A method for eliminating analog signal transmission errors by digital compensation

Abstract

The application belongs to the technical field of signal transmission, and discloses a method for eliminating analog signal transmission error through digital compensation, which specifically comprises the following steps: in addition to the original signal transmitting circuit part, a signal detecting part composed of MCU, ADC and a communication module is arranged at the signal transmitting end; a signal detecting part composed of MCU and ADC communication module and a control part capable of controlling the signal at the output end to be offset and gain varied are arranged at the signal receiving end; the signal at the receiving end is collected by the MCU to compare with the data of the transmitting end communication module, and the difference between the two data is calculated to obtain the correction value of the amplitude and offset; the gain and offset of the signal are changed by controlling the offset and gain circuit part at the receiving end, so that the transmission error is eliminated, and the gain and offset control method is realized by using DAC, PGA and other components; the deviation of the frequency response can also be calculated according to the requirement, and is corrected by the gain and offset control circuit part.

Description

Technical Field

[0001] This invention belongs to the field of signal transmission technology, and in particular relates to a method for eliminating analog signal transmission errors through digital compensation. Background Technology

[0002] In analog signal transmission involving the conversion of different physical quantities (such as photoelectric conversion), errors in offset and gain (amplitude) often occur, and sometimes there are also errors in the response of high-frequency or low-frequency signals.

[0003] To address these technical problems, this invention proposes a method for eliminating errors, characterized by digital control, simple hardware, strong versatility, and easy implementation in existing solutions. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for eliminating analog signal transmission errors through digital compensation.

[0005] This invention is implemented as follows: a method for eliminating analog signal transmission errors through digital compensation, characterized in that the method specifically includes:

[0006] S1: In addition to the original signal transmission circuit, the signal transmitting end also includes a signal detection section consisting of an MCU, an ADC, and a communication module;

[0007] S2: The signal receiving end has a signal detection section consisting of an MCU and an ADC communication module, as well as a control section that can control the output signal to shift and change gain.

[0008] S3: At the receiving end, the MCU controls the ADC to collect the signal from the receiving end and compare it with the data from the communication module at the transmitting end. Based on the difference between the two data, the correction values ​​for amplitude and offset are calculated.

[0009] S4: By controlling the offset and gain circuit at the receiving end to change the signal gain and offset, transmission errors are eliminated. The gain and offset control method is implemented using components such as DAC and PGA.

[0010] S5: Depending on the requirements, the frequency response deviation can also be calculated and corrected through the gain and offset control circuit.

[0011] Furthermore, the input signal at the transmitting end of the signal is simultaneously driven by an operational amplifier to drive the ADC.

[0012] Furthermore, the MCU interfaces the ADC results with typical digital signal transmission methods, including optical communication modules, wireless communication modules, isolated or non-isolated communication ICs, etc.

[0013] Furthermore, the ADC communication module can be a common ADC chip, or an ADC chip with its own driver that does not require an external operational amplifier driver, or it can be the ADC built into the MCU.

[0014] Furthermore, the MCU is a digital processing IC such as an FPGA, used to process data from the ADC and communication module.

[0015] Furthermore, the output signal of the signal receiving end is adjusted for gain via a VGA, PGA, or digitally controlled attenuator, or via a controllable gain photoelectric receiving module, or via a controllable gain photoelectric receiving tube.

[0016] Furthermore, the offset control can be achieved through an adder circuit, controlling the bias voltage of the photoelectric receiving module, and adding bias current through a bias resistor.

[0017] Furthermore, the use of a DAC can omit the output operational amplifier for a DAC with a built-in operational amplifier, or omit the external DAC for an MCU or other digital processing IC with a built-in DAC, used to control a VGA or controllable gain optoelectronic receiving module, or bias resistors, etc.

[0018] Furthermore, the signal output of the signal receiving end can be directly output or further processed by adding buffer operational amplifiers, differential operational amplifiers, etc., depending on the actual needs of the connected equipment. The equipment can be a signal acquisition card, oscilloscope, network analyzer, or industrial control equipment, etc.

[0019] Furthermore, a frequency response compensation function can be inserted before or after the PGA to control or compensate the frequency response.

[0020] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions protected by this invention are analyzed from the following aspects:

[0021] First, addressing the technical problems existing in the prior art and the difficulty in solving them, this paper closely analyzes, in conjunction with the technical solution to be protected by this invention and the results and data obtained during the research and development process, how the technical solution of this invention solves the technical problems, and the inventive technical effects brought about by solving these problems. The specific description is as follows:

[0022] (1) The hardware structure of the present invention is relatively simple, requiring only the addition of an auxiliary digital transmission part to the original transmitter.

[0023] (2) It is highly flexible and not limited to the photoelectric transmission examples mentioned above (including but not limited to electromagnetic transmission, radio frequency modulation transmission, etc.). For most analog transmission schemes that have signal errors due to objective reasons during transmission, this invention can be used to improve performance. Moreover, depending on the needs, auxiliary functions can be further expanded through MCU programs, such as transmission self-testing, manual adjustment of offset, etc.

