CN113364719A - OFDM-based electromagnetic wave transmission while drilling system - Google Patents
OFDM-based electromagnetic wave transmission while drilling system Download PDFInfo
- Publication number
- CN113364719A CN113364719A CN202110585416.4A CN202110585416A CN113364719A CN 113364719 A CN113364719 A CN 113364719A CN 202110585416 A CN202110585416 A CN 202110585416A CN 113364719 A CN113364719 A CN 113364719A
- Authority
- CN
- China
- Prior art keywords
- signal
- module
- ofdm
- conversion
- frame
- 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.)
- Granted
Links
Images
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
- H04L27/2649—Demodulators
- H04L27/26524—Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
-
- 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
- H04L27/2656—Frame synchronisation, e.g. packet synchronisation, time division duplex [TDD] switching point detection or subframe 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
- 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
- H04L27/2662—Symbol 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
- H04L27/2666—Acquisition of further OFDM parameters, e.g. bandwidth, subcarrier spacing, or guard interval length
-
- 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
- H04L27/2669—Details of algorithms characterised by the domain of operation
- H04L27/2671—Time domain
-
- 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
- H04L27/2669—Details of algorithms characterised by the domain of operation
- H04L27/2672—Frequency domain
-
- 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
- H04L27/2688—Resistance to perturbation, e.g. noise, interference or fading
-
- 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
- H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
- H04L27/2691—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation involving interference determination or cancellation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L7/00—Arrangements for synchronising receiver with transmitter
- H04L7/0008—Synchronisation information channels, e.g. clock distribution lines
- H04L7/0012—Synchronisation information channels, e.g. clock distribution lines by comparing receiver clock with transmitter clock
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Discrete Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
The invention discloses an OFDM-based electromagnetic wave transmission while drilling system, which is high in signal transmission rate and solves the problem of high error rate in a channel transmission process. The invention adopts OFDM modulation and demodulation, can flexibly distribute information bits according to the actual condition of a channel, can more effectively utilize limited bandwidth resources, improves the service quality of the whole system, can resist multipath and narrow-band interference, and improves the error rate performance.
Description
Technical Field
The invention belongs to the field of electromagnetic wave transmission, and particularly relates to an OFDM-based electromagnetic wave transmission while drilling system.
Background
With the increase of the demand of China for underground resources, China increasingly explores useful substances in the seabed and other strata. The measurement while drilling radio electromagnetic wave transmission technology mainly uses lower frequency electromagnetic waves to transmit real-time data measured by a logging instrument in the underground drilling process. However, as the degree of exploration increases, the types of oil and gas reservoirs in China become more and more complex, and the difficulty of oil exploitation becomes more and more high. How to accurately and effectively understand the condition of a downhole hydrocarbon reservoir so as to maximize oil production becomes an urgent problem to be solved in the current society. The existing electromagnetic wave transmission system while drilling on the market adopts more modulation and demodulation methods such as BPSK and MSK, when BPSK coherent demodulation is performed, the stratum is high-consumption dispersive coal quality, the signal to noise ratio is low, the bandwidth is narrow, intersymbol interference is caused by chromatic dispersion, the phase ambiguity occurs in carrier recovery, the phenomenon of 'reverse phase operation' occurs in the demodulation process, the recovered digital signals '1' and '0' are inverted, the modulation mode has high error rate in practical engineering application, the transmission rate is low, usually only a few bits/s can be achieved, and the requirement of high-speed logging while drilling can not be met. The MSK signal transmission is easily affected by the stratum environment, and the system performance of the MSK signal transmission is not higher than that of BPSK signals.
Disclosure of Invention
Aiming at the defects in the prior art, the OFDM-based electromagnetic wave transmission while drilling system provided by the invention solves the problems that the signal transmission rate is not high when a carrier signal with lower frequency is used for transmission in the prior art and the error rate of the signal is reduced in the channel transmission process.
