CN104695948A - Logging cable telemetry system - Google Patents
Logging cable telemetry system Download PDFInfo
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- CN104695948A CN104695948A CN201510123363.9A CN201510123363A CN104695948A CN 104695948 A CN104695948 A CN 104695948A CN 201510123363 A CN201510123363 A CN 201510123363A CN 104695948 A CN104695948 A CN 104695948A
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- logging cable
- signal
- baseband signal
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Remote Sensing (AREA)
- Geophysics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
The invention relates to the technical field of logging and provides an underground device, a ground device and a logging cable telemetry system which are used for logging cable telemetry. The transmission speed and the stability of a narrow-band uneven channel, and the cable transmission capability in the logging cable telemetry system can be improved, the signal distortion is revised and the circuit complexity is extremely reduced, so that the data transmission from an underground instrument to a ground system has the properties of high speed, strong reliability and low time delaying.
Description
Technical field
The present invention relates to logging technique field, particularly relate to a kind of WELL LOGGING CABLE TELECOMMUNICATION SYSTEM.
Background technology
WELL LOGGING CABLE TELECOMMUNICATION SYSTEM is that oil well geologic information can critical path from downhole transmitted to ground-based computer, it is included in a kind of communication system in logger, for converting data to physical signalling and uploading (or download) to receiving equipment through cable channel.
WELL LOGGING CABLE TELECOMMUNICATION SYSTEM mainly contains the function of three aspects:
(1) by downhole instrument collection and quantize data be transferred to ground;
(2) control command that ground system sends is sent to downhole instrument;
(3) for downhole instrument is powered.
Because log data is mainly from down-hole terrestrial system transmission data, and down order data volume from ground to down-hole is less, therefore the key problem of WELL LOGGING CABLE TELECOMMUNICATION SYSTEM be study how from downhole instrument terrestrial system fast, stable, transmission of large capacity data timely.
Current WELL LOGGING CABLE TELECOMMUNICATION SYSTEM, because the available band scope of logging cable is narrow, be generally no more than 200KHz, and available bandwidth is not fixed, which limits the capacity of transmission system, cause transmission capacity lower.In addition, by the manufactured materials of cable and the impact of process technology, cable is difficult to form strict uniform transmission medium, makes channel uneven, and signal attenuation is serious and distortion is comparatively large, and signal is difficult to be resumed on ground.
Summary of the invention
For solving the above-mentioned problems in the prior art, the embodiment of the present invention provides a kind of downhole hardware of logging cable the spread of the rumours on the one hand, and downhole hardware comprises the baseband signal generation module, Digital Up Convert module, Linear Driving module and the down-hole transformer module that are connected successively;
Baseband signal generation module, for producing I road and Q railway digital baseband signal according to raw log data;
Digital Up Convert module, for up-conversion is carried out on I road and Q railway digital baseband signal, and changes into analog if signal;
Linear Driving module, for improving voltage magnitude and the current amplitude of analog if signal;
Down-hole transformer module, for the output signal of Linear Driving module being carried out isolating and amplifying, then is input in logging cable.
On the other hand, the embodiment of the present invention additionally provides a kind of ground installation of logging cable the spread of the rumours, and ground installation comprises ground level transformer module, linear receiver module, Digital Down Converter Module and baseband signal processing module;
Ground level transformer module is used for the input signal of ground installation to carry out isolating and reducing;
Linear receiver module, for reducing voltage magnitude and the current amplitude of the output signal of ground level transformer module;
Digital Down Converter Module, for the output signal of linear receiver module is carried out down coversion, and converts data signal to;
Baseband signal processing module, for recovering raw log data from the output signal of Digital Down Converter Module.
On the other hand, the embodiment of the present invention additionally provides a kind of WELL LOGGING CABLE TELECOMMUNICATION SYSTEM, and WELL LOGGING CABLE TELECOMMUNICATION SYSTEM comprises logging cable, downhole hardware as above and ground installation as above;
Logging cable, for being transferred to the output signal of downhole hardware in ground installation.