[0024] (3) Compared with hardware compensation, digital compensation can also track and compensate for some nonlinear characteristics, such as nonlinear changes in the working point of laser tubes and LEDs, thus avoiding possible signal distortion.

[0025] (4) The present invention has been tested through actual hardware construction. For deliberately added transmission interference (such as vibration), the effect of external interference is almost invisible before the principle is broken (signal disappears, hardware is physically damaged). The signal is monitored by an oscilloscope or voltmeter and the value is stable and unchanged.

[0026] Second, considering the technical solution as a whole or from a product perspective, the technical effects and advantages of the technical solution to be protected by this invention are specifically described as follows:

[0027] It can greatly improve the transmission accuracy of analog signals when using sound, light, electricity and electricity as media, and the peripheral circuit is simplified, making it very flexible to use.

[0028] Third, as supporting evidence of the inventiveness of this invention, it is also reflected in the following important aspects:

[0029] The expected benefits and commercial value of the technical solution of this invention after transformation are as follows:

[0030] It has immeasurable value in sensor applications and some precision signal transmission applications.

[0031] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad: no similar products have been found at present.

[0032] (3) The technical solution of the present invention solves the technical problem that people have been eager to solve but have never been able to achieve: when transmitting analog signals through different media, the signal integrity or accuracy is often not ideal due to factors such as nonlinearity and temperature drift during transmission. The present invention can largely compensate for signal distortion caused by external factors such as nonlinearity and temperature. Attached Figure Description

[0033] Figure 1 This is a flowchart of a method for eliminating analog signal transmission errors through digital compensation, provided in an embodiment of the present invention.

[0034] Figure 2This is the basic photoelectric transmission method provided in the embodiments of the present invention;

[0035] Figure 3 This is an improved photoelectric transmission method provided in the embodiments of the present invention;

[0036] Figure 4 This is an example of a signal output method provided in an embodiment of the present invention;

[0037] Figure 5 This is an example of the frequency response compensation function provided in the embodiments of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] This invention provides a method for eliminating analog signal transmission errors through digital compensation, characterized in that the method specifically includes:

[0040] S1: In addition to the original signal transmission circuit, the signal transmitting end also includes a signal detection section consisting of an MCU, an ADC, and a communication module;

[0041] S2: The signal receiving end has a signal detection section consisting of an MCU and an ADC communication module, as well as a control section that can control the output signal to shift and change gain.

[0042] S3: At the receiving end, the MCU controls the ADC to collect the signal from the receiving end and compare it with the data from the communication module at the transmitting end. Based on the difference between the two data, the correction values ​​for amplitude and offset are calculated.

[0043] S4: By controlling the offset and gain circuit at the receiving end to change the signal gain and offset, transmission errors are eliminated. The gain and offset control method is implemented using components such as DAC and PGA.

[0044] S5: Depending on the requirements, the frequency response deviation can also be calculated and corrected through the gain and offset control circuit.

[0045] The principle of this invention is illustrated here using photoelectric transmission as an example.

[0046] Basic photoelectric transmission methods are shown below. Figure 2 .

[0047] Part 1.a. The input signal drives the LED or laser tube via a driver (or an electro-optical module in the finished product) to obtain the corresponding optical signal.

[0048] Part 1.b. The optical signal is transmitted to the receiving end via optical fiber, optical coupler, or direct optical transmission.

[0049] Part 1.c. The photodetector, in conjunction with a receiving IC or amplifier (or a finished photodetector module), converts the optical signal back into an electrical signal.

[0050] Throughout the entire optoelectronic transmission process, performance deviations of optoelectronic devices and the actual method of optical transmission will significantly affect signal offset and gain. Especially when direct optical transmission is the only option due to objective reasons, signal offset errors can reach unacceptable levels. Furthermore, environmental factors such as temperature can also cause uncertainties in frequency response.

[0051] Figure 3 Improvements made to this invention.

[0052] Sending part:

[0053] Part 2.a. Based on the original design, the input signal is simultaneously driven by an operational amplifier to power the ADC.

[0054] Section 2.b. The MCU interfaces the ADC results with typical digital signal transmission methods (such as optical communication modules, wireless communication modules, isolated or non-isolated communication ICs, etc.) or any communication method that meets the requirements.

[0055] The ADC can be a common ADC chip, an ADC chip with its own driver (no external op-amp driver required), or an ADC built into the MCU.

[0056] Depending on the requirements, the MCU can also be a digital processing IC such as an FPGA.

[0057] Receiving section:

[0058] Section 2.c. Based on the existing configuration, the signal output gain is adjusted via a VGA, PGA, or digitally controlled attenuator. Alternatively, it can be adjusted using a controllable gain photoelectric receiver module or a controllable gain photoelectric receiver tube. Figure 3 Take the PGA as an example.

[0059] If gain control is not required, the relevant components can be omitted.

