Low-power synchronous 5G backscatter communication method, system, device and medium

Abstract

The present invention discloses a low-power synchronous 5G backscatter communication method, system, device and medium, belonging to the field of backscatter communication, and the method comprises: step 1, a backscatter tag obtains a 5G envelope of a 5G signal of any content sent by a 5G base station, quantizes the 5G envelope to obtain envelope quantization data, detects whether the envelope quantization data has mirror symmetry based on symmetrical differential synchronization, and when it is determined to have mirror symmetry, obtains a main synchronization signal through mirror symmetry detection, and modulates data at a synchronized position according to the obtained main synchronization signal, performs backscatter transmission, and subsequent synchronization is determined by using the main synchronization signal period; step 2, a receiver receives the backscatter transmission signal and demodulates the carried data therefrom. The method can use a continuous 5G signal as a carrier, realize accurate synchronization with the carrier with low power consumption and low computing resources to correctly demodulate the tag data, and ensure the reliability of 5G backscatter transmission.

Description

Technical Field

[0001] The present invention relates to the field of backscatter communication technology, and in particular to a low-power synchronous 5G backscatter communication method, system, device and medium. Background Art

[0002] The rapid development of the Internet of Things (IoT) is expected to connect billions or even trillions of devices to the Internet, but the scale brings significant energy management challenges. Backscatter communication is emerging in the field of IoT as a solution to provide ultra-low power connectivity for small sensors. Ambient backscatter is favored because it reduces deployment cost and complexity by leveraging existing infrastructure. A typical ambient backscatter communication covers the following process: first, the ambient transmitter sends radio to provide a carrier for backscatter communication; second, the backscatter tag synchronizes with the carrier to align the frame and carry the sensing data on the carrier; finally, the receiver receives the backscatter signal to obtain the sensing data. However, traditional ambient backscattering cannot balance accessibility and high data rates. Nevertheless, 5G New Radio (NR) provides an emerging and promising solution. First, 5G provides higher data rates due to broadband. Second, 5G supports more connections due to frequency and spatial diversity. Third, 5G is more accessible due to continuous transmission.

[0003] Synchronization is an essential part of wireless transmission, because the lack of synchronization tags will randomly modulate data on the incoming carrier, increasing inter-symbol interference and reducing the achievable throughput. A large amount of literature has been devoted to designing high-precision synchronization algorithms, which usually combine autocorrelation and cross-correlation to achieve time and frequency synchronization. The reason is that autocorrelation has strong resistance to frequency offset and weak resistance to noise, while cross-correlation is the opposite. These energy-consuming algorithms are often suitable for active radios with sufficient resources, but cannot meet the needs of passive radios with limited resources. In addition, compared with high-data-rate active radios, passive radios do not require the same data rate as active radios in order to adapt to low-energy IoT application scenarios. As a result, the requirements for passive synchronization are much lower than active synchronization that reaches nanoseconds, and are often required at the microsecond level.

[0004] To save energy, backscatter radios use passive envelope detectors to extract carrier envelopes instead of IQ sample data, which compromises the ability of autocorrelation to resist frequency offset to some extent. Therefore, previous backscatter systems mainly used cross-correlation methods for signal synchronization. Unfortunately, the traditional cross-correlation method cannot achieve 5G signal synchronization under different cell IDs using a single template because there are three different primary synchronization signal (PSS) sequences. In order to accommodate 5G signals with different cell IDs, cross-correlation-based synchronization requires three predefined synchronization templates. Therefore, we naturally consider the fine timing synchronization (NFT) of 5G NR, which involves cross-correlating the received 5G signal with all three templates to identify the correlation peak and locate the PSS. The passive cross-correlation is expressed as: Where S is the received 5G envelope, t is the time delay, L is the template size (equal to the PSS size), and P(i) is the i-th PSS ( ). NFT inter-correlation requires multipliers and adders, of which is the PSS size. Next, we consider the feasibility of implementing these calculations on a typical low-power FPGA AGLN250. At a 1MHz sampling rate and a template size of 36 bits per symbol length, a 12×12 multiplier and adder require 456 and 25 D flip-flops, respectively. Therefore, NFT requires 162,387 D flip-flops, far exceeding the resource capacity of AGLN250, which has a total of 6,144 D flip-flops. As a result, although NFT achieves the desired synchronization accuracy, it consumes huge computing resources due to the pre-storage of three templates and cannot meet the low power consumption requirements of the backscatter communication system.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a low-power synchronous 5G backscatter communication method, system, device and medium, which can use continuous 5G signals as carriers, achieve precise synchronization with the carrier with low power consumption and low computing resources to correctly demodulate tag data, ensure the reliability of 5G backscatter transmission, and thus solve the above-mentioned technical problems existing in the prior art.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A low-power synchronous 5G backscatter communication method, comprising:

