTMB signal of the external radiation source, and a reference signal of time domain synchronization is obtained according to the time domain correlation between the reference signal and the standard PN sequence, wherein the reference signal comprises a plurality of frames of DTMB signals.
The standard PN sequence refers to a PN sequence for checking the DTMB broadcasting standard, that is, the standard PN sequence in the embodiment of the present application is the same as the signal sequence of the frame header portion of the DTMB signal, so that the time domain synchronization of each frame DTMB signal in the reference signal is implemented by using the autocorrelation between the standard PN and the frame header portion of the DTMB signal.
Step S120, according to the frequency deviation rough estimation of the reference signal of the time domain synchronization, carrying out frequency deviation compensation on each frame of DTMB signal of the reference signal, and demodulating each frame of DTMB signal after the frequency deviation compensation to obtain a data body of each frame of DTMB signal.
In the prior art, the frequency offset rough estimation obtained according to the reference signal of the time domain synchronization is used as the final frequency offset estimation result of the reference signal, and only the signal sequence of the DTMB frame head part is used in the whole frequency offset estimation process, so that the frequency offset estimation error of the reference signal of the DTMB type in the prior art is larger.
Unlike the prior art, the present embodiment performs frequency offset compensation on each frame of DTMB signal in the reference signal by using frequency offset coarse estimation, so that the DTMB signal after frequency offset compensation can be demodulated, for example, by using a channel equalization technique and a constellation judgment technique, to demodulate a data body in a signal frame from the DTMB signal. Therefore, the demodulated data body can be subjected to framing processing according to the signal format of the DTMB, the signal reconstruction is carried out on each frame of the DTMB signal in the reference signal, the frequency offset fine estimation is carried out on the original reference signal by utilizing the reconstructed complete DTMB signal, and the frequency offset estimation precision is improved.
The complete DTMB signal includes a frame header portion and a frame body portion of the DTMB signal, and compared with the prior art that only the frame header portion is used to estimate the frequency offset, the frequency offset estimation accuracy can be significantly improved by using the complete DTMB signal to estimate the frequency offset.
And step S130, framing the data body obtained through demodulation in a DTMB signal format to obtain a reconstructed reference signal.
Step S140, obtaining the frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal.
As can be seen from the frequency offset estimation method shown in fig. 1, in the embodiment of the present application, a reference signal is obtained through a DTMB signal, a frequency offset coarse estimation of each frame of DTMB signal in the reference signal is obtained according to the autocorrelation characteristics of each frame of DTMB signal in the reference signal and a standard PN sequence, frequency offset compensation is performed on a corresponding DTMB signal frame in the reference signal by using the frequency offset coarse estimation, so that the compensated DTMB signal frame can be demodulated, and then framing processing of the DTMB signal is performed on the demodulated data body based on the signal format of the DTMB signal, so as to obtain a reconstructed reference signal, and a frequency offset fine estimation of each frame of DTMB signal in the reference signal is obtained by using the time domain correlation characteristics between the reconstructed reference signal and the reference signal.
According to the frequency offset estimation method for the DTMB external radiation source radar reference signal, the frequency offset with higher precision at the estimated position can be estimated only by demodulating and reconstructing the received reference signal, the problem of large frequency offset estimation error in the existing scheme is solved, and the method is simple and easy to implement and has higher practicability.
As shown in fig. 2, the frequency offset estimation process in the embodiment of the present application includes: the four processes of S1 preprocessing, S2 signal demodulation, S3 signal reconstruction and S4 frequency offset estimation are described in detail by the following embodiments.
S1, pretreatment:
in the external radiation source radar, an antenna of a direct wave channel is aligned with a DTMB transmitting tower, an irradiation signal of the DTMB transmitting tower is received, and a radio receiver of a communication system samples radio signals according to a preset sampling frequency and a preset center frequency, for example, samples the DTMB signals according to a preset sampling frequency of 30.24 MHz; the radio frequency signal is converted into an intermediate frequency signal by a receiver, a digital baseband signal x of the reference signal is obtained according to the intermediate frequency signal, the sampling frequency of the digital baseband signal x is 30.24MHz, and the center frequency is zero.
