CN114070691B - Implanted energy and data time-sharing wireless transmission system and design method thereof - Google Patents
Implanted energy and data time-sharing wireless transmission system and design method thereof Download PDFInfo
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Abstract
The invention relates to an implantable energy and data time-sharing wireless transmission system and a design method thereof. The upper computer transmits the instructions to be executed by the lower computer and the energy required by the lower computer to the lower computer in a sine voltage mode through the LCC topology circuit. The energy and data of the upper computer are transmitted in a time-sharing multiplexing mode, and the energy and the data occupy different time slices. In the energy transmission time slice, energy is transmitted through the LCC topology circuit by taking sine voltage as a carrier. In the information transmission time slice, the information is modulated by the FSK modulation circuit and then transmitted in the form of voltage. On one side of the lower computer, the FSK modulation circuit modulates the acquired input signals in an FSK mode and then transmits the input signals to the upper computer through the bilateral LCC circuit. The invention adopts a time-sharing multiplexing mode to switch the energy and data transmission modes, and adopts independent resonance points, thereby greatly reducing the difficulty of uplink data transmission, optimizing the power consumption and the volume of the system and reducing the complexity of the system.
Description
Technical Field
The system belongs to the technical field of biomedical electronics, and particularly relates to an implantable energy and data time-sharing wireless transmission system based on bilateral LCC topology and a design method thereof.
Technical Field
Monitoring and control of vital signs of the human body is critical for the treatment of some diseases. For example, for patients diagnosed with glaucoma, measuring ocular pressure in real time and timely administration of drugs is important to prevent exacerbation. For another example, the vital signs of the fetus are detected in real time through the wearable equipment, so that a more effective intervention pointer is provided for premature delivery and uterine curettage, the health of the pregnant woman and the fetus can be better ensured, and the medical cost is reduced. Fully implantable systems are considered to be the ultimate solution for these diseases. They use the energy collection mode to meet the self power consumption, and upload and download of data are realized by wireless communication. Currently, most research is performed on the combination of magnetic induction wireless power transmission technology and wireless communication modules as a main implantable system solution. They integrate miniature coils on the implantable device for collecting the energy transmitted in from outside the body and send out the collected signals using external communication modules such as bluetooth, zigBee, etc. These studies separate wireless communication and energy transmission into independent physical links, which greatly increases the difficulty of designing the system, and the requirement of an external communication module on an antenna must increase the volume of the system. Therefore, these methods are very challenging to apply to occasions with very severe requirements on volume and power consumption, such as brain-computer interfaces and tonometers.
The advantage of using double-side LCC to topology a plurality of resonance points is utilized, and a novel wireless energy and data time-sharing transmission system and a design method thereof are provided. The carrier wave of the transmission information and the transmission energy are set at different resonance points, and the energy and the data transmission mode are switched in a time-sharing multiplexing mode. The independent resonance point mode is adopted, so that a complex information loading process and a communication protocol are not needed, the difficulty of uplink data transmission is greatly reduced, the power consumption and the volume of the system are optimized, and the complexity of the system is reduced.
Disclosure of Invention
The invention aims to provide an implantable energy and data time-sharing wireless transmission system based on double-side LCC topology and a design method thereof. The data transmission function of time division multiplexing is added on the basis of the bilateral LCC wireless power transmission technology, and the data transmission function mainly relates to a basic circuit and a communication protocol required by data transmission.
An implantable energy and data time-sharing wireless transmission system comprises an upper computer, a bilateral LCC topology circuit and a lower computer; the upper computer and the lower computer wirelessly transmit energy and data through a bilateral LCC topology circuit; the lower computer comprises a FSK (Frequency Shift Keying) modulation circuit, a frequency discrimination circuit, a rectification circuit and a demodulation module. The FSK modulation circuit is used for realizing the modulation of the transmission information in the double-sided LCC topology, and the frequency discrimination circuit is used for separating the information transmission time slices and the energy transmission time slices. The upper computer adopts a time division multiplexing transmission mode to transmit energy and data, and a frequency discrimination circuit of the lower computer is needed to separate energy and data transmission time slices.
