技术领域technical field
本发明属于无线射频识别(RFID)技术领域，具体涉及一种基于反向散射信号对接近目标物体的手势检测方法。The invention belongs to the technical field of radio frequency identification (RFID), and in particular relates to a gesture detection method for an approaching target object based on backscattering signals.
背景技术Background technique
现如今，手势检测为许多自动化计算系统提供了极大便利，目前主要应用于智能控制、城市安全、虚拟现实、军事化等诸多领域。在多个物体共存的环境中，如何通过手势检测识别用户接近的目标物体常常被众多研究者津津乐道。目前手势检测的主要技术有：基于图像识别，基于生物信号，基于无线信号等。Nowadays, gesture detection provides great convenience for many automated computing systems, and is currently mainly used in many fields such as intelligent control, urban security, virtual reality, and militarization. In an environment where multiple objects coexist, how to recognize the target object approached by the user through gesture detection is often talked about by many researchers. At present, the main technologies of gesture detection are: based on image recognition, based on biological signals, based on wireless signals, etc.
基于图像识别的技术，此技术前期通过相机拍摄采集一些照片或视频，并结合图像处理、模式识别等技术建立运动行为指示器，从而实现手势动作识别的目的。此技术对环境要求严格，对光线要求苛刻，最为主要的是在涉及隐私的问题中，基于图像的技术发展十分有限。基于生物信号的技术，此技术通常利用一些特殊仪器来检测识别运动，例如：利用肌电图、脑电图收集信号并与已知基础动作信号作比较，最终借助一些生物技术及信号处理技术来识别动作。此技术最明显的缺点是：需要专业设备来完成检测，通常情况下这些设备都是大型的、不可携带或携带困难的，这对很多用户来说很不方便。基于无线信号的技术，可以通过在用户手指上贴上被动式RFID标签，利用标签的运动来识别用户手指的动作变化。此技术的主要缺点是，依赖于设备器材，在识别手势动作前期可能还需要训练。Based on image recognition technology, this technology collects some photos or videos by camera in the early stage, and combines image processing, pattern recognition and other technologies to establish motion behavior indicators, so as to realize the purpose of gesture recognition. This technology has strict requirements on the environment and light. The most important thing is that in the issue of privacy, the development of image-based technology is very limited. Based on biosignal technology, this technology usually uses some special instruments to detect and identify movements, for example: use electromyography and electroencephalography to collect signals and compare them with known basic movement signals, and finally use some biotechnology and signal processing techniques to Recognize actions. The most obvious disadvantage of this technique is that it requires specialized equipment to complete the test, which is usually large, non-portable or difficult to carry, which is very inconvenient for many users. Based on wireless signal technology, passive RFID tags can be pasted on the user's fingers, and the movement of the tags can be used to identify the movement changes of the user's fingers. The main disadvantage of this technology is that it depends on equipment and equipment, and training may be required in the early stage of gesture recognition.
综上，目前通常使用的手势检测技术，如基于图像识别，基于生物信号，基于无线信号技术。要么是在某些环境中操作实施较为困难，要么设备成本较高。因此，一种无特别专业设备、准确性高、成本低、使用方便的在多个物体中对用户接近某一目标物体的手势检测识别方法的提出是非常有价值的。To sum up, the gesture detection technologies commonly used at present, such as based on image recognition, based on biological signals, based on wireless signal technology. Either it is difficult to operate and implement in some environments, or the equipment cost is high. Therefore, it is very valuable to propose a gesture detection and recognition method for a user approaching a certain target object among multiple objects without special professional equipment, high accuracy, low cost and easy to use.
发明内容Contents of the invention
为了解决现有技术中的问题，本发明提出一种基于反向散射信号对接近目标物体的手势检测方法，当手接近多个RFID标签时收集反向散射信号，被动监听阅读器和RFID标签的通信过程，通过分析评估信号的变化创造性地解决在多个贴有标签物体共存的情况下，检测确定手真正靠近的目标物体，成本低检测效率高。In order to solve the problems in the prior art, the present invention proposes a gesture detection method based on the backscatter signal to approach the target object. When the hand approaches multiple RFID tags, the backscatter signal is collected, and the interaction between the reader and the RFID tag is passively monitored. In the communication process, through the analysis and evaluation of signal changes, it creatively solves the problem of detecting and determining the target object that the hand is really close to when multiple labeled objects coexist, with low cost and high detection efficiency.