The technical scheme of the embodiment of the present invention, the transfer rate of the uneven channel in arrowband in WELL LOGGING CABLE TELECOMMUNICATION SYSTEM and stability and cable transmission capacity can be promoted, corrected signal distortion, great reduction circuit complexity, makes to have two-forty, reliability is strong, time delay is low characteristic from the transmission of the data of downhole instrument terrestrial system.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the structural representation of the embodiment of the downhole hardware of logging cable the spread of the rumours of the present invention;
Fig. 2 is the structural representation of the baseband signal generation module of the downhole hardware of logging cable the spread of the rumours of the present invention;
Fig. 3 is the structural representation of the Digital Up Convert module of the downhole hardware of logging cable the spread of the rumours of the present invention;
Fig. 4 is the structural representation of the embodiment of the ground installation of logging cable the spread of the rumours of the present invention;
Fig. 5 is the structural representation of the Digital Down Converter Module of the ground installation of logging cable the spread of the rumours of the present invention;
Fig. 6 is the structural representation of the baseband signal processing module of the ground installation of logging cable the spread of the rumours of the present invention;
Fig. 7 is the structural representation of the embodiment of WELL LOGGING CABLE TELECOMMUNICATION SYSTEM of the present invention.
Detailed description of the invention
Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
Fig. 1 is the structural representation of the embodiment of the downhole hardware of logging cable the spread of the rumours of the present invention.
This downhole hardware 100 comprises baseband signal generation module 110, Digital Up Convert module 120, Linear Driving module 130 and down-hole transformer module 140.
Wherein, baseband signal generation module 110, for producing I road and Q railway digital baseband signal according to raw log data.Preferably, baseband signal generation module 110 can comprise the coding unit 111, IQ map unit 112, pulse shape filter unit 113 and the filtering interpolation unit 114 that connect successively, as shown in Figure 2.The front end log data be ready for sending can be carried out channel coding by baseband signal generation module 110, forms I and Q two-way digital baseband signal, then sends into Digital Up Convert module 120 respectively through pulse shape filter unit 113, filtering interpolation unit 114.
Exemplary, coding unit 111 can adopt following coding rule:
A
n=2D
’ n-1，B
n=A
n-A
n-2
Wherein, { D
nserial No. waiting for transmission, { A
nsequence after level conversion, { B
n{ A
nthe sequence that obtains through correlative coding, { D
' nreceiving terminal receiving sequence { R
nthrough associated translation obtain data sequence.
Data are divided into I and Q two-way by the digital signal processor TMS320F2812 that IQ map unit 112 can utilize TI company to produce, and then insert some redundancy symbols, thus improve the error-detection error-correction ability of signal.
Pulse shape filter unit 113 can use square root raised cosine filter, and raised cosine formed filter rolloff-factor 0.2,16:1 is sampled, to eliminate the intersymbol interference because timing error brings.
In order to reduce the impact of spectral aliasing, improve sample rate, the CIC(interpolation cascade integral comb filter that filtering interpolation unit 114 can use level Four 32 times to extract) wave filter carries out cascade, and interpolation is carried out to source data code stream, thus obtains good flatness in signal band.
Digital Up Convert module 120, for up-conversion is carried out on I road and Q railway digital baseband signal, and changes into analog if signal.As shown in Figure 3, Digital Up Convert module 120 can comprise the first Direct Digital Synthesizer (DDS) 121, anti-sinc filter 122 and the digital to analog converter (DAC) 123 that connect successively.The centre frequency of signal for being mixed with carrier wave by the signal from baseband signal generation module 110, thus is moved in higher frequency by Digital Up Convert module 120, and directly converts data signal to analog signal.
Preferably, the Digital Up Convert chip AD9857 of the high integration that Digital Up Convert module 120 can adopt ADI company to produce, can be put into numeric field by the problem in conventional simulation territory and solve in the mode of discrete signal, simplify the difficulty of circuit realiration.The IQ two paths of signals of AD9857 to input carries out modulation and forms modulated signal, and the anti-cic filter through AD9857 inside, interpolation filter, anti-sinc filter, amplitude multiplier, then modulated signal is sent into the DAC of 14, form the analog if signal after modulation.Select the fundamental frequency of frequency as carrier wave of 200KHz.Low side can avoid the crosstalk (roughly at 30 ~ 50KHz) of down going channel, is high-endly no more than 320KHz, can away from the interference of less than well site power supply 45 ~ 65Hz and 51 time harmonic component.Digital Up Convert chip AD9857 can accept complex I/Q data input, realize the up-conversion modulation of the multi-signals such as PAM, QAM, ASK, FSK, with 14Bit device digital upconverter, 200MHz internal clock speed, be integrated with 4 ~ 20 times of programmable clock frequency multipliers of locking indicator, single-ended or differential input clock can be selected.When use 64QAM modulation, when signal to noise ratio is not less than 26dB, band efficiency is 6bps/Hz, by the channel width of 200KHz, then adopts the spread of the rumours speed of cable during 64QAM to reach 1.2Mbps, thus realizes the high-speed transfer of data.
