Method and system for controlling backscattering circuit based on multi-subcarrier modulation
阅读说明：本技术 一种基于多子载波调制控制反向散射电路的方法及系统 (Method and system for controlling backscattering circuit based on multi-subcarrier modulation ) 是由 朱丰源 冯宇达 李倩茹 田晓华 王新兵 于 2020-05-13 设计创作，主要内容包括：本发明提供了一种基于多子载波调制控制反向散射电路的方法及系统,包括：反向散射标签的多子载波调制算法；步骤M1：基于相位的数字振荡器,决定最终的逻辑输出0/1；步骤M2：根据多个相位的数字振荡器的逻辑输出,基于输出决策模块,决定最后输出给射频开关的控制信号的逻辑值0/1；所述输出决策模块是多个相位的数字振荡器的逻辑输出投票选择最后输出给射频开关的控制信号的逻辑值。本发明的方法可以运用于任何反向散射或非传统意义上的反向散射电路。实现多载波为数字域的算法,而不对模拟电路做限制。(The invention provides a method and a system for controlling a backscattering circuit based on multi-subcarrier modulation, which comprises the following steps: a multi-subcarrier modulation algorithm of the backscattering label; step M1: a phase-based digital oscillator that determines a final logic output 0/1; step M2: determining 0/1 a logic value of a control signal to be finally output to the radio frequency switch based on the output decision module according to the logic output of the digital oscillator of the plurality of phases; the output decision module is used for voting and selecting the logic value of the control signal finally output to the radio frequency switch by the logic output of the digital oscillators with multiple phases. The method of the present invention can be applied to any backscatter or backscatter circuit in the unconventional sense. The multi-carrier is realized as an algorithm of a digital domain without limitation to an analog circuit.)
1. A method for controlling a backscatter circuit based on multi-subcarrier modulation, comprising: a multi-subcarrier modulation algorithm of the backscattering label;
step M1: a phase-based digital oscillator, decision logic output 0/1;
step M2: determining 0/1 a logic output of a control signal to be finally output to the radio frequency switch based on the output decision module according to the logic outputs of the digital oscillators of the plurality of phases;
the output decision module is used for voting and selecting the logic value of the control signal finally output to the radio frequency switch by the logic output of the digital oscillator with a plurality of phases.
2. The method for controlling a backscatter circuit based on multi-subcarrier modulation according to claim 1, wherein the step M1 comprises:
the digital oscillator based on the phase stores a specific phase in a register according to the subcarrier frequency of the digital oscillator of the phase and adds the specific phase with the phase stored in the original register every time according to a preset sampling clock; each time a particular phase is stored as a fixed value, the digital oscillator makes an interval decision based on the phase added value and then determines the logic output 0/1.
3. The method of claim 2, wherein the digital oscillator interval decision based on the phase addition value comprises: and the digital oscillator makes interval judgment according to the decimal part after the phase addition and/or the digital oscillator makes uniform numerical value change according to the phase addition numerical value, so that decimal points in the phase addition numerical value move, and the phase addition integer is obtained to make interval judgment.
4. The method for controlling a backscatter circuit based on multi-subcarrier modulation according to claim 1, wherein the step M2 comprises: multiple subcarrier modulation requires multiple digital oscillators, which provide multiple 0/1 outputs; and determining the logic value 0/1 of the control signal finally output to the radio frequency switch according to a voting method based on the output decision module.
5. The method of claim 4, wherein the voting method is performed according to a plurality of logic values 0/1 provided by a plurality of digital oscillators, and when the number of logic values 0 is greater than the number of logic values 1, a logic value 0 is finally output; when the number of the logic values 0 is smaller than that of the logic values 1, finally outputting the logic values 1; when the number of logic values 0 is equal to the number of logic values 1, logic values 0 or logic values 1 are finally output.
6. The method for controlling a backscatter circuit based on multi-subcarrier modulation of claim 1, wherein the carrier of the multi-subcarrier modulation algorithm of the backscatter tag comprises: a microcontroller and editable logic circuitry.
7. A system for controlling a backscatter circuit based on multi-subcarrier modulation, comprising: a multi-subcarrier modulation algorithm of the backscattering label;
module M1: a phase-based digital oscillator, decision logic output 0/1;
module M2: determining 0/1 a logic output of a control signal to be finally output to the radio frequency switch based on the output decision module according to the logic outputs of the digital oscillators of the plurality of phases;
the output decision module is used for voting and selecting the logic value of the control signal finally output to the radio frequency switch by the logic output of the digital oscillator with a plurality of phases.
8. The system of claim 7, wherein the module M1 comprises:
the digital oscillator based on the phase stores a specific phase in a register according to the subcarrier frequency of the digital oscillator of the phase and adds the specific phase with the phase stored in the original register every time according to a preset sampling clock; every time the specific phase stored is a fixed value, the digital oscillator makes interval judgment according to the phase addition value, and then logic output 0/1 is determined;
the digital oscillator makes interval judgment according to the phase addition value, and the interval judgment comprises the following steps: and the digital oscillator makes interval judgment according to the decimal part after the phase addition and/or the digital oscillator makes uniform numerical value change according to the phase addition numerical value, so that decimal points in the phase addition numerical value move, and the phase addition integer is obtained to make interval judgment.
9. The system of claim 7, wherein the module M2 comprises: multiple subcarrier modulation requires multiple digital oscillators, which provide multiple 0/1 outputs; based on the output decision module, according to the voting method, the logic value 0/1 of the control signal finally output to the radio frequency switch is determined;
the voting method is output according to a plurality of logic values 0/1 provided by a plurality of digital oscillators, and when the number of logic values 0 is greater than the number of logic values 1, the logic value 0 is finally output; when the number of the logic values 0 is smaller than that of the logic values 1, finally outputting the logic values 1; when the number of logic values 0 is equal to the number of logic values 1, logic values 0 or logic values 1 are finally output.
10. The system of claim 7, wherein the carrier of the multiple subcarrier modulation algorithm of the backscatter tag comprises: a microcontroller and editable logic circuitry.
Technical Field
The present invention relates to the field of communications, and in particular, to a method and system for controlling a backscatter circuit based on multi-subcarrier modulation, and more particularly, to an algorithm capable of implementing multi-subcarrier modulation and how to provide the output of the algorithm to the circuit without any limitation on the backscatter radio frequency circuit.
Background
Backscatter communications have attracted considerable attention in recent years in the field of the internet of things. The main characteristic is that the communication is realized by modulating the external electromagnetic wave. Since there is no need to actively generate electromagnetic waves, power consumption is very low, only a few tens of microwatts, even if Wi-Fi communication is generated (see BryceKellogg et al NSDI paper 2016). However, there are three problems with current backscatter devices: (a) low communication rate, (b) insufficient network capacity, and (c) insufficient support for long-range protocols. In terms of rate, the current highest rate backscatter communication device can only upload data at the physical layer at 11Mbps (brecekellogg, 2016). In terms of capacity, current backscatter devices can only support 48 devices communicating in the same Wi-Fi band. In support of long-distance protocols, the current backscatter system only supports the LoRa protocol (vamsitala, Mehrdad Hessar,2017), but does not support other long-distance protocols, such as LTE-M and other protocols. The multi-subcarrier modulation technology is greatly helpful for solving the three problems. The OFDM technology is a typical multi-subcarrier modulation technology, has extremely high frequency spectrum utilization rate and is suitable for high-speed communication; the OFDMA technology based on OFDM is a key technology for increasing capacity, and is applied to a new generation of 802.11 protocol and 4G,5G network; in addition, the LTE-M protocol also requires the implementation of multi-subcarrier modulation to be compatible with the physical layer mode of LTE.
Patent document CN106506426B (application number: 201610885466.3) discloses a backscatter communication modulation method based on an OFDM (orthogonal frequency division multiplexing) carrier. The modulation method is used for a backscattering communication system, and the backscattering communication system comprises a radio frequency source, a reader and a label; the method mainly comprises the following steps: the radio frequency source transmits OFDM carrier signals to the label; the tag receives OFDM signals, and further comprises a backscattering antenna and a radio frequency energy collection module, wherein the radio frequency energy collection module is used for collecting energy of the OFDM signals in the tag environment, and the backscattering antenna is used for sending information bits to a reader; the reader receives and decodes the backscattered signal from the tag.
Disclosure of Invention
In view of the defects in the prior art, the present invention provides a method and system for controlling a backscatter circuit based on multi-subcarrier modulation.
The invention provides a method for controlling a backscattering circuit based on multi-subcarrier modulation, which comprises the following steps: a multi-subcarrier modulation algorithm of the backscatter tag;
step M1: a phase-based digital oscillator, decision logic output 0/1;
step M2: determining 0/1 a logic value of a control signal to be finally output to the radio frequency switch based on the output decision module according to the logic output of the digital oscillator of the plurality of phases;
the output decision module is used for voting and selecting the logic value of the control signal finally output to the radio frequency switch by the logic output of the digital oscillators with multiple phases.
Preferably, the step M1 includes:
the digital oscillator based on the phase stores a specific phase in a register according to the subcarrier frequency of the digital oscillator of the phase and adds the specific phase with the phase stored in the original register every time according to a preset sampling clock; each time a particular phase is stored as a constant value, the digital oscillator makes an interval decision based on the phase added value and then determines the logic output 0/1.
Preferably, the digital oscillator making interval judgment according to the phase addition value includes: and the digital oscillator makes interval judgment according to the decimal part after phase addition and/or the digital oscillator makes uniform numerical value change according to the phase addition numerical value, so that decimal points in the phase addition numerical value move to obtain a phase addition integer for interval judgment.
Preferably, the step M2 includes: multiple subcarrier modulation requires multiple digital oscillators, which provide multiple 0/1 outputs; and determining the logic value 0/1 of the control signal finally output to the radio frequency switch according to a voting method based on the output decision module.
Preferably, the voting method is output according to a plurality of logic values 0/1 provided by a plurality of digital oscillators, and when the number of logic values 0 is greater than the number of
Preferably, the carrier of the multi-subcarrier modulation algorithm of the backscatter tag comprises: a microcontroller and an editable logic circuit.
The invention provides a system for controlling a backscattering circuit based on multi-subcarrier modulation, which comprises the following components: a multi-subcarrier modulation algorithm of the backscattering label;
module M1: a phase-based digital oscillator, decision logic output 0/1;
module M2: determining 0/1 a logic value of a control signal to be finally output to the radio frequency switch based on the output decision module according to the logic output of the digital oscillator of the plurality of phases;
the output decision module is used for voting and selecting the logic value of the control signal finally output to the radio frequency switch by the logic output of the digital oscillators with multiple phases.
Preferably, said module M1 comprises:
the digital oscillator based on the phase stores a specific phase in a register according to the subcarrier frequency of the digital oscillator of the phase and adds the specific phase with the phase stored in the original register every time according to a preset sampling clock; every time the specific phase is stored as a fixed value, the digital oscillator makes interval judgment according to the phase addition value, and then logic output 0/1 is determined;
the digital oscillator makes interval judgment according to the phase addition value, and the interval judgment comprises the following steps: and the digital oscillator makes interval judgment according to the decimal part after phase addition and/or the digital oscillator makes uniform numerical value change according to the phase addition numerical value, so that decimal points in the phase addition numerical value move to obtain a phase addition integer for interval judgment.
Preferably, said module M2 comprises: multiple subcarrier modulation requires multiple digital oscillators, which provide multiple 0/1 outputs; based on the output decision module, according to the voting method, the logic value 0/1 of the control signal finally output to the radio frequency switch is determined;
the voting method is output according to a plurality of logic values 0/1 provided by a plurality of digital oscillators, and when the number of logic values 0 is greater than the number of
Preferably, the carrier of the multi-subcarrier modulation algorithm of the backscatter tag comprises: a microcontroller and an editable logic circuit.
Compared with the prior art, the invention has the following beneficial effects:
1. the method provided by the invention can enable the backscattering equipment to realize multi-subcarrier modulation, thereby supporting wider communication protocols.
2. The method of the invention enables the backscatter devices to communicate in an OFDM manner, thereby achieving higher spectral efficiency.
3. The method of the present invention can be applied to any backscatter or backscatter circuit in the unconventional sense. The algorithm that the multi-carrier is a digital domain is realized, and the analog circuit is not limited;
4. the final output is a 1bit logic control signal, so that the circuit is compatible with any existing backscattering circuit; this is because backscatter communications naturally require a switching function of impedance; the logic signals generated by the algorithm provided by the present invention can be used to control the impedance switching. The logic signal generated by the algorithm provided by the invention can be used for controlling impedance switching.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
fig. 1 is a block diagram of an exemplary design of a phase based digital oscillator according to the present invention.
FIG. 2 is a diagram illustrating an output decision device for deciding an output according to inputs of a plurality of digital oscillators according to the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
The invention provides a multi-subcarrier modulation technology suitable for backscattering communication. The technology is an arithmetic method of a digital domain, can support multi-subcarrier modulation only by two switchable impedances on a radio frequency circuit, and can be suitable for most of the existing backscatter circuits.