为了实现以上目的，本发明所采用的技术方案为：包括以下步骤：In order to achieve the above object, the technical solution adopted in the present invention is: comprise the following steps:
1)在有多个RFID标签共存的情况下，通过监听RFID标签与阅读器的反向散射通信过程，获取多个RFID标签的EPC信号；1) In the case of coexistence of multiple RFID tags, the EPC signals of multiple RFID tags are obtained by monitoring the backscatter communication process between the RFID tag and the reader;
2)对获取的RFID标签的EPC信号进行重新编码；2) re-encoding the EPC signal of the acquired RFID tag;
3)根据步骤2)的编码特点进行解码；3) decoding according to the encoding characteristics of step 2);
4)在步骤3)的基础上，使用RFID标签的EPC序文的一部分P1作为输入信号，并计算P1的离散系数作为度量检测标准，当手接近某一标签时，若该标签的离散系数变化最大，则该标签为手接近的目标标签。4) On the basis of step 3), use part P1of the EPC preamble of the RFID tag as the input signal, and calculate the discrete coefficientof P1 as the measurement standard. When the hand approaches a certain tag, if the discrete coefficient of the tag If the change is the largest, the label is the target label for the hand approach.
所述步骤1)中阅读器以ALOHA原理选择通信参数并控制通信进程，阅读器在其阅读范围内对RFID标签进行查询，RFID标签随机选择16位的随机数进行回复，如果阅读器只收到一个RFID标签的回复并能成功解码，将发送ACK通知RFID标签，然后RFID标签以EPC信息回复阅读器。In the step 1), the reader selects communication parameters and controls the communication process based on the ALOHA principle. The reader queries the RFID tag within its reading range, and the RFID tag randomly selects a 16-bit random number to reply. If the reader only receives An RFID tag's reply can be successfully decoded, and an ACK will be sent to notify the RFID tag, and then the RFID tag will reply to the reader with EPC information.
所述步骤1)中采用通用软件无线电外设USRP作为监听器，被动监听RFID标签和阅读器的反向散射通信过程。In the step 1), the general software radio peripheral USRP is used as a listener to passively monitor the backscatter communication process between the RFID tag and the reader.
所述步骤2)中对RFID标签的EPC信号采用米勒-4编码方式进行重新编码，一位包含四个子载波周期。In the step 2), the EPC signal of the RFID tag is re-encoded using the Miller-4 encoding method, and one bit includes four subcarrier periods.
所述步骤2)重新编码包括以下步骤：首先通过检测RFID标签的EPC信号的每个低电平下最后一个点，高低电平长度相同为0，否则为1，重新编码的0和1通过比较相邻点的间隔▽I进行区分，如果▽I＞M(M＝40)，则为1，否则为0。Described step 2) recoding comprises the following steps: first by detecting the last point of each low level of the EPC signal of the RFID tag, the length of the high and low levels is the same as 0, otherwise it is 1, and the recoded 0 and 1 are compared The interval ▽I between adjacent points is used to distinguish, if ▽I>M (M=40), then it is 1, otherwise it is 0.
所述步骤2)中在10M/s的采样率下，子载波周期的采样数总数为30，包含15个高电平点和15个低电平点。In the step 2) at a sampling rate of 10M/s, the total number of samples in the subcarrier period is 30, including 15 high-level points and 15 low-level points.
所述步骤3)中根据米勒-4编码方式进行解码，将每四个连续符号转化为1位。In the step 3), decoding is performed according to the Miller-4 coding method, and every four consecutive symbols are converted into 1 bit.
所述步骤3)中解码值根据四个连续符号中“1”的位置来决定，若四个连续符号中“1”的位置为第二位或者第三位，则解码值为1，否则为0。In said step 3), the decoded value is determined according to the position of "1" in the four consecutive symbols, if the position of "1" in the four consecutive symbols is the second or third bit, the decoded value is 1, otherwise it is 0.
所述步骤4)中P1的离散系数CV的计算公式为：CV＝σ/μ，其中，σ是标准差，μ是平均数。The calculation formulaof the dispersion coefficient CV of P1 in the step 4) is: CV=σ/μ, where σ is the standard deviation, and μ is the mean.