Linear Driving module 130, for improving voltage magnitude and the current amplitude of the analog if signal that Digital Up Convert module 120 exports.In order to ensure signal of telecommunication transmission on long cables, need the current driving ability strengthening the signal of telecommunication.If from up-converter module signal out without Linear Driving module, improve voltage magnitude and the electric current of signal, due to the resistive attenuation of long cable, signal cannot be sent to ground decode system.Preferably, according to the characteristic of logging cable, signal voltage can be brought up to and be greater than 15V by Linear Driving module, and electric current is not less than 100mA.Exemplary, the SN75454B chip that Linear Driving module can use TI company to produce, the current value of signal is brought up to 200mA, and voltage brings up to 30V, thus overcomes signal decay on long cables.
Down-hole transformer module 140, for the output signal of Linear Driving module 130 being carried out isolating and amplifying, then sends into logging cable.Exemplary, the mode transformer of coiling voluntarily can be used to carry out signal isolation in down-hole, its turn ratio is 1:1.
Preferably, this downhole hardware 100 also can comprise down-hole low-pass filtering module, down-hole low-pass filtering module is arranged between Digital Up Convert module 120 and Linear Driving module 130, for the out-of-band noise of filtering analog if signal, then inputs to Linear Driving module 130.Exemplary, the second-order low-pass filter that this down-hole low-pass filtering module can use the ADA4841-1 produced by ADI company to form carrys out the out-of-band noise of filtered signal.ADA4841-1 is a unity gain stable, low noise and low distortion, rail-to-rail output amplifier, and maximum static current is 1.5 mA.The output voltage swing of ADA4841-1 can reach 50 below mV of arbitrary power rail, and common mode input scope can be low to moderate negative supply voltage.This device can drive the capacitive load of the highest 10 pF, and peaking is minimum.
The present embodiment, can increase substantially the message transmission rate in the downhole hardware of logging cable the spread of the rumours, effective improving data transmission efficiency, reduces distorted signals, reduces the complexity of circuit.
Fig. 4 is the structural representation of the embodiment of the ground installation of logging cable the spread of the rumours of the present invention.
This ground installation 200 comprises ground level transformer module 210, linear receiver module 220, Digital Down Converter Module 230 and baseband signal processing module 240;
Ground level transformer module 210 is for being undertaken isolating and reducing by the input signal of ground installation.The mode transformer of coiling voluntarily can be used to carry out signal isolation, and its turn ratio is 1:1.
Linear receiver module 220, for reducing voltage magnitude and the current amplitude of the output signal of ground level transformer module 210; Signal, after ground level transformer module 210, still may have larger electric current or higher voltage, directly can not deliver to instrument or the main coding chip of next stage.Preferably, the differential line receiver DS78C20J that high common-mode voltage can be used to input, reduces electric current and the voltage of signal, makes it the input being suitable as low pass filter.
Digital Down Converter Module 230, for the output signal of linear receiver module 220 is carried out down coversion, and converts data signal to; Preferably, Digital Down Converter Module 230 can comprise the analog-digital converter (ADC) 231, second Direct Digital Synthesizer (DDS) 232 and decimation filter 233 that connect successively, as shown in Figure 5.Decimation filter 233 comprises first decimation filter with fixed coefficient and second decimation filter with program control coefficient.The output signal of linear receiver module 220 can mix with carrier wave by Digital Down Converter Module 230, its centre frequency is moved in lower frequency, and directly converts analog signal to data signal.
Exemplary, Digital Down Converter Module 230 can adopt the Digital Down Convert chip AD6620 of ADI company, first converts the analog signal of reception to data signal, and demodulation restores I road and Q road signal, again respectively through the decimation filter of its inside, then by certain formatted output I/Q data.
Different from the frequency-conversion processing mode of simulation, Digital Down Converter Module 230 is when numeric field processes signal, do not need Error Feedback to be adjusted to frequency mixer again, so just accurately can be eliminated the distortion in transmission by some digital algorithm, simplify the process of down coversion.
Baseband signal processing module 240, for recovering raw log data in the output signal from Digital Down Converter Module 230.As shown in Figure 6, baseband signal processing module 240 can comprise the matched filtering unit 241, balanced unit 242 and the channel decoding unit 243 that connect successively.
Matched filtering unit 241 can adopt raised cosine filter, and rolloff-factor is identical with base band shaping filter, makes the ratio of the signal transient power of output and noise average power maximum.
Balanced unit 242 can adopt adaptive equalizer, and adaptive equalizer adopts Godard algorithm, carries out amplitude equalization, can adopt 128 taps based on normalization minimum mean-square calculation.Godard algorithm can utilize the statistical property of QAM signal preferably, can solve convergence and the convergence rate problem of blind equalization algorithm simultaneously.