As shown in fig. 3, the process of obtaining the reference signal by the receiver, that is, the reference signal formed by the multi-frame DTMB digital baseband signal in this embodiment includes:
the method comprises the steps of converting a radio signal received by a radio signal receiver at a direct wave channel in real time into an electric signal, amplifying the processable electric signal through a low noise amplifier, performing mixing filtering on the amplified electric signal through an analog down-conversion module to obtain an analog intermediate frequency signal, performing high-speed sampling on the analog intermediate frequency signal through an analog-to-digital conversion module to obtain a digital intermediate frequency signal, and performing mixing filtering on the digital intermediate frequency signal through a digital down-conversion module to obtain a DTMB digital baseband signal.
After the DTMB digital baseband signal is obtained, the DTMB digital baseband signal is filtered by a filter adopted by the broadcasting signal standard of DTMB, for example, a root raised cosine filter with a roll-off coefficient of 0.05 is adopted to filter the DTMB digital baseband signal, the filtered DTMB digital baseband signal is extracted to make the sampling rate conform to the standard demodulation sampling rate, for example, 4 times of downsampling is carried out on the filtered DTMB digital baseband signal to make the sampling rate become the standard rate of 7.56 MHz.
The local standard PN sequence is generated according to the broadcasting standard of the DTMB signal, and the standard PN sequence refers to the same PN sequence as that of the frame header portion of the DTMB signal. Because the acquired reference signal in the embodiment of the application comprises multi-frame DTMB signals, and the signal sequence of the frame header part of each frame DTMB signal is the same as the standard PN sequence, the part of the signal has good autocorrelation characteristics, and according to the time-domain autocorrelation characteristics of the part of the signal, the time-domain synchronization of each frame DTMB signal in the reference signal can be realized. Summarizing in the autocorrelation calculation process, observing a time domain sliding correlation peak through a standard PN sequence and a reference signal, and determining the frame head position of each frame of DTMB signal according to the correlation peak.
After determining the frame header position of each frame of DTMB signal in the reference signal, the frame header portions of two adjacent frame signals may be used to perform coarse frequency offset estimation, that is, the frequency offset of the current frame DTMB signal is determined according to the frame header portion of the current frame DTMB signal and the frame header portion of the previous frame DTMB signal, for example, the frequency offset coarse estimation of the ith frame DTMB signal of the reference signal is obtained according to the following formula (1):
in the formula (1), x (N) is the reference signal, N is the frequency point of the reference signal, i is the frame number, N is the length of the DTMB signal, M is the length of the standard PN sequence, T s For sampling interval f i ' coarse frequency offset estimation for ith frame DTMB signal [ alpha ]]* To take the conjugate operator, arg () is the argument operator.
After obtaining the frequency offset rough estimation of each frame of DTMB signal of the reference signal, the method can be based on exp (2 pi nf i 'T s ) And carrying out frequency offset compensation on the ith frame of DTMB signal, wherein each frame of DTMB signal after frequency offset compensation can be demodulated.
S2, signal demodulation:
for convenience in describing the demodulation and reconstruction process of the DTMB signal according to the embodiment of the present application, the frame format characteristics of the DTMB signal will be described with reference to fig. 4.
As shown in fig. 4, each frame of DTMB signal includes two parts, a frame header part and a frame body part, the frame header part is composed of a standard PN sequence, and is divided into three modes of 420, 595 and 945 according to the length of the standard PN sequence; the frame body portion includes system data and a data body. Each frame of DTMB signal includes 4200 symbols, the frame body portion includes 3780 symbols of data, the system data includes 36 symbols, and the remaining 3744 symbols are data bodies, and the system data generally includes frame body mode indication symbols, modulation and code rate mode symbols, and so on.