与现有技术相比，本发明在贴有多个标签物体共存的情况下，标签以随机顺序向阅读器回复其EPC，需要将所收集的信号与源标签能够一一联系对应，当手接近RFID标签时，会导致反向散射的射频信号产生特别明显的变化。本发明通过被动监听阅读器和RFID标签的反向散射通信过程，通过解码算法来准确区分不同标签的信号，最后通过分析RFID标签EPC序文的离散系数特征来确定用户真正要接近的目标物体，通过分析评估信号的变化创造性地解决在多个贴有标签物体共存的情况下，检测确定手真正靠近的目标物体。由于本发明中所用RFID标签属被动式标签，成本很低，因此能够在实际部署系统中，长期提供低成本高效率的检测。在本发明的检测手势的方法原理是基于分析贴有RFID标签物体的反向散射信号来完成检测，相比于现有检测技术，本发明不需要携带任何设备，对用户也没有局限性，使用十分方便。Compared with the prior art, in the present invention, when multiple tagged objects coexist, the tags reply their EPCs to the reader in a random order, and it is necessary to associate the collected signals with the source tags one by one. When using RFID tags, it will cause a particularly obvious change in the backscattered RF signal. The present invention accurately distinguishes the signals of different tags by passively monitoring the backscattering communication process between the reader and the RFID tag, and finally determines the target object that the user really wants to approach by analyzing the discrete coefficient characteristics of the EPC preamble of the RFID tag. The analysis and evaluation of signal changes creatively solves the problem of detecting and determining the target object that the hand is really close to when multiple labeled objects coexist. Since the RFID tag used in the present invention is a passive tag with very low cost, it can provide low-cost and high-efficiency detection for a long time in the actual deployment system. The principle of the method for detecting gestures in the present invention is based on analyzing the backscattering signals of objects with RFID tags to complete the detection. Compared with the existing detection technology, the present invention does not need to carry any equipment and has no limitations for users. Very convenient.
进一步，本发明与现有设备(COTS)兼容，遵从EPCglobalC1G2协议。在本发明中，阅读器和标签通过发射射频信号持续通信，USRP监听分析反向散射通信信号，通过对EPC的重新编码和解码的处理达到准确检测接近目标物体手势的目的。经大量实验论证，在本发明中多个贴有标签的物体最小间距为5cm，当间距为30cm时准确率几乎达到100％，整个发明的平均准确率为92％。Further, the present invention is compatible with existing equipment (COTS) and complies with the EPCglobalC1G2 protocol. In the present invention, the reader and the tag continuously communicate by transmitting radio frequency signals, USRP monitors and analyzes backscattered communication signals, and achieves the purpose of accurately detecting gestures close to the target object through re-encoding and decoding processing of EPC. A large number of experiments demonstrate that the minimum distance between multiple labeled objects in the present invention is 5 cm, and when the distance is 30 cm, the accuracy rate is almost 100%, and the average accuracy rate of the entire invention is 92%.
附图说明Description of drawings
图1是EPCglobal C1G2反向散射协议示意图；Figure 1 is a schematic diagram of the EPCglobal C1G2 backscatter protocol;
图2a是PIE符号图、图2b为米勒-4子载波序列图、图2c为米勒-4序文图；Figure 2a is a PIE symbol diagram, Figure 2b is a Miller-4 subcarrier sequence diagram, and Figure 2c is a Miller-4 sequence diagram;
图3是重新编码的样例图；Figure 3 is a recoded sample image;
图4是EPC解码算法流程图；Fig. 4 is the flow chart of EPC decoding algorithm;
图5是EPC解码算法示意图；Fig. 5 is a schematic diagram of an EPC decoding algorithm;
图6a是接近标签1时离散系数变化图，图6b是接近标签2时离散系数变化图。Fig. 6a is a variation diagram of the dispersion coefficient when approaching the tag 1, and Fig. 6b is a variation diagram of the dispersion coefficient when approaching the tag 2.
具体实施方式detailed description
下面结合具体的实施例和说明附图对本发明作进一步的解释说明。The present invention will be further explained below in conjunction with specific embodiments and accompanying drawings.
