CN114189254A - Ultralow-power-consumption LoRa communication system and communication method based on single-frequency oscillator - Google Patents
Ultralow-power-consumption LoRa communication system and communication method based on single-frequency oscillator Download PDFInfo
- Publication number
- CN114189254A CN114189254A CN202111267411.3A CN202111267411A CN114189254A CN 114189254 A CN114189254 A CN 114189254A CN 202111267411 A CN202111267411 A CN 202111267411A CN 114189254 A CN114189254 A CN 114189254A
- Authority
- CN
- China
- Prior art keywords
- lora
- frequency
- square wave
- signal
- switching circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- QVFWZNCVPCJQOP-UHFFFAOYSA-N chloralodol Chemical compound CC(O)(C)CC(C)OC(O)C(Cl)(Cl)Cl QVFWZNCVPCJQOP-UHFFFAOYSA-N 0.000 title claims abstract description 100
- 238000004891 communication Methods 0.000 title claims abstract description 61
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000010355 oscillation Effects 0.000 claims abstract description 18
- 239000003990 capacitor Substances 0.000 claims description 25
- 238000001228 spectrum Methods 0.000 claims description 11
- 238000010897 surface acoustic wave method Methods 0.000 claims description 11
- 230000005540 biological transmission Effects 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 8
- 239000013078 crystal Substances 0.000 claims description 7
- 238000012546 transfer Methods 0.000 claims description 6
- 239000010453 quartz Substances 0.000 claims description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 5
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 238000003786 synthesis reaction Methods 0.000 claims description 4
- 108010003272 Hyaluronate lyase Proteins 0.000 claims description 3
- 230000002452 interceptive effect Effects 0.000 claims description 3
- 230000008901 benefit Effects 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 8
- 238000012986 modification Methods 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 230000002194 synthesizing effect Effects 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/02—Transmitters
- H04B1/04—Circuits
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
- H04W52/0209—Power saving arrangements in terminal devices
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B2001/6912—Spread spectrum techniques using chirp
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Transceivers (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The invention provides an ultra-low power consumption LoRa communication system and a communication method based on a single-frequency oscillator. During communication, the digital processor generates a corresponding LoRa baseband square wave signal according to original data, and the LoRa baseband square wave signal is used as a control signal of the phase switching circuit; the single-frequency oscillating circuit generates a single-frequency signal with stable amplitude as the input of the phase switching circuit; and the phase switching circuit switches the phase of the single-frequency signal output by the single-frequency oscillation circuit according to the high and low levels of the LoRa baseband square wave signal and outputs the phase to an antenna. Compared with the traditional LoRa chip, the ultra-low power consumption LoRa communication system and the communication method provided by the invention have the advantages of low power consumption and low cost; compared with LoRa backscattering communication, the invention has the advantage of no need of a base station on the basis of keeping low power consumption and low cost.
Description
Technical Field
The invention relates to the field of electronic circuits, in particular to an ultralow-power-consumption LoRa communication system and method based on a single-frequency oscillator.
Background
The LoRa adopts the spread spectrum modulation technology to realize high sensitivity, uses lower power consumption to realize remote wireless communication, and is suitable for long-distance, low-power consumption, low-rate internet of things application scene. In recent years, all groups are also distributed aiming at the LoRa industry, a large number of industrial applications of falling to the ground are developed in vertical fields of smart cities, smart parks, smart buildings, smart security and the like, and the prospect is very wide. Currently, the LoRa communication technology is mainly divided into two types: the traditional LoRa communication technology adopting Semtech SX1276/7/8/9 series chips and the LoRa backscattering communication technology proposed by the university of Washington in the United states.
According to the technical scheme shown in FIG. 1, the traditional SX1276/7/8/9 series chip integrates a radio frequency PLL, a multiplier and a DAC/ADC; in order to transmit the LoRa signal with a certain power, radio frequency analog circuits such as VGA and power amplifier are also required to be integrated. Therefore, the LoRa chip has high cost (for example SX1278, currently sold at 40-50 @10pcs) and large power consumption (20-125 mA).
