WO2016107557A1

WO2016107557A1 - Self-adapting wired communication method and logging method and device

Info

Publication number: WO2016107557A1
Application number: PCT/CN2015/099516
Authority: WO
Inventors: 裴彬彬; 赵帅; 岳宏图; 王晓鹏; 赵立业; 费尔南德斯拉米雷斯·胡安塞巴斯蒂安
Original assignee: 西安格威石油仪器有限公司
Priority date: 2014-12-30
Filing date: 2015-12-29
Publication date: 2016-07-07
Also published as: CN105306391A; CA2984118A1

Abstract

A self-adapting wired communication method and logging method and device are provided in the present invention. The self-adapting wired communication method includes: S1: a first terminal sends communication data and training data to a second terminal according to a communication parameter; S2: the second terminal evaluates the communication condition of a channel according to the training data, and adjusts the communication parameter used to send the communication data according to the evaluation result; S3: the second terminal sends the adjusted communication parameter to the first terminal to update the communication parameter. The present invention may implement self-adapting channel evaluation, thus improving the stability of the communication system.

Description

Adaptive wired communication method and logging method and device

Technical field

The invention relates to the field of remote logging technology, and in particular to an adaptive wired communication method and a logging method and device.

Background technique

At present, in the communication method based on the wired connection, the signal inevitably has a bit error phenomenon in the transmission process, and the cause of the phenomenon includes the transmission line factor and the device environment factor. Since the application environment of the common communication system is relatively stable, it is usually tested before the normal communication, and then a series of communication parameters are adjusted according to the test result, and the use of the above communication parameters can be effectively used in the normal communication process to effectively overcome the error band. The problem that comes.

However, for certain environmentally unstable application scenarios, especially for example, wireline logging, cable perforating, cable-threading, etc., the communication equipment is in a complex environment and requires real-time communication through long-distance cable lines. It is said that due to environmental impacts, such as the invisible communication cable between the well and the downhole, the temperature change in the underground environment is large, and the communication cable will be stretched at any time, it will have a great impact on the efficiency of data transmission, so ordinary The communication method is completely unable to meet the demand.

Some of the existing dedicated logging systems are mostly improved in coding mode or modulation mode. For the unstable environment, communication interruption can only be solved by re-communication training after communication interruption, and such system pairs The requirements for communication cables are high and can only be applied to a particular type of cable. For example, the document US 2010/0295702 A1 discloses a two-way pre-equalization system for high-speed remote transmission of downhole cable communication using OFDM (Orthogonal). Frequency Division Multiplexing (OFDM) modulation scheme that compensates for narrow bandwidth, high attenuation, and multi-noise of downhole cables using trellis coded modulation and Reed Solomon coding to improve the efficiency of the communication system. However, the system does not improve the communication adaptability. It can be seen that such systems have poor stability and do not have dynamic adaptive functions.

Summary of the invention

To this end, the technical problem to be solved by the present invention is to improve the stability of the communication system and to make it adaptable to suit various communication hardware and application environments.

The present invention provides an adaptive wired communication method, including: S1: a first terminal sends communication data and training data to a second terminal according to a communication parameter; S2: the second terminal evaluates channel communication conditions according to the training data, and Adjusting, according to the evaluation result, a communication parameter used to send the communication data; S3: the second terminal sends the adjusted communication parameter to the first terminal to update the communication parameter.

Further, the method further includes repeatedly performing the steps S1 to S3.

Further, before the step S3, the method further includes: the second terminal acquiring a clock frequency of the first terminal; and the second terminal transmitting the adjusted communication parameter according to the clock frequency.

Further, before the step S1, the method further includes: the second terminal performs frame synchronization check.

Further, the first terminal sends the logging data and the training data to the second terminal by using a digital multi-carrier modulation method; the second terminal sends the Communication parameters.

Further, the communication parameter includes at least one of a frequency domain equalization parameter, a bit allocation parameter, and a channel coding parameter.