The upper computer transmits the instructions to be executed by the lower computer and the energy required by the lower computer to the lower computer in the form of sine voltage through the LCC topology circuit. The energy and data of the upper computer are transmitted in a time-sharing multiplexing mode, and the energy and the data occupy different time slices. In the energy transmission time slice, energy is transmitted through the LCC topology circuit by taking sine voltage as a carrier. In the information transmission time slice, the information is modulated by the FSK modulation circuit and then transmitted in the form of voltage. On one side of the lower computer, the FSK modulation circuit modulates the acquired input signals (human body information acquired by the sensor) according to an FSK mode and then transmits the input signals to the upper computer through the bilateral LCC circuit.
Based on a bilateral LCC wireless electric energy transmission system, time-sharing transmission of energy and information is realized through an FSK modulation circuit, a frequency discrimination circuit and a communication protocol.
The specific design method is as follows:
step one, determining the size, shape and number of turns of a primary main coil L1 and a secondary coil L2 in double-side LCC topology according to an implantable application scene, and measuring inductance values of the primary main coil L1 and the secondary coil L2. The primary coil is responsible for the transmission of energy and data in an implantable scene.
And step two, selecting a resonant frequency according to the data transmission and energy transmission requirements of the implanted system. The wireless power transmission system based on double-side LCC topology has two resonance points, in the system, a high-frequency point is used for data transmission, and a low-frequency point is used for energy transmission.
For a communication system with a fixed signal-to-noise ratio and modulation depth, the higher the carrier frequency, the higher the symbol transmission rate. In the context of the present system, the carrier frequency depends on the values of the elements of the double sided LCC topology, as well as the values of the primary and secondary primary coils L1 and L2.
Determining the values of all elements of the double-sided LCC topology circuit: selecting LCC topology L based on the energy transmission frequency and the data transmission frequency determined in the second step 1p ,L 1s ,C 1p ,C 1s ,C 2p ,C 2s Wherein L is 1p 、L 1s Series inductance respectively topological-modified for primary side LCC and secondary side LCC 1p 、C 1s Series capacitors respectively topological-connected with LCC of primary side and secondary side 2p 、C 2s And the parallel capacitors are respectively topological-added to the LCC of the primary side and the secondary side. The frequency value expression of the two resonance points is:
l in the above 1 The inductance value of the main coil. When determining the parameter values of the LCC topology components, the frequency value determined by the parameter is calculated by the above formula.
Step four, determining the resonant frequency of the circuit: the built system was stimulated with a signal generator and the output waveform was observed at the output using an oscilloscope. And recording the maximum value point of the output voltage, wherein the frequency point at the moment is a resonance frequency point, and the point with the larger frequency value is the frequency point corresponding to the data transmission carrier and the frequency point with the smaller frequency value is an energy transmission frequency point.
The actual circuit has deviation from the ideal condition, and the result obtained by the calculation in the step three needs to be verified to determine the frequency of the actual circuit.
Step five, designing an FSK modulation circuit: in order to enable transmission of data, information to be transmitted must be loaded onto a carrier wave. The communication system of the system adopts a digital modulation mode to carry out information transfer and adoptsThe signal required for the generation of the DDS (Direct Digital Synthesis) signal generator is taken. The sine wave voltage Y [ i ]]N-point sampling was performed as follows:
and storing the obtained voltage value into an N-bit ROM of the FSK modulation circuit. When specific modulation is carried out, the N-bit data and the modulation signal are operated, and the calculated result is output to a digital-to-analog converter (DAC) to generate a required waveform. Modulation of the FSK modulation circuit is accomplished by changing the clock used to read the ROM data. The carrier frequency of the FSK modulation circuit is determined by the clock for reading the ROM and the sampling point number N, and the specific relation is as follows:
wherein f carrier For carrier frequency, f clock For driving the frequency of the ROM. />
FSK modulation consists in varying the frequency of the carrier signal, that is to say the frequency of the carrier voltage signal is f1 when a logic 1 needs to be transmitted and f2 when a logic 0 needs to be transmitted. As can be seen from the above, the carrier frequency f is changed carrier Can be controlled by varying the frequency f of the driving ROM clock clock Realizing the method.