In 2017, computer scientists and electrical engineers at the university of washington, usa, proposed a "long-range backscattering" LoRa communication system as shown in fig. 2, which realizes low-power-consumption and low-cost LoRa data transmission by reflecting radio signals transmitted by a base station. In 2018, the seventh nine research institute of the middle ship group also proposed a "passive LoRa" communication technology based on the technology. Although this kind of communication technology has advantages of cost and power consumption, it is not widely used because a backscattering communication mechanism is adopted, and a high-power base station must be additionally equipped in the system.
Disclosure of Invention
Aiming at the technical problems in the prior art, the invention provides an ultralow-power-consumption LoRa communication system and a communication method based on a single-frequency oscillator.
According to a first aspect of the present invention, an ultra-low power consumption LoRa communication system based on a single frequency oscillator is provided, which includes a digital processor, a single frequency oscillation circuit and a phase switching circuit; the digital processor is used for generating a corresponding LoRa baseband square wave signal according to original data during communication, and the LoRa baseband square wave signal is used as a control signal of the phase switching circuit; the single-frequency oscillating circuit is used for generating a single-frequency signal with stable amplitude as the input of the phase switching circuit; and the phase switching circuit is used for switching the phase of the single-frequency signal output by the single-frequency oscillation circuit according to the high-low level of the LoRa baseband square wave signal and outputting the phase to an antenna.
On the basis of the technical scheme, the invention can be improved as follows.
Optionally, the single-frequency oscillation circuit includes a resistor R1, a resistor R2, a capacitor C1, a capacitor C2, a capacitor C3, a resonant inductor L1, a radio frequency transistor Q1, and an XTAL 1; an output end of the digital processor is connected with an enabling end of a resistor R2, the other end of the resistor R2 is electrically connected with a base of the radio frequency transistor Q1 and is grounded through an XTAL1, an emitter of the radio frequency transistor Q1 is grounded through a capacitor C1 and a resistor R1 respectively, a collector of the radio frequency transistor Q1 is electrically connected with a first end of the capacitor C3, a second end of the capacitor C3 is electrically connected with the phase switching circuit, a first end of the capacitor C3 is also grounded through the resonant inductor L1 and a capacitor C2, and a common termination power source VCC of the resonant inductor L1 and the capacitor C2 is connected with the ground.
Optionally, XTAL1 is a quartz crystal or a surface acoustic wave SAW resonator/filter, and the frequency of the XTAL1 is determined according to the LoRa communication frequency band; the radio frequency transistor Q1 is model BFT 15A.
Optionally, the phase place switching circuit includes radio frequency switching device and signal delay device, the radio frequency switching device is double-pole double-throw switch, the signal delay device is lambda/2 transmission line or multistage LC equivalent circuit, digital processor will generate the output of loRa baseband square wave signal extremely the radio frequency switching device, and single frequency oscillating circuit passes through the second end of electric capacity C3 with the stable single frequency signal output of amplitude extremely the radio frequency switching device, signal delay device connects the radio frequency switching device forms the return circuit.
According to a second aspect of the present invention, there is provided a single frequency oscillator-based ultra-low power consumption LoRa communication method, including: the LoRa communication system comprises a digital processor, a single-frequency oscillation circuit and a phase switching circuit, and the LoRa communication method comprises the following steps: during communication, the digital processor generates a corresponding LoRa baseband square wave signal according to original data, and the LoRa baseband square wave signal is used as a control signal of the phase switching circuit; the single-frequency oscillating circuit generates a single-frequency signal with stable amplitude as the input of the phase switching circuit; and the phase switching circuit switches the phase of the single-frequency signal output by the single-frequency oscillation circuit according to the high and low levels of the LoRa baseband square wave signal and outputs the phase to an antenna.