Further, in the step S2, when the communication parameter is a bit allocation parameter, adjusting, according to the evaluation result, the communication parameter used to transmit the communication data comprises: acquiring a signal to noise ratio of the channel; according to the signal to noise ratio The number of bits allocated to the audio is adjusted, the signal to noise ratio being proportional to the number of bits.

Or in the step S2, when the communication parameter is a channel coding parameter, adjusting communication parameters used for transmitting the communication data according to the evaluation result includes: acquiring a channel bandwidth and a sub-band bandwidth; acquiring a number of channels, the number of channels Is the ratio of the channel bandwidth to the sub-band bandwidth, and the number of channels is an integer power of two.

Further, the second terminal communicates with the first terminal in a time division multiplexing manner.

The invention also provides a logging method, comprising: the adaptive wired communication method transmitting logging data, wherein the first terminal is a downhole end, and the second terminal is an uphole end.

Accordingly, the present invention provides an adaptive wired communication system, including: a first terminal and a second terminal, wherein the first terminal is configured to send communication data and training data to the second terminal according to a communication parameter; The second terminal is configured to evaluate channel communication conditions according to the training data, and Adjusting, according to the evaluation result, a communication parameter used to send the communication data; and transmitting the adjusted communication parameter to the first terminal.

Compared with the prior art, the adaptive wired communication method and the logging method and device provided by the present invention evaluate the training data sent by the first terminal by using the second terminal, and adjust the communication parameters in real time according to the evaluation result, and then adjust the The subsequent communication parameters are sent to the first terminal, so that the first terminal can transmit data by using the real-time adjusted communication parameters, and the adaptive channel evaluation function is realized, which increases the stability of the communication system.

DRAWINGS

In order to make the content of the present invention easier to understand, the present invention will be further described in detail below with reference to the accompanying drawings

1 is a flowchart of an adaptive wired communication method according to a first embodiment of the present invention;

2 is a schematic structural diagram of an adaptive wired communication system according to a third embodiment of the present invention.

detailed description

The adaptive wired communication method provided by the present invention is applicable to a wired communication system, especially for a scenario where the communication environment is relatively complicated, for example, the ambient temperature of the communication terminal often changes greatly, and the lines between the communication terminals are often stretched. .

A first embodiment of the present invention provides an adaptive wired communication method, where the method includes:

S1: The first terminal sends the communication data and the training data to the second terminal according to the communication parameter. The communication data refers to data having practical meaning; the training sequence is a sequence known by the two ends of the communication before normal communication, and is used to enable the second terminal to determine the impact response characteristic of the channel, and the number of training data can be based on actual needs. The situation is set.

S2: The second terminal evaluates channel communication conditions according to the training data, and adjusts communication parameters used to send the communication data according to the evaluation result. The content of the evaluation may include content such as time domain equalization, frequency domain equalization, signal to noise ratio, and bit allocation of the channel, and the second terminal may determine an error of the communication data according to the original content of the training data and the actually received training data content, the error. The communication condition of the channel can be reflected, and then the second terminal can dynamically adjust the communication parameters according to the communication conditions of the channel to reduce the influence of channel conditions on the communication data. Various channels are known Evaluation methods, those skilled in the art should understand that existing channel estimation methods are feasible.

S3: The second terminal sends the adjusted communication parameter to the first terminal to update the communication parameter.

After the method is executed, the first terminal may use the adjusted communication parameter to send data, and the communication rate may change according to the characteristics of the channel. If the channel condition becomes better, the communication rate will increase; otherwise, the communication rate will decrease. This achieves the goal of automatic adaptation to channel changes.

In the above step S2, if the evaluation result indicates that the current channel condition has not reached the preset minimum communication requirement, the normal communication state may be terminated, the debugging or communication training may be restarted, and the normal communication state is entered again after the training is completed.

According to the adaptive wired communication method provided by the embodiment, the second terminal evaluates the channel communication condition in the normal communication process, and adjusts the communication parameter in real time according to the evaluation result, and then sends the adjusted communication parameter to the first terminal, so that The first terminal can transmit data by using real-time adjusted communication parameters, and realizes the function of adaptive communication.