Step six, designing a frequency discrimination circuit: the discriminator is implemented by three filters. Two of which are LC band-pass filters which allow the frequencies of passage to be omega respectively 1 And omega 2 The other filter is an RC low pass filter with a very low cut-off frequency. When a signal exists at the output end of one filter, the frequency of the signal currently being transmitted can be determined; the discriminator transmits the signal to the next stage of signal processing circuitry (which can be matched to the usual signal processing circuitry). And when the frequency discrimination result is the wireless energy transmission frequency, rectifying and filtering the signal and then charging the energy storage element. And when the frequency discrimination result is the data transmission frequency, carrying out low-pass filtering on the signal to finish demodulation. When the frequency discrimination result is a direct current signal, the upper computer releases the communication link, and the lower computer occupies the link to transmit data to the upper computer.
In the system, energy and data are transmitted in a time-sharing way through different frequencies, so that a receiving end needs to identify which frequency the carrier wave is in a current link, and different carrier wave signals are input into different processing circuits.
When the frequency discrimination result is the energy transmission frequency point, the frequency discrimination circuit switches the analog gating switch to the battery charging circuit, and inputs an input signal to the energy storage element for charging after rectifying and filtering.
When the frequency discrimination result is the data transmission frequency point, the upper computer is indicated to want to transmit data to the lower computer. The frequency discriminator switches the analog gating switch to the demodulation module, and a filter circuit in the demodulation module extracts data to perform data response operation.
When the frequency discrimination result is a direct current signal, the receiving end has no energy and no data to be transmitted at the moment. The upper computer releases the transmission link and gives it to the lower computer for control. The frequency discrimination circuit switches the analog gating switch to the FSK modulation circuit. The FSK modulation circuit is used for transmitting and loading data acquired by an external sensor onto a carrier wave to complete modulation, and carrying out power amplification on the modulated signal and sending the modulated signal to an upper computer through the LCC topology circuit.
Step seven, designing a communication protocol: the number of carrier periods occupied for transmitting one bit of data is 3*n, wherein n depends on the merits of the communication environment, and the value of n is greater as the communication environment is worse. When the logic 1 needs to be transmitted, the number of carriers occupied by the high level is 2n, and the number of carriers occupied by the low level is n. When logic 0 needs to be transmitted, the number of carriers occupied by the high level is n, and the number of carriers occupied by the low level is 2 n. The transmitted logical value is determined by determining the proportion of time occupied by the high level at the time of demodulation. The bit rate of the transmitted data at this time is:
from the above equation, the smaller the number of carrier periods occupied by transmitting one bit, the higher the data transmission rate. Meanwhile, the data transmission rate of the system can be improved by improving the working carrier frequency of the system. In the present system, it is provided that the host always maintains the highest priority for the double-sided LCC circuit, whether it is the transfer of system power or data. In the data transmission time slice, if the host computer has data to be transmitted, the bus is directly occupied. If the host does not need to transmit data, the bus is released at the data transmission time slice, and the slave transmits the data to the host.
The invention does not need to integrate additional communication modules and design special antennas, thereby greatly reducing the complexity of an implantable communication system and the power consumption and the volume of the system. The energy and information are switched in a time-sharing multiplexing mode, so that the modulation and demodulation of a communication system are facilitated. The data transmission and the energy transmission are arranged at different frequency points, so that the cost of system modulation can be reduced compared with other wireless data and energy transmission systems at the same time.
Drawings
FIG. 1 is a simplified circuit diagram of a two-sided LCC topology wireless power transfer system;
FIG. 2 is a system overview block diagram;
FIG. 3 is a block diagram of an FSK communication system;
FIG. 4 is a block diagram of an implementation of an FSK communication system;
FIG. 5 is a circuit diagram of an R-2R resistor network;
fig. 6 is a waveform of a receiving end of the implantable energy and data time-sharing transmission system.