Optionally, the digital processor generates a corresponding LoRa baseband square wave signal according to the original data, including: according to a direct digital frequency synthesis (DDS) principle, a fixed Chirp Spread Spectrum (CSS) square wave sequence is obtained by utilizing Matlab calculation, the CSS square wave sequence comprises all components of a LoRa lead code, a synchronization symbol, a down-chirp and symbol data, and a complete LoRa baseband square wave signal is synthesized by intercepting different segments of the CSS square wave sequence.
Optionally, the digital processor generates a corresponding LoRa baseband square wave signal according to the original data, including: obtaining N symbol values N through data scrambling, coding and interleaving0……Nn-1And calculates the total number Num of symbols to be transmittedsymN + 13; calculating the address offset Addr of each symbol valueoffset[i]And the number Num of DMA bits of each symbol valueDMAbit[i]. Addroffset[0]Load the source address of DMA and at the same time, load NumDMAbit[0]Loading a DMA counter, starting DMA transmission, and entering a low power consumption mode; addr for the next symbol is automatically loaded immediately after each DMA transfer is completedoffset[i]And NumDMAbit[i]Until all symbols have been output.
Optionally, the calculating of the address offset Addr of each symbol valueoffset[i]And the number Num of DMA bits of each symbol valueDMAbit[i]The method comprises the following steps: when the CSS waveform with the symbol value of N needs to be output, the current pointer is increased by P multiplied by N/2 on the basis of the base addressSFThe offset of the bit, the CSS waveform when the LoRa preamble is N ═ 0, the address offset corresponding to the down chirp is 2 × P, and the address offset of each symbol is:
where P is the number of bits required for each symbol value period, SF is a spreading factor, and considering that the down-chirp occupies 21/4 symbol periods, the number of DMA transmission bits for each symbol value is:
optionally, the frequency of the single-frequency signal generated by the single-frequency oscillation circuit is foscThe central frequency of the LoRa baseband square wave signal generated by the digital processing device is fBThe output center frequency of the phase switching circuit is fLoRa＝fosc+fBLoRa signal and center frequency of fInterference＝fosc－fBThe image of (1) is the interfering LoRa signal.
The invention provides an ultralow power consumption LoRa communication system and a communication method based on a single-frequency oscillator, wherein the communication system mainly comprises a low-power consumption digital processing device, a low-power consumption single-frequency oscillator and a phase switching circuit, and has the advantages of low power consumption and low cost compared with the traditional LoRa chip; compared with LoRa backscattering communication, the invention has the advantage of no need of a base station on the basis of keeping low power consumption and low cost.
Drawings
Fig. 1 is a schematic structural diagram of an internal system of a LoRa communication chip in prior art 1;
fig. 2 is a schematic diagram of the composition of a LoRa communication system in prior art 2;
fig. 3 is a schematic structural diagram of an ultra-low power consumption LoRa communication system based on a single frequency oscillator according to the present invention;
fig. 4 is a schematic diagram of the principle of synthesizing the LoRa baseband signal by a digital processor such as an MCU;
fig. 5 is a flowchart of the digital processing device such as the low power consumption MCU outputting the LoRa baseband signal;
fig. 6 is a schematic circuit diagram of an ultra-low power consumption LoRa communication system based on a single frequency oscillator according to the present invention;
fig. 7-1 is a schematic diagram of an output signal of a single frequency oscillator and a frequency spectrum thereof, fig. 7-2 is a schematic diagram of a control signal of a phase switching circuit and a frequency spectrum thereof, and fig. 7-3 is a schematic diagram of an output signal of a phase switching circuit and a frequency spectrum thereof.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
Based on the defects in the background art, the invention provides an ultra-low power consumption LoRa communication system based on an oscillator, which can realize LoRa data transmission without a matched base station on the basis of keeping low power consumption and low cost. The ultra-low power consumption LoRa communication system mainly comprises three parts: a digital processor (taking MCU as an example), a single frequency oscillator circuit, and a phase switching circuit, as shown in fig. 3. Wherein the single-frequency oscillation circuit is used for generating a single-frequency signal with stable amplitude and frequency fosc. The digital processors such as MCU generate corresponding LoRa baseband square waves according to the original data during communication, and the center frequency is fB. The phase switching circuit switches the phase (0 or pi) of the single-frequency signal output by the oscillating circuit according to the high and low levels of the LoRa baseband square wave and outputs the phase to the antenna.