Further, the method in this embodiment further includes: repeatedly performing the steps S1 to S3. That is, the method can be executed cyclically, so that each time the first terminal sends the communication data and the training data, the adjusted communication parameters sent by the second terminal after the previous execution of the method are used, and the method can make the first terminal each time. The communication parameters used to transmit data are consistent with the current channel communication conditions, thereby increasing the stability of the communication system.

In order to increase the transmission data speed on a limited bandwidth communication line, preferably, the first terminal may transmit the log data and the training data to the second terminal using a digital multi-carrier modulation scheme. The communication parameter includes at least one of a frequency domain equalization parameter, a bit allocation parameter, and a channel coding parameter.

Further, in the step S2, when the communication parameter is a bit allocation parameter, adjusting the communication parameters used for transmitting the communication data according to the evaluation result includes:

The second terminal acquires a signal to noise ratio of the channel;

The second terminal adjusts the number of bits allocated to the audio according to the signal to noise ratio, and the signal to noise ratio is proportional to the number of bits, that is, the higher the signal to noise ratio, the more bits allocated to the audio.

Alternatively, in the step S2, when the communication parameter is a channel coding parameter, adjusting the communication parameters used for transmitting the communication data according to the evaluation result includes:

The second terminal acquires a channel bandwidth and a sub-band bandwidth;

The second terminal acquires the number of channels, the number of channels being a ratio of the channel bandwidth to the sub-band bandwidth, and the number of channels is an integer power of two.

In the above embodiment, the frequency band of the channel is divided into a plurality of adjacent sub-bands, each of which is assigned a fixed frequency, and all of the fixed frequencies are integer multiples of the sub-band bandwidth (the range is 1 to 64 times). Each of the audio frequencies carries a certain amount of information, and the number of bits allocated to the audio (2 bits to 15 bits) depends on the signal to noise ratio of the audio band. When the first terminal utilizes the above preferred modulation mode, the data transmission rate is high, and the rate can be adjusted according to the signal to noise ratio of the channel, and has strong anti-interference performance and the like.

Further, the second terminal may send the communication parameter to the first terminal by using a phase modulation manner. Compared with the first terminal, the second terminal needs to send less data, and the environment is relatively stable. The second terminal in this embodiment uses phase modulation to transmit data, which is simple and reliable, and has high real-time performance.

In order to keep the clock frequencies of the two communicating parties consistent, further, before the step S3, the method further includes:

The second terminal acquires a clock frequency of the first terminal;

The second terminal transmits the adjusted communication parameter according to the clock frequency.

Specifically, the second terminal can determine the clock frequency of the information sending end (ie, the first terminal) by acquiring the phase information of the communication data. Because the environment in which the first terminal is located may be harsh, for example, the high temperature environment may affect the crystal frequency to change continuously, thereby affecting the rate of data running thereon, so the second terminal acquires the first terminal in real time during the communication process. Clock frequency. The second terminal then generates the clock frequency. For example, the digital frequency synthesizer can output the frequency to synchronize the clock frequency of the first terminal and the second terminal, thereby improving communication efficiency.

Further, before the step S1, the method further includes:

S0, the second terminal performs frame synchronization check.

Specifically, before performing step S1, that is, before normal communication, the first terminal and the second terminal may perform communication training first. The preferred solution belongs to a preferred communication training solution, that is, the second terminal may be based on the communication training process. The content of the training data sent by the first terminal determines a frame positioning sequence to ensure that in the normal communication process, the second terminal can accurately identify the starting position of each actual communication data and determine the criterion of the frame out of synchronization. If the communication data generates an error due to the error in the normal communication process, the second terminal may determine whether the system is in an out-of-synchronization state according to the out-of-synchronization criterion, and if the step has been lost, the positioning sequence may be immediately captured, and accordingly, the first terminal Then, it is possible to retransmit only the erroneous frame without retransmitting all the communication data, thereby further improving the communication efficiency.

