Information and energy simultaneous transmission method and system based on nonlinear circuit model

Abstract

The invention discloses a simultaneous information and energy transmission method and system based on a non-linear circuit model, and belongs to the technical field of wireless communication, the simultaneous information and energy transmission method comprises the steps that waveform parameters and indexes of the waveform parameters are optimized through centralized decision making by a transmitting end, and low-complexity circuit regulation based on a lookup table is executed by a receiving end; and a closed-loop adaptive triggering mechanism based on an energy acquisition state is introduced, so that the information demodulation performance is ensured, the energy acquisition efficiency is improved, the calculation complexity of a receiving end is reduced, and the method is suitable for wireless communication nodes with limited energy. When a channel state or a load condition changes, performance degradation caused by nonlinear coupling can be sensed and compensated in time, and the accuracy of energy collection efficiency and the stability of information demodulation performance are ensured. Furthermore, the information demodulation performance is ensured, collaborative optimization of information transmission and energy transmission is achieved, and the method has good engineering realizability and application and popularization value.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, and more specifically, relates to a method and system for simultaneous signal and energy transmission based on a nonlinear circuit model. Background Technology

[0002] With the rapid development of near-zero power IoT communication technology, how to ensure communication performance while continuously powering terminal nodes has become an important research direction in the field of wireless communication. Simultaneous information and energy transmission technology, by carrying information and energy in the same radio frequency signal, provides a solution for energy-constrained nodes that eliminates the need for battery replacement or reduces manual maintenance costs, and has broad application prospects.

[0003] In existing simultaneous information and energy transmission technologies, power division is widely used in system designs where the receiver simultaneously demodulates information and harvests energy due to its simple structure and ease of implementation. For the energy harvesting process, numerous studies have modeled and analyzed the nonlinear characteristics of the energy harvesting module, for example, using diode exponential models or higher-order polynomial models to characterize the nonlinear mapping relationship between the input RF signal and the DC output, and using this to optimize waveform design or resource allocation. However, in most existing power division-based simultaneous information and energy transmission schemes, the power division module itself and its coupling relationship with the energy harvesting module are usually simplified. Specifically, the power division module is often modeled as an ideal linear device, and its power division ratio is treated as a fixed parameter or an independently adjustable linear variable.

[0004] Under simplified modeling assumptions, waveform optimization and power allocation strategies cannot accurately reflect the transmission process of RF signals between the power allocation module, energy harvesting module, and information demodulation circuit in the actual system, leading to discrepancies between theoretical analysis results and actual hardware implementation. When channel conditions or load conditions change, it is difficult to detect and compensate for performance degradation caused by nonlinear coupling in a timely manner, thus affecting energy harvesting efficiency. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of existing technologies, the present invention provides a method and system for simultaneous information and energy transmission based on a nonlinear circuit model, the purpose of which is to solve the technical problem of low energy harvesting efficiency in existing simultaneous information and energy transmission technologies.

[0006] To achieve the above objectives, according to one aspect of the present invention, a signal-energy simultaneous transmission method based on a nonlinear circuit model is provided, applied to a signal-energy simultaneous transmission system including a transmitter and a receiver; the receiver includes, in sequence, a power distribution module, an energy acquisition module, and a status detection module; it also includes an information demodulation module connected to the power distribution module; the transmitter and the receiver share a nonlinear circuit model characterizing the nonlinear relationship between the input energy and output energy of the energy acquisition module; the signal-energy simultaneous transmission method includes: S1: The receiving end sends the current operating status of the energy harvesting module to the transmitting end; the transmitting end selects optimized waveform parameters from the preset waveform parameter set based on the current operating status of the energy harvesting module, the nonlinear circuit model, and the current channel status, and then proceeds to S2; S2: The transmitting end sends a first radio frequency signal carrying the parameter index corresponding to the optimized waveform parameters to the receiving end using the optimized waveform parameters; the receiving end determines the optimized circuit parameters corresponding to the optimized waveform parameters according to the parameter index in the first radio frequency signal, configures the power distribution module according to the optimized circuit parameters, and proceeds to S3; S3: The transmitting end sends a second radio frequency signal carrying information and energy to the receiving end according to the optimized waveform parameters; the receiving end uses the configured power distribution module to provide part of the energy in the second radio frequency signal to the energy acquisition module, and provides the other part of the energy to the information demodulation module for demodulation of the second radio frequency signal, and then proceeds to S4; S4: Use the state detection module to obtain the current working state of the energy harvesting module and compare it with the predicted working state. If the comparison result meets the preset conditions, return to S1; otherwise, return to S3.