In order to achieve the purpose of the invention, the invention adopts the technical scheme that: an OFDM-based electromagnetic wave transmission while drilling system comprises a ground demodulation part and a downhole modulation part which are in communication connection;
the ground demodulation part comprises a first filtering module, an ADC (analog to digital converter) module, a first FPGA (field programmable gate array) module and a first DSP (digital signal processor) module; the input end of the first filtering module is connected with a ground receiving antenna, and the output end of the first filtering module is connected to the first FPGA module through the ADC conversion module; the first FPGA module is connected with a first DSP module, and the first DSP module is also connected with a ground PC;
the underground modulation part comprises a second DSP module, a second FPGA module, a first DAC conversion module and an operational amplifier module; the second DSP module is connected with the second FPGA module, the second FPGA module is connected with the operational amplifier module through the first DAC conversion module, and the operational amplifier module is connected with the underground transmitting antenna through the first signal amplifying circuit.
Further, the use method of the electromagnetic wave transmission while drilling system is as follows:
s1, carrying out OFDM modulation by the underground second DSP module to obtain an OFDM signal;
s2, sending the OFDM signals into the second FPGA module, carrying out serial data transmission processing according to the SPI interface time sequence, sending the OFDM signals into the first DAC conversion module through the SPI interface, converting the OFDM signals into analog signals, and transmitting the analog signals to the operational amplifier module to obtain amplified and filtered signals;
s3, transmitting the amplified and filtered signals through a first signal amplifying circuit and a downhole transmitting antenna;
s4, receiving signals transmitted by the underground transmitting antenna through the ground receiving antenna, filtering the signals through the first filtering module, and transmitting the filtered signals to the ADC conversion module for signal conversion to obtain third conversion signals;
and S5, sending the third conversion signal to the first DSP module through the McBSP0 interface for OFDM demodulation, and completing uplink transmission of the electromagnetic wave while drilling.
Further, in step S1, the OFDM signal modulation is performed in the second DSP module, and the specific method for obtaining the OFDM signal is as follows:
s1.1, carrying out scrambling operation on the coded signals, and then carrying out M-QAM mapping on each subcarrier in the scrambled signals according to a bit allocation table to obtain frame signals;
s1.2, inserting pilot frequency into the frame signal, calculating the power of the frame signal, and acquiring frequency domain data of the frame signal;
s1.3, carrying out inverse fast Fourier transform on the frequency domain data, and inserting a guard interval to obtain an OFDM signal.
Further, the frame signal in step S1.1 includes a channel activation frame, a training synchronization frame, a training frame, a channel analysis frame, a signal-to-noise ratio estimation frame, a data synchronization frame, and a superframe synchronization frame.
Further, the specific method for performing OFDM demodulation in step S5 is as follows:
s5.1, performing symbol synchronization calibration on the third conversion signal, performing symbol coarse synchronization on the calibrated signal, and performing Fast Fourier Transform (FFT) according to the coarse synchronization signal to obtain a conversion signal;
s5.2, carrying out channel tracking on the converted signal to obtain the frequency domain response of the channel;
s5.3, carrying out frequency domain equalization according to the transformed signal and the frequency domain response;
and S5.4, sequentially carrying out demapping, descrambling and RS decoding on the frequency domain equalization signal to finish OFDM demodulation.
Further, after the converted signal is obtained in step S5.1, the sampling clocks of the transmitting end and the receiving end are synchronized, specifically: the conversion signal is sequentially subjected to pilot frequency extraction, time synchronization, AFC processing and VCXO processing to complete the sampling clock synchronization of the transmitting end and the receiving end;
and the processed conversion signal is transmitted to an ADC conversion module for processing, and symbol synchronization correction is carried out according to the processed conversion signal and the third conversion signal.
The invention has the beneficial effects that:
(1) the invention provides an OFDM-based electromagnetic wave transmission while drilling system, which is high in signal transmission rate and solves the problem of high error rate in a channel transmission process.
(2) The invention adopts OFDM modulation and demodulation, can flexibly distribute information bits according to the actual condition of a channel, can more effectively utilize limited bandwidth resources, improves the service quality of the whole system, can resist multipath and narrow-band interference, and improves the error rate performance.
Drawings
Fig. 1 is a schematic diagram of an OFDM-based electromagnetic wave transmission while drilling system according to the present invention.
Fig. 2 is a schematic diagram of an OFDM modulation process in the present invention.