[0009] Step 1, the backscatter tag receives 5G signals of any content sent from the 5G base station, uses an envelope detector to obtain the envelopes of these signals, quantizes the 5G envelope to obtain envelope quantization data, detects whether the envelope quantization data has mirror symmetry based on symmetrical differential synchronization, and when it is determined to have mirror symmetry, obtains the first main synchronization signal in the envelope quantization data through mirror symmetry detection, starts modulating data at the synchronized position according to the obtained main synchronization signal, and performs backscatter transmission. For subsequent synchronization after the start of backscatter transmission, the position of the next main synchronization signal is determined by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal;

[0010] Step 2: The receiver receives the backscatter transmission signal of the backscatter tag and demodulates the carried data from the signal.

[0011] A low-power synchronous 5G backscatter communication system, used to implement the low-power synchronous 5G backscatter communication method of the present invention, comprising:

[0012] A backscatter tag and a receiver; wherein,

[0013] The backscatter tag can obtain the 5G envelope of the 5G signal of any content sent by the 5G base station, quantize the 5G envelope to obtain envelope quantization data, detect whether the envelope quantization data has mirror symmetry based on symmetrical differential synchronization, and when it is determined to have mirror symmetry, obtain the first main synchronization signal in the envelope quantization data through mirror symmetry detection, start modulating data at the synchronized position according to the obtained main synchronization signal, and perform backscatter transmission; for subsequent synchronization after the start of backscatter transmission, the position of the next main synchronization signal is determined by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal;

[0014] The receiver is in communication connection with the backscatter tag, and can receive the backscatter transmission signal of the backscatter tag and demodulate the carried data from the signal.

[0015] A processing device, comprising:

[0016] at least one memory for storing one or more programs;

[0017] At least one processor can execute one or more programs stored in the memory. When the one or more programs are executed by the processor, the processor can implement the method described in the present invention.

[0018] A readable storage medium stores a computer program, which can implement the method described in the present invention when the computer program is executed by a processor.

[0019] Compared with the prior art, the low-power synchronous 5G backscatter communication method, system, device and medium provided by the present invention have the following beneficial effects:

[0020] Since the backscatter tag uses an envelope detector to obtain the 5G signal envelope and uses a voltage comparator to quantize the envelope, the mirror symmetry of the quantized envelope data is used to detect the main synchronization signal, and the data is modulated at the synchronization position according to the obtained main synchronization signal, which can reduce the synchronization power consumption under the premise of ensuring the synchronization accuracy. Under the requirement of achieving a synchronization error lower than 8 microseconds, the sampling rate of the synchronization method of the present invention is 3.84MHz. Since the synchronization error and delay decrease with the increase of the sampling rate, the minimum synchronization error and delay are 0.01 microseconds and 0.3 microseconds, the synchronization method of the present invention has the least resource consumption, which is lower than the resource capacity of 6,144 of the low-power AGLN250, while other existing methods far exceed its resources. In particular, at the minimum sampling rate of 3.84MHz that meets the synchronization requirements, the synchronization method of the present invention requires 0 multipliers, 127 adders and 3175 D flip-flops, while the existing NFT method, SST method and SA method consume 277299 D flip-flops, 574455 D flip-flops and 95933 D flip-flops for related computing resources to meet the synchronization requirements, which are 87 times, 181 times and 30 times higher than the synchronization method using differential of the present invention. Therefore, the comprehensive performance of the synchronization method in the present invention in terms of synchronization accuracy and resource consumption is optimal. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0022] Figure 1 A flowchart of a low-power synchronous 5G backscatter communication method provided in an embodiment of the present invention.

[0023] Figure 2 An observation diagram with mirror symmetry of symbol 0 in the 5G envelope of the low-power synchronous 5G backscatter communication method provided in an embodiment of the present invention.

[0024] Figure 3 An observation diagram of symbols 1 and 3 in a 5G envelope of the low-power synchronous 5G backscatter communication method provided in an embodiment of the present invention, which do not have mirror symmetry.

[0025] Figure 4An observation diagram of symbol 2 in the 5G envelope of the low-power synchronous 5G backscatter communication method provided in an embodiment of the present invention without mirror symmetry.

[0026] Figure 5 A schematic diagram of a symmetric differential synchronization process for a low-power synchronous 5G backscatter communication method provided in an embodiment of the present invention.

[0027] Figure 6 A schematic diagram of synchronization errors at different sampling rates of a low-power synchronous 5G backscatter communication method provided in an embodiment of the present invention.

[0028] Figure 7 A schematic diagram of synchronization delay at different sampling rates for a low-power synchronous 5G backscatter communication method provided in an embodiment of the present invention.

[0029] Figure 8 A schematic diagram of the structure of a low-power synchronous 5G backscatter communication system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in combination with the specific content of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0031] First, the terms that may be used in this article are explained as follows:

[0032] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0033] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0034] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0035] Unless otherwise specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this article can be understood according to specific circumstances.

[0036] The orientation or position relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the drawings and are only for the convenience and simplification of description, and do not explicitly or implicitly indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation of this document.

[0037] The scheme provided by the present invention is described in detail below. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professionals in the field. If the specific conditions are not specified in the embodiments of the present invention, they are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturers are not specified in the reagents or instruments used in the embodiments of the present invention, they are all conventional products that can be purchased commercially.

[0038] like Figure 1 As shown, an embodiment of the present invention provides a low-power synchronous 5G backscatter communication method, including:

[0039] Step 1, the backscatter tag receives 5G signals of any content sent from the 5G base station, uses an envelope detector to obtain the envelopes of these signals, quantizes the 5G envelope to obtain envelope quantization data, detects whether the envelope quantization data has mirror symmetry based on symmetrical differential synchronization, and when it is determined to have mirror symmetry, obtains the first main synchronization signal in the envelope quantization data through mirror symmetry detection, starts modulating data at the synchronized position according to the obtained main synchronization signal, and performs backscatter transmission. For subsequent synchronization after the start of backscatter transmission, the position of the next main synchronization signal is determined by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal;

[0040] Step 2: The receiver receives the backscatter transmission signal of the backscatter tag and demodulates the carried data from the signal.

[0041] Preferably, in step 1 of the above method, when it is determined that there is mirror symmetry, the first main synchronization signal is obtained by mirror symmetry detection in the following manner, including:

[0042] When detecting the main synchronization signal for the first time, after receiving the envelope quantization data obtained by quantizing the 5G envelope, the first main synchronization signal is detected by finding the minimum value of the differential sum based on symmetric differential synchronization within a sliding window of the main synchronization signal length.

[0043] See also Figure 5 Preferably, in the above method, the backscatter tag obtains the first main synchronization signal by symmetric differential synchronization detection within a sliding window of the main synchronization signal length in the following manner, including:

[0044] According to the following formula (1), the two envelope amplitudes in the sliding window are subtracted, the absolute value is taken, and the sum is accumulated to obtain: , formula (1) is:

[0045] (1);

[0046] In the above formula (1), the meanings of the parameters are as follows: t is the center time of the sliding window; n represents the sampling point n away from the center time of the sliding window; is the length of the primary synchronization signal; S() is the 5G envelope of the received 5G signal;

[0047] By finding formula (1) Minimum value of To detect the first main synchronization signal.

[0048] Preferably, in step 1 of the above method, the position of the next main synchronization signal is determined by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal in the following manner, including:

[0049] The previous main synchronization signal detected is added with the number of cycles of the main synchronization signal to obtain the next main synchronization signal.

[0050] See also Figure 8 The embodiment of the present invention further provides a low-power synchronous 5G backscatter communication system, which is used to implement the above-mentioned low-power synchronous 5G backscatter communication method, including:

[0051] A backscatter tag and a receiver; wherein,

[0052] The backscatter tag can obtain the 5G envelope of the 5G signal of any content sent by the 5G base station, quantize the 5G envelope to obtain envelope quantization data, detect whether the envelope quantization data has mirror symmetry based on symmetrical differential synchronization, and when it is determined to have mirror symmetry, obtain the first main synchronization signal in the envelope quantization data through mirror symmetry detection, start modulating data at the synchronized position according to the obtained main synchronization signal, and perform backscatter transmission; for subsequent synchronization after the start of backscatter transmission, the position of the next main synchronization signal is determined by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal;

[0053] The receiver is in communication connection with the backscatter tag, and can receive the backscatter transmission signal of the backscatter tag and demodulate the carried data from the signal.

[0054] Preferably, in the above system, when the backscatter tag is determined to have mirror symmetry, the first main synchronization signal is obtained by mirror symmetry detection in the following manner, including:

[0055] When detecting the main synchronization signal for the first time, after receiving the envelope quantization data obtained by quantizing the 5G envelope, the first main synchronization signal is detected by finding the minimum value of the differential sum based on symmetric differential synchronization within a sliding window of the main synchronization signal length.

[0056] Preferably, in the above system, the backscatter tag obtains the first primary synchronization signal by symmetric differential synchronization detection within a sliding window of the primary synchronization signal length in the following manner, including:

[0057] According to the following formula (1), the two envelope amplitudes in the sliding window are subtracted, the absolute value is taken, and the sum is accumulated to obtain: , formula (1) is:

[0058] (1);

[0059] In the above formula (1), the meanings of the parameters are as follows: t is the center time of the sliding window; n represents the sampling point n away from the center time of the sliding window; is the length of the primary synchronization signal; S() is the 5G envelope of the received 5G signal;

[0060] By finding formula (1) Minimum value of To detect the first main synchronization signal.

[0061] Preferably, in the above system, the backscatter tag determines the position of the next main synchronization signal by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal in the following manner, including:

[0062] The previous main synchronization signal detected is added with the number of cycles of the main synchronization signal to obtain the next main synchronization signal.

[0063] The embodiment of the present invention further provides a processing device, comprising:

[0064] at least one memory for storing one or more programs;

[0065] At least one processor can execute one or more programs stored in the memory, and when the one or more programs are executed by the processor, the processor can implement the above method.

[0066] The embodiments of the present invention further provide a readable storage medium storing a computer program, which can implement the above method when the computer program is executed by a processor.

[0067] The synchronization method of the present invention can be called SD+: differential is used for the first PSS detection and PSS periodicity is used for subsequent PSS detection. Other existing synchronization methods include the following: 1) NFT: a synchronization method in which three PSS cross-correlations are used for PSS detection; 2) SST: autocorrelation is used for symmetry determination and three half PSS cross-correlations are used for PSS detection synchronization; 3) SA: autocorrelation is used for PSS detection synchronization; 4) SD method for the first detection of the present invention: differential is used for PSS detection; 5) SD+: differential is used for the first PSS detection and PSS periodicity is used for subsequent PSS detection, that is, the synchronization method of the present invention.

[0068] (1) Synchronization accuracy and delay:

[0069] like Figure 6 , Figure 7As shown in the figure, the synchronization errors and delays of NFT, SST, SA and SD at different sampling rates are evaluated. First, it can be seen that the minimum sampling rates required for different methods to achieve synchronization requirements are different. In order to achieve a synchronization error below 8 microseconds, the minimum sampling rates required for NFT, SST, SA and SD are 1.92MHz, 7.68MHz, 3.84MHz and 3.84MHz respectively. The reason for the different minimum sampling rates is that NFT has the longest template, the best performance, and the lowest required sampling rate; while SST has a poor autocorrelation effect for determining symmetry at low sampling rates. When the symmetric position found is delayed, the synchronization result of the cross-correlation will be further deteriorated, resulting in the highest sampling rate. In addition, it can be observed that for all synchronization methods, the synchronization error and delay decrease with the increase of sampling rate, and the minimum synchronization error and delay are 0.01 microseconds and 0.3 microseconds.

[0070] (2) Resource consumption:

[0071] The resource consumption of these synchronization methods at different sampling rates was evaluated. As shown in Table 1, it can be seen that the SD method has the least resource consumption, which is lower than the resource capacity of the low-power AGLN250 of 6,144, while other methods far exceed its resources. In particular, at the minimum sampling rate of 3.84MHz that meets the synchronization requirements, SD requires 0 multipliers, 127 adders, and 3175 D flip-flops, while the NFT, SST, and SA methods consume 277299 D flip-flops, 574455 D flip-flops, and 95933 D flip-flops for related computing resources to meet the synchronization requirements, which are 87 times, 181 times, and 30 times higher than the SD method using differential in the present invention.

[0072] Table 1 shows the synchronization resource consumption at different sampling rates

[0073]

[0074] From the above, it can be seen that the NFT method performs cross-correlation with three types of PSS respectively to detect PSS, and the cross-correlation involves a large number of multiplication operations, which consumes a lot of computing resources. SST uses the mirror symmetry of the PSS envelope, first uses autocorrelation to determine the symmetry to reduce the number of cross-correlation executions, and then determines the symmetric position and performs cross-correlation with half of the PSS to halve the template length. Although the computing resource consumption of SST is significantly reduced compared to NFT, it still exceeds the resource capacity of the low-power AGLN250. SA observes that the PSS envelope has a unique mirror image, and only takes the autocorrelation of SST to detect PSS by judging whether the envelope has mirror symmetry. However, the resource consumption of the multiplier is much greater than that of the adder. The present invention proposes that SD uses the envelope equality of the mirror symmetric position to convert multiplication into addition, and uses differential detection of PSS. As a result, SD greatly reduces resource consumption and meets the requirements of low-power synchronization. The present invention uses differential SD and SD+ to achieve the best comprehensive performance in terms of synchronization accuracy and resource consumption.

[0075] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the solution provided by the embodiment of the present invention is described in detail with specific embodiments below.

[0076] Embodiment 1:

[0077] like Figure 1 As shown, the present invention proposes a 5G network backscatter communication method based on low-power synchronization. In the 5G envelope, the primary synchronization signal (PSS) is the only mirror-symmetric one. 5G uses a synchronization signal block (SSB) for downlink synchronization. Its symbol 0 only contains PSS, and symbols 1 and 3 are composed of a physical broadcast channel (PBCH). The PBCH carries a master information block (MIB) that changes. Symbol 2 is composed of PBCH and a secondary synchronization signal (SSS), which also changes. Figures 2 to 4 The envelopes of different SSB symbols are shown, and it can be found that only symbol 0 has mirror symmetry, which means that the PSS envelope has unique symmetry. Therefore, by using this feature, the PSS can be detected by finding the mirror symmetry position. Although this method lacks noise-resistant cross-correlation and is difficult to support low signal-to-noise ratio (SNR) application scenarios, it provides the possibility for low-power synchronization.

[0078] The synchronization methods include the following: 1) NFT: three PSS cross-correlations are used for PSS detection; 2) SST: autocorrelation is used for symmetry determination and three half PSS cross-correlations are used for PSS detection; 3) SA: autocorrelation is used for PSS detection; 4) SD: differential is used for PSS detection, which is the method of the first synchronous detection of PSS in the present invention; 5) SD+: differential is used for the first PSS detection and PSS periodicity is used for subsequent PSS detection, which is the synchronization method of the present invention.

[0079] Among them, the simple method is to use autocorrelation to find the symmetric position and locate the center of the PSS, which can be called symmetry-based autocorrelation synchronization (SA). Autocorrelation consumes only one-third of the resources required for cross-correlation with half of the PSS because it only correlates with the symmetric position without the need for three templates. The autocorrelation calculation resources of SA depend on the size of the sliding window, which is fixed to the size of one PSS. The only way to reduce the window size is to reduce the sampling rate. Therefore, when the sampling rate is 1MHz, the window size corresponds to a 36-bit PSS size, which consumes 55 multipliers, 87 adders, and 27255 D flip-flops, which still exceeds the resource capacity of AGLN250. However, SA requires a minimum sampling rate of at least greater than 1 MHz to meet the required accuracy requirements, which means that it consumes even more resources. The main reason is that the multipliers consume far more resources than the adders, about 18 times the latter.

[0080] To this end, the key idea is to convert the multiplier into an adder to reduce the consumption of computing resources. The 5G NR PSS is complex conjugate symmetric, that is, . so, , This characteristic can be used to convert multiplication into addition and subtraction, so the present invention proposes differential synchronization (SD) based on symmetry. Figure 3 As shown in FIG. 1 , this method subtracts the absolute values ​​of the two envelope amplitudes in the sliding window symmetric to obtain the sum of the two envelope amplitudes in the sliding window of the length of a PSS, and then adds them up, which is expressed as:

[0081] (1),

[0082] Where t is the window center time. In the ideal noise-free case, when If it is equal to 0, it means that PSS is detected. However, due to the existence of noise, is approximately equal to 0. As a result, cannot be exactly 0. Therefore, by finding Minimum value of To detect PSS. According to equation (1), SD consumes 0 multipliers and adders, which only requires 875 D flip-flops, which is less than the total resource capacity of AGLN250.

[0083] The SD method has met the requirement of low computational resource consumption, but its total computational cost is high because it increases linearly with the number of samples, which is equal to , where N is the number of samples. For example, when the tag samples the 5G signal at 5 MHz, and a PSS period is at least 5 ms, when the total time consumption is exactly 10 PSS periods, the number of samples N=250000, =167, resulting in a total computational effort of SD of 4.15×10^7, which is very high. To this end, the present invention proposes using differentials for the first PSS detection and PSS periodicity for subsequent PSS detection, i.e., SD+, which still uses the differentials of SD for the first PSS detection. After determining the first PSS, the PSS periodicity is used to determine the subsequent PSS by adding integer multiples of the PSS period. SD+ only requires differentials for the first PSS detection, greatly reducing the total computational effort to approximately 1 / N to 25,000 / N of SD.

[0084] In summary, the effects of the method in the embodiment of the present invention and other methods are compared as follows:

[0085] (1) Synchronization accuracy and delay:

[0086] Figure 5 The synchronization errors and delays of NFT, SST, SA and SD at different sampling rates are evaluated. First, we can see that the minimum sampling rates required to achieve synchronization are different for different methods. To achieve a synchronization error below 8 microseconds, the minimum sampling rates required for NFT, SST, SA and SD are 1.92MHz, 7.68MHz, 3.84MHz and 3.84MHz respectively. The reason for the different minimum sampling rates is that NFT has the longest template, the best performance and the lowest sampling rate; while SST has a poor autocorrelation effect for determining symmetry at low sampling rates. When the symmetry position is found to be delayed, it will further deteriorate the synchronization result of the cross-correlation, resulting in the highest sampling rate. In addition, we observe that for all synchronization methods, the synchronization error and delay decrease with the increase of sampling rate, and the minimum synchronization error and delay are 0.01 microseconds and 0.3 microseconds.

[0087] (2) Resource consumption:

[0088] We also evaluate the resource consumption of these synchronizations at different sampling rates. As shown in Table 1 above, it is observed that SD has the least resource consumption, which is lower than the resource capacity of the low-power AGLN250 by 6,144, while other methods far exceed its resources. In particular, at the minimum sampling rate of 3.84 MHz to meet the synchronization requirements, SD requires 0 multipliers, 127 adders, and 3,175 D flip-flops, while NFT, SST, and SA consume 277, 299, 574, 455, and 95,933 D flip-flops for related computational resources to meet the synchronization requirements, which are 87, 181, and 30 times higher than SD using differential.

[0089] In summary, the differential SD and SD+ methods of the present invention have the best comprehensive performance in terms of synchronization accuracy and resource consumption.

[0090] Embodiment 2:

[0091] This embodiment provides a low-power synchronous 5G network backscatter communication system, which is used to implement the backscatter communication method of embodiment 1. The system includes:

[0092] A backscatter tag and a receiver; wherein,

[0093] The backscatter tag sends a 5G signal of any content based on a 5G base station. The backscatter tag first uses an envelope detector to obtain a high-quality 5G envelope, then quantizes the envelope through a voltage comparator, and transmits the quantized data to the FPGA of the backscatter tag. The FPGA runs a symmetric differential synchronization and periodic detection synchronization algorithm, first using differential technology to determine whether the envelope has mirror symmetry. When the symmetry is determined, it indicates that the PSS is detected. Then, the tag starts modulating data at the synchronized position and performs backscatter transmission. Finally, the receiver demodulates the tag data, and subsequent synchronization is determined by the periodicity of the PSS. This system can achieve low-power synchronization and reduce the power consumption and computing resources of the 5G network backscatter communication system.

[0094] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0095] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A low-power synchronous 5G backscatter communication method, characterized in that: include: Step 1, the backscatter tag receives 5G signals of any content sent from the 5G base station, uses an envelope detector to obtain the envelopes of these signals, quantizes the 5G envelope to obtain envelope quantization data, detects whether the envelope quantization data has mirror symmetry based on symmetrical differential synchronization, and when it is determined to have mirror symmetry, obtains the first main synchronization signal in the envelope quantization data through mirror symmetry detection, starts modulating data at the synchronized position according to the obtained main synchronization signal, and performs backscatter transmission. For subsequent synchronization after the start of backscatter transmission, the position of the next main synchronization signal is determined by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal; Step 2: The receiver receives the backscatter transmission signal of the backscatter tag and demodulates the carried data from the signal.