[0007] Furthermore, the nonlinear circuit model stored at the transmitter is used for waveform optimization, which takes the operating state of the energy harvesting module and the channel state as known conditions, and the waveform parameters as variables.

[0008] Furthermore, the constraints of the nonlinear circuit model stored at the transmitter include: maximizing energy harvesting efficiency, meeting transmission power limits, and satisfying information demodulation signal-to-noise ratio requirements.

[0009] Furthermore, the nonlinear circuit model stored at the receiver uses the optimized waveform parameters and their indexes selected by the transmitter, the current channel state, and the operating state of the energy harvesting module as known conditions, and the circuit parameters as variables.

[0010] Furthermore, the constraints of the nonlinear circuit model stored at the receiving end include: maximizing energy harvesting efficiency, meeting the circuit's safe operating range, and satisfying the signal-to-noise ratio requirements for information demodulation.

[0011] Furthermore, configuring the power distribution module according to the optimized circuit parameters includes: controlling the power distribution module to control the power ratio allocated to the energy harvesting module and the information demodulation module according to the optimized circuit parameters using adjustable impedance elements.

[0012] Further, S4 includes: using the state detection module to obtain the current working state of the energy acquisition module, including: output voltage and its rate of change; using the output voltage and its rate of change to calculate the actual energy acquisition efficiency of the energy acquisition module; comparing the actual energy acquisition efficiency with the predicted energy acquisition efficiency in the predicted working state corresponding to the current communication environment; returning to S1 when the comparison result meets the preset conditions, otherwise returning to S3.

[0013] According to another aspect of the present invention, a signal-energy simultaneous transmission system is provided, comprising: a transmitter and a receiver; for performing the aforementioned signal-energy simultaneous transmission method based on a nonlinear circuit model.

[0014] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: (1) The information and energy simultaneous transmission method provided by this invention optimizes waveform parameters and their indices through centralized decision-making at the transmitting end, performs low-complexity circuit control based on lookup tables at the receiving end, and introduces a closed-loop adaptive triggering mechanism based on energy acquisition status. This method improves energy acquisition efficiency while ensuring information demodulation performance and reduces the computational complexity of the receiving end, making it suitable for energy-constrained wireless communication nodes. When channel conditions or load conditions change, it can promptly detect and compensate for performance degradation caused by nonlinear coupling, ensuring the accuracy of energy acquisition efficiency and the stability of information demodulation performance. Furthermore, this invention achieves coordinated optimization of information transmission and energy transmission while ensuring information demodulation performance, demonstrating good engineering feasibility and application promotion value.

[0015] (2) Based on the modeling of the nonlinear characteristics of the energy harvesting module, this scheme further considers the role and constraints of the nonlinear circuit models of the transmitter storage and receiver, so that the optimization of waveform parameters and optimization of circuit parameters are more in line with the actual hardware working characteristics, thereby improving the modeling accuracy and energy harvesting efficiency.

[0016] (3) In this scheme, adjustable impedance elements are used to control the power ratio distributed to the energy acquisition module and the information demodulation module, which is simple to operate and has strong stability.