Fig. 3 is a schematic diagram of an OFDM demodulation process according to the present invention.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
As shown in FIG. 1, an OFDM-based electromagnetic wave transmission while drilling system comprises a surface demodulation part and a downhole modulation part which are in communication connection;
the ground demodulation part comprises a first filtering module, an ADC (analog to digital converter) module, a first FPGA (field programmable gate array) module and a first DSP (digital signal processor) module; the input end of the first filtering module is connected with a ground receiving antenna, and the output end of the first filtering module is connected to the first FPGA module through the ADC conversion module; the first FPGA module is connected with a first DSP module, and the first DSP module is also connected with a ground PC;
the underground modulation part comprises a second DSP module, a second FPGA module, a first DAC conversion module and an operational amplifier module; the second DSP module is connected with the second FPGA module, the second FPGA module is connected with the operational amplifier module through the first DAC conversion module, and the operational amplifier module is connected with the underground transmitting antenna through the first signal amplifying circuit.
The use method of the electromagnetic wave transmission while drilling system comprises the following steps:
s1, carrying out OFDM modulation by the underground second DSP module to obtain an OFDM signal;
s2, sending the OFDM signals into the second FPGA module, carrying out serial data transmission processing according to the SPI interface time sequence, sending the OFDM signals into the first DAC conversion module through the SPI interface, converting the OFDM signals into analog signals, and transmitting the analog signals to the operational amplifier module to obtain amplified and filtered signals;
s3, transmitting the amplified and filtered signals through a first signal amplifying circuit and a downhole transmitting antenna;
s4, receiving signals transmitted by the underground transmitting antenna through the ground receiving antenna, filtering the signals through the first filtering module, and transmitting the filtered signals to the ADC conversion module for signal conversion to obtain third conversion signals;
and S5, sending the third conversion signal to the first DSP module through the McBSP0 interface for OFDM demodulation, and completing uplink transmission of the electromagnetic wave while drilling.
As shown in fig. 2, the specific method for performing OFDM signal modulation in the second DSP module in step S1 to obtain an OFDM signal includes:
s1.1, carrying out scrambling operation on the signal, and then carrying out M-QAM mapping on each subcarrier in the scrambled signal according to a bit allocation table to obtain a frame signal;
s1.2, inserting pilot frequency into the frame signal, calculating the power of the frame signal, and acquiring frequency domain data of the frame signal;
s1.3, carrying out inverse fast Fourier transform on the frequency domain data, and inserting a guard interval to obtain an OFDM signal.
The frame signal in step S1.1 includes a channel activation frame, a training synchronization frame, a training frame, a channel analysis frame, a signal-to-noise ratio estimation frame, a data synchronization frame, and a superframe synchronization frame.
The DSP performs OFDM modulation as shown in fig. 2, and the OFDM modulator receives and modulates data sent from the ground, where the user data is a physical layer packet after physical layer packing and FEC encoding. In digital communications, the long-term transmission of a bit "1" or a bit "0" by a transmitter may affect the establishment and maintenance of bit synchronization. Therefore, it is necessary to use a scrambling code at the transmitting end to avoid the adverse effect of such signals on the receiving end. The user data transmitted by the transmitting terminal is firstly scrambled, then a mapper performs M-QAM mapping on each subcarrier according to a bit allocation table, and the mapped signals are sent to a framer to generate various frame signals: the OFDM signal demodulation method comprises a channel activation frame, a training synchronization frame, a training frame, a channel analysis frame, a signal-to-noise ratio estimation frame, a data synchronization frame and a superframe synchronization frame, wherein at the demodulator end, the related demodulation operation of the OFDM signal is carried out by detecting frame signals. Although the channel used can be equalized by the training sequence in the receiver and the frequency deviation between symbols can be corrected, the remaining frequency deviation between symbols still exists, and the deviation does not disappear with the passage of time, but gradually accumulates, and the accumulation can cause the phase deviation of all sub-carriers. To avoid this effect, the reference phase needs to be tracked using a pilot signal. The IFFT is to transform the frequency domain data of each subchannel into time domain data to form a time domain OFDM modulated signal; the modulated OFDM symbols need to insert a guard interval to eliminate inter-symbol interference.
As shown in fig. 3, the specific method for performing OFDM demodulation in step S5 includes:
s5.1, performing symbol synchronization calibration on the third conversion signal, performing symbol coarse synchronization on the calibrated signal, and performing Fast Fourier Transform (FFT) according to the coarse synchronization signal to obtain a conversion signal;
s5.2, carrying out channel tracking on the converted signal to obtain the frequency domain response of the channel;
s5.3, carrying out frequency domain equalization according to the transformed signal and the frequency domain response;
and S5.4, sequentially carrying out demapping, descrambling and RS decoding on the frequency domain equalization signal to finish OFDM demodulation.