Further, in the implementation, the second terminal communicates with the first terminal in a time division multiplexing manner. The working mode of the adaptive wired communication method in this embodiment is a time division transmission mode, that is, the second terminal and the transmission signal switch of the first terminal are respectively opened in the allocated time, which is specifically the second terminal when the first terminal is opened. When the second terminal is turned on, the first terminal is closed, and the second terminal sends data to the first terminal. This makes it possible for two communication terminals to transmit data to each other using a single physical channel.

In the field of logging, since the environment in which the downhole end and the communication line are located is relatively complicated, and the types of communication cables are many, the second embodiment of the present invention further provides a logging method, which utilizes the above adaptive wired communication. The method sends log data, the first terminal is a downhole end, and the second terminal is an uphole end.

The method includes three states: an initial state, a training state, and a normal state. When the system is started, the initialization state is first entered, and when the command to start training is received, the training state is entered; if the training is successful Then, it enters the normal state, and if the training fails, it returns to the initialization state; in the normal state, data communication can be performed, and if it is found through the channel evaluation that an abnormality cannot be communicated, the initialization state is returned.

The training state includes: a process of establishing uplink and downlink communications, and determining communication parameters and uplink communication rates through training. The training of downlink communication is first performed, that is, the training of phase modulation (PSK) mode. At this time, the transmission signal switch of the well is turned on, the transmission signal switch of the well is closed, the fixed training sequence is sent by the ground, and the decoding is received by the underground. The received signal determines the decoding parameters. When the downlink training is completed, start uplink digital multi-carrier modulation (DMM-Digital Multicarrier) Modulation) training. At this time, the signal switch on the well is turned off, and the down signal switch is turned on. The main contents of the training include AGC Training, TEQ Training, DDS Training, and frame. Synchronization Training, FEQ Training, Bit Loading, Reed Solomon RS Parameter Computer, when the synchronization training is completed, the system's working mode is switched to the time division transmission mode. The emission signal switches of the uphole and downhole are respectively opened in the allocated time. When the well is opened, the well is closed, and the well is transmitted to the well. When the well is opened, the well is closed, and the well sends a signal to the well. Part of the parameters are transmitted downhole through the Information Exchange. Then, you can enter normal mode and start normal data transmission.

The normal mode includes: normal uplink and downlink data communication (up and down codec is determined by the training mode). The working mode is time-division transmission mode. The emission signal switches of the uphole and downhole are respectively opened in the allocated time. When the well is opened, the well is closed, and the well is transmitted to the well. When the well is opened, the well is closed, and the well sends a signal to the well. Downhole uplink coding includes, interleave, Reed Solomon coding (RS Encode), constellation coding (QAM Encode), inverse fast Fourier transform (IFFT), automatic gain (AGC); uplink decoding including, automatic gain (AGC) ), time domain equalization (TEQ), fast Fourier transform (FFT), frequency domain equalization (FEQ), clock synchronization (CLK Adjust), constellation decoding (QAM Decode), Reed Solomon decoding (RS Decode), data deinterleaving (Deinterleave). In the normal mode, adaptive channel estimation (Self-adaption) is performed according to the received signal, and the FEQ parameter and the Bit Loading parameter are adjusted according to the evaluation result, and the Bit Loading parameter is simultaneously transmitted to the downhole coding system. This can automatically adapt to changes in the logging cable channel and improve system stability. If the channel evaluation fails to communicate normally, it exits the normal state and enters the initialization state.

When the logging method provided by the embodiment is used for logging, the communication cable used between the upper end of the well and the lower end of the well may be a seven-core logging cable, a single-core logging cable, a three-core logging cable, etc., different cable frequencies. Response, channel bandwidth, and signal-to-noise ratio are different. Single-channel uplink data rate when using seven-core logging cable can exceed 1000KBPS, downlink data rate exceeds 25KBPS; uplink data rate when using single-core logging cable exceeds 300KBPS, single-channel uplink data rate when using three-core logging cable More than 800KBPS, the specific data rate depends on the frequency response of the cable, the signal-to-noise ratio of the channel, and the number of channels.

The method can automatically adapt according to the physical characteristics of different cables and the communication environment, so that the logging efficiency is higher and the adaptation range is wider.

A third embodiment of the present invention provides an adaptive wired communication system. As shown in FIG. 2, the system includes: a first terminal and a second terminal, where

The first terminal is configured to send communication data and training data to the second terminal according to the communication parameter;

The second terminal is configured to evaluate channel communication conditions according to the training data, and adjust a communication parameter used to send the communication data according to the evaluation result; and send the adjusted communication parameter to the first terminal.

According to the adaptive wired communication system provided by the embodiment, the second terminal evaluates the channel communication condition in the normal communication process, and adjusts the communication parameter in real time according to the evaluation result, and then sends the adjusted communication parameter to the first terminal, so that The first terminal can transmit data by using real-time adjusted communication parameters, and realizes the function of adaptive communication.

It is apparent that the above-described embodiments are merely illustrative of the examples, and are not intended to limit the embodiments. Other variations or modifications of the various forms may be made by those skilled in the art in light of the above description. There is no need and no way to exhaust all of the implementations. Obvious changes or variations resulting therefrom are still within the scope of the invention.

Claims

An adaptive wired communication method, comprising:

S1: The first terminal sends the communication data and the training data to the second terminal according to the communication parameter.

S2: the second terminal evaluates channel communication conditions according to the training data, and adjusts, according to the evaluation result, a communication parameter used to send the communication data;

S3: The second terminal sends the adjusted communication parameter to the first terminal to update the communication parameter.
The adaptive wired communication method according to claim 1, wherein the method further comprises: repeatedly performing the steps S1 to S3.
The adaptive wired communication method according to claim 1 or 2, further comprising: before the step S3, further comprising:

The second terminal acquires a clock frequency of the first terminal;

The second terminal sends the adjusted communication parameter according to the clock frequency.
The adaptive wired communication method according to claim 1 or 2, further comprising: before the step S1, further comprising:

The second terminal performs frame synchronization check.
The adaptive wired communication method according to claim 1 or 2, wherein the first terminal transmits the logging data and the training data to the second terminal using a digital multi-carrier modulation method; The second terminal transmits the communication parameter to the first terminal using a phase modulation manner.
The adaptive wired communication method according to claim 5, wherein the communication parameter comprises at least one of a frequency domain equalization parameter, a bit allocation parameter, and a channel coding parameter.
The adaptive wired communication method according to claim 6, wherein in the step S2, when the communication parameter is a bit allocation parameter, adjusting communication parameters used for transmitting the communication data according to the evaluation result includes :

Obtaining the signal to noise ratio of the channel;

Adjusting a number of bits allocated to audio according to the signal to noise ratio, the signal to noise ratio being proportional to the number of bits; or

In the step S2, when the communication parameter is a channel coding parameter, adjusting the communication parameters used for transmitting the communication data according to the evaluation result includes:

Obtaining channel bandwidth and subband bandwidth;

Obtaining a number of channels, the number of channels being a ratio of the channel bandwidth to the sub-band bandwidth, and the number of channels being an integer power of two.
The adaptive wired communication method according to claim 1 or 2, wherein the second terminal communicates with the first terminal in a time division multiplexing manner.
A logging method, comprising:

The logging data is transmitted using the adaptive wired communication method of any one of claims 1-8, wherein the first terminal is a downhole end and the second terminal is an uphole end.
An adaptive wired communication system, comprising: a first terminal and a second terminal, wherein

The first terminal is configured to send communication data and training data to the second terminal according to the communication parameter;

The second terminal is configured to evaluate channel communication conditions according to the training data, and adjust a communication parameter used to send the communication data according to the evaluation result; and send the adjusted communication parameter to the first terminal.