[0017] (4) This scheme introduces a closed-loop adaptive triggering mechanism based on the actual working state of energy harvesting. When the system parameter configuration deviates from the effective working range, it can trigger joint optimization in a timely manner, thereby improving the stability and robustness of the information and energy transmission system under dynamic channel and load condition changes. Furthermore, it calculates the actual energy harvesting efficiency by collecting the output voltage and its rate of change of the energy harvesting module. This method has low computational complexity but can accurately reflect the working state of the energy harvesting module, which is convenient for subsequent comparison with the predicted working state of the energy harvesting module corresponding to the current communication environment. Attached Figure Description

[0018] Figure 1 This is a flowchart of the simultaneous signal transmission method according to Embodiment 1 of the present invention; Figure 2 This is a block diagram of the signal-to-energy simultaneous transmission system according to Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the closed-loop adaptive triggering logic according to Embodiment 1 of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0020] Example 1 This invention provides a signal-energy simultaneous transmission method based on a nonlinear circuit model, applied to a signal-energy simultaneous transmission system including a transmitter and a receiver; the receiver includes, in sequence, a power distribution module, an energy harvesting module, and a status detection module; it also includes an information demodulation module connected to the power distribution module; the transmitter and receiver share a nonlinear circuit model characterizing the nonlinear relationship between the input energy and output energy of the energy harvesting module; the signal-energy simultaneous transmission method includes: S1: The receiving end sends the current operating status of the energy harvesting module to the transmitting end; the transmitting end selects optimized waveform parameters from the preset waveform parameter set based on the current operating status of the energy harvesting module, the nonlinear circuit model, and the current channel status, and then proceeds to S2; S2: The transmitting end sends a first radio frequency signal carrying the parameter index corresponding to the optimized waveform parameters to the receiving end using the optimized waveform parameters; the receiving end determines the optimized circuit parameters corresponding to the optimized waveform parameters according to the parameter index in the first radio frequency signal, configures the power distribution module according to the optimized circuit parameters, and proceeds to S3; S3: The transmitting end sends a second radio frequency signal carrying information and energy to the receiving end according to the optimized waveform parameters; the receiving end uses the configured power distribution module to provide part of the energy in the second radio frequency signal to the energy acquisition module, and provides the other part of the energy to the information demodulation module for demodulation of the second radio frequency signal, and then proceeds to S4; S4: Use the state detection module to obtain the current working state of the energy harvesting module and compare it with the predicted working state. If the comparison result meets the preset conditions, return to S1; otherwise, return to S3.

[0021] Figure 1 This is a flowchart of a signal transmission method according to an embodiment of the present invention. Figure 1 This simultaneous interpretation method includes the following steps: First, the joint optimization phase begins. The transmitter pre-stores and maintains a nonlinear circuit model, which characterizes the nonlinear relationship between the input and output energy of the RF signal in the power distribution module and the energy harvesting module. In this phase, based on the channel state information, circuit parameter information, and energy harvesting state information fed back from the receiver, the transmitter performs joint optimization calculations on a predefined set of waveform parameters to determine optimized waveform parameters and optimized circuit parameters that match the current channel and load conditions.

[0022] Subsequently, the parameter synchronization and configuration phase begins. Based on the joint optimization results, the transmitter selects the corresponding parameter index from the waveform parameter set and generates and transmits the radio frequency (RF) signal using the waveform parameters corresponding to that index. Upon receiving the RF signal, the receiver retrieves the parameter index from the signal and configures the receiver circuit parameters accordingly, ensuring that the receiver's circuit operating state corresponds to the optimized circuit parameters.

[0023] Next, the system enters the steady-state operating phase. In this phase, the transmitter continuously transmits radio frequency signals using optimized waveform parameters, while the receiver, while maintaining its circuit parameter configuration, simultaneously performs information demodulation and energy harvesting operations, thereby achieving simultaneous transmission of information and energy.