The symbol coarse synchronization is performed in a time domain, and can roughly estimate the initial position of an OFDM symbol, namely, the position of an FFT window is determined, so that a data segment which is not interfered by front and rear symbols can be extracted to participate in FFT operation, and the aim of correct demodulation is fulfilled.
After the converted signal is obtained in step S5.1, sampling clock synchronization between the transmitting end and the receiving end is performed, specifically: and sequentially carrying out pilot frequency extraction, time synchronization, AFC (automatic frequency control) processing and VCXO (voltage controlled oscillator) processing on the converted signal to finish the sampling clock synchronization of the transmitting end and the receiving end.
And the processed conversion signal is transmitted to an ADC conversion module for processing, and symbol synchronization correction is carried out according to the processed conversion signal and the third conversion signal.
In this embodiment, during the data exchange process, the demodulation software performs descrambling, demapping and RS decoding operations on the signal to demodulate the signal, and recovers the original data packet transmitted by the transmitter through demodulation. The demapping mainly implements demodulation of a modulated signal, and many channels with noise interference and poor transmission performance are encountered in a signal transmission process, which may cause errors in the signal transmission process, so that a receiving end cannot receive correct information. In order to effectively solve the problem, RS codes are used to correct errors of information, thereby ensuring the reliability of transmission.
Claims (6)
1. An OFDM-based electromagnetic wave transmission while drilling system is characterized by comprising a ground demodulation part and a downhole modulation part which are in communication connection;
the ground demodulation part comprises a first filtering module, an ADC (analog to digital converter) module, a first FPGA (field programmable gate array) module and a first DSP (digital signal processor) module; the input end of the first filtering module is connected with a ground receiving antenna, and the output end of the first filtering module is connected to the first FPGA module through the ADC conversion module; the first FPGA module is connected with a first DSP module, and the first DSP module is also connected with a ground PC;
the underground modulation part comprises a second DSP module, a second FPGA module, a first DAC conversion module and an operational amplifier module; the second DSP module is connected with the second FPGA module, the second FPGA module is connected with the operational amplifier module through the first DAC conversion module, and the operational amplifier module is connected with the underground transmitting antenna through the first signal amplifying circuit.
2. The OFDM-based electromagnetic wave transmission while drilling system as recited in claim 1, wherein the electromagnetic wave transmission while drilling system is used by:
s1, carrying out OFDM modulation by the underground second DSP module to obtain an OFDM signal;
s2, sending the OFDM signals into the second FPGA module, carrying out serial data transmission processing according to the SPI interface time sequence, sending the OFDM signals into the first DAC conversion module through the SPI interface, converting the OFDM signals into analog signals, and transmitting the analog signals to the operational amplifier module to obtain amplified and filtered signals;
s3, transmitting the amplified and filtered signals through a first signal amplifying circuit and a downhole transmitting antenna;
s4, receiving signals transmitted by the underground transmitting antenna through the ground receiving antenna, filtering the signals through the first filtering module, and transmitting the filtered signals to the ADC conversion module for signal conversion to obtain third conversion signals;
and S5, sending the third conversion signal to the first DSP module through the McBSP0 interface for OFDM demodulation, and completing uplink transmission of the electromagnetic wave while drilling.
3. The OFDM-based electromagnetic wave transmission while drilling system of claim 2, wherein in step S1, the OFDM signal is modulated in the second DSP module, and the specific method for obtaining the OFDM signal is as follows:
s1.1, carrying out scrambling operation on the signal, and then carrying out M-QAM mapping on each subcarrier in the scrambled signal according to a bit allocation table to obtain a frame signal;
s1.2, inserting pilot frequency into the frame signal, calculating the power of the frame signal, and acquiring frequency domain data of the frame signal;
s1.3, carrying out inverse fast Fourier transform on the frequency domain data, and inserting a guard interval to obtain an OFDM signal.