Exemplary, the digital signal processor TMS320F2812 that baseband signal processing module 240 can adopt TI company to produce carries out equilibrium treatment to I/Q data, to the uneven Characteristic Compensation of Medical Sensors of the channel of cable, then carry out channel-decoding, remove the coding of redundancy and obtain timing information, thus recover primary signal, then send into follow-up data processing link.
Preferably, ground installation 200 also comprises ground low-pass filtering module, ground low-pass filtering module is arranged between linear receiver module 220 and Digital Down Converter Module 230, for the out-of-band noise in the output signal of the linear receiver module 220 of filtering, then inputs in Digital Down Converter Module 230.Exemplary, the second-order low-pass filter that ground low-pass filtering module can use the ADA4841-1 chip produced by ADI company to form carrys out the out-of-band noise of filtered signal.
The present embodiment, can increase substantially the message transmission rate in the ground installation of logging cable the spread of the rumours, effective improving data transmission efficiency, reduces distorted signals, reduces the complexity of circuit.
Fig. 7 is the structural representation of the embodiment of WELL LOGGING CABLE TELECOMMUNICATION SYSTEM of the present invention.
WELL LOGGING CABLE TELECOMMUNICATION SYSTEM comprises logging cable, downhole hardware and ground installation;
Logging cable, for being transferred to the output signal of downhole hardware in ground installation.
Wherein, this downhole hardware can be the downhole hardware in above-described embodiment, and this ground installation can be the ground installation in above-described embodiment, does not repeat them here.
The technical scheme of the embodiment of the present invention, the transfer rate of the uneven channel in arrowband in WELL LOGGING CABLE TELECOMMUNICATION SYSTEM and stability and cable transmission capacity can be promoted, corrected signal distortion, great reduction circuit complexity, makes to have two-forty, reliability is strong, time delay is low characteristic from the transmission of the data of downhole instrument terrestrial system.
The foregoing is only preferred embodiment of the present invention, be not intended to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.
Claims (10)
1. the downhole hardware of logging cable the spread of the rumours, is characterized in that, described downhole hardware comprises the baseband signal generation module, Digital Up Convert module, Linear Driving module and the down-hole transformer module that are connected successively;
Described baseband signal generation module, for producing I road and Q railway digital baseband signal according to raw log data;
Described Digital Up Convert module, for up-conversion is carried out on described I road and Q railway digital baseband signal, and changes into analog if signal;
Described Linear Driving module, for improving voltage magnitude and the current amplitude of described analog if signal;
Described down-hole transformer module, for the output signal of described Linear Driving module being carried out isolating and amplifying, then is input in logging cable.
2. device as claimed in claim 1, it is characterized in that, described baseband signal generation module comprises the coding unit, IQ map unit, pulse shape filter unit and the filtering interpolation unit that connect successively; Described pulse shape filter unit comprises square root raised cosine filter, and described filtering interpolation unit comprises the cascade integral comb filter that level Four 32 times extracts.
3. device as claimed in claim 1, it is characterized in that, described Digital Up Convert module comprises the first Direct Digital Synthesizer connected successively, anti-sinc filter and digital to analog converter.
4. the device as described in any one of claim 1-3, it is characterized in that, described downhole hardware also comprises down-hole low-pass filtering module, described down-hole low-pass filtering module is arranged between described Digital Up Convert module and described Linear Driving module, for the out-of-band noise of analog if signal described in filtering, then input to described Linear Driving module.
5. the ground installation of logging cable the spread of the rumours, is characterized in that, described ground installation comprises the ground level transformer module be connected successively, linear receiver module, Digital Down Converter Module and baseband signal processing module;
Described ground level transformer module is used for the input signal of described ground installation to carry out isolating and reducing;
Described linear receiver module, for reducing voltage magnitude and the current amplitude of the output signal of described ground level transformer module;
Described Digital Down Converter Module, for the output signal of described linear receiver module is carried out down coversion, and converts data signal to;
Described baseband signal processing module, for recovering raw log data in the output signal from described Digital Down Converter Module.
6. device as claimed in claim 5, it is characterized in that, described Digital Down Converter Module comprises the analog-digital converter, the second Direct Digital Synthesizer and the decimation filter that connect successively; Described decimation filter comprises first decimation filter with fixed coefficient and second decimation filter with program control coefficient.
7. device as claimed in claim 5, is characterized in that, described linear receiver module comprises the differential linear receiver with common-mode voltage input.