Detailed Description
The present system is further described below with reference to the accompanying drawings.
A design method of an implantable energy and data time-sharing wireless transmission system specifically comprises the following steps:
step one, according to the implantable application scenario, as shown in fig. 1, the size, shape and number of turns of the primary coil L1 and the secondary coil L2 in the double-sided LCC topology are determined, and the inductance value is measured. This primary coil is responsible for the transmission of energy and data in an implantable scene. The system enlarges the size of the components in equal proportion, and is convenient for prototype verification of the proposed system. The primary main coil L1 and the secondary coil L2 selected by the system are planar spiral coils, the diameter of the coils is 10CM, and the inductance value is 24uH.
And step two, selecting a resonant frequency according to the data transmission and energy transmission requirements of the implanted system. The wireless power transmission system based on double-side LCC topology has two resonance points, in the system, a high-frequency point is used for data transmission, and a low-frequency point is used for energy transmission. For a communication system with a fixed signal-to-noise ratio and modulation depth, the higher the carrier frequency, the higher the symbol transmission rate. The size of the components adopted for prototype verification of the system is larger than that of the actual application, and the values of the components are larger than that of the actual application, so that the values of all frequency points in the prototype verification stage are larger than that of the actual application. The energy transmission frequency point value of the system is 520kHz, and the signal transmission frequency point value is 6.1MHz.
And thirdly, determining the values of all elements of the double-sided LCC topology circuit. Selecting LCC topology L based on the energy transmission frequency and the data transmission frequency determined in the second step 1p ,L 1s ,C 1p ,C 1s ,C 2p ,C 2s Is a value of (2). Wherein L is 1p 、L 1s Series inductance respectively topological-modified for primary side LCC and secondary side LCC 1p 、C 1s Series capacitors respectively topological-connected with LCC of primary side and secondary side 2p 、C 2s And the parallel capacitors are respectively topological-added to the LCC of the primary side and the secondary side. The two resonance point expressions of the circuit are:
the parameters of each component set by the system are shown in the following table:
the air gap between the primary main coil L1 and the secondary coil L2 of the system is 5CM, the compensating inductances on two sides are hollow spiral inductances, the diameters of the coils of the compensating inductances on two sides are 7CM, the turns of the coils are 8 turns, and the inductance is 5.6uH. The compensation capacitor is a 0603 encapsulated polymer capacitor.
Step four, determining the resonant frequency of the circuit: the magnitude of the resonance point frequency needs to be determined again experimentally on the basis of the above calculation. The built system is excited by using a standard sine wave signal source, and an output waveform is observed at an output end. Recording the maximum value point of the output voltage, wherein the frequency point at the moment is a resonance frequency point. The point with the larger frequency value is the frequency point corresponding to the data transmission carrier, and the frequency point with the smaller frequency value is the energy transmission frequency point. The frequency points obtained by the test are 520kHz and 6.1MHz.
Step five, designing an FSK modulation circuit: an overall diagram of the system is shown in fig. 2. In order to enable transmission of data, information to be transmitted must be loaded onto a carrier wave. FSK (Frequency Shift Keying) is a widely applied modulation method, the communication system of the system uses a digital modulation mode to transfer information, and a DDS (Direct Digital Synthesis) mode is adopted to generate a required signal. The sine wave voltage Y [ i ]]N-point sampling was performed as follows:
and storing the obtained voltage value into the N-bit ROM. When specific modulation is carried out, the N-bit data and the modulation signal are operated, and the calculated result is output to the DAC to generate the needed waveform. Modulation of the FSK is accomplished by changing the clock used to read the ROM data. The carrier frequency of the FSK is determined by the clock for reading the ROM and the sampling point number N, and the specific relation is as follows:
a block diagram of an FSK communication system is shown in fig. 3. The modulation of FSK can be accomplished by changing the clock used to read the ROM data, for example, when 1 logic is required to be output, the frequency divider frequency division factor is 2, then the clock frequency driving the ROM is 104MHz, and the corresponding output sine wave frequency is 6.1MHz. When the logic 0 needs to be output, the frequency division coefficient of the frequency divider is 4, and the frequency of the output sine wave is 3.05MHz. The system uses FPGA to simulate the whole system, which is used to implement the FSK implementation block diagram shown in fig. 4. The clock frequency of the FPGA is 50MHz, and the FPGA is multiplied to 208MHz by using a phase-locked loop and then input into two frequency dividers. One of the frequency dividers has a frequency division coefficient of 20M, the state of the flag is output after every 20ms, and the other frequency divider has a frequency division coefficient of 2 or 6, which are different according to the value of the flag. Sine wave signals of different frequencies can be output due to different frequency division coefficients and the number of bits of the ROM. In the data output module, information is transferred onto a carrier wave to complete modulation of signals.