4. The OFDM-based electromagnetic wave while drilling transmission system according to claim 3, wherein the frame signal in step S1.1 includes a channel activation frame, a training synchronization frame, a training frame, a channel analysis frame, a signal-to-noise ratio estimation frame, a data synchronization frame and a superframe synchronization frame.
5. The OFDM-based electromagnetic wave transmission while drilling system of claim 4, wherein the specific method for OFDM demodulation in step S5 is as follows:
s5.1, performing symbol synchronization calibration on the third conversion signal, performing symbol coarse synchronization on the calibrated signal, and performing Fast Fourier Transform (FFT) according to the coarse synchronization signal to obtain a conversion signal;
s5.2, carrying out channel tracking on the converted signal to obtain the frequency domain response of the channel;
s5.3, carrying out frequency domain equalization according to the transformed signal and the frequency domain response;
and S5.4, sequentially carrying out demapping, descrambling and RS decoding on the frequency domain equalization signal to finish OFDM demodulation.
6. The OFDM-based electromagnetic wave transmission while drilling system of claim 5, wherein after the transformed signal is obtained in step S5.1, the sampling clock synchronization between the transmitting end and the receiving end is performed, specifically: the conversion signal is sequentially subjected to pilot frequency extraction, time synchronization, AFC processing and VCXO processing to complete the sampling clock synchronization of the transmitting end and the receiving end;
and the processed conversion signal is transmitted to an ADC conversion module for processing, and symbol synchronization correction is carried out according to the processed conversion signal and the third conversion signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110585416.4A CN113364719B (en) | 2021-05-27 | 2021-05-27 | OFDM-based electromagnetic wave transmission while drilling system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110585416.4A CN113364719B (en) | 2021-05-27 | 2021-05-27 | OFDM-based electromagnetic wave transmission while drilling system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113364719A true CN113364719A (en) | 2021-09-07 |
| CN113364719B CN113364719B (en) | 2023-03-31 |
Family
ID=77527883
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110585416.4A Active CN113364719B (en) | 2021-05-27 | 2021-05-27 | OFDM-based electromagnetic wave transmission while drilling system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113364719B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7016425B1 (en) * | 1999-01-15 | 2006-03-21 | Sony International (Europe) Gmbh | Quasi-differential modulation/demodulation method for multi-amplitude digital modulated signals and OFDM system |
| US20100039286A1 (en) * | 2008-08-18 | 2010-02-18 | Halliburton Energy Services, Inc. | Symbol Synchronization for Downhole OFDM Telemetry |
| CN102134992A (en) * | 2010-01-27 | 2011-07-27 | 罗仁泽 | High-speed wired duplex communication method and device for information between well and ground |
| CN102457462A (en) * | 2010-11-01 | 2012-05-16 | 西安石油大学 | Method for transmitting signal in bored well by utilizing OFDM (Orthogonal Frequency Division Multiplexing) technology |
| CN107037489A (en) * | 2017-06-21 | 2017-08-11 | 电子科技大学 | A kind of automatic compensation device of induction logging directly coupling signal |
| CN108063657A (en) * | 2017-12-13 | 2018-05-22 | 电子科技大学 | Well logging data NC-OFDM sonic transmissions methods based on compressed sensing |
| CN108111455A (en) * | 2017-12-13 | 2018-06-01 | 电子科技大学 | Well logging data V-OFDM sonic transmissions methods based on compressed sensing |
| CN111155988A (en) * | 2020-01-03 | 2020-05-15 | 电子科技大学 | Multi-frequency resistivity measuring device |
| CN111786927A (en) * | 2020-06-23 | 2020-10-16 | 青岛拓准测控技术有限公司 | Orthogonal frequency division multiplexing while-drilling data transmission method, system, storage medium and application |
| WO2020232460A1 (en) * | 2019-05-14 | 2020-11-19 | Onesubsea Ip Uk Limited | Machine learning technics with system in the loop for oil & gas telemetry systems |
-
2021
- 2021-05-27 CN CN202110585416.4A patent/CN113364719B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7016425B1 (en) * | 1999-01-15 | 2006-03-21 | Sony International (Europe) Gmbh | Quasi-differential modulation/demodulation method for multi-amplitude digital modulated signals and OFDM system |