Specifically, a digital processor such as an MCU calculates a fixed CSS square wave sequence according to the direct digital frequency synthesis principle by using Matlab, where the CSS square wave sequence includes two up-chirps and one down-chirp, as shown in fig. 4. Then, the CSS square wave sequence is written into a memory of a digital processing unit such as a low-power consumption MCU. Since the CSS square wave sequence includes all elements of the LoRa preamble, the synchronization symbol, the down-chirp, and the symbol data CSS waveform, a complete LoRa baseband square wave signal can be synthesized by cutting different segments. The detailed flow of the LoRa baseband square wave signal synthesis scheme can be seen in fig. 5, and mainly includes the following steps:
utilizing low workConsuming resources of calculation, logic, peripheral (mainly DMA and SPI) and the like of digital processing units such as MCU and the like, firstly, sequentially carrying out scrambling → error correction coding → anti-interference interleaving → Gray coding on original data to obtain N symbol values N0……Nn-1And calculates the total number Num of symbols to be transmittedsymN +13 (for example, a preamble of 8 symbols in length).
Secondly, when the CSS waveform with the symbol value of N needs to be output, only the current pointer needs to be increased by P multiplied by N/2 on the basis of the base addressSFThe offset of the bits is sufficient. And the LoRa preamble may be considered as a CSS waveform when N is 0. In addition, the down chirp corresponds to an address offset of 2 × P. The address offset for each symbol is therefore:
where P is the number of bits required for each symbol period and SF is the spreading factor. Considering that the down-chirp occupies 21/4 symbol periods, the number of DMA transfer bits per symbol unit is:
③ Addroffset[0]Load the source address of DMA and at the same time, load NumDMAbit[0]The DMA counter is loaded. Then the DMA transfer is initiated and the low power mode is entered. Addr for the next symbol is automatically loaded immediately after each DMA transfer is completedoffset[i]And NumDMAbit[i]Until all symbols have been output, the whole flow is as shown in fig. 5.
The single-frequency oscillating circuit can be a low-power-consumption phase-locked loop PLL integrated circuit (chip) or a low-power-consumption single-frequency oscillating circuit based on discrete devices such as a transistor/MOS (metal oxide semiconductor) tube, an SAW (surface acoustic wave) resonator/filter/quartz crystal and the like, is used for generating a radio-frequency carrier signal with stable amplitude and single frequency, has low power consumption characteristic and high direct current → radio frequency energy conversion efficiency as much as possible. The invention takes a crystal oscillation circuit/SAW surface acoustic wave resonant circuit as an example, and the circuit form can adopt a b-e type circuit (also called Miller circuit), as shown in FIG. 6.
As shown in fig. 6, the single-frequency oscillation circuit includes a resistor R1, a resistor R2, a capacitor C1, a capacitor C2, a capacitor C3, a resonant inductor L1, a radio frequency transistor Q1, and an XTAL 1.
An output end of the digital processor is connected with an enabling end of a resistor R2, the other end of the resistor R2 is electrically connected with a base of the radio frequency transistor Q1 and is grounded through an XTAL1, an emitter of the radio frequency transistor Q1 is grounded through a capacitor C1 and a resistor R1 respectively, a collector of the radio frequency transistor Q1 is electrically connected with a first end of the capacitor C3, a second end of the capacitor C3 is electrically connected with the phase switching circuit, a first end of the capacitor C3 is also grounded through the resonant inductor L1 and a capacitor C2, and a common terminal of the resonant inductor L1 and the capacitor C2 is connected with a power supply VCC.