本发明包括以下步骤：The present invention comprises the following steps:
1)在有多个RFID标签共存的情况下，采用通用软件无线电外设USRP作为监听器，被动监听RFID标签与阅读器的反向散射通信过程，阅读器以ALOHA原理选择通信参数并控制通信进程，阅读器在其阅读范围内对RFID标签进行查询，RFID标签随机选择16位的随机数进行回复，如果阅读器只收到一个RFID标签的回复并能成功解码，将发送ACK通知RFID标签，然后RFID标签以EPC信息回复阅读器，从而获取多个RFID标签的EPC信号；1) In the case of multiple RFID tags coexisting, the general software radio peripheral USRP is used as the monitor to passively monitor the backscatter communication process between the RFID tag and the reader, and the reader selects the communication parameters and controls the communication process based on the ALOHA principle , the reader queries the RFID tag within its reading range, and the RFID tag randomly selects a 16-digit random number to reply. If the reader only receives a reply from the RFID tag and can successfully decode it, it will send an ACK to notify the RFID tag, and then The RFID tag replies to the reader with EPC information, so as to obtain the EPC signals of multiple RFID tags;
2)对获取的RFID标签的EPC信号进行重新编码，采用米勒-4编码方式进行重新编码，一位包含四个子载波周期，在10M/s的采样率下，子载波周期的采样数总数为30，包含15个高电平和15个低电平，重新编码包括以下步骤：首先通过检测RFID标签的EPC信号的每个低电平下最后一个点，高低电平长度相同为0，否则为1，重新编码的0和1通过比较相邻点的间隔▽I进行区分，如果▽I＞M(M＝40)，则为1，否则为0；2) Re-encode the EPC signal of the acquired RFID tag, and use the Miller-4 encoding method to re-encode. One bit contains four subcarrier periods. At a sampling rate of 10M/s, the total number of samples of the subcarrier period is 30, including 15 high levels and 15 low levels, recoding includes the following steps: firstly, by detecting the last point of each low level of the EPC signal of the RFID tag, the length of the high and low levels is the same as 0, otherwise it is 1 , the recoded 0 and 1 are distinguished by comparing the interval ▽I of adjacent points, if ▽I>M (M=40), then it is 1, otherwise it is 0;
3)根据步骤2)的米勒-4编码方式的编码特点进行解码，将每四个连续符号转化为1位，解码值根据四个连续符号中“1”的位置来决定，若四个连续符号中“1”的位置为第二位或者第三位，则解码值为1，否则为0；3) Decode according to the encoding characteristics of the Miller-4 encoding method in step 2), convert every four consecutive symbols into 1 bit, and the decoded value is determined according to the position of "1" in the four consecutive symbols, if four consecutive symbols If the position of "1" in the symbol is the second or third bit, the decoded value is 1, otherwise it is 0;
4)在步骤3)的基础上，使用RFID标签的EPC序文的一部分P1作为输入信号，并计算P1的离散系数作为度量检测标准，P1的离散系数CV的计算公式为：CV＝σ/μ，其中，σ是标准差，μ是平均数，当手接近某一标签时，若该标签的离散系数变化最大，则该标签为手接近的目标标签。4) On the basis of step 3), use a part P1of the EPC preamble of the RFID tag asan input signal, and calculate the dispersion coefficient of P1 as the measurement standard, and the calculation formulaof the dispersion coefficient CV of P1 is: CV=σ /μ, where σ is the standard deviation and μ is the average. When the hand approaches a certain label, if the dispersion coefficient of the label changes the most, then the label is the target label that the hand approaches.
参见图1，超高频被动RFID系统反向散射通信协议过程为：Referring to Figure 1, the UHF passive RFID system backscatter communication protocol process is:
在被动RFID通信中，标签是从阅读器发出的信号中获取能量的。EPCglobalC1G2协议是处理超高频RFID阅读器和被动标签交互的主流商业标准。阅读器以ALOHA原理选择通信参数并控制通信进程，阅读器在其阅读范围内对标签进行查询，标签随机选择16位的随机数进行回复，也就是RN16。如果阅读器只收到一个标签的回复并能成功解码，它将发送ACK通知标签。然后标签以EPC信息回复阅读器。图1显示了每个进程中信号的端点，清楚地阐明了通信过程。In passive RFID communication, the tag gets its energy from the signal sent by the reader. The EPCglobal C1G2 protocol is the mainstream commercial standard for handling the interaction between UHF RFID readers and passive tags. The reader uses the ALOHA principle to select communication parameters and control the communication process. The reader queries the tag within its reading range, and the tag randomly selects a 16-bit random number to reply, which is RN16. If the reader only receives a reply from a tag and can successfully decode it, it will send an ACK to notify the tag. The tag then replies to the reader with the EPC information. Figure 1 shows the endpoints of signals in each process, clearly illustrating the communication process.