[0024] During the steady-state operation phase, the receiver continuously or periodically enters the condition-triggered phase. The receiver monitors the actual operating state of the energy harvesting module and compares the monitored actual operating state with the operating state predicted based on the nonlinear circuit model and the current parameter combination. When it is determined that the actual operating state does not match the predicted operating state and the preset triggering condition is met, the receiver sends feedback information to the transmitter, triggering the method flow to return to the joint optimization phase and start a new round of parameter joint optimization.

[0025] Through the above steps, a closed-loop adaptive information and energy transfer method based on the energy harvesting status is formed, ensuring energy harvesting efficiency.

[0026] Figure 2 This is a block diagram of a simultaneous signal and energy transmission system according to an embodiment of the present invention. The system includes a transmitter and a receiver, which communicate with each other via a wireless channel. The transmitter includes a transmission control unit and a radio frequency (RF) unit. The transmission control unit stores a nonlinear circuit model and a predefined set of waveform parameters, and centrally selects and determines the waveform parameters and parameter indices based on channel state information and energy harvesting state information fed back from the receiver. The RF unit is connected to the transmission control unit and generates and transmits RF signals according to the selected waveform parameters. The receiver includes a receiving antenna, a power distribution module, an energy harvesting module, an information demodulation module, a state detection module, and a receiving control unit. The receiving antenna receives RF signals from the transmitter and inputs the received RF signals into the power distribution module.

[0027] As an optional implementation, the nonlinear circuit model stored at the transmitting end is used for waveform optimization, which takes the operating state of the energy harvesting module and the channel state as known conditions, and the waveform parameters as variables. Further, the nonlinear circuit model stored at the receiving end takes the optimized waveform parameters and their indexes selected by the transmitting end, the current channel state, and the operating state of the energy harvesting module as known conditions, and the circuit parameters as variables.

[0028] As an optional implementation, the constraints of the nonlinear circuit model stored at the transmitting end include: maximizing energy harvesting efficiency, meeting transmit power limits, and satisfying information demodulation signal-to-noise ratio requirements. Further, the constraints of the nonlinear circuit model stored at the receiving end include: maximizing energy harvesting efficiency, meeting circuit safety operating range requirements, and satisfying information demodulation signal-to-noise ratio requirements.

[0029] Furthermore, configuring the power distribution module according to the optimized circuit parameters includes: controlling the power distribution module to control the power ratio allocated to the energy harvesting module and the information demodulation module according to the optimized circuit parameters using adjustable impedance elements.

[0030] It should be noted that the nonlinear circuit model is used to characterize the nonlinear relationship between waveform parameters, power distribution module parameters, and energy harvesting efficiency, in order to solve the problem of inaccurate model building when optimizing waveforms and circuit parameters in existing solutions. For example, its construction process may include the following steps: A1: Transmitted signal modeling. The transmitter can use multi-tone signals, represented as:

[0031] in These are amplitude, frequency, and phase, respectively.

[0032] A2: Modeling the output voltage of the receiver power distribution module. The signal reaches the receiving antenna through the channel and then passes through the power distribution module. The power distribution module selects a transistor as the adjustable impedance element. Based on the power ratio of the received signal at each frequency, the admittance of the transistor at different frequencies is weighted and averaged; its resistance can be expressed as... , where frequency and bias voltage Admittance The effect can be obtained through small-signal simulation. The power allocation module allocates power to the energy harvesting module and the information demodulation module in the following proportions:

[0033]

[0034] in The equivalent impedance of the energy harvesting module. This is the equivalent impedance of the information demodulation module. Therefore, the equivalent input voltage of the energy harvesting module is:

[0035] in For channel coefficients.