[0060] Part 2.d. Based on the original design, offset control is added. There are several ways to achieve this, such as using an adder circuit, controlling the bias voltage of the photoelectric receiving module, or adding bias current through a bias resistor. These will not be listed exhaustively; the last method will be used to illustrate the principle of this invention.

[0061] If the offset control is not required, the relevant components can be omitted.

[0062] Section 2.e. Based on the existing design, add an ADC to acquire signal output. Add a communication module corresponding to the transmitter for communication (such as an optical communication module, wireless communication module, etc.).

[0063] Section 2.e. Based on the existing system, add an MCU (or FPGA, etc., depending on requirements). This is used to process data from the ADC and communication modules.

[0064] Section 2.f. Add a DAC and DAC output op-amp as needed (the output op-amp can be omitted for DACs with built-in op-amps, or for MCUs or other digital processing ICs with built-in DACs, the external DAC can be omitted), for controlling VGA or controllable gain optoelectronic receiver modules, or bias resistors, etc. Or any components mentioned above that need to interface with the DAC to achieve the corresponding function; here, controlling the bias resistor is taken as an example.

[0065] The signal output depends on the needs of the actual connected equipment; it can be output directly or further processed by adding buffered operational amplifiers, differential operational amplifiers, etc. The equipment can be a signal acquisition card, oscilloscope, network analyzer, or industrial control equipment, etc. Figure 3 These are just some examples.

[0066] Optional Figure 4 This is for frequency response compensation. This section can be inserted... Figure 3 Before or after the PGA, frequency response control or compensation is achieved. Since frequency response compensation is a very broad design, it is impossible to list all examples; the examples and implementations in the illustrations are merely to illustrate the functions achievable by this invention.

[0067] To demonstrate the inventiveness and technical value of the present invention, this section provides specific product or related technology application examples of the technical solution.

[0068] This invention has been tested through actual hardware setup for photoelectric conversion. For deliberately added transmission interference (such as vibration), the effect of external interference is almost invisible before it causes fundamental damage (signal disappearance, physical damage to hardware). Monitoring the signal with an oscilloscope or voltmeter shows that the value remains stable.

[0069] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or by software executed by various types of processors, or by a combination of the above-described hardware circuitry and software, such as firmware.

[0070] In the physical photoelectric conversion test, when the basic photoelectric transmission method was used to transmit the analog signal, the output signal amplitude changed by more than 30-50% when the temperature change at the transmitting end was 30 degrees or the optical fiber transmitting the signal underwent a 5cm diameter circular change. However, with the improved structure of this invention, the output signal amplitude changed by less than 1% when the temperature change was 30 degrees or the optical fiber transmitting the signal underwent a 5cm diameter circular change.

[0071] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for eliminating analog signal transmission errors through digital compensation, characterized in that, The method specifically includes: S1: In addition to the original signal transmission circuit, the signal transmitting end also includes a signal detection section consisting of an MCU, an ADC, and a communication module; S2: The signal receiving end has a signal detection section consisting of an MCU, an ADC, and a communication module, as well as a control section that can control the output signal to make offset and gain changes; S3: At the receiving end, the MCU controls the ADC to collect the signal output from the receiving end and compare it with the data from the communication module at the transmitting end. The difference between the two data is used to calculate and obtain the correction values ​​for amplitude and offset. S4: Then, by controlling the offset and gain circuit of the receiving end, the gain and offset of the signal are changed, thereby eliminating the transmission error; S5: The deviation in frequency response is calculated and then corrected by the gain and offset control circuit.

2. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, The input signal at the transmitting end of the signal is simultaneously driven by an operational amplifier to drive the ADC.

3. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, The MCU interfaces the ADC output with typical digital signal transmission methods, including optical communication modules, wireless communication modules, and isolated or non-isolated communication ICs.

4. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, The ADC mentioned is a common ADC chip, or an ADC chip with its own driver that does not require external operational amplifier driving, or an ADC built into the MCU.

5. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, The MCU is an FPGA used to process data from the ADC and communication module.

6. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, The signal output from the signal receiving end is adjusted for gain via a VGA, PGA, or digitally controlled attenuator, or via a controllable gain photoelectric receiving module, or via a controllable gain photoelectric receiving tube.

7. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, The offset can be controlled by either an adder circuit, controlling the bias voltage of the photoelectric receiving module, or by adding bias current through a bias resistor.

8. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, For DACs with built-in op-amps, the output op-amp is omitted; or for MCUs or other digital processing ICs with built-in DACs, the external DAC is omitted. This is used to control VGA or controllable gain optoelectronic receiver modules, or as a bias resistor.

9. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, The signal output from the signal receiving end can be directly output to a signal acquisition card, oscilloscope, network analyzer, or industrial control equipment; or a buffered operational amplifier or differential operational amplifier can be added for further processing before outputting to the signal acquisition card, oscilloscope, network analyzer, or industrial control equipment.

10. The method for eliminating analog signal transmission errors through digital compensation as described in claim 1, characterized in that, Frequency response compensation functions can be inserted before or after the PGA to control or compensate for the frequency response.

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