The output of FSK waveform also involves the construction of DAC, and in implantable devices, it is not possible to connect DAC modules externally to construct the system. In practical applications, an R-2R weight resistor DAC as shown in FIG. 5 may be integrated on a silicon substrate.
And step six, designing a frequency discrimination circuit. In this design, energy and data are transmitted in time-sharing mode through different frequencies, so that it is necessary to identify which frequency the carrier wave is in the current link at the receiving end, and different carrier signals are input into different processing circuits. When the frequency discrimination result is the energy transmission frequency point, the frequency discrimination circuit switches the analog gating switch to the battery charging circuit. The input signal is filtered by the rectifying circuit and then is input to the energy storage element for charging.
When the frequency discrimination result is the data transmission frequency point, the upper computer is indicated to want to transmit data to the lower computer. The frequency discriminator switches the analog gating switch to the demodulation module, and a filter circuit in the demodulation module extracts data and sends the data to the next-stage execution unit. The execution unit can complete the functions of electrically stimulating the tissues in the tested organism and the like.
When the frequency discrimination result is a direct current signal, the receiving end has no energy and no data to be transmitted at the moment. The upper computer releases the transmission link and gives it to the lower computer for control. The frequency discrimination circuit switches the analog gating switch to the FSK modulation circuit. Data acquired by an external sensor in the FSK modulation circuit is transmitted and loaded on a carrier wave to complete modulation, and a modulated signal is subjected to power amplification and is sent to an upper computer through a coil.
The discriminator is implemented by three filters. Two of which are LC band-pass filters which allow the frequencies of passage to be omega respectively 1 And omega 2 The other filter is an RC low pass filter with a very low cut-off frequency. When a certain filter isWhen the output end has a signal, the frequency of the signal currently being transmitted can be determined, and the frequency discriminator transmits the signal to a signal processing circuit of the next stage (the signal processing circuit can be matched with a common signal processing circuit). And when the frequency discrimination result is the wireless energy transmission frequency, rectifying and filtering the signal and then charging the energy storage element. And when the frequency discrimination result is the data transmission frequency, carrying out low-pass filtering on the signal to finish demodulation. When the frequency discrimination result is a direct current signal, the upper computer releases the communication link, and the lower computer occupies the link to transmit data to the upper computer.
The system adopts a time-sharing multiplexing mode to transmit energy and data. The system switches among three working modes of data uplink, data downlink and energy transmission, and the frequency discriminator is used for switching hardware connection in different modes.
And step seven, designing a communication protocol. The number of carrier periods occupied for transmitting one bit of data is 3*n, where n depends on the modulation scheme and the communication system. When the logic 1 needs to be transmitted, the number of carriers occupied by the high level is 2n, and the number of carriers occupied by the low level is n. When logic 0 needs to be transmitted, the number of carriers occupied by the high level is n, and the number of carriers occupied by the low level is 2 n. The transmitted logical value can be determined by determining the proportion of time occupied by the high level at the time of demodulation. The bit rate of the transmitted data at this time is:
from the above equation, the smaller the number of carrier periods occupied by transmitting one bit, the higher the data transmission rate. Meanwhile, the data transmission rate of the system can be improved by improving the working carrier frequency of the system. However, due to the presence of various parasitic capacitances, an increase in carrier frequency tends to increase the power consumption of the system.