2. The low-power synchronous 5G backscatter communication method according to claim 1, characterized in that: In the step 1, when it is determined that there is mirror symmetry, a first main synchronization signal is obtained by mirror symmetry detection in the following manner, including: When detecting the main synchronization signal for the first time, after receiving the envelope quantization data obtained by quantizing the 5G envelope, the first main synchronization signal is detected by finding the minimum value of the differential sum based on symmetric differential synchronization within a sliding window of the main synchronization signal length.

3. The low-power synchronous 5G backscatter communication method according to claim 2, characterized in that: The backscatter tag obtains a first primary synchronization signal by symmetric differential synchronization detection within a sliding window of a primary synchronization signal length in the following manner, including: According to the following formula (1), the two envelope amplitudes in the sliding window are subtracted, the absolute value is taken, and the sum is accumulated to obtain: , formula (1) is: （1）； In the above formula (1), the meanings of the parameters are as follows: t is the center time of the sliding window; n represents the sampling point n away from the center time of the sliding window; is the length of the primary synchronization signal; S() is the 5G envelope of the received 5G signal; By finding formula (1) Minimum value of To detect the first main synchronization signal.

4. The low-power synchronous 5G backscatter communication method according to any one of claims 1 to 3, characterized in that: In step 1, the position of the next main synchronization signal is determined by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal in the following manner, including: The previous main synchronization signal detected is added with the number of cycles of the main synchronization signal to obtain the next main synchronization signal.

5. A low-power synchronous 5G backscatter communication system, characterized in that: A 5G backscatter communication method for implementing low-power synchronization according to any one of claims 1 to 4, comprising: A backscatter tag and a receiver; wherein, The backscatter tag can obtain the 5G envelope of the 5G signal of any content sent by the 5G base station, quantize the 5G envelope to obtain envelope quantization data, detect whether the envelope quantization data has mirror symmetry based on symmetrical differential synchronization, and when it is determined to have mirror symmetry, obtain the first main synchronization signal in the envelope quantization data through mirror symmetry detection, start modulating data at the synchronized position according to the obtained main synchronization signal, and perform backscatter transmission; for subsequent synchronization after the start of backscatter transmission, the position of the next main synchronization signal is determined by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal; The receiver is in communication connection with the backscatter tag, and can receive the backscatter transmission signal of the backscatter tag and demodulate the carried data from the signal.

6. The low-power synchronous 5G backscatter communication system according to claim 5, characterized in that: When the backscatter tag is determined to have mirror symmetry, the first primary synchronization signal is obtained by mirror symmetry detection in the following manner, including: When detecting the main synchronization signal for the first time, after receiving the envelope quantization data obtained by quantizing the 5G envelope, the first main synchronization signal is detected by finding the minimum value of the differential sum based on symmetric differential synchronization within a sliding window of the main synchronization signal length.

7. The low-power synchronous 5G backscatter communication system according to claim 6, characterized in that: The backscatter tag obtains a first primary synchronization signal by symmetric differential synchronization detection within a sliding window of a primary synchronization signal length in the following manner, including: According to the following formula (1), the two envelope amplitudes in the sliding window are subtracted, the absolute value is taken, and the sum is accumulated to obtain: , formula (1) is: （1）； In the above formula (1), the meanings of the parameters are as follows: t is the center time of the sliding window; n represents the sampling point n away from the center time of the sliding window; is the length of the primary synchronization signal; S() is the 5G envelope of the received 5G signal; By finding formula (1) Minimum value of To detect the first main synchronization signal.

8. The low-power synchronous 5G backscatter communication system according to claim 6, characterized in that: The backscatter tag determines the position of the next main synchronization signal by counting based on the position of the previous main synchronization signal using the periodicity of the main synchronization signal in the following manner, including: The previous main synchronization signal detected is added with the number of cycles of the main synchronization signal to obtain the next main synchronization signal.

9. A processing device, characterized in that: include: at least one memory for storing one or more programs; At least one processor is capable of executing one or more programs stored in the memory, and when the one or more programs are executed by the processor, the processor is capable of implementing the method described in any one of claims 1 to 4.

10. A readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 can be implemented.

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