XTAL1 is a quartz crystal or surface acoustic wave SAW resonator/filter, and its frequency is mainly determined by LoRa communication frequency bands, such as 315M band, 433M band, 470M band, 868M band, 915M band, etc. The Q1 is a low power consumption rf transistor or rf MOS transistor, in this embodiment, the Q1 is an rf transistor with a model number of BFT 15A. L1 is collector resonance inductance, R1 is emitter resistance, R2 is base resistance, C1 is emitter capacitance, C2 is power supply decoupling capacitance, and C3 is output coupling capacitance. EN is an enable terminal and defaults to low level to turn off the oscillator circuit to save power, and is high level only during LoRa communication.
Phase place shift circuit includes radio frequency switching device and signal delay device, the radio frequency switching device is double-pole double-throw switch, the signal delay device is lambda/2 transmission line or multistage LC equivalent circuit, digital processor exports the loRa baseband square wave signal that generates to the radio frequency switching device, and single frequency oscillation circuit passes through the second end of electric capacity C3 exports the stable single frequency signal of amplitude to the radio frequency switching device, and the signal delay device is connected the radio frequency switching device and is formed the return circuit.
Specifically, the phase switching circuit is configured to change a phase of the radio frequency carrier signal output by the single frequency oscillation circuit, so that the phase switching circuit can implement phase switching between 0 and pi according to the control signal. To achieve this function, a scheme of "radio frequency switching device + signal delay device" may be adopted, as shown in fig. 6. The radio frequency switch adopts a double-pole double-throw type ADG936 series, and can also be combined by a plurality of single-pole type switches. The signal delay device adopts a lambda/2 transmission line, and can also be replaced by a multi-stage LC equivalent circuit.
The signal input to the phase switching circuit is the carrier (frequency f) of the oscillatorosc) The control input is LoRa baseband square wave (the center frequency of the fundamental frequency is f)B). When the higher harmonics are ignored, the output is LoRa signal (center frequency f)LoRa＝fosc+fB) LoRa signal (center frequency f) interfering with imageInterference＝fosc－fB). Fig. 7 shows waveforms and frequency spectrums of the signals, where fig. 7 shows waveforms and frequency spectrums corresponding to different points, specifically, fig. 7-1 shows an output signal of a single-frequency oscillation circuit and a frequency spectrum thereof, fig. 7-2 shows a control signal of a phase switching circuit and a frequency spectrum thereof, and fig. 7-3 shows an output signal of a phase switching circuit and a frequency spectrum thereof.
The ultra-low power consumption LoRa communication system of the embodiment of the invention mainly comprises a low power consumption digital processing device, a low power consumption single-frequency oscillator and a phase switching circuit, wherein a method for synthesizing a complete LoRa baseband square wave signal by intercepting a segment of a specific CSS square wave sequence is provided based on the low power consumption digital processing device such as an MCU; the low-power consumption single-frequency oscillator adopts a quartz crystal/SAW resonance circuit and outputs a single-frequency carrier wave with stable amplitude; the phase switching circuit controls the transmission delay of the carrier wave through the radio frequency switch to realize the switching of the phases 0 and pi.
Compared with the prior art, the method has the advantages that:
1) the power consumption is low, and the total current consumption of the LoRa communication system provided by the invention is less than or equal to 200 muA under the condition of 2V power supply, and is two orders of magnitude lower than that of the traditional LoRa chip.
2) The low cost is achieved, the LoRa communication system mainly adopts the cheap crystal/SAW resonator and the radio frequency switch, and the cost is only 1/3-1/4 of the traditional LoRa chip.
3) Compared with the LoRa communication technology based on backscattering, the method provided by the invention can realize LoRa communication without additionally arranging a base station.