在多个物体中对用户接近某一目标物体的手势检测方法具体步骤如下：The specific steps of the gesture detection method for the user approaching a certain target object in multiple objects are as follows:
1)通过监听RFID标签与阅读器的反向散射通信过程，首先获取多个标签的EPC信号，值得注意的是监听器只能获取信号并不能解码识别EPC信号来源于哪个标签，为此采用重新编码再解码的方式来解决这个问题；1) By monitoring the backscatter communication process between the RFID tag and the reader, first obtain the EPC signals of multiple tags. It is worth noting that the monitor can only obtain the signal and cannot decode and identify which tag the EPC signal comes from. Encoding and decoding to solve this problem;
2)重新编码：被动式RFID标签的编码方式为米勒-4，也就是一位包含四个子载波周期，如图2a～2c，在10M/s的采样率下，子载波周期的采样数是固定值，即总数为30，其中包含15个高电平，15个低电平，对标签EPC信号重新编码：重新编码通过检测每个低电平下最后一个点，高低电平长度相同为“0”，重新编码的“0”和“1”通过比较相邻点的间隔(▽I)进行区分，如果▽I＞M(M＝40)，则为“1”，否则，则为“0”，重新编码的样例如图3所示；2) Recoding: The encoding method of passive RFID tags is Miller-4, that is, one bit contains four subcarrier periods, as shown in Figure 2a~2c, at a sampling rate of 10M/s, the sampling number of subcarrier periods is fixed The value, that is, the total is 30, including 15 high levels and 15 low levels, re-encode the label EPC signal: re-encode by detecting the last point under each low level, and the length of the high and low levels is the same as "0 ", the recoded "0" and "1" are distinguished by comparing the interval (▽I) of adjacent points, if ▽I>M (M=40), then it is "1", otherwise, it is "0" , the recoded sample is shown in Figure 3;
3)解码：解码算法利用米勒-4编码的特点来设计的，其编码方式如图2a～2c，即每四个子载波周期组成1位，将四个连续符号转化为1位，如果符号“1”在四个符号的中间(第二位或者第三位)，则将这样的四个符号转化为1，否则为0，具体解码算法的流程如图4所示，其中b表示开始索引，e表示结束索引；3) Decoding: The decoding algorithm is designed using the characteristics of Miller-4 encoding. The encoding method is shown in Figure 2a~2c, that is, every four subcarrier periods form 1 bit, and four consecutive symbols are converted into 1 bit. If the symbol " 1" is in the middle of the four symbols (the second or third), then convert such four symbols into 1, otherwise it is 0, the flow of the specific decoding algorithm is shown in Figure 4, where b represents the start index, e indicates the end index;
例如将图3中序列执行解码算法，输入的符号序列为：For example, the decoding algorithm is executed for the sequence in Figure 3, and the input symbol sequence is:
S＝000000100000100100100000100001000100001，需要解码的位数L＝11，如图5所示，在A中四个符号为“0100”，即可得解码值为1，在B中四个符号为“0000”，即可得解码值为0，最终输出序列B＝01011100110，其序文P2＝010111；S=000000100000100100100000100001000100001, the number of digits to be decoded L=11, as shown in Figure 5, the four symbols in A are "0100", the decoding value can be 1, and the four symbols in B are "0000", namely The decoded value can be obtained as 0, the final output sequence B=01011100110, and its preamble P2 =010111;
4)计算离散系数：在贴有RFID标签的多个物体中，目的是找出在众多用户手真正接近的物体，在步骤3)基础上，为了保证数据独立性，使用如图2c所示的EPC序文的一部分P1作为输入信号，并计算P1的离散系数(用CV表示)作为度量检测标准，其定义为：CV＝σ/μ，其中，σ是标准差，μ是平均数，当手接近某一标签时，若该标签的离散系数变化最大，则该标签为手接近的目标标签。4) Calculation of discrete coefficients: Among the multiple objects with RFID tags, the purpose is to find out the objects that are really close to the hands of many users. On the basis of step 3), in order to ensure data independence, use the method shown in Figure 2c A part of the EPC preamble, P1 , is used as the input signal, and the dispersion coefficient of P1 (expressed in CV) is calculated as the measurement standard, which is defined as: CV=σ/μ, where σ is the standard deviation, μ is the mean number, when When the hand approaches a certain tag, if the dispersion coefficient of the tag changes the most, then the tag is the target tag of the hand approaching.