| US20100039286A1 (en) * | 2008-08-18 | 2010-02-18 | Halliburton Energy Services, Inc. | Symbol Synchronization for Downhole OFDM Telemetry |
| CN102134992A (en) * | 2010-01-27 | 2011-07-27 | 罗仁泽 | High-speed wired duplex communication method and device for information between well and ground |
| CN102457462A (en) * | 2010-11-01 | 2012-05-16 | 西安石油大学 | Method for transmitting signal in bored well by utilizing OFDM (Orthogonal Frequency Division Multiplexing) technology |
| CN107037489A (en) * | 2017-06-21 | 2017-08-11 | 电子科技大学 | A kind of automatic compensation device of induction logging directly coupling signal |
| CN108063657A (en) * | 2017-12-13 | 2018-05-22 | 电子科技大学 | Well logging data NC-OFDM sonic transmissions methods based on compressed sensing |
| CN108111455A (en) * | 2017-12-13 | 2018-06-01 | 电子科技大学 | Well logging data V-OFDM sonic transmissions methods based on compressed sensing |
| WO2020232460A1 (en) * | 2019-05-14 | 2020-11-19 | Onesubsea Ip Uk Limited | Machine learning technics with system in the loop for oil & gas telemetry systems |
| CN111155988A (en) * | 2020-01-03 | 2020-05-15 | 电子科技大学 | Multi-frequency resistivity measuring device |
| CN111786927A (en) * | 2020-06-23 | 2020-10-16 | 青岛拓准测控技术有限公司 | Orthogonal frequency division multiplexing while-drilling data transmission method, system, storage medium and application |
Non-Patent Citations (3)
| Title |
|---|
| 孙旭东: ""随钻电磁波协同传输模拟电路系统研究"", 《中国优秀硕士学位论文全文数据库》 * |
| 廖辉然: ""随钻电磁波协同传输数字系统研究"", 《中国优秀硕士学位论文全文数据库》 * |
| 蔡小庆;陈晓芳;李昆;: "油气井下声传输的OFDM调制方法研究" * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113364719B (en) | 2023-03-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7561614B2 (en) | Communication apparatus and communication method using digital wavelet multi carrier transmission system | |
| US8369425B2 (en) | Robust channel estimation in communication systems | |
| US7787550B2 (en) | Combined frame alignment and timing recovery in digital subscriber line (DSL) communications systems | |
| CA2298722C (en) | Estimation of frequency offsets in ofdm communication systems | |
| US20190052374A1 (en) | Calibrating A Digital Telemetry System | |
| CN103107968B (en) | Wireless communication receiver, wireless communication receiver method and phase noise compensation device | |
| AU2001282726A1 (en) | Communication system using OFDM | |
| CN102891824B (en) | Based on the noise diffusion suppressing method of radio frequency pilot tone in high-speed light DFT-S OFDM modulation system | |
| CN101179356A (en) | Data transmitting, receiving method and device | |
| CN110300079B (en) | MSK signal coherent demodulation method and system | |
| WO2008122144A1 (en) | Method and apparatus for digital signal reception | |
| KR20020075836A (en) | Pilot signal transmission technique and digital communication system using same | |
| CN106508104B (en) | A kind of method of extension remote measurement coherent receiver frequency offset estimation range | |
| CN110266625B (en) | Demodulation method and system based on dynamic threshold judgment of QPSK modulation with frame synchronization code hidden in information code | |
| EP1751880A1 (en) | Cellular communications system using baseband carrier injection and related methods | |
| CN103023830A (en) | Turbo iteration detecting device and method directing at big carrier frequency excursion | |
| CN100396063C (en) | Method for global digital broadcasting based on differential amplitude and phase combining modulation | |
| CN113364719B (en) | OFDM-based electromagnetic wave transmission while drilling system | |
| CN101202564B (en) | Channel initialization method | |
| CN108123724A (en) | A kind of communication system based on shortwave narrowband waveform | |
| CN110149289B (en) | Frame structure design method for large frequency offset download wave frequency offset estimation | |
| EP2090049A1 (en) | Amplitude-differential phase shift keying modulation apparatus and method | |
| Zhao et al. | A high-speed well logging telemetry system based on low-power FPGA | |
| EP2103065B1 (en) | Method and system for data transmission with decreased bit error rate | |
| Kobayashi | A novel coherent demodulation for M-QAM OFDM signal operating in the burst mode |
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 |