It should be noted that, in the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to relevant descriptions of other embodiments for parts that are not described in detail in a certain embodiment.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (9)
1. An ultra-low power consumption LoRa communication system based on a single-frequency oscillator is characterized by comprising a digital processor, a single-frequency oscillation circuit and a phase switching circuit;
the digital processor is used for generating a corresponding LoRa baseband square wave signal according to original data during communication, and the LoRa baseband square wave signal is used as a control signal of the phase switching circuit;
the single-frequency oscillating circuit is used for generating a single-frequency signal with stable amplitude as the input of the phase switching circuit;
and the phase switching circuit is used for switching the phase of the single-frequency signal output by the single-frequency oscillation circuit according to the high-low level of the LoRa baseband square wave signal and outputting the phase to an antenna.
2. The LoRa communication system according to claim 1, characterized in that, the single frequency oscillation circuit includes resistance R1, resistance R2, electric capacity C1, electric capacity C2, electric capacity C3, resonant inductance L1, radio frequency transistor Q1 and XTAL 1;
an output end of the digital processor is connected with an enabling end of a resistor R2, the other end of the resistor R2 is electrically connected with a base of the radio frequency transistor Q1 and is grounded through an XTAL1, an emitter of the radio frequency transistor Q1 is grounded through a capacitor C1 and a resistor R1 respectively, a collector of the radio frequency transistor Q1 is electrically connected with a first end of the capacitor C3, a second end of the capacitor C3 is electrically connected with the phase switching circuit, a first end of the capacitor C3 is also grounded through the resonant inductor L1 and a capacitor C2, and a common termination power source VCC of the resonant inductor L1 and the capacitor C2 is connected with the ground.
3. The LoRa communication system of claim 2, wherein XTAL1 is a quartz crystal or surface acoustic wave SAW resonator/filter with frequencies determined according to LoRa communication band; the radio frequency transistor Q1 is model BFT 15A.
4. The LoRa communication system of claim 2, wherein the phase switching circuit comprises a radio frequency switching device and a signal delay device, the radio frequency switching device is a double-pole double-throw switch, the signal delay device is a λ/2 transmission line or a multi-stage LC equivalent circuit, the digital processor outputs the generated LoRa baseband square wave signal to the radio frequency switching device, and the single frequency oscillating circuit outputs a single frequency signal with stable amplitude to the radio frequency switching device through the second end of the capacitor C3, and the signal delay device is connected with the radio frequency switching device to form a loop.
5. The LoRa communication method of the ultra-low power consumption LoRa communication system based on the single frequency oscillator is characterized in that the LoRa communication system comprises a digital processor, a single frequency oscillation circuit and a phase switching circuit, and the LoRa communication method comprises the following steps:
during communication, the digital processor generates a corresponding LoRa baseband square wave signal according to original data, and the LoRa baseband square wave signal is used as a control signal of the phase switching circuit;
the single-frequency oscillating circuit generates a single-frequency signal with stable amplitude as the input of the phase switching circuit;
and the phase switching circuit switches the phase of the single-frequency signal output by the single-frequency oscillation circuit according to the high and low levels of the LoRa baseband square wave signal and outputs the phase to an antenna.
6. The LoRa communication method of claim 5, wherein the digital processor generates corresponding LoRa baseband square wave signals from raw data, comprising:
according to a direct digital frequency synthesis (DDS) principle, a fixed Chirp Spread Spectrum (CSS) square wave sequence is obtained by utilizing Matlab calculation, the CSS square wave sequence comprises all components of a LoRa lead code, a synchronization symbol, a down-chirp and symbol data, and a complete LoRa baseband square wave signal is synthesized by intercepting different segments of the CSS square wave sequence.