The FSK waveform obtained at the output of the system is shown in fig. 6, which in fact occupies 30 carrier cycles of 1bit at a carrier frequency of 6.1MHz, at a data transmission bit rate of 25.4kbps. As can be seen from the figure, the receiving-end waveform cannot be instantaneously switched from the energy transmission mode to the information transmission mode, but has a buffering time of about 10 cycles.
Regardless of whether the system is transferring energy or data, the host always maintains the highest priority on the bus. In the data transmission time slice, if the host computer has data to be transmitted, the bus is directly occupied. If the host does not need to transmit data, the bus is released at the data transmission time slice, and the slave transmits the data to the host.
The proportion of the time slices occupied by the system transmission data and the transmission energy can be flexibly adjusted, a load detection circuit can be arranged at the upper computer end, and the load size is detected on the time slices for transmitting the energy, so that the charging state is obtained to change the proportion occupied by the charging time slices.
Claims (2)
1. A design method of an implantable energy and data time-sharing wireless transmission system is characterized in that: the method specifically comprises the following steps:
step one, determining the size, shape and number of turns of a primary main coil L1 and a secondary coil L2 in double-side LCC topology according to an implantable application scene, and measuring inductance values of the primary main coil L1 and the secondary coil L2; the main coil is responsible for energy and data transmission in an implantable scene;
selecting a resonant frequency according to the data transmission and energy transmission requirements of the implanted system; the wireless power transmission system based on double-side LCC topology is provided with two resonance points, wherein in the system, a high-frequency point is used for data transmission, and a low-frequency point is used for energy transmission;
determining the values of all elements of the double-sided LCC topology circuit: selecting LCC topology L based on the energy transmission frequency and the data transmission frequency determined in the second step 1p ,L 1s ,C 1p ,C 1s ,C 2p ,C 2s Wherein L is 1p 、L 1s Series inductance respectively topological-modified for primary side LCC and secondary side LCC 1p 、C 1s Series capacitors respectively topological-connected with LCC of primary side and secondary side 2p 、C 2s Parallel capacitors respectively topological-added for LCC of the primary side and the secondary side; the frequency value expression of the two resonance points is:
l in the above 1 The inductance value of the main coil; when determining parameter values of each component of LCC topology, calculating the frequency value determined by the parameter by the above formula;
step four, determining the resonant frequency of the circuit: exciting the built system by using a signal generator, and observing an output waveform at an output end by using an oscilloscope; recording the maximum value point of the output voltage, wherein the frequency point at the moment is a resonance frequency point, and the point with a larger frequency value is a frequency point corresponding to a data transmission carrier and the frequency point with a smaller frequency value is an energy transmission frequency point;
step five, designing an FSK modulation circuit: in order to enable transmission of data, information to be transmitted must be loaded onto a carrier wave; the communication system of the system adopts a digital modulation mode to carry out information transfer and adopts signals required by the generation of a DDS signal generator; the sine wave voltage Y [ i ]]N-point sampling was performed as follows:
storing the obtained voltage value into an N-bit ROM of the FSK modulation circuit; when specific modulation is carried out, the N-bit data and the modulation signal are operated, and the calculated result is output to a digital-to-analog converter to generate a required waveform; the FSK modulation is completed by changing the clock used for reading ROM data; the carrier frequency of the FSK modulation circuit is determined by the clock for reading the ROM and the sampling point number N, and the specific relation is as follows:
wherein f carrier For carrier frequency, f clock A frequency for driving the ROM;
FSK modulation consists in changing the frequency of the carrier signal, that is to say when a logic 1 needs to be transmitted,the frequency of the carrier voltage signal is f1, and when logic 0 needs to be transmitted, the frequency of the carrier voltage signal is f2; as can be seen from the above, the carrier frequency f is changed carrier Can be controlled by varying the frequency f of the driving ROM clock clock Realizing;
step six, designing a frequency discrimination circuit: the frequency discriminator is realized by three filters; two of which are LC band-pass filters which allow the frequencies of passage to be omega respectively 1 And omega 2 The other filter is an RC low-pass filter with low cut-off frequency; when a signal exists at the output end of one filter, the frequency of the signal currently being transmitted can be determined, and the frequency discriminator transmits the signal to a signal processing circuit of the next stage; when the frequency discrimination result is the wireless energy transmission frequency, rectifying and filtering the signal and charging the energy storage element; when the frequency discrimination result is the data transmission frequency, carrying out low-pass filtering on the signal to complete demodulation; when the frequency discrimination result is a direct current signal, the upper computer releases a communication link, and the lower computer occupies the link to transmit data to the upper computer;
step seven, designing a communication protocol: the number of carrier periods occupied by transmitting one bit of data is 3*n, wherein n depends on the advantages and disadvantages of the communication environment, and the value of n is larger when the communication environment is worse; when the logic 1 needs to be transmitted, the number of carriers occupied by the high level is 2n, and the number of carriers occupied by the low level is n; when logic 0 needs to be transmitted, the number of carriers occupied by the high level is n, and the number of carriers occupied by the low level is 2 n; determining the transmitted logic value by judging the proportion of time occupied by the high level during demodulation; the bit rate of the transmitted data at this time is:
from the above formula, the smaller the number of carrier periods occupied by transmitting one bit, the higher the data transmission rate; meanwhile, the data transmission rate of the system can be improved by improving the working carrier frequency of the system; in the system, whether the system energy is transmitted or the data is transmitted, the host always keeps the highest priority to the double-side LCC circuit; in the data transmission time slice, if the host computer has data to be transmitted, the bus is directly occupied; if the host does not need to transmit data, the bus is released at the data transmission time slice, and the slave transmits the data to the host.
2. An implantable energy and data time-sharing wireless transmission system designed according to the method of claim 1, wherein: comprises an upper computer, a bilateral LCC topology circuit and a lower computer; the upper computer and the lower computer wirelessly transmit energy and data through a bilateral LCC topology circuit; the lower computer comprises an FSK modulation circuit, a frequency discrimination circuit, a rectifying circuit and a demodulation module, wherein the FSK modulation circuit is used for realizing the modulation of transmission information in the topology of the LCC at two sides, and the frequency discrimination circuit is used for separating an information transmission time slice from an energy transmission time slice;
the upper computer transmits the instruction to be executed by the lower computer and the energy required by the lower computer to the lower computer in a sine voltage form through the LCC topology circuit; the energy and the data of the upper computer are transmitted in a time-sharing multiplexing mode, and the energy and the data occupy different time slices; in the energy transmission time slice, energy is transmitted by using sinusoidal voltage as a carrier through an LCC topology circuit; in the information transmission time slice, after the information is modulated by the FSK modulation circuit, the information is transmitted in a voltage form; on one side of the lower computer, the FSK modulation circuit modulates the acquired input signals in an FSK mode and then transmits the input signals to the upper computer through the bilateral LCC circuit;
when the frequency discrimination result is an energy transmission frequency point, the frequency discrimination circuit switches the analog gating switch to the battery charging circuit, and inputs an input signal to the energy storage element for charging after being filtered by the rectifying circuit;
when the frequency discrimination result is a data transmission frequency point, the upper computer is indicated to want to transmit data to the lower computer at the moment; the frequency discriminator switches the analog gating switch to the demodulation module, and a filter circuit in the demodulation module extracts data to perform data response operation;
when the frequency discrimination result is a direct current signal, the receiving end has no energy and no data to be transmitted at the moment; the upper computer releases the transmission link and gives it to the lower computer for control; the frequency discrimination circuit switches the analog gating switch to the FSK modulation circuit; the FSK modulation circuit is used for transmitting and loading data acquired by an external sensor onto a carrier wave to complete modulation, and carrying out power amplification on the modulated signal and sending the modulated signal to an upper computer through the LCC topology circuit.
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| US4763103A (en) * | 1985-02-14 | 1988-08-09 | Enertec | Process and method for wide band transmission, particularly for data transmission over an electricity distribution network |
| US4694471A (en) * | 1986-05-05 | 1987-09-15 | Blesser Barry A | Digital data communicating |
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