在本发明中，通过实验可知，将贴有标签的多个物体放在桌上，用手接近某一物体，目标标签的离散系数变化比其他标签大。如图6a和6b显示了离散系数作为度量标准的结果，当手接近标签1，其离散系数变化比标签2大，相反当手接近标签2，其离散系数改变较大，因此当手接近某一标签时，目标标签具有明显的离散系数变化。In the present invention, it can be known through experiments that when multiple objects with labels are placed on the table and one object is approached by hand, the variance of the dispersion coefficient of the target label is larger than that of other labels. Figures 6a and 6b show the results of the dispersion coefficient as a metric. When the hand approaches label 1, its dispersion coefficient changes more than label 2. On the contrary, when the hand approaches label 2, its dispersion coefficient changes greatly. Therefore, when the hand approaches a certain When labeling, the target label has a significant variation of the coefficient of dispersion.
综上所述，本发明在多个物体的情况下能通过离散系数的变化检测出用户接近的目标物体手势。本发明通过对EPC的重新编码，再以米勒-4编码原理为依据设计解码算法，最后借助离散系数检测确定用户真正接近的物体，其检测准确率高达92％。To sum up, in the case of multiple objects, the present invention can detect the gesture of the target object approached by the user through the change of the dispersion coefficient. The present invention re-encodes the EPC, then designs a decoding algorithm based on the Miller-4 encoding principle, and finally determines the object really approached by the user by means of discrete coefficient detection, and the detection accuracy rate is as high as 92%.
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| CN201610873092.3ACN106484109A (en) | 2016-09-30 | 2016-09-30 | A kind of gesture detecting method docking close-target object based on back-scattered signal |
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| CN201610873092.3ACN106484109A (en) | 2016-09-30 | 2016-09-30 | A kind of gesture detecting method docking close-target object based on back-scattered signal |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107135017A (en)* | 2017-04-28 | 2017-09-05 | 电子科技大学 | Backscatter communication system signal method of sending and receiving |
| CN109388927A (en)* | 2018-09-10 | 2019-02-26 | 西安交通大学 | Lightweight joint qualification method based on finger tip impedance and RFID label tag physical layer signal |
| CN113810445A (en)* | 2020-06-16 | 2021-12-17 | 香港理工大学深圳研究院 | A radio frequency identification method, radio frequency identification device and server |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701342A (en)* | 2003-08-29 | 2005-11-23 | 赛宝技术公司 | RFID system with selectable backscatter parameters |
| WO2016109046A1 (en)* | 2014-12-30 | 2016-07-07 | Google Inc. | Systems and methods of automated arming and disarming of a security system |
| CN105844756A (en)* | 2016-04-22 | 2016-08-10 | 西安交通大学 | People counting method based on radio frequency backscatter signal |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701342A (en)* | 2003-08-29 | 2005-11-23 | 赛宝技术公司 | RFID system with selectable backscatter parameters |
| WO2016109046A1 (en)* | 2014-12-30 | 2016-07-07 | Google Inc. | Systems and methods of automated arming and disarming of a security system |
| CN105844756A (en)* | 2016-04-22 | 2016-08-10 | 西安交通大学 | People counting method based on radio frequency backscatter signal |
| Title |
|---|
| HAN DING.ETL: "Device-free Detection of Approach and Departure Behaviors using Backscatter Communication", 《UBICOMP"16 PROCEEDINGS OF THE 2016 ACM INTERNATIONAL JOINT CONFERENCE ON PERVASIVE AND UBIQUITOUS COMPUTING》* |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107135017A (en)* | 2017-04-28 | 2017-09-05 | 电子科技大学 | Backscatter communication system signal method of sending and receiving |
| CN109388927A (en)* | 2018-09-10 | 2019-02-26 | 西安交通大学 | Lightweight joint qualification method based on finger tip impedance and RFID label tag physical layer signal |
| CN109388927B (en)* | 2018-09-10 | 2020-07-28 | 西安交通大学 | Lightweight joint authentication method based on fingertip impedance and RFID label physical layer signal |
| CN113810445A (en)* | 2020-06-16 | 2021-12-17 | 香港理工大学深圳研究院 | A radio frequency identification method, radio frequency identification device and server |
| CN113810445B (en)* | 2020-06-16 | 2023-06-30 | 香港理工大学深圳研究院 | Radio frequency identification method, radio frequency identification device and server |
| Publication | Publication Date | Title |
|---|---|---|
| Cheng et al. | In-air gesture interaction: Real time hand posture recognition using passive RFID tags | |
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