8. device as claimed in claim 5, it is characterized in that, described baseband signal processing module comprises the matched filtering unit, balanced unit and the channel decoding unit that connect successively; Described matched filtering unit comprises raised cosine filter; Described balanced unit comprises adaptive equalizer, and described adaptive equalizer adopts Godard algorithm, carries out amplitude equalization based on normalization minimum mean-square calculation.
9. the device as described in any one of claim 5-8, it is characterized in that, described ground installation also comprises ground low-pass filtering module, described ground low-pass filtering module is arranged between described linear receiver module and described Digital Down Converter Module, for the out-of-band noise in the output signal of receiver module linear described in filtering, then input in described Digital Down Converter Module.
10. a WELL LOGGING CABLE TELECOMMUNICATION SYSTEM, is characterized in that, described WELL LOGGING CABLE TELECOMMUNICATION SYSTEM comprises logging cable, the downhole hardware as described in any one of claim 1-4 and the ground installation as described in any one of claim 5-9;
Described logging cable, for being transferred to the output signal of described downhole hardware in ground installation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510123363.9A CN104695948A (en) | 2015-03-20 | 2015-03-20 | Logging cable telemetry system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510123363.9A CN104695948A (en) | 2015-03-20 | 2015-03-20 | Logging cable telemetry system |
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040207538A1 (en) * | 2000-06-22 | 2004-10-21 | Halliburton Energy Services, Inc. | Burst QAM downhole telemetry system |
| CN1781272A (en) * | 2003-02-10 | 2006-05-31 | 哈利伯顿能源服务公司 | Downhole telemetry system using discrete multi-tone modulation in a wireless communication medium |
| CN101158284A (en) * | 2007-11-05 | 2008-04-09 | 聂泳培 | Single-core cable well logging data high speed transmission system |
| US7787525B1 (en) * | 1999-12-24 | 2010-08-31 | Schlumberger Technology Corporation | Method and apparatus for transmission of well-bore data on multiple carrier frequencies |
| CN201610752U (en) * | 2009-10-21 | 2010-10-20 | 西安威尔罗根能源科技有限公司 | Telemetry system capable of realizing high-speed transmission by utilizing OFDM technology |
| CN201674524U (en) * | 2010-05-17 | 2010-12-15 | 中国海洋石油总公司 | Underground modulator-demodulator |
| CN102045289A (en) * | 2009-10-21 | 2011-05-04 | 西安威尔罗根能源科技有限公司 | Remote transmission system for realizing high-speed transmission by utilizing OFDM (Orthogonal Frequency Division Multiplexing) technology |
| 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 |
| CN202850989U (en) * | 2012-09-21 | 2013-04-03 | 中国海洋石油总公司 | High speed data transmission system based on single-core logging cable |
-
2015
- 2015-03-20 CN CN201510123363.9A patent/CN104695948A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7787525B1 (en) * | 1999-12-24 | 2010-08-31 | Schlumberger Technology Corporation | Method and apparatus for transmission of well-bore data on multiple carrier frequencies |
| US20040207538A1 (en) * | 2000-06-22 | 2004-10-21 | Halliburton Energy Services, Inc. | Burst QAM downhole telemetry system |
| CN1781272A (en) * | 2003-02-10 | 2006-05-31 | 哈利伯顿能源服务公司 | Downhole telemetry system using discrete multi-tone modulation in a wireless communication medium |
| CN101158284A (en) * | 2007-11-05 | 2008-04-09 | 聂泳培 | Single-core cable well logging data high speed transmission system |
| CN201610752U (en) * | 2009-10-21 | 2010-10-20 | 西安威尔罗根能源科技有限公司 | Telemetry system capable of realizing high-speed transmission by utilizing OFDM technology |
| CN102045289A (en) * | 2009-10-21 | 2011-05-04 | 西安威尔罗根能源科技有限公司 | Remote transmission system for realizing high-speed transmission by utilizing OFDM (Orthogonal Frequency Division Multiplexing) technology |
| 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 |
| CN201674524U (en) * | 2010-05-17 | 2010-12-15 | 中国海洋石油总公司 | Underground modulator-demodulator |
| CN202850989U (en) * | 2012-09-21 | 2013-04-03 | 中国海洋石油总公司 | High speed data transmission system based on single-core logging cable |
Non-Patent Citations (2)
| Title |
|---|
| 习郑虎: "多制式数字基带信号发生技术", 《中北大学硕士学位论文》 * |
| 闫奎: "基于QAM技术的电缆遥传系统的研究", 《西安科技大学硕士学位论文》 * |
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Application publication date: 20150610 |