7. The LoRa communication method of claim 6, wherein the digital processor generates corresponding LoRa baseband square wave signals from raw data, comprising:
obtaining N symbol values N through data scrambling, coding and interleaving0……Nn-1And calculates the total number Num of symbols to be transmittedsym＝n+13；
Calculating the address offset Addr of each symbol valueoffset[i]And the number Num of DMA bits of each symbol valueDMAbit[i]；
Addroffset[0]Load the source address of DMA and at the same time, load NumDMAbit[0]Loading a DMA counter, starting DMA transmission, and entering a low power consumption mode;
addr for the next symbol is automatically loaded immediately after each DMA transfer is completedoffset[i]And NumDMAbit[i]Until all symbols have been output.
8. The LoRa communication method as claimed in claim 7, wherein the calculating of the address offset Addr of each symbol valueoffset[i]And D of each symbol valueMA bit number NumDMAbit[i]The method comprises the following steps:
when the CSS waveform with the symbol value of N needs to be output, the current pointer is increased by P multiplied by N/2 on the basis of the base addressSFThe offset of the bit, the CSS waveform when the LoRa preamble is N ═ 0, the address offset corresponding to the down chirp is 2 × P, and the address offset of each symbol is:
where P is the number of bits required per symbol value period and SF is the spreading factor, taking into account that the down-chirp occupies 21/4For each symbol period, the number of DMA transfer bits per symbol value is:
9. the LoRa communication method according to claim 5, wherein the single frequency oscillating circuit generates the single frequency signal with a frequency foscThe central frequency of the LoRa baseband square wave signal generated by the digital processing device is fBThe output center frequency of the phase switching circuit is fLoRa＝fosc+fBLoRa signal and center frequency of fInterference＝fosc－fBThe image of (1) is the interfering LoRa signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111267411.3A CN114189254B (en) | 2021-10-29 | 2021-10-29 | Ultra-low power consumption LoRa communication system and communication method based on single-frequency oscillator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111267411.3A CN114189254B (en) | 2021-10-29 | 2021-10-29 | Ultra-low power consumption LoRa communication system and communication method based on single-frequency oscillator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114189254A true CN114189254A (en) | 2022-03-15 |
| CN114189254B CN114189254B (en) | 2024-02-23 |
Family
ID=80601639
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111267411.3A Active CN114189254B (en) | 2021-10-29 | 2021-10-29 | Ultra-low power consumption LoRa communication system and communication method based on single-frequency oscillator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114189254B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115695121A (en) * | 2022-10-08 | 2023-02-03 | 中国地质大学（武汉） | Chirp slope keying modulation-based scattering communication method and system |
| CN116436743A (en) * | 2023-04-06 | 2023-07-14 | 南京厚华通信设备有限责任公司 | Waveform coding timing synchronization recovery method in LoRa modulation |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201886763U (en) * | 2010-12-10 | 2011-06-29 | 惠州市德赛视听科技有限公司 | Intelligent household appliance control device based on blu-ray player system |
| CN109462419A (en) * | 2018-11-15 | 2019-03-12 | 中国船舶重工集团公司第七〇九研究所 | A kind of LoRa scatter communication system based on DDS direct digital synthesis technique |
| US20200052734A1 (en) * | 2016-10-18 | 2020-02-13 | University Of Washington | Backscatter systems, devices, and techniques utilizing css modulation and/or higher order harmonic cancellation |
| CN212570019U (en) * | 2020-07-20 | 2021-02-19 | 中山智联未来科技有限公司 | Ultra-low power consumption livestock body temperature monitoring system based on LoRa scattering communication |
| CN113194052A (en) * | 2021-04-01 | 2021-07-30 | 上海交通大学 | Reconfigurable radio frequency direct digital modulation communication system |
-
2021
