CN109756251B - Environment backscattering communication system based on frequency control array radio frequency source and communication method thereof - Google Patents
Environment backscattering communication system based on frequency control array radio frequency source and communication method thereof Download PDFInfo
- Publication number
- CN109756251B CN109756251B CN201910055676.3A CN201910055676A CN109756251B CN 109756251 B CN109756251 B CN 109756251B CN 201910055676 A CN201910055676 A CN 201910055676A CN 109756251 B CN109756251 B CN 109756251B
- Authority
- CN
- China
- Prior art keywords
- radio frequency
- reader
- array
- label
- signal
- 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.)
- Expired - Fee Related
Links
Images
Abstract
The invention discloses an environment backscattering communication system based on a frequency control array radio frequency source and a communication method thereof, wherein the system adopts the frequency control array radio frequency source to send signals to realize environment backscattering communication, namely, a tag utilizes the existing frequency control array signals in the air to communicate with a reader, the maximum mutual information of tag symbols and received signals is utilized to obtain channel capacity, and the detection performance of the environment backscattering communication system is determined by a differential detection method. Compared with the traditional environment backscattering communication, the frequency control array radio frequency source replaces a phased array radio frequency source, and the characteristics of distance-angle-time dependent wave beams of the frequency control array are fully utilized, so that the purposes of improving the transmission rate of the tag and the reader and improving the error rate performance are achieved. Under the condition of the same number of antennas as the phased array, the method obtains larger channel capacity and smaller system error rate, has better detection performance, and provides technical support for future development and application popularization of the internet of things.
Description
Technical Field
The invention belongs to the technical field of communication of the Internet of things, and particularly relates to an environment backscattering communication system based on a frequency control array radio frequency source and a communication method thereof.
Background
The technology of the internet of things is one of the key technologies of the 5G communication system, wherein the energy problem is a great challenge of the technology of the internet of things. For some devices with expensive battery replacement and complex maintenance operations, energy harvesting is an ideal way to maintain the device working properly for a long period of time. The backscattering technology is an energy collection technology, but the traditional backscattering technology is limited by short communication distance and needs a special radio frequency signal source, and the problem is solved by a novel backscattering technology, namely an environmental backscattering (ambienterbackscatter) technology. The environment backscattering technology is that a tag/sensor utilizes wireless radio frequency signals existing in the environment, such as mobile phone signals, television broadcast signals, WiFi signals and the like, as carrier frequency signals for modulating own information, a special carrier wave generator is not needed, the function of communication with a reader/receiving end is realized, and the 'green Internet of things' is facilitated to be realized. The basic communication principle of the environmental backscattering technology is as follows: the tag represents two states of '0' and '1' by not reflecting and reflecting the received wireless signal; the reader/receiving end adopts a corresponding signal processing mode to further detect the two states according to the difference and the characteristics of the received signals under the two conditions of the reflected signals and the non-reflected signals. At present, research on environmental backscatter communication mainly focuses on the design of a receiver and a reflector prototype, and known detection methods mainly include differential detection, average power detection and detection by using the cyclic prefix characteristic of an OFDM signal, so that channel estimation can be avoided, but the transmission rate is low and the error rate is high.
Radio frequency signals existing in the environment are various, and radio frequency signals in a traditional environment backscatter communication system are common-frequency signals transmitted by an omnidirectional antenna, and comprise a single-antenna radio frequency source or a multi-antenna phase array radio frequency source. The signal detection performance can be improved to a certain extent by utilizing the phased array radio frequency source, but the phased array cannot realize the energy focusing of wireless signals on the distance dimension. The frequency control array applies different frequency offsets to different array elements at the same time to transmit coherent signals, so that the frequency of signals transmitted by each antenna array element is different, and distance-dependent beams can be provided. Because of the distance-angle-time dependency, frequency-controlled array beams have attracted attention in the fields of radar, secure communication and the like. Therefore, in order to further improve the channel capacity and the detection performance, an environment backscattering communication system based on a frequency control array radio frequency signal source and a communication method thereof are provided.
Disclosure of Invention
Aiming at the defects in the prior art, the environment backscattering communication system based on the frequency control array radio frequency source and the communication method thereof solve the problems of small channel capacity and low detection performance in the traditional environment backscattering communication system.
In order to achieve the purpose of the invention, the invention adopts the technical scheme that: an environment backscattering communication system based on a frequency control array radio frequency source comprises the frequency control array radio frequency source, a tag and a reader;
the frequency control array radio frequency source comprises a plurality of array elements, each array element is connected with a tag and a reader, and the tags are further connected with the readers.
Furthermore, the frequency control array radio frequency source is used for transmitting radio frequency signals to the label and the reader;
the label modulates the label symbol to the received radio frequency signal to generate a reflection link signal and forwards the reflection link signal to the reader;
the reader recovers the label symbol from the received signal and determines the detection performance parameters of the environment backscattering communication system;
the reader receives a signal transmitted by a frequency control array radio frequency source, wherein the signal is a direct link signal;
the signal transmitted by the tag received by the reader is a reflected link signal.
Further, the tag is a single antenna tag; the reader is a single antenna reader.
Furthermore, the detection performance parameters of the environment backscatter communication system include mutual information quantity between the tag and the reader, channel capacity between the tag and the reader, and error rate;
wherein, the mutual information quantity I (a) between the label and the readerm；rk) Comprises the following steps:
in the formula, amFor label sendingThe mth tag symbol of (1);
rka signal received for a reader;
pisending the probability that the label symbol is 0 or 1 for the label, and i is 0, 1;
l is rkThe number of interval blocks of the probability density function of (1);
p(rk,li) when label symbol i is sent by label, signal rkThe probability represented by the l-th interval;
log2(. cndot.) represents the base 2 logarithm;
the channel capacity C between the tag and the reader is:
in the formula, max (·) is a maximum operation sign;
bit error rate Pb-minComprises the following steps:
in the formula, ThAn optimal threshold value for the ambient backscatter system;
q (-) is a functional symbol, and
t is the integration time constant.
A communication method of an environment backscattering communication system based on a frequency control array radio frequency source comprises the following steps:
s1, configuring array element parameters of a frequency control array radio frequency source, further determining the initial phase of the radio frequency signal transmitted by each array element, and transmitting the radio frequency signal to the tag and the reader through the array elements;
s2, receiving radio frequency signals emitted by a frequency control array radio frequency source through a label, modulating label symbols into the received radio frequency signals through a differential coding modulation method, generating reflection link signals and forwarding the reflection link signals to a reader;
and S3, recovering the label symbol by a differential detection method according to the signal received by the reader, and realizing the environmental backscatter communication.
Further, in step S1, the array element parameters of the frequency-controlled array rf source include an array element number N, an array element spacing d, and a carrier frequency f of a reference array element0And its frequency offset Δ f;
initial phase phi n of radio frequency signal transmitted by each array element0Comprises the following steps:
in the formula, R1nIs the distance from the nth array element in the frequency control array radio frequency source to the reader, and R1n＝R1-(n-1)dcosθ1，n＝1,2,...,N，R1The distance between a reference array element in a frequency control array radio frequency source and a reader is obtained;
θ1the azimuth angle from a reference array element in a frequency control array radio frequency source to a reader is obtained;
and c is the speed of light.
Further, in step S2, when the frequency-controlled array rf source transmits the kth rf signal, the reflected link signal c generated by the tag is generatedk'(θ2,R2(ii) a t) is:
in the formula, theta2The azimuth angle from a reference array element to a label in a frequency control array radio frequency source is obtained;
R2the distance between a reference array element in a frequency control array radio frequency source and a label is obtained;
t is time;
Pstransmitting the transmission power of a radio frequency signal for an array element of a frequency control array radio frequency source;
α is the attenuation coefficient of the label;
g is the channel coefficient of the label and the reader;
amthe mth tag symbol transmitted for the tag;
xkthe symbol of the kth radio frequency signal transmitted by each array element in the frequency control array radio frequency source is shown, wherein K is 1,2, and K is the number of the symbols of the radio frequency signal transmitted by the frequency control array radio frequency source;
e(·)is an exponential function with natural numbers as the base;
j is an imaginary unit;
h2nchannel coefficients from the nth array element to the tag in the frequency controlled array radio frequency source are set, wherein N is 1, 2.
R2nIs the distance from the nth array element to the label in the frequency control array radio frequency source, and R2n＝R2-(n-1)dcosθ2Wherein N is 1, 2.
Further, the signals received by the reader in the step S3 include a direct link signal, a reflected link signal and a noise signal;
when the frequency control array radio frequency source transmits the kth radio frequency signal, the signal r received by the readerkComprises the following steps:
in the formula, h1nA channel coefficient from an nth array element in a frequency control array radio frequency source to a reader is obtained, and N is 1, 2.
G is a reflection coefficient, and
nk(n) white noise subject to a gaussian distribution;
further, the method for recovering the tag symbol by the differential detection method in step S3 specifically includes:
s31, determining the statistical test quantity phi of the signal received by the readerm；
S32, determining the optimal threshold T when the environmental backscattering communication system detects the signalh；
S33, determining | Φm|>ThWhether the result is true or not;
if yes, the mth tag symbol received by the reader is '1';
if not, the mth tag symbol received by the reader is "0". The invention has the beneficial effects that: the invention adopts the frequency control array radio frequency source to send signals to realize the environment backscattering communication, namely, the label utilizes the existing frequency control array signals in the air to communicate with the reader, the maximum mutual information of label symbols and received signals is utilized to obtain the channel capacity, and the detection performance of the environment backscattering communication system is determined by a differential detection method. Compared with the traditional environment backscattering communication, the frequency control array radio frequency source replaces a phased array radio frequency source, and the characteristics of distance-angle-time dependent wave beams of the frequency control array are fully utilized, so that the purposes of improving the transmission rate of the tag and the reader and improving the error rate performance are achieved. Under the condition of the same number of antennas as the phased array, the method obtains larger channel capacity and smaller system error rate, has better detection performance, and provides technical support for future development and application popularization of the internet of things.
Drawings
Fig. 1 is a structural diagram of an environmental backscatter communication system based on a frequency-controlled array radio frequency source according to the present invention.
Fig. 2 is a flow chart of a communication method of the environmental backscatter communication system based on the frequency-controlled array radio frequency source according to the present invention.
Fig. 3 is a schematic diagram illustrating a comparison of channel capacities of a communication system when a frequency control array signal is used as an rf source and a phased array signal is used as an rf source in an embodiment of the present invention.
Fig. 4 is a schematic diagram illustrating a comparison of error rate curves of a communication system when a frequency control array signal is used as an rf source and a phased array signal is used as an rf source in an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.
As shown in fig. 1, an environment backscatter communication system based on a frequency controlled array radio frequency source includes a frequency controlled array radio frequency source, a tag and a reader;
the frequency control array radio frequency source comprises a plurality of array elements, each array element is connected with a tag and a reader, and the tag is also connected with the reader; wherein the tag is a single antenna tag; the reader is a single antenna reader.
The frequency control array radio frequency source is used for transmitting radio frequency signals and sending the radio frequency signals to the tag and the reader;
the label modulates the label symbol to the received radio frequency signal to generate a reflection link signal and forwards the reflection link signal to the reader;
the reader recovers the label symbol from the received signal and determines the detection performance parameters of the environment backscattering communication system;
the reader receives a signal transmitted by a frequency control array radio frequency source, wherein the signal is a direct link signal;
the signal transmitted by the tag received by the reader is a reflected link signal.
As shown in fig. 2, the present invention further provides a communication method of an environmental backscatter communication system based on a frequency-controlled array radio frequency source, including the following steps:
s1, configuring array element parameters of a frequency control array radio frequency source, further determining the initial phase of the radio frequency signal transmitted by each array element, and transmitting the radio frequency signal to the tag and the reader through the array elements;
s2, receiving radio frequency signals emitted by a frequency control array radio frequency source through a label, modulating label symbols into the received radio frequency signals through a differential coding modulation method, generating reflection link signals and forwarding the reflection link signals to a reader;
and S3, recovering the label symbol by a differential detection method according to the signal received by the reader, and realizing the environmental backscatter communication.
In the step S1, the array element parameters of the frequency-controlled array rf source include an array element number N, an array element spacing d, and a carrier frequency f of a reference array element0And its frequency offset Δ f;
initial phase phi of radio frequency signal transmitted by each array elementn0Comprises the following steps:
in the formula, R1nIs the distance from the nth array element in the frequency control array radio frequency source to the reader, and R1n＝R1-(n-1)dcosθ1，n＝1,2,...,N，R1The distance between a reference array element in a frequency control array radio frequency source and a reader is obtained;
θ1the azimuth angle from a reference array element in a frequency control array radio frequency source to a reader is obtained;
and c is the speed of light.
In step S2, when the frequency-controlled array rf source transmits the kth rf signal, the reflected link signal c generated by the tagk'(θ2,R2(ii) a t) is:
in the formula, theta2The azimuth angle from a reference array element to a label in a frequency control array radio frequency source is obtained;
R2the distance between a reference array element in a frequency control array radio frequency source and a label is obtained;
t is time;
Pstransmission of RF signals for array elements of a frequency-controlled array RF sourcePower;
α is the attenuation coefficient of the label;
g is the channel coefficient of the label and the reader;
amthe mth tag symbol transmitted for the tag;
xkthe symbol of the kth radio frequency signal transmitted by each array element in the frequency control array radio frequency source is shown, wherein K is 1,2, and K is the number of the symbols of the radio frequency signal transmitted by the frequency control array radio frequency source;
e(·)is an exponential function with natural numbers as the base;
j is an imaginary unit;
h2nchannel coefficients from the nth array element to the tag in the frequency controlled array radio frequency source are set, wherein N is 1, 2.
R2nIs the distance from the nth array element to the label in the frequency control array radio frequency source, and R2n＝R2-(n-1)dcosθ2Wherein N is 1, 2.
The signals received by the reader in the step S3 include direct link signals, reflected link signals and noise signals;
when the frequency control array radio frequency source transmits the kth radio frequency signal, the signal r received by the readerkComprises the following steps:
in the formula, h1nA channel coefficient from an nth array element in a frequency control array radio frequency source to a reader is obtained, and N is 1, 2.
G is a reflection coefficient, and
nk(n) white noise subject to a gaussian distribution;
the method for recovering the tag symbol by the differential detection method in step S3 includes:
s31, determining the statistical test quantity phi of the signal received by the readerm；
Transmitting K x at array element of frequency control array radio frequency sourcekDuring the symbol time, the tags all transmit tag symbols amConstructing a statistical test quantity phimComprises the following steps:
Φm＝m-m-1
wherein the content of the first and second substances,mis the average power of the signal received by the reader, and
| is an operator for solving an absolute value;
s32, determining the optimal threshold T when the environmental backscattering communication system detects the signalh；
Obtaining the optimal threshold value T of the environmental backscattering system according to the statistical test quantity and the minimum bit error rate criterionhComprises the following steps:
in the formula, mu0,
Are respectively amWhen equal to 0mMean and variance of the distribution;
μ1,
is amWhen 1 is truemMean and variance of distribution；
S33, determining | Φm|>ThWhether the result is true or not;
if yes, the mth tag symbol received by the reader is '1';
if not, the mth tag symbol received by the reader is "0".
In the invention, after the reader recovers the tag symbol, the detection performance parameters of the environment backscatter communication system can be determined according to the tag symbol and the signal received by the reader, wherein the detection performance parameters comprise the mutual information quantity between the tag and the reader, the channel capacity between the tag and the reader and the error rate;
wherein, the mutual information quantity I (a) between the label and the readerm；rk) Comprises the following steps:
in the formula, piSending the probability that the label symbol is 0 and the label symbol is 1 for the label, wherein i is 0 and 1;
l is rkThe number of interval blocks of the probability density function of (1);
p(rk,li) when label symbol i is sent by label, signal rkThe probability represented by the l-th interval;
log2(. cndot.) represents the base 2 logarithm;
the channel capacity C between the tag and the reader is:
in the formula, max (·) is a maximum operation sign;
obtaining the bit error rate P according to the optimal threshold valueb-minComprises the following steps:
wherein Q (·) is a functional symbol, and
t is the integration time constant.
In one embodiment of the invention, an example for verifying the effectiveness of an environmental backscatter communication system is provided, wherein the number N of the control array radio frequency source array elements is 64, the array element spacing d is 0.05 m, and the carrier frequency f of the reference array element0Setting the horizontal line as an x axis, setting the frequency offset of each array element of the frequency control array radio frequency source as 0MHz,3MHz,6MHz, a12000m, the elevation angle theta from the reference array element to the reader in the frequency control array radio frequency source 160 °, the transmitted kth transmitted rf signal symbol x of each array elementk(K1, 2.., K1000) is a gaussian distribution subject to a mean value of 0 and a variance of 1, and the transmission power P iss＝10dB；
The label at (30 degrees, 2000m) receives the signal transmitted from the frequency control array radio frequency source, and the channel coefficient of the label and the reader is g-1.1221-i 0.7761 (g ═ 1.1221-i 0.7761: (2000 m)
Imaginary number), the attenuation coefficient at the label is 0.7, the label information symbol is kept unchanged in the period of K-1000 RF source symbols, and the distance R from the reference array element on the frequency control array RF source to the label22000m, the elevation angle theta from the reference array element to the label on the frequency control array radio frequency source 230 degrees, the distance between each array element in the frequency control array radio frequency source and the label is 2000m,1999.96m,1999.92m,.., 1997.44m, and the channel coefficient between the nth array element on the frequency control array radio frequency source and the label
Channel coefficient from nth array element on frequency control array radio frequency source to reader
Reflection coefficient G α gamxkThe phase of the reflected signal is 0 pi, 3.67 pi, 7.34 pi,. eta, 670.32 pi, nk(N) (N1, 2.., N64) is white gaussian noise subject to a mean of 0 and a variance of 1; the probability that the tag sends "0" and "1" is p0＝p1When the number of blocks L of the probability density function of the received signal is 700 and the signal-to-noise ratio of the rf source is set to 0dB,5dB,10dB,15dB,20dB,25dB, and 30dB, respectively, the signal received by the reader is:
the corresponding channel capacities are 0.0225, 0.0573, 0.0929, 0.1430, 0.1750, 0.2035, 0.2124 (symbols). When K is 1000 and the rf source transmit snrs are 0dB,5dB,10dB,15dB,20dB,25dB, and 30dB, the average powers are:
according to the differential detection method, based on the criterion of minimum bit error rate, the optimal threshold of the corresponding signal-to-noise ratio is obtained to be 0.112, 0.214, 0.467, 1.232, 3.649, 11.293, 35.465, and the bit error rate is 0.4849, 0.4710, 0.4371, 0.3393, 0.1247, 0.0021, 0.0001.
Fig. 3 shows the comparison of the channel capacities of the communication system when the frequency control array signal is used as the radio frequency source and the phased array is used as the radio frequency source, respectively, fig. 4 shows the comparison of the error rate curves of the communication system when the frequency control array signal is used as the radio frequency source and the phased array is used as the radio frequency source, respectively, and it can be seen from fig. 3 and fig. 4 that under the condition of the same number of antennas as the phased array, the method of the present invention can obtain a larger channel capacity and a better detection performance.
The invention has the beneficial effects that: the invention adopts the frequency control array radio frequency source to send signals to realize the environment backscattering communication, namely, the label utilizes the existing frequency control array signals in the air to communicate with the reader, the maximum mutual information of label symbols and received signals is utilized to obtain the channel capacity, and the detection performance of the environment backscattering communication system is determined by a differential detection method. Compared with the traditional environment backscattering communication, the frequency control array radio frequency source replaces a phased array radio frequency source, and the characteristics of distance-angle-time dependent wave beams of the frequency control array are fully utilized, so that the purposes of improving the transmission rate of the tag and the reader and improving the error rate performance are achieved. Under the condition of the same number of antennas as the phased array, the method obtains larger channel capacity and smaller system error rate, has better detection performance, and provides technical support for future development and application popularization of the internet of things.
Claims (4)
1. An environment backscattering communication system based on a frequency control array radio frequency source is characterized by comprising the frequency control array radio frequency source, a label and a reader;
the frequency control array radio frequency source comprises a plurality of array elements, each array element is connected with a tag and a reader, and the tag is also connected with the reader;
the frequency control array radio frequency source is used for transmitting radio frequency signals to the label and the reader;
the label modulates the label symbol to the received radio frequency signal to generate a reflection link signal and forwards the reflection link signal to the reader;
the reader recovers the label symbol from the received signal and determines the detection performance parameters of the environment backscattering communication system;
the reader receives a signal transmitted by a frequency control array radio frequency source, wherein the signal is a direct link signal;
the reader receives a signal transmitted by the label as a reflected link signal;
the detection performance parameters of the environment backscattering communication system comprise mutual information quantity between the tag and the reader, channel capacity between the tag and the reader and error rate;
wherein, the mutual information quantity I (a) between the label and the readerm；rk) Comprises the following steps:
in the formula, amThe mth tag symbol transmitted for the tag;
rka signal received for a reader;
pisending the probability that the label symbol is 0 or 1 for the label, and i is 0, 1;
l is rkThe number of interval blocks of the probability density function of (1);
p(rk,li) when label symbol i is sent by label, signal rkThe probability represented by the l-th interval;
log2(. cndot.) represents the base 2 logarithm;
the channel capacity C between the tag and the reader is:
in the formula, max (·) is a maximum operation sign;
bit error rate Pb-minComprises the following steps:
in the formula, ThAn optimal threshold value for the ambient backscatter system;
q (-) is a functional symbol, and
t is the integration time constant.
μ0,
Transmitting label symbols a for labels respectivelymAverage power of signal received by reader when 0mMean and variance of the distribution;
μ1,
transmitting label symbols a for labels respectivelymAverage power of signal received by reader when 1mMean and variance of the distribution.
2. The frequency-gated array radio frequency source based ambient backscatter communication system of claim 1, wherein the tag is a single antenna tag; the reader is a single antenna reader.
3. A communication method of an environment backscattering communication system based on a frequency control array radio frequency source is characterized by comprising the following steps:
s1, configuring array element parameters of a frequency control array radio frequency source, further determining the initial phase of the radio frequency signal transmitted by each array element, and transmitting the radio frequency signal to the tag and the reader through the array elements;
s2, receiving radio frequency signals emitted by a frequency control array radio frequency source through a label, modulating label symbols into the received radio frequency signals through a differential coding modulation method, generating reflection link signals and forwarding the reflection link signals to a reader;
s3, recovering the label symbol by a differential detection method according to the signal received by the reader, and realizing environment backscattering communication;
in step S1, the array element parameters of the frequency-controlled array rf source include an array element number N, an array element spacing d, and a carrier frequency f of a reference array element0And its frequency offset Δ f;
initial phase of radio frequency signal transmitted by each array element
Comprises the following steps:
in the formula, R1nIs the distance from the nth array element in the frequency control array radio frequency source to the reader, and R1n＝R1-(n-1)dcosθ1，n＝1,2,...,N，R1The distance between a reference array element in a frequency control array radio frequency source and a reader is obtained;
θ1the azimuth angle from a reference array element in a frequency control array radio frequency source to a reader is obtained;
c is the speed of light;
in step S2, when the frequency-controlled array rf source transmits the kth rf signal, the reflected link signal c generated by the tagk'(θ2,R2(ii) a t) is:
in the formula, theta2The azimuth angle from a reference array element to a label in a frequency control array radio frequency source is obtained;
R2the distance between a reference array element in a frequency control array radio frequency source and a label is obtained;
t is time;
Pstransmitting the transmission power of a radio frequency signal for an array element of a frequency control array radio frequency source;
α is the attenuation coefficient of the label;
g is the channel coefficient of the label and the reader;
amthe mth tag symbol transmitted for the tag;
xkthe symbol of the kth radio frequency signal transmitted by each array element in the frequency control array radio frequency source is shown, wherein K is 1,2, and K is the number of the symbols of the radio frequency signal transmitted by the frequency control array radio frequency source;
e(·)to be fromAn exponential function with a number as the base;
j is an imaginary unit;
h2nchannel coefficients from the nth array element to the tag in the frequency controlled array radio frequency source are set, wherein N is 1, 2.
R2nIs the distance from the nth array element to the label in the frequency control array radio frequency source, and R2n＝R2-(n-1)dcosθ2Wherein N is 1, 2.., N;
φnthe phase of the radio frequency signal transmitted by each array element at any moment;
the signals received by the reader in the step S3 include direct link signals, reflected link signals and noise signals;
when the frequency control array radio frequency source transmits the kth radio frequency signal, the signal r received by the readerkComprises the following steps:
in the formula, h1nA channel coefficient from an nth array element in a frequency control array radio frequency source to a reader is obtained, and N is 1, 2.
G is a reflection coefficient, and
nk(n) white noise subject to a gaussian distribution;
4. the communication method of the environmental backscatter communication system based on the frequency controlled array radio frequency source as claimed in claim 3, wherein the method for recovering the tag symbol by the differential detection method in step S3 is specifically:
s31, determining the statistical test quantity phi of the signal received by the readerm；
S32, determining the optimal threshold T when the environmental backscattering communication system detects the signalh；
S33, determining | Φm|＞ThWhether the result is true or not;
if yes, the mth tag symbol received by the reader is '1';
if not, the mth tag symbol received by the reader is "0".
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910055676.3A CN109756251B (en) | 2019-01-22 | 2019-01-22 | Environment backscattering communication system based on frequency control array radio frequency source and communication method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910055676.3A CN109756251B (en) | 2019-01-22 | 2019-01-22 | Environment backscattering communication system based on frequency control array radio frequency source and communication method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109756251A CN109756251A (en) | 2019-05-14 |
| CN109756251B true CN109756251B (en) | 2020-07-14 |
Family
ID=66404855
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910055676.3A Expired - Fee Related CN109756251B (en) | 2019-01-22 | 2019-01-22 | Environment backscattering communication system based on frequency control array radio frequency source and communication method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109756251B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110784248B (en) * | 2019-11-01 | 2020-11-24 | 电子科技大学 | Frequency control array environment backscattering communication self-adaptive detection method based on double thresholds |
| WO2021237392A1 (en) * | 2020-05-25 | 2021-12-02 | Qualcomm Incorporated | Environment sensing using radio frequencies |
| CN113935449A (en) * | 2020-06-29 | 2022-01-14 | 太原理工大学 | Signal sending and receiving method of backscattering communication system |
| CN112165366B (en) * | 2020-09-21 | 2022-06-07 | 西安交通大学 | Method for determining optimal threshold value applied to signal detection of environmental backscattering system |
| CN112671456A (en) * | 2020-12-11 | 2021-04-16 | 兰州交通大学 | Optimal label selection method in backscattering communication |
| CN113099534B (en) * | 2021-03-29 | 2023-10-27 | 西北工业大学 | Resource allocation method for environment backscatter communication system |
| CN117014026A (en) * | 2022-04-27 | 2023-11-07 | 维沃移动通信有限公司 | Backscattering communication method and apparatus |
| WO2024026607A1 (en) * | 2022-08-01 | 2024-02-08 | Qualcomm Incorporated | Maintaining authentication integrity of signals from backscattering-based communications devices |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105303137A (en) * | 2015-10-29 | 2016-02-03 | 北京交通大学 | Threshold determining method of reader-writer of ambient backscatter system |
| CN106506426A (en) * | 2016-10-11 | 2017-03-15 | 电子科技大学 | Backscatter communication modulator approach based on OFDM carrier waves |
| CN106685538A (en) * | 2016-11-01 | 2017-05-17 | 清华大学 | Environment backscattering system and signal transmission method thereof |
| CN107911193A (en) * | 2017-09-29 | 2018-04-13 | 浙江大学 | The symbol detection method of environment backscatter system based on Differential Manchester Encoding |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7511665B2 (en) * | 2005-12-20 | 2009-03-31 | The United States Of America As Represented By The Secretary Of The Air Force | Method and apparatus for a frequency diverse array |
| US9680520B2 (en) * | 2013-03-22 | 2017-06-13 | University Of Washington Through Its Center For Commercialization | Ambient backscatter tranceivers, apparatuses, systems, and methods for communicating using backscatter of ambient RF signals |
-
2019
- 2019-01-22 CN CN201910055676.3A patent/CN109756251B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105303137A (en) * | 2015-10-29 | 2016-02-03 | 北京交通大学 | Threshold determining method of reader-writer of ambient backscatter system |
| CN106506426A (en) * | 2016-10-11 | 2017-03-15 | 电子科技大学 | Backscatter communication modulator approach based on OFDM carrier waves |
| CN106685538A (en) * | 2016-11-01 | 2017-05-17 | 清华大学 | Environment backscattering system and signal transmission method thereof |
| CN107911193A (en) * | 2017-09-29 | 2018-04-13 | 浙江大学 | The symbol detection method of environment backscatter system based on Differential Manchester Encoding |
Non-Patent Citations (2)
| Title |
|---|
| 频控阵特性及其发射波束控制研究;李静迟;《中国优秀硕士学位论文全文数据库》;20160315;正文第3.1-3.4节 * |
| 频控阵阵列参数优化设计及其目标定位研究;王永兵;《中国优秀硕士学位论文全文数据库》;20160215;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109756251A (en) | 2019-05-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109756251B (en) | Environment backscattering communication system based on frequency control array radio frequency source and communication method thereof | |
| CN110830097B (en) | Active and passive reciprocal symbiotic transmission communication system based on reflecting surface | |
| CN106506426B (en) | Backscatter communication modulator approach based on OFDM carrier wave | |
| CN110224965B (en) | Semi-blind receiver design method based on OFDM backscattering communication system | |
| US10382161B2 (en) | Wireless networking communication methods, systems, and devices operable using harvested power | |
| Bletsas et al. | The art of signal processing in backscatter radio for μW (or less) Internet of Things: Intelligent signal processing and backscatter radio enabling batteryless connectivity | |
| US8154450B2 (en) | Optimization for finding direction of arrival in smart antennas | |
| CN102122993B (en) | Method and device of remote underwater acoustic communication | |
| CN113207174A (en) | Backscattering communication method, device and system | |
| Muratkar et al. | Battery-less internet of things–A survey | |
| CN110784248B (en) | Frequency control array environment backscattering communication self-adaptive detection method based on double thresholds | |
| US11419162B2 (en) | Method for extracting environment information leveraging directional communication | |
| Zeng et al. | Statistical covariance based signal detection for ambient backscatter communication systems | |
| JP4345800B2 (en) | Wireless communication device | |
| Bae et al. | OmniScatter: extreme sensitivity mmWave backscattering using commodity FMCW radar | |
| CN110545128B (en) | Cooperative transmission optimization method in environment backscatter array communication system | |
| US20230097295A1 (en) | Backscatter transmitter and signal transmission method | |
| CN115834315A (en) | High-speed OFDM subcarrier environment backscattering communication method and system | |
| CN114185019A (en) | Intelligent reflecting surface assisted radar communication cooperative target detection method and electronic equipment | |
| Chen et al. | Signal detection with channel estimation error for full duplex wireless system utilizing ambient backscatter | |
| Umezawa et al. | 30-GHz OFDM radar and wireless communication experiment using radio over fiber technology | |
| Chen et al. | Semi-blind detection of ambient backscatter signals from multiple-antenna tags | |
| CN105471804A (en) | Millimeter wave NOLS (Non line of Sight) communication system and method | |
| El-Hadidy et al. | Cost-Effective Testbed for Cognitive Long-Range Communications based on Antenna Array and Software Defined Radio | |
| CN111919396B (en) | Proximity detection using multiple power levels |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200714 Termination date: 20220122 |