[0036] A3: Energy modeling at the input of the energy harvesting module. The rectifier circuit of the energy harvesting module is a single diode. The received signal induces second-order and higher-order DC components in the diode. Crossing occurs between signals at different frequencies, and the total energy can be expressed as:

[0037] A4 energy harvesting module output energy modeling. In low-to-medium power energy harvesting, the second-order DC signal is the dominant term, and at the operating point... Performing a Taylor expansion nearby, the input DC current can be expressed as: , These are the second-order Taylor expansion coefficients. After the received signal passes through the energy harvesting module, the energy is stored in a storage container of size [value missing]. The energy obtained in the capacitor can be expressed as:

[0038] A5 Energy Harvesting Efficiency Modeling. Obtaining the Energy Efficiency Function. .

[0039] Further, S4 includes: using the state detection module to obtain the current working state of the energy acquisition module, including: output voltage and its rate of change; using the output voltage and its rate of change to calculate the actual energy acquisition efficiency of the energy acquisition module; comparing the actual energy acquisition efficiency with the predicted energy acquisition efficiency in the predicted working state corresponding to the current communication environment; returning to S1 when the comparison result meets the preset conditions, otherwise returning to S3.

[0040] Figure 3 This is a schematic diagram of the closed-loop adaptive triggering logic according to an embodiment of the present invention. It describes the closed-loop triggering mechanism of the receiver based on the energy harvesting state and its low-complexity implementation.

[0041] During steady-state operation, the receiving end's state detection module samples the output state of the energy harvesting module. The sampled state parameters include, but are not limited to, the rectified output voltage, the rate of change of the output voltage, or combinations thereof. Based on the sampled state parameters, the receiving control unit obtains the actual operating state of the energy harvesting module. Simultaneously, based on the currently used waveform parameter index and circuit parameter configuration, the receiving control unit retrieves the corresponding predicted operating state information from the nonlinear circuit model. The receiving control unit compares the actual operating state with the predicted operating state and calculates the difference between the two.

[0042] When the difference consistently exceeds a preset tolerance threshold for a certain period of time, or accumulates to exceed a preset threshold over a period of time, the receiving control unit determines that the current parameter configuration has deviated from the effective operating range and generates a trigger signal. The trigger signal is sent to the transmitting end via a feedback link to trigger a new round of joint optimization. The receiving end does not directly perform real-time optimization calculations of waveform or circuit parameters; instead, it pre-stores the optimization results of the circuit parameters in the form of a lookup table. The receiving end only needs to configure the circuit parameters based on the received parameter index using the lookup table, thereby significantly reducing the computational complexity and energy consumption of the receiving end.

[0043] Example 2 This embodiment provides a signal-energy simultaneous transmission system, including: a transmitter and a receiver; used to execute the signal-energy simultaneous transmission method based on a nonlinear circuit model.

[0044] As an optional implementation, the power distribution module is an adjustable power divider based on the Wilkinson power divider structure. Preferably, its isolation branch is equipped with a transistor, and its equivalent impedance is changed by adjusting the gate bias voltage of the transistor, thereby realizing continuous adjustment of the power distribution ratio. It is used to send the received radio frequency signal to the energy acquisition module and the information demodulation module respectively according to the adjustable power distribution ratio.

[0045] As an optional implementation, the energy harvesting module includes a rectifier circuit, an impedance matching network, a low-pass filter, and a storage capacitor, used to rectify and store the radio frequency signal allocated to the module to provide energy support for the receiver.

[0046] The information demodulation module is used to demodulate the radio frequency signals allocated to the module in order to obtain the information data carried therein.

[0047] The status detection module is connected to the energy acquisition module and is used to sample electrical parameters that characterize the working status of the energy acquisition module, and send the sampling results to the receiving control unit.

[0048] The receiving control unit is used to complete the parameter configuration of the receiving circuit according to the received parameter index, and to maintain the parameter settings of the power distribution module unchanged during the steady-state operation phase; at the same time, the receiving control unit is also used to perform judgment on the actual working state, and generate feedback information to send to the transmitting end when the conditions are met.

[0049] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should be noted that the terms "in one embodiment," "for example," and "again" in this invention are intended to illustrate the invention and are not intended to limit the invention.

[0050] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for simultaneous information and energy transmission based on a nonlinear circuit model, characterized in that, An information-energy simultaneous transmission system is applied to a transmitter and a receiver; the receiver includes, in sequence, a power distribution module, an energy acquisition module, and a status detection module; it also includes an information demodulation module connected to the power distribution module; the transmitter and receiver share a nonlinear circuit model characterizing the nonlinear relationship between the input energy and output energy of the energy acquisition module; the information-energy simultaneous transmission method includes: S1: The receiving end sends the current operating status of the energy harvesting module to the transmitting end; the transmitting end selects optimized waveform parameters from a preset waveform parameter set based on the current operating status of the energy harvesting module, the nonlinear circuit model, and the current channel status, and then proceeds to S2; S2: The transmitting end sends a first radio frequency signal carrying the parameter index corresponding to the optimized waveform parameters to the receiving end using the optimized waveform parameters; the receiving end determines the optimized circuit parameters corresponding to the optimized waveform parameters according to the parameter index in the first radio frequency signal, configures the power distribution module according to the optimized circuit parameters, and proceeds to S3; S3: The transmitting end sends a second radio frequency signal carrying information and energy to the receiving end according to the optimized waveform parameters; the receiving end uses the configured power distribution module to provide part of the energy in the second radio frequency signal to the energy acquisition module, and provides the other part of the energy to the information demodulation module for demodulation of the second radio frequency signal, and then proceeds to S4; S4: Use the state detection module to obtain the current working state of the energy harvesting module and compare it with the predicted working state. If the comparison result meets the preset conditions, return to S1; otherwise, return to S3.

2. The signal-energy simultaneous transmission method based on a nonlinear circuit model as described in claim 1, characterized in that, The nonlinear circuit model stored at the transmitter is used for waveform optimization, which takes the operating state of the energy harvesting module and the channel state as known conditions, and the waveform parameters as variables.

3. The signal-energy simultaneous transmission method based on a nonlinear circuit model as described in claim 2, characterized in that, The constraints of the nonlinear circuit model stored at the transmitter include: maximizing energy harvesting efficiency, meeting transmission power limits, and satisfying information demodulation signal-to-noise ratio requirements.

4. The signal-energy simultaneous transmission method based on a nonlinear circuit model as described in claim 1, characterized in that, The nonlinear circuit model stored at the receiver uses the optimized waveform parameters and their indexes selected by the transmitter, the current channel state, and the working state of the energy harvesting module as known conditions, and the circuit parameters as variables.

5. The signal-energy simultaneous transmission method based on a nonlinear circuit model as described in claim 4, characterized in that, The constraints of the nonlinear circuit model stored at the receiving end include: maximizing energy harvesting efficiency, meeting the circuit's safe operating range, and satisfying the signal-to-noise ratio requirements for information demodulation.

6. The signal-energy simultaneous transmission method based on a nonlinear circuit model as described in claim 1, characterized in that, The step of configuring the power distribution module according to the optimized circuit parameters includes: controlling the power distribution module to control the power ratio allocated to the energy acquisition module and the information demodulation module according to the optimized circuit parameters using adjustable impedance elements.

7. The signal-energy simultaneous transmission method based on a nonlinear circuit model as described in claim 1, characterized in that, S4 includes: using the state detection module to obtain the current working state of the energy acquisition module, including: output voltage and its rate of change; using the output voltage and its rate of change to calculate the actual energy acquisition efficiency of the energy acquisition module; comparing the actual energy acquisition efficiency with the predicted energy acquisition efficiency in the predicted working state corresponding to the current communication environment; returning to S1 when the comparison result meets the preset conditions, otherwise returning to S3.

8. A simultaneous signal transmission system, characterized in that, include: Transmitter and receiver; Used to perform the signal and energy simultaneous transmission method based on a nonlinear circuit model as described in any one of claims 1-7.

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