For the DTMB signal with the frame format characteristic, in one embodiment of the present application, each frame of DTMB signal after frequency offset compensation is demodulated by the following steps:
carrying out channel estimation and equalization on each frame of DTMB signal after frequency offset compensation to obtain a constellation map of a frame body part of each frame of DTMB signal; for example, carrying out least square channel estimation of the time domain on each frame of DTMB signal after frequency offset compensation according to a standard PN sequence to obtain a channel impulse response H, and carrying out Fourier transformation on the channel impulse response H to obtain a channel response H of a frequency domain; in order to eliminate the influence of the frame header part on the signal equalization process, optionally, the frame header part in the DTMB signal is eliminated, and channel equalization is performed on the frame body part of each frame of the DTMB signal by using the channel response H, so as to obtain a constellation map of the frame body part of each frame of the DTMB signal.
In general, by performing constellation decision on the constellation map, the data constellation points of the data body can be obtained, that is, the data body of each frame of DTMB signal in the reference signal is obtained.
The demodulation process of the DTMB signal of each frame in the reference signal is thus completed by the above-described embodiment.
S3, signal reconstruction:
in one embodiment of the present application, framing in DTMB signal format is performed on the data body obtained by demodulation, so as to obtain a reconstructed reference signal, which includes:
firstly, concatenating system data of a frame body part and a data body in a frequency domain, and carrying out Fourier transform on the concatenated frame body part to obtain a concatenated time domain frame body part; and then inserting a frame header part formed by a standard PN sequence in front of the frame bodies of the time domain frame body parts after the concatenation to obtain a reconstructed DTMB signal of each frame.
In the reconstruction of the DTMB signal, the average power of the signal in the header portion should be ensured to be 2 times that of the signal in the body portion.
In practical application, the reconstruction process further includes upsampling and shaping filtering the DTMB signal obtained by framing, for example, upsampling 4 times to a sampling frequency of 30.24MHz is performed on the DTMB signal obtained by framing, filtering the DTMB signal by using a root raised cosine filter with a roll-off coefficient of 0.05 to obtain a reconstructed DTMB signal, and sequentially reconstructing each frame DTMB signal in the reference signal to obtain a reconstructed reference signal.
S4, estimating frequency offset:
as shown in fig. 5, the reconstructed reference signal has a one-to-one correspondence with the frame number of the original reference signal. Therefore, in one embodiment of the present application, according to the correspondence, it is possible to determine the current frame DTMB signal and the adjacent frame DTMB signal of the reference signal, and determine the current frame DTMB signal and the adjacent frame DTMB signal of the reconstructed reference signal; and obtaining the frequency offset fine estimation of the current frame DTMB signal of the reference signal according to the current frame DTMB signal and the adjacent frame DTMB signal of the reference signal and the current frame DTMB signal and the adjacent frame DTMB signal of the reconstructed reference signal.
Specifically, the frequency offset fine estimation of the ith frame DTMB signal of the reference signal is obtained according to the following formula (2):
in the formula (2), x (N) is the reference signal, y (N) is the number of frequency points of the reference signal, i is the frame number, N is the length of the DTMB signal, T s For sampling interval f i And (5) carrying out frequency offset fine estimation on the ith frame of DTMB signal.
As can be seen from comparison with the formula (1), the range of the frequency points of the reference signal in the formula (1) is [0, M ], and the range of the frequency points of the reference signal in the formula (2) and the reconstructed reference signal is [0, N-1]. That is, in the prior art, only the frame header part of the DTMB signal is used in the frequency offset estimation, but the complete DTMB signal in the reference signal is used in the embodiment of the present application, so that the frequency offset estimation accuracy of the embodiment of the present application will be significantly improved.
The embodiment of the present application further provides a frequency offset estimation device 600, as shown in fig. 6, and a schematic structural diagram of a frequency offset device in the embodiment of the present application is provided, where the device 600 includes:
the preprocessing unit 610 is configured to obtain a reference signal through a DTMB signal of an external radiation source, and obtain a reference signal with time domain synchronization according to a time domain correlation between the reference signal and a standard PN sequence, where the reference signal includes a multi-frame DTMB signal;
the demodulation unit 620 is configured to perform frequency offset compensation on each frame of DTMB signal of the reference signal according to the frequency offset coarse estimation of the time domain synchronous reference signal, and demodulate each frame of DTMB signal after the frequency offset compensation to obtain a data body of each frame of DTMB signal;
a reconstruction unit 630, configured to perform framing in DTMB signal format on the data body obtained by demodulation, so as to obtain a reconstructed reference signal;
and the estimation unit 640 is configured to obtain a frequency offset fine estimation of the reference signal according to the time domain correlation between the reference signal and the reconstructed reference signal.
In one embodiment of the present application, the demodulation unit 620 is configured to perform channel estimation and equalization on each frame of DTMB signal after frequency offset compensation, so as to obtain a constellation map of a frame body portion of each frame of DTMB signal; and carrying out constellation judgment on the constellation mapping diagram to obtain the data constellation points of the data body.
In one embodiment of the present application, the demodulation unit 620 is specifically configured to perform time domain least square channel estimation on each frame of DTMB signal after frequency offset compensation according to the standard PN sequence, so as to obtain a channel impulse response; and carrying out channel equalization on the frame body part of each frame of the DTMB signal by utilizing the channel impulse response to obtain a constellation map of the frame body part of each frame of the DTMB signal.
In one embodiment of the present application, the DTMB signal format includes a frame header portion and a frame body portion, the frame body portion including system data and a data body; a reconstruction unit 630, configured to concatenate the system data of the frame body portion with the data body in the frequency domain, and perform fourier transform on the concatenated frame body portion to obtain a concatenated time domain frame body portion; and inserting a frame header part formed by a standard PN sequence in front of the frame bodies of the time domain frame body parts after the concatenation to obtain a reconstructed DTMB signal of each frame.
In one embodiment of the present application, the estimating unit 640 is configured to determine, according to a one-to-one correspondence between the frame numbers of the reference signal and the reconstructed reference signal, a current frame DTMB signal and an adjacent frame DTMB signal of the reference signal, and determine a current frame DTMB signal and an adjacent frame DTMB signal of the reconstructed reference signal; and obtaining the frequency offset fine estimation of the current frame DTMB signal of the reference signal according to the current frame DTMB signal and the adjacent frame DTMB signal of the reference signal and the current frame DTMB signal and the adjacent frame DTMB signal of the reconstructed reference signal.
In one embodiment of the present application, the estimation unit 640 is specifically configured to perform the following formulaObtaining the frequency offset fine estimation of the ith frame DTMB signal of the reference signal; wherein x (N) is a reference signal, y (N) is a reconstructed reference signal, N is the frequency number of the reference signal, i is a frame number, N is the length of the DTMB signal, T s For sampling interval f i And (5) carrying out frequency offset fine estimation on the ith frame of DTMB signal.
In one embodiment of the present application, the demodulation unit 620 is further configured to perform the following formulaObtaining a frequency offset rough estimation of an ith frame DTMB signal of the reference signal; wherein x (N) is a reference signal, N is a frequency point of the reference signal, i is a frame number, N is a length of the DTMB signal, M is a length of a standard PN sequence, T s For sampling interval f i ' is a coarse estimate of the frequency offset of the ith frame DTMB signal.
In one embodiment of the present application, the demodulation unit 620 is further configured to perform the demodulation according to the formula exp (2pi nf i 'T s ) And performing frequency offset compensation on the ith frame DTMB signal.
It can be understood that the above frequency offset estimation device can implement each step of the frequency offset estimation method provided in the foregoing embodiment, and the relevant explanation about the frequency offset estimation method is applicable to the frequency offset estimation device, which is not repeated herein.
Fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present application. Referring to fig. 7, at the hardware level, the electronic device includes a processor, and optionally an internal bus, a network interface, and a memory. The Memory may include a Memory, such as a Random-Access Memory (RAM), and may further include a non-volatile Memory (non-volatile Memory), such as at least 1 disk Memory. Of course, the electronic device may also include hardware required for other services.
The processor, network interface, and memory may be interconnected by an internal bus, which may be an ISA (Industry Standard Architecture ) bus, a PCI (Peripheral Component Interconnect, peripheral component interconnect standard) bus, or EISA (Extended Industry Standard Architecture ) bus, among others. The buses may be classified as address buses, data buses, control buses, etc. For ease of illustration, only one bi-directional arrow is shown in FIG. 7, but not only one bus or type of bus.
And the memory is used for storing programs. In particular, the program may include program code including computer-operating instructions. The memory may include memory and non-volatile storage and provide instructions and data to the processor.
The processor reads the corresponding computer program from the nonvolatile memory to the memory and then runs the computer program to form the frequency offset estimation device on a logic level. The processor is used for executing the programs stored in the memory and is specifically used for executing the following operations:
acquiring a reference signal through a DTMB signal of an external radiation source, and acquiring a reference signal of time domain synchronization according to the time domain correlation of the reference signal and a standard PN sequence, wherein the reference signal comprises a plurality of frames of DTMB signals;
according to the frequency deviation rough estimation of the time domain synchronous reference signal, carrying out frequency deviation compensation on each frame of DTMB signal of the reference signal, and demodulating each frame of DTMB signal after the frequency deviation compensation to obtain a data body of each frame of DTMB signal;
framing the data body obtained through demodulation in a DTMB signal format to obtain a reconstructed reference signal;
and obtaining the frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal.
The method performed by the frequency offset estimation device disclosed in the embodiment shown in fig. 1 of the present application may be applied to a processor or implemented by the processor. The processor may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or by instructions in the form of software. The processor may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but also digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The disclosed methods, steps, and logic blocks in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in hardware, in a decoded processor, or in a combination of hardware and software modules in a decoded processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method.
The electronic device may further execute the method executed by the frequency offset estimation device in fig. 1, and implement the function of the frequency offset estimation device in the embodiment shown in fig. 1, which is not described herein again.
The embodiments of the present application also provide a computer readable storage medium storing one or more programs, where the one or more programs include instructions, which when executed by an electronic device including a plurality of application programs, enable the electronic device to perform a method performed by the frequency offset estimation apparatus in the embodiment shown in fig. 1, and specifically are configured to perform:
acquiring a reference signal through a DTMB signal of an external radiation source, and acquiring a reference signal of time domain synchronization according to the time domain correlation of the reference signal and a standard PN sequence, wherein the reference signal comprises a plurality of frames of DTMB signals;
according to the frequency deviation rough estimation of the time domain synchronous reference signal, carrying out frequency deviation compensation on each frame of DTMB signal of the reference signal, and demodulating each frame of DTMB signal after the frequency deviation compensation to obtain a data body of each frame of DTMB signal;
framing the data body obtained through demodulation in a DTMB signal format to obtain a reconstructed reference signal;
and obtaining the frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal.
It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.
The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.
Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and changes may be made to the present application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. which are within the spirit and principles of the present application are intended to be included within the scope of the claims of the present application.
Claims (9)
1. A method for frequency offset estimation, the method comprising:
acquiring a reference signal through a DTMB signal of an external radiation source, and acquiring a reference signal of time domain synchronization according to the time domain correlation of the reference signal and a standard PN sequence, wherein the reference signal comprises a plurality of frames of DTMB signals, the DTMB signal format comprises a frame head part and a frame body part, and the frame body part comprises system data and a data body;
according to the frequency deviation rough estimation of the time domain synchronous reference signal, carrying out frequency deviation compensation on each frame of DTMB signal of the reference signal, and demodulating each frame of DTMB signal after the frequency deviation compensation to obtain a data body of each frame of DTMB signal;
framing the data body obtained through demodulation in a DTMB signal format to obtain a reconstructed reference signal;
obtaining frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal;
and framing the data body obtained by demodulation in a DTMB signal format to obtain a reconstructed reference signal, wherein the method comprises the following steps:
the system data of the frame body part and the data body are connected in series in the frequency domain, and Fourier transformation is carried out on the frame body part after the series connection to obtain a time domain frame body part after the series connection;
and inserting a frame header part formed by a standard PN sequence in front of the frame bodies of the time domain frame body parts after the concatenation to obtain a reconstructed DTMB signal of each frame.
2. The method of claim 1, wherein demodulating the frequency offset compensated DTMB signal per frame to obtain the data body of the DTMB signal per frame comprises:
carrying out channel estimation and equalization on each frame of DTMB signal after frequency offset compensation to obtain a constellation map of a frame body part of each frame of DTMB signal;
and carrying out constellation judgment on the constellation mapping diagram to obtain the data constellation points of the data body.
3. The method of claim 2, wherein performing channel estimation and equalization on the frequency offset compensated DTMB signal per frame comprises:
carrying out time domain least square channel estimation on each frame of DTMB signal after frequency offset compensation according to the standard PN sequence to obtain channel impulse response;
carrying out channel equalization on the frame body part of each frame of DTMB signal by utilizing the channel impulse response to obtain a constellation map of the frame body part of each frame of DTMB signal;
framing the data body obtained through demodulation in a DTMB signal format to obtain a reconstructed reference signal, wherein the method comprises the following steps:
the system data of the frame body part and the data body are connected in series in the frequency domain, and Fourier transformation is carried out on the frame body part after the series connection to obtain a time domain frame body part after the series connection;
and inserting a frame header part formed by a standard PN sequence in front of the frame bodies of the time domain frame body parts after the concatenation to obtain a reconstructed DTMB signal of each frame.
4. The method of claim 1, wherein obtaining the fine estimate of the frequency offset of the reference signal based on the time domain correlation of the reference signal and the reconstructed reference signal comprises:
according to the one-to-one correspondence between the frame numbers of the reference signal and the reconstructed reference signal, determining a current frame DTMB signal and an adjacent frame DTMB signal of the reference signal, and determining the current frame DTMB signal and the adjacent frame DTMB signal of the reconstructed reference signal;
and obtaining the frequency offset fine estimation of the current frame DTMB signal of the reference signal according to the current frame DTMB signal and the adjacent frame DTMB signal of the reference signal and the current frame DTMB signal and the adjacent frame DTMB signal of the reconstructed reference signal.
5. The method of claim 4, wherein obtaining the fine frequency offset estimate of the current frame DTMB signal of the reference signal based on the current frame DTMB signal of the reference signal and the neighboring frame DTMB signal and the reconstructed current frame DTMB signal of the reference signal and the neighboring frame DTMB signal, comprises:
according to the formulaObtaining the frequency offset fine estimation of the ith frame DTMB signal of the reference signal;
wherein x (N) is a reference signal, y (N) is a reconstructed reference signal, N is the frequency number of the reference signal, i is a frame number, N is the length of the DTMB signal, T s For sampling interval f i And (5) carrying out frequency offset fine estimation on the ith frame of DTMB signal.
6. The method of claim 1, wherein the coarse frequency offset estimate of the time domain synchronized reference signal is obtained by:
according to the formulaObtaining a frequency offset rough estimation of an ith frame DTMB signal of the reference signal;
wherein x (N) is a reference signal, N is a frequency point of the reference signal, i is a frame number, N is a length of the DTMB signal, M is a length of a standard PN sequence, T s For sampling interval f i ' is a coarse estimate of the frequency offset of the ith frame DTMB signal.
7. The method of claim 6, wherein performing frequency offset compensation on each frame of DTMB signal of the reference signal comprises:
according to formula exp (2 pi nf i 'T s ) And performing frequency offset compensation on the ith frame DTMB signal.
8. A frequency offset estimation apparatus, the apparatus comprising:
the preprocessing unit is used for acquiring a reference signal through a DTMB signal of an external radiation source, and obtaining a reference signal with time domain synchronization according to the time domain correlation between the reference signal and a standard PN sequence, wherein the reference signal comprises a multi-frame DTMB signal, the DTMB signal format comprises a frame head part and a frame body part, and the frame body part comprises system data and a data body;
the demodulation unit is used for carrying out frequency offset compensation on each frame of DTMB signal of the reference signal according to the frequency offset rough estimation of the reference signal in the time domain synchronization, and demodulating each frame of DTMB signal after the frequency offset compensation to obtain a data body of each frame of DTMB signal;
a reconstruction unit, configured to perform framing in DTMB signal format on the data body obtained by demodulation, so as to obtain a reconstructed reference signal;
the estimation unit is used for obtaining frequency offset fine estimation of the reference signal according to the time domain correlation of the reference signal and the reconstructed reference signal; the method is particularly used for concatenating the system data of the frame body part and the data body in the frequency domain, and carrying out Fourier transform on the concatenated frame body part to obtain a concatenated time domain frame body part; and inserting a frame header part formed by a standard PN sequence in front of the frame bodies of the time domain frame body parts after the concatenation to obtain a reconstructed DTMB signal of each frame.
9. An electronic device, comprising:
a processor; and
a memory arranged to store computer executable instructions that, when executed, cause the processor to perform the frequency offset estimation method of any of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210418672.9A CN114944974B (en) | 2022-04-20 | 2022-04-20 | Frequency offset estimation method and device and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210418672.9A CN114944974B (en) | 2022-04-20 | 2022-04-20 | Frequency offset estimation method and device and electronic equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114944974A CN114944974A (en) | 2022-08-26 |
| CN114944974B true CN114944974B (en) | 2024-03-08 |
Family
ID=82907848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210418672.9A Active CN114944974B (en) | 2022-04-20 | 2022-04-20 | Frequency offset estimation method and device and electronic equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114944974B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116506093B (en) * | 2023-06-26 | 2023-08-18 | 北京智芯微电子科技有限公司 | Method, device, equipment, chip and medium for configuring downlink demodulation reference signals |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102143117A (en) * | 2011-03-31 | 2011-08-03 | 福州大学 | Time-frequency synchronization joint estimation method based on multi-carrier receiver of digital television media broadcast (DTMB) system |
| CN102707271A (en) * | 2012-05-31 | 2012-10-03 | 武汉大学 | System utilizing CMMB (China Mobile Multimedia Broadcasting) signal to detect target and method thereof |
| CN102821079A (en) * | 2012-09-04 | 2012-12-12 | 中国电子科技集团公司第五十四研究所 | Carrier frequency deviation estimation and compensation method of single-carrier frequency domain balance system in great-frequency deviation condition |
| CN106169984A (en) * | 2016-07-28 | 2016-11-30 | 武汉大学 | A kind of match tracing channel estimation methods being applicable to the reconstruct of DTMB external illuminators-based radar reference signal |
| CN110535559A (en) * | 2019-08-02 | 2019-12-03 | 武汉大学苏州研究院 | A kind of WiFi external illuminators-based radar reference signal reconstruct method and system |
| WO2021195333A1 (en) * | 2020-03-27 | 2021-09-30 | Qualcomm Incorporated | Iterative reference signal symbol reconstruction and channel estimation |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10243682B2 (en) * | 2016-08-22 | 2019-03-26 | Phasorlab, Inc. | Time-domain and frequency-domain approach to frequency offset correction method for LTE SC-FDMA uplink |
-
2022
- 2022-04-20 CN CN202210418672.9A patent/CN114944974B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102143117A (en) * | 2011-03-31 | 2011-08-03 | 福州大学 | Time-frequency synchronization joint estimation method based on multi-carrier receiver of digital television media broadcast (DTMB) system |
| CN102707271A (en) * | 2012-05-31 | 2012-10-03 | 武汉大学 | System utilizing CMMB (China Mobile Multimedia Broadcasting) signal to detect target and method thereof |
| CN102821079A (en) * | 2012-09-04 | 2012-12-12 | 中国电子科技集团公司第五十四研究所 | Carrier frequency deviation estimation and compensation method of single-carrier frequency domain balance system in great-frequency deviation condition |
| CN106169984A (en) * | 2016-07-28 | 2016-11-30 | 武汉大学 | A kind of match tracing channel estimation methods being applicable to the reconstruct of DTMB external illuminators-based radar reference signal |
| CN110535559A (en) * | 2019-08-02 | 2019-12-03 | 武汉大学苏州研究院 | A kind of WiFi external illuminators-based radar reference signal reconstruct method and system |
| WO2021195333A1 (en) * | 2020-03-27 | 2021-09-30 | Qualcomm Incorporated | Iterative reference signal symbol reconstruction and channel estimation |
Non-Patent Citations (5)
| Title |
|---|
| A Spectrum Sensing Algorithm for DTMB-A based on Accumulated Autocorrelation of Multiple Frames;Yunchuan Huang等;《2021 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB)》;全文 * |
| DTMB外辐射源雷达参考信号纯度对探测性能的影响分析;万显荣;唐慧;王俊芳;赵志欣;;系统工程与电子技术(第04期);全文 * |
| DTMB系统定时同步与频偏估计的算法研究;曹凡;《中国优秀硕士论文电子期刊网》;全文 * |
| WiFi外辐射源雷达参考信号重构及其对探测性能影响研究;饶云华;明燕珍;林静;朱逢园;万显荣;龚子平;;雷达学报(第03期);全文 * |
| 一种基于数字电视地面广播照射源的外辐射源雷达快速杂波相消算法;张各各;王俊;刘玉春;;电子与信息学报(第01期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114944974A (en) | 2022-08-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110417697B (en) | Precise frequency measurement method for high-dynamic weak MPSK signal | |
| CN108988928B (en) | Method for detecting double-channel single-pulse angle error in frequency domain | |
| US20210231816A9 (en) | Signal acquisition method and device | |
| CN114944974B (en) | Frequency offset estimation method and device and electronic equipment | |
| CN109655847B (en) | Fast capturing method suitable for dynamic signal | |
| CN112034419B (en) | Propagation delay estimation method and device for 5G positioning | |
| CN107171693A (en) | Broadband interference suppressing method based on Waveform Reconstructing | |
| CN111934710A (en) | High-dynamic spread spectrum signal rapid acquisition algorithm | |
| CN110191079B (en) | Non-coherent combined capturing method and device | |
| CN112968850A (en) | Weak BPSK signal carrier capturing method | |
| CN115616628B (en) | GNSS antenna array receiver blind beam forming method based on angle tracking loop | |
| CN110958035A (en) | Frequency secondary capturing device and method based on triangular envelope fitting | |
| CN113406672B (en) | Piecewise linear frequency modulation interference elimination method based on self-adaptive windowing | |
| CN113541706B (en) | Narrow-band interference suppression method based on transform domain processing | |
| CN113726699B (en) | Anti-frequency-offset communication satellite antenna real-time calibration method and device | |
| JP3630581B2 (en) | Spread modulation signal receiver | |
| CN109547129B (en) | Stepping weighting Tong detection method | |
| CN102307164A (en) | Digital frequency estimation method and system | |
| CN108226968B (en) | Navigation signal rapid capturing method | |
| CN112764063A (en) | Method for realizing capture processing and receiver | |
| CN115412125B (en) | Large-frequency-offset direct-spread signal first-order differential bit synchronization method and system | |
| CN117176518B (en) | Frequency offset estimation method, device, electronic equipment and storage medium | |
| CN116015346B (en) | Cascade inhibition-based unbalanced aliasing spread spectrum signal blind separation method | |
| CN114362805B (en) | Short-time burst signal processing method and device | |
| CN115061165B (en) | Navigation spread spectrum signal capturing method and system based on low-loss down-sampling strategy |
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 |