- 2021-10-29 CN CN202111267411.3A patent/CN114189254B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201886763U (en) * | 2010-12-10 | 2011-06-29 | 惠州市德赛视听科技有限公司 | Intelligent household appliance control device based on blu-ray player system |
| US20200052734A1 (en) * | 2016-10-18 | 2020-02-13 | University Of Washington | Backscatter systems, devices, and techniques utilizing css modulation and/or higher order harmonic cancellation |
| CN109462419A (en) * | 2018-11-15 | 2019-03-12 | 中国船舶重工集团公司第七〇九研究所 | A kind of LoRa scatter communication system based on DDS direct digital synthesis technique |
| CN212570019U (en) * | 2020-07-20 | 2021-02-19 | 中山智联未来科技有限公司 | Ultra-low power consumption livestock body temperature monitoring system based on LoRa scattering communication |
| CN113194052A (en) * | 2021-04-01 | 2021-07-30 | 上海交通大学 | Reconfigurable radio frequency direct digital modulation communication system |
Non-Patent Citations (2)
| Title |
|---|
| 唐晓庆 等: "基于直接数字频率合成的远距离散射通信方法", 《电子与信息学报》 * |
| 唐晓庆 等: "基于直接数字频率合成的远距离散射通信方法", 《电子与信息学报》, 31 December 2019 (2019-12-31), pages 1 - 3 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115695121A (en) * | 2022-10-08 | 2023-02-03 | 中国地质大学（武汉） | Chirp slope keying modulation-based scattering communication method and system |
| CN115695121B (en) * | 2022-10-08 | 2024-05-31 | 中国地质大学（武汉） | Scatter communication method and system based on chirp slope keying modulation |
| CN116436743A (en) * | 2023-04-06 | 2023-07-14 | 南京厚华通信设备有限责任公司 | Waveform coding timing synchronization recovery method in LoRa modulation |
| CN116436743B (en) * | 2023-04-06 | 2023-12-05 | 南京厚华通信设备有限责任公司 | Waveform coding timing synchronization recovery method in LoRa modulation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114189254B (en) | 2024-02-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114189254B (en) | Ultra-low power consumption LoRa communication system and communication method based on single-frequency oscillator | |
| CN102201819B (en) | Frequency synthesis source applied by DDS short-wave transmitter based on CPLD design | |
| CN101572558B (en) | Intermediate frequency transceiving chip | |
| CN110488228B (en) | Linear frequency modulation signal generation method and device and storage medium | |
| JP5007891B2 (en) | Clock signal generation method and apparatus for quadrature sampling | |
| CN101847992A (en) | Frequency synthesis system for enhancing spectrum purity of direct digital frequency synthesizer | |
| CN103326718B (en) | A kind of rf chain of rubidium frequency standard | |
| CN201541235U (en) | Microwave signal source module | |
| CN201571043U (en) | Broadband frequency synthesizer with FFH and small step | |
| CN201509196U (en) | Intermediate-frequency transceiver chip | |
| CN202978895U (en) | Low phase noise frequency synthesizer | |
| CN205986861U (en) | Frequency hopping circuit is advanced in ultra wide band small step | |
| CN204439829U (en) | Multifunction radar waveform generator and multiband radar expanding system | |
| CN103439690B (en) | A kind of ultra wide band radar frequency synthesizer device | |
| CN1250259A (en) | Radio circuit apparatus and radio communication equipment | |
| CN110429942A (en) | Digital shortwave determines frequency/Frequency Hopping Communication Signal source module | |
| CN102801668B (en) | A kind of radio frequency transmitter | |
| CN203014777U (en) | Simplified frequency agility frequency synthesizer based on DDS non-linear characteristics | |
| CN102437818B (en) | Frequency synthesizer and radio frequency reader | |
| CN114172526A (en) | Ultra-low power consumption LoRa transmitter based on crystal oscillator circuit | |
| CN202696580U (en) | Double-tuned phase-locked rapid hopping source | |
| CN202720330U (en) | P-waveband frequency synthesizer with fast frequency hopping, small frequency step, low phase noise, and low spurious level | |
| CN207995069U (en) | A kind of low noise, low spurious, small stepping, fast frequency synthesizer device | |
| CN202395753U (en) | 100MHz-850MHz broadband excitation signal source | |
| CN221127316U (en) | Device for generating X-band frequency modulation continuous wave |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |