WO2022078331A1

WO2022078331A1 - Signal transmitting and signal receiving method, terminal, and communication device

Info

Publication number: WO2022078331A1
Application number: PCT/CN2021/123300
Authority: WO
Inventors: 魏旭昇; 姜大洁; 秦飞
Original assignee: 维沃移动通信有限公司
Priority date: 2020-10-14
Filing date: 2021-10-12
Publication date: 2022-04-21
Also published as: CN114374406B; CN114374406A

Abstract

Disclosed by the present application are a signal transmitting and signal receiving method, terminal, and communication device, the signal sending method comprising: receiving a first signal, said first signal being obtained on the basis of a first spread-spectrum sequence spreading; on the basis of the second spread-spectrum sequence, superimposing a local signal on said first signal, and performing backscatter transmission; wherein the result of the product of said first spread-spectrum sequence and said second spread-spectrum sequence is a third spread-spectrum sequence, and the inner product of said third spread-spectrum sequence and said first spread-spectrum sequence is zero.

Description

Signal transmission and signal reception method, terminal and communication device

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 202011098298.6 filed in China on October 14, 2020, the entire contents of which are incorporated herein by reference.

technical field

The present application belongs to the field of communication technologies, and in particular relates to a signal transmission and signal reception method, a terminal and a communication device.

Background technique

In the future B5G and 6G communication systems, how to improve the energy utilization efficiency and realize green communication/environment-friendly communication is an important research topic. Backscatter technology is a passive or low-energy technology, and its technical feature is that it can transmit its own information by directly reflecting the surrounding environment signals.

The advantages of environmental backscatter technology are: it uses surrounding radio frequency signals and does not require specific spectrum resources; the transmission of radio frequency signals and the reception of backscattered signals are generally not the same device; the backscattering device can collect surrounding signals. Its own energy storage to further support its own communication. Due to the above technical characteristics of environmental backscattering technology, it is one of the key technologies to realize 6G green communication, reduce the energy loss of communication systems, and promote energy conservation and environmental protection.

In the process of realizing this application, the inventor found that when the existing environmental backscattering technology is applied, the receiving end will be interfered by the interference signal. However, since the backscattering device in the environmental backscattering technology is usually a passive device or an energy-limited device, the device tag does not send a pilot/training signal to the receiving end, and the receiving end cannot use the pilot/training signal according to the existing method. Eliminate distractions. Therefore, how to eliminate interference and improve the success rate of environmental backscatter communication is an urgent problem to be solved.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a signal transmission and signal reception method, a terminal, and a communication device, which can solve the problem of interference of interfering signals in the existing environmental backscattering technology.

In a first aspect, a signal sending method is provided, applied to a communication device, including:

receiving a first signal, where the first signal is obtained by spreading based on a first spreading sequence;

Based on the second spreading sequence, superimposing the local signal on the first signal, and performing backscatter transmission;

Wherein, the product of the first spreading sequence and the second spreading sequence is a third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.

In a second aspect, a signal sending device is provided, including:

a receiving module, configured to receive a first signal, where the first signal is obtained by spreading based on a first spreading sequence;

a processing module, configured to superimpose the local signal on the first signal based on the second spreading sequence, and perform backscatter transmission;

In a third aspect, a signal receiving method is provided, applied to a terminal, including:

sending a first signal, where the first signal is obtained by spreading based on a first spreading sequence;

Receiving a second signal, the second signal is that after the backscattering tag receives the first signal, the local signal is superimposed on the first signal based on the second spread spectrum sequence, and the backscattering transmission is performed. ;

despreading the second signal based on a third spreading sequence;

In a fourth aspect, a signal receiving apparatus is provided, comprising:

a sending module, configured to send a first signal, where the first signal is obtained by spreading based on a first spreading sequence;

The receiving module is configured to receive a second signal, and the second signal is that after receiving the first signal, the backscattering tag superimposes the local signal on the first signal based on the second spreading sequence, and performs sent by backscatter;

a processing module, configured to despread the second signal based on the third spreading sequence;

In a fifth aspect, a communication device is provided, comprising a processor, a memory, and a program or instruction stored on the memory and executable on the processor, when the program or instruction is executed by the processor, The steps of implementing the method for transmitting a signal according to the first aspect above are implemented.

In a sixth aspect, a terminal is provided, including a processor, a memory, and a program or instruction stored on the memory and executable on the processor. When the program or instruction is executed by the processor, the The steps of the signal receiving method according to the third aspect above.

In a seventh aspect, a readable storage medium is provided, and a program or an instruction is stored on the readable storage medium, and when the program or instruction is executed by a processor, the signal sending method as described in the first aspect above is implemented, or The steps of implementing the signal receiving method as described in the third aspect above.

In an eighth aspect, a chip is provided, the chip includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used for running programs or instructions of an environmental backscattering device or a terminal, corresponding to The steps of implementing the signal sending method as described in the first aspect above, or implementing the signal receiving method as described in the third aspect.

In the embodiment of the present application, the first spreading sequence and the second spreading sequence are respectively used to perform spread spectrum processing on the signal at the transmitting end and the reflected signal of the environmental scattering device, and the third spreading sequence is obtained based on the two spreading sequences. The frequency sequence is used for despreading the received signal at the receiving end, which can effectively eliminate the interference signal and improve the reliability of the signal.

Description of drawings

FIG. 1 is a block diagram of an environmental backscatter communication system according to an embodiment of the present application;

FIG. 2 is a schematic flowchart of a signal sending method provided by an embodiment of the present application;

3 is a schematic structural diagram of a signal transmission apparatus provided by an embodiment of the present application;

FIG. 4 is a schematic flowchart of a signal receiving method provided by an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a signal receiving apparatus provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of an entity structure of a communication device provided by an embodiment of the present application;

7 is a schematic diagram of a hardware structure of a communication device implementing an embodiment of the present application;

FIG. 8 is a schematic diagram of a hardware structure of a terminal implementing an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

The terms "first", "second" and the like in the description and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It is to be understood that the terms so used are interchangeable under appropriate circumstances so that the embodiments of the present application can be practiced in sequences other than those illustrated or described herein, and that "first", "second" distinguishes Usually it is a class, and the number of objects is not limited. For example, the first object may be one or multiple.

It is worth noting that the technologies described in the embodiments of the present application are not limited to Long Term Evolution (Long Term Evolution, LTE)/LTE Evolution (LTE-Advanced, LTE-A) systems or New Radio (New Radio, NR) systems, It can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), orthogonal frequency Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) and other systems. The techniques described in the embodiments of the present application can be used not only for the above-mentioned systems and radio technologies, but also for other systems and radio technologies. However, the following description describes a New Radio (NR) system for example purposes, and uses NR terminology in most Generation, 6G) communication system.

FIG. 1 shows a block diagram of an ambient backscatter communication system to which the embodiments of the present application can be applied. The ambient backscatter communication system includes a terminal 11 and an ambient backscatter device 12 . Wherein, the terminal 11 may also be called a terminal device, a receiving end or a user terminal (User Equipment, UE), and the terminal 11 may be a mobile phone, a tablet computer (Tablet Personal Computer), a laptop computer (Laptop Computer) or a notebook computer , Personal Digital Assistant (PDA), PDA, Netbook, Ultra-mobile Personal Computer (UMPC), Mobile Internet Device (MID) or Vehicle-mounted Equipment (VUE), Pedestrian Terminal (PUE) and other terminal side equipment. The environmental backscattering device 12 is a smart device with a backscattering function, capable of backscattering ambient radio frequency signals, such as a wearable device (Wearable Device). glasses etc. It should be noted that the specific types of the terminal 11 and the environmental backscattering device 12 are not limited in the embodiments of the present application.

In a system to which this embodiment of the present application can be applied, the sending of the ambient radio frequency signal and the reception of the backscattered signal are performed by the same device terminal 11 , that is, the external ambient radio frequency signal is directly sent by the transmitting end of the backscattered signal receiving device terminal 11 signal acts as. That is to say, the terminal 11 includes a signal transmitting end and a signal receiving end at the same time: the signal transmitting end sends out a radio frequency signal, which can be used as an environmental radio frequency signal;

After receiving the signal from the transmitting end, the environmental backscattering device 12 with backscattering function reflects and transmits the received environmental radio frequency signal according to the reflection rule defined by itself, and sends out backscattering signal to transmit its own information. The backscattered signal sent by the environmental backscattering device 12 is received by the terminal 11. While receiving the useful reflected signal, the terminal 11 will be affected by the self-interference generated by the self-transmitted signal at the receiving end, and at the same time, the transmitted signal will be affected by the surrounding environment. The influence of the interfering signal reaching the receiving end after reflection.

The signal sending method, signal receiving method, apparatus, device, and terminal provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings through specific embodiments and application scenarios thereof.

FIG. 2 is a schematic flowchart of a signal sending method provided by an embodiment of the present application. The method can be applied to a communication device, and the communication device may be an ambient backscatter (ambient backscatter) device. The type of equipment can include: bracelets, earphones, glasses, etc. As shown in Figure 2, the method includes:

Step 201: Receive a first signal, where the first signal is obtained by spreading based on a first spreading sequence.

Specifically, the execution subject of the embodiment of the present application may be an environmental backscattering device, which has a backscattering function and can receive an environmental radio frequency signal from the environment, and the environmental radio frequency signal may be referred to as a first signal. The first signal is sent by a radio frequency signal sending device (the terminal 11 shown in FIG. 1 ) in the environment around the environmental backscattering device, and the radio frequency signal sending device needs to use a radio frequency signal before sending the first signal. For a specific spreading sequence, the chip signal to be sent (such as the signal x(t) in FIG. 1 ) is subjected to spreading processing to obtain the first signal. The specific spreading sequence may be referred to as the first spreading sequence.

Understandably, backscattering is the reflection of waves, particles or signals back from the direction they came from, and is diffuse reflection due to scattering. In the environmental backscattering technology, the backscattering device is usually a passive device or an energy-limited device, which can communicate by reflecting the radio frequency signal of the surrounding environment, and the signal reflected by the backscattering device is called the backscattering signal . For example, the backscattering device tag expresses the two states of 0 or 1 by reflecting or not reflecting the surrounding radio frequency signal. The backscattering signal receiving device judges the two states according to the difference in the received signal when the tag reflects or does not reflect. state, and then detect the original 0 or 1 information sent by the tag.

Spread spectrum refers to a communication technology that spreads the spectrum of the signal to be sent to a wider bandwidth than its original bandwidth. The expansion of the frequency band is completed by an independent code sequence, which is realized by the method of coding and modulation. The code sequence is the spreading sequence. The spread spectrum sequence is equivalent to the carrier of the signal to be sent in the coded modulation, and acts as a carrier.

Step 202, based on the second spreading sequence, superimpose the local signal on the first signal, and perform backscatter transmission. The product of the first spreading sequence and the second spreading sequence is the third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.

Specifically, after receiving the first signal according to the above steps, the backscattering device superimposes the local signal on the first signal, and further spreads the superimposed signal with another spreading sequence to form a reverse The scattered signal is sent out. The other spreading sequence used by the backscattering device may be referred to as the second spreading sequence.

It can be understood that, after the backscattering device sends the backscattered signal through backscattering, the signal receiving end can receive the second signal including the spread spectrum signal. In addition, the signal receiving end can obtain the first spreading sequence and the second spreading sequence, and can multiply the first spreading sequence and the second spreading sequence to obtain the third spreading sequence. After that, despread the received second signal by using the third spreading sequence to obtain a useful signal sent by the backscattering device, so as to achieve the purpose of eliminating the interference signal in the second signal. With reference to Fig. 1, the useful signal actually includes the chip signal x(t) to be sent in the radio frequency signal transmitting device, the local signal b(t) of the backscattering device, and the integrated channel signal h ₃ (t) of the backscattering signal ).

Wherein, by multiplying the corresponding elements of the first spreading sequence and the second spreading sequence in the embodiment of the present application, a new sequence can be obtained, which is called a third spreading sequence. Moreover, the third spreading sequence and the first spreading sequence satisfy a certain constraint relationship, that is, the inner product is 0.

Wherein, when using the second spreading sequence to perform the spreading processing, the starting and ending positions of the first spreading sequence in the first signal can be obtained first, and the superimposed signal is subjected to spreading processing at the same starting and ending positions. . That is, the signal can be spread-spectrum processed on the basis of chip synchronization. It can be known that a data signal (such as logic 1 or 0) is usually encoded by a plurality of encoded signals, and one of the encoded signals is called a chip. The chip is equivalent to the carrier function in the analog modulation, and is the carrier of the digital signal.

In the signal transmission method provided by the embodiment of the present application, the first spreading sequence and the second spreading sequence are respectively used to perform spread spectrum processing on the signal of the transmitting end and the reflected signal of the environmental scattering device, and based on the two spread spectrum sequences, the The third spreading sequence is used for despreading the signal received at the receiving end, which can effectively eliminate the interference signal and improve the reliability of the signal.

Optionally, the first spreading sequence and the second spreading sequence belong to the same walsh-hadamard matrix.

Specifically, the first spreading sequence and the second spreading sequence in the embodiment of the present application may be two columns selected from the same walsh-hadamard matrix, which are called walsh sequences. Among them, the two selected walsh sequences can ensure that the result of multiplying each symbol in their sequences by twos produces another walsh sequence, which can be used as a third spreading sequence.

It can be understood that the walsh-hadamard is a non-sinusoidal orthogonal transformation method that decomposes the signal into a set of basis functions. The columns of the walsh-hadamard matrix form an orthogonal sequence, and each column is called a walsh sequence. The walsh sequence is a typical orthogonal code with good autocorrelation properties and zero cross-correlation properties everywhere.

In this embodiment of the present application, the first spreading sequence and the second spreading sequence are selected from the same walsh-hadamard matrix, which can make good use of the orthogonal characteristic of the walsh-hadamard matrix, so that while effectively eliminating the interference signal at the receiving end, it can Effectively improve signal transmission efficiency and reliability.

Optionally, none of the first spreading sequence, the second spreading sequence and the third spreading sequence are all 1 sequences.

Specifically, considering that the walsh-hadamard matrix in the embodiment of the present application is a complete walsh-hadamard matrix, there must be a unique sequence of all 1s in it. And if only part of the walsh-hadamard matrix is used, it may not include the all-ones sequence. Therefore, for a complete walsh-hadamard matrix or a partial walsh-hadamard matrix with an all-one sequence, since the all-one sequence multiplied by any sequence is still the original sequence, the inner product of the original sequence and itself is usually not 0, and interference cannot be achieved. Therefore, when selecting the walsh sequence according to the above-mentioned embodiment, the all-1 sequence needs to be removed from the walsh-hadamard matrix, and two walsh sequences are selected from the remaining sequences as the first spreading sequence respectively. and the second spreading sequence. Meanwhile, in order to effectively utilize the orthogonal characteristic of the walsh-hadamard matrix for interference cancellation, it is required that the third spreading sequence obtained by multiplying the first spreading sequence and the second spreading sequence cannot be an all-one sequence. In the case where there is no all-one sequence in the walsh-hadamard matrix, the above limitation in the embodiment of the present application may not be imposed. It can be understood that an all-1 sequence refers to a sequence in which each element in the sequence has a value of 1.

In the embodiment of the present application, by limiting the first spreading sequence, the second spreading sequence, and the third spreading sequence to not be all-one sequences, the operation process can be simplified and the accuracy of the operation result can be improved.

It should be noted that, in the signal sending method provided by the embodiments of the present application, the execution body may be a signal sending device, or a control module in the signal sending device for executing the signal sending method. In the embodiments of the present application, a signal transmitting method performed by a signal transmitting apparatus is used as an example to describe the signal transmitting apparatus provided by the embodiments of the present application.

The structure of the signal sending apparatus according to the embodiment of the present application is shown in FIG. 3 , which is a schematic structural diagram of the signal sending apparatus provided in the embodiment of the present application. It includes: a receiving module 301 and a processing module 302 . in:

The receiving module 301 is used for receiving the first signal, and the first signal is obtained by spreading based on the first spreading sequence; the processing module 302 is used for superimposing the local signal on the first signal based on the second spreading sequence, and performing reverse operation Scatter send. The product of the first spreading sequence and the second spreading sequence is the third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.

The signal sending apparatus in this embodiment of the present application may be an apparatus, or may be a component, an integrated circuit, or a chip in an environmental backscattering device. The device can be a mobile device or a non-mobile device. Exemplarily, the movable device may include, but is not limited to, the types of environmental backscattering devices 12 listed above, and the non-mobile device may be a server, a network attached storage (NAS), a personal computer (personal computer, PC). ), a television (television, TV), a teller machine or a self-service machine, etc., which are not specifically limited in the embodiments of the present application.

The signal sending device in the embodiment of the present application may be a device having an operating system. The operating system may be an Android (Android) operating system, an ios operating system, or other possible operating systems, which are not specifically limited in the embodiments of the present application.

The signal sending apparatus provided in the embodiment of the present application can implement the processes implemented in FIG. 2 and the above-mentioned signal sending method embodiments, and achieve the same technical effect. To avoid repetition, details are not repeated here.

FIG. 4 is a schematic flowchart of a signal receiving method provided by an embodiment of the present application. The method can be applied to a terminal. As shown in FIG. 4 , the method includes:

Step 401: Send a first signal, where the first signal is obtained by spreading based on a first spreading sequence.

Specifically, the execution subject of the embodiment of the present application may be a terminal. Referring to FIG. 1 , before sending a radio frequency signal, the terminal first performs spread spectrum processing on the signal to be transmitted x(t) using a specific spread spectrum sequence to obtain a spread spectrum signal, is called the first signal, and the first signal is sent out. The specific spreading sequence used is called the first spreading sequence, and the to-be-sent signal x(t) is a chip signal encoded by the encoded signal.

It can be understood that spread spectrum refers to a communication technology that spreads the spectrum of the signal to be sent to a wider bandwidth than its original bandwidth. The expansion of the frequency band is completed by an independent code sequence, using coding and modulation. method, wherein the code sequence is a spreading sequence. The spread spectrum sequence is equivalent to the carrier of the signal to be sent in the coded modulation, and acts as a carrier.

Step 402: Receive a second signal, where the second signal is sent by the backscatter tag after receiving the first signal, superimposing the local signal on the first signal based on the second spread spectrum sequence, and performing backscatter transmission.

Specifically, after the first signal is sent out according to the above steps, the first signal will diverge and transmit outward. When the first signal reaches the ambient reflection scattering device, it will be reflected by the ambient backscattering device to generate a backscattering signal. At the same time, the first signal will be reflected by the surrounding environment, such as walls, obstacles, etc., to form an environmental reflection signal, and the first signal itself will generate a self-interference signal.

Therefore, after sending the first signal, the terminal will simultaneously receive the backscattered signal reflected by the environmental backscattering device, the environmental reflected signal reflected by the surrounding environment, and the self-interference signal generated by itself, which together constitute the second signal . The environment reflected signal reflected from the surrounding environment and the self-interference signal of the first signal together constitute the interference signal of the terminal.

Wherein, when the first signal is transmitted to the ambient directional scattering device, after receiving the first signal, the backscattering device superimposes the local signal on the first signal, and uses another spread spectrum sequence to further perform the superimposed signal on the superimposed signal. Spread spectrum processing to form a backscattered signal and send it out. The other spreading sequence used by the backscattering device may be referred to as the second spreading sequence. After the backscattering device sends the backscattered signal through backscattering, the signal receiving end can receive the second signal including the spread spectrum signal.

Wherein, when using the second spread spectrum sequence to perform the spread spectrum processing, the environmental backscattering device can obtain the start and end positions of the first spread spectrum sequence in the first signal, and compare the superimposed The signal is spread spectrum processed. That is, the signal can be spread-spectrum processed on the basis of chip synchronization. It can be known that a data signal (such as logic 1 or 0) is usually encoded by a plurality of encoded signals, and one of the encoded signals is called a chip. The chip is equivalent to the carrier function in the analog modulation, and is the carrier of the digital signal.

Step 403: Despread the second signal based on the third spreading sequence. The product of the first spreading sequence and the second spreading sequence is the third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.

Specifically, after acquiring the second signal, the terminal also needs to acquire the second spreading sequence used when the environmental backscattering device performs the spreading processing, and obtain the third spreading sequence accordingly. After that, despread the received second signal by using the third spreading sequence to obtain a useful signal sent by the backscattering device, so as to achieve the purpose of eliminating the interference signal in the second signal. With reference to Fig. 1, the useful signal actually includes the chip signal x(t) to be sent in the radio frequency signal transmitting device, the local signal b(t) of the backscattering device, and the integrated channel signal h ₃ (t) of the backscattering signal ).

In the signal receiving method provided by the embodiment of the present application, the first spreading sequence and the second spreading sequence are respectively used to perform spread spectrum processing on the signal of the transmitting end and the reflected signal of the environmental scattering device, and based on the two spreading sequences, the The third spreading sequence is used for despreading the signal received at the receiving end, which can effectively eliminate the interference signal and improve the reliability of the signal.

Specifically, considering that the walsh-hadamard matrix in the embodiment of the present application is a complete walsh-hadamard matrix, there must be a unique sequence of all 1s in it. And if only part of the walsh-hadamard matrix is used, it may not include all-ones sequences. Therefore, for a complete walsh-hadamard matrix or a partial walsh-hadamard matrix with an all-one sequence, since the all-one sequence multiplied by any sequence is still the original sequence, the inner product of the original sequence and itself is usually not 0, and interference cannot be achieved. Therefore, when selecting the walsh sequence according to the above-mentioned embodiment, the all-1 sequence needs to be removed from the walsh-hadamard matrix, and two walsh sequences are selected from the remaining sequences as the first spreading sequence respectively. and the second spreading sequence. Meanwhile, in order to effectively utilize the orthogonal characteristic of the walsh-hadamard matrix for interference cancellation, it is required that the third spreading sequence obtained by multiplying the first spreading sequence and the second spreading sequence cannot be an all-one sequence. In the case where there is no all-one sequence in the walsh-hadamard matrix, the above limitation in the embodiment of the present application may not be imposed. It can be understood that an all-1 sequence refers to a sequence in which each element in the sequence has a value of 1.

In the embodiment of the present application, by limiting the first spreading sequence, the second spreading sequence and the third spreading sequence as not all 1 sequences, the operation process can be simplified and the accuracy of the operation result can be improved.

Further, before the step of despreading the second signal based on the third spreading sequence, the signal receiving method of the embodiment of the present application further includes: determining the second spreading sequence used by the backscattered tag; The first spreading sequence and each symbol in the second spreading sequence are multiplied two by two to obtain a third spreading sequence.

Specifically, before the terminal in this embodiment of the present application performs despreading processing on the received second signal, it first needs to obtain a spreading sequence used for despreading, that is, a second spreading sequence. Specifically, the second spread spectrum sequence may be allocated by the terminal to the environmental backscattering device in advance and stored in the local memory, or may be selected by the environmental backscattering device and fed back to the terminal, or may be carried in the handshake In the signal, this embodiment of the present application does not limit this.

After that, the terminal obtains each element symbol in the sequence according to the obtained first spreading sequence and the second spreading sequence, and multiplies the corresponding element symbols in the two sequences by two to obtain a plurality of new element symbols , and use these new element symbols to form a third spreading sequence.

It should be noted that, in the signal receiving method provided by the embodiments of the present application, the execution body may be a signal receiving device, or a control module in the signal receiving device for executing the signal receiving method. In the embodiment of the present application, the signal receiving device provided by the embodiment of the present application is described by taking a signal receiving device performing a signal receiving method as an example.

The structure of the signal receiving apparatus according to the embodiment of the present application is shown in FIG. 5 , which is a schematic structural diagram of the signal receiving apparatus provided in the embodiment of the present application. It includes: a sending module 501 , a receiving module 502 and a processing module 503 . in:

The sending module 501 is used for sending a first signal, and the first signal is obtained by spreading based on the first spreading sequence; the receiving module 502 is used for receiving a second signal, and the second signal is that after the backscattering tag receives the first signal, The local signal is superimposed on the first signal based on the second spreading sequence, and backscattered and sent; the processing module 503 is configured to despread the second signal based on the third spreading sequence. The product of the first spreading sequence and the second spreading sequence is the third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.

Further, the processing module is also used for: determining the second spreading sequence used by the backscattered tag; multiplying each symbol in the first spreading sequence and the second spreading sequence two by two to obtain a third spreading sequence .

The signal receiving apparatus in this embodiment of the present application may be a device, or may be a component, an integrated circuit, or a chip in a terminal. The device may be a mobile terminal or a non-mobile terminal. Exemplarily, the mobile terminal may include, but is not limited to, the types of terminals 11 listed above, and the non-mobile terminal may be a server, a network attached storage (NAS), a personal computer (personal computer, PC), a television ( television, TV), teller machine, or self-service machine, etc., which are not specifically limited in the embodiments of the present application.

The signal receiving device in the embodiment of the present application may be a device having an operating system. The operating system may be an Android (Android) operating system, an ios operating system, or other possible operating systems, which are not specifically limited in the embodiments of the present application.

The signal receiving apparatus provided in the embodiment of the present application can implement the processes implemented in FIG. 4 and the above-mentioned signal receiving method embodiments, and achieve the same technical effect. To avoid repetition, details are not repeated here.

To further illustrate the embodiments of the present application, a more detailed description is given below with reference to the system structure of FIG. 1 , but the scope of protection of the present application is not limited.

With reference to Figure 1, where x(t) is the signal to be sent, h ₁ (t) is the self-interference channel, h ₂ (t) is the integrated channel of the signal reflected by the environment at the receiving end, and h ₃ (t) is the backscattering channel The integrated channel of the signal, b(t) is the backscattering device signal.

First, at the transmitting end of the terminal, the signal to be transmitted is spread by using the first spreading sequence to obtain and transmit the first signal.

Secondly, on the basis of synchronizing with the chip level of the terminal transmitting end and the terminal receiving end, on the environmental backscattering label device, the transmitted signal generated according to the received signal is multiplied by the second spreading sequence at the chip level. The sequence and the spreading sequence at the transmitting end of the terminal belong to the same walsh-hadamard matrix, and the spreading sequence is known by the transmitting end. In addition, neither the spreading sequence nor the spreading sequence at the transmitting end is an all-one sequence.

Then, the receiving end of the terminal can obtain or calculate the third spreading sequence to be used for despreading according to the first spreading sequence used by the transmitting end and the second spreading sequence used by the environmental backscattering label device.

Finally, the terminal receiving end uses the calculated third spreading sequence to despread the received signal, thereby recovering the received signal.

That is to say, firstly use the first spreading sequence to spread the signal at the transmitting end and send it out; then the tag device uses the second spreading sequence to superimpose on the received signal and reflect it, while ensuring transmission in the symbol level interval The same data, that is, the spread spectrum of the reflected signal cells; finally, the third spread spectrum sequence is used for despreading at the receiving signal end.

At the chip level, the interference signal received by the receiver at a discrete time k can be expressed as:

Among them, cm (k) is a set of spreading sequences of length L, such as walsh-hadamard sequences, _m is any one of the total L sequences (except the all-1 sequence), assuming that the channel is maintained over the entire L chips constant.

After receiving the transmitted signal from the transmitter, the backscattering tag device transmits the local signal b(t) through backscattering, and superimposes another spread spectrum sequence c _l (k) on the backscattered signal at the chip level . The backscattered signal transmitted at the chip level is finally expressed as:

Then the received signal at the receiving end can be expressed as:

where n is white noise.

In the case where the receiver and backscatter device tags are synchronized and the receiver knows the spread spectrum sequence c _l ( _k ) over which the backscatter device tags are superimposed, the multiplication of cm (k and ) _cl (k) will give Generate another spreading sequence:

c _j (k)= _cm (k)cl (k), k∈[1, _L ].

Finally, using cj(k) to despread the received y(k) signal at the receiving end, we get:

According to the characteristics of the walsh code, the inner product of c _j (k) and _cm (k) is 0, so that the self-interference noise can be eliminated.

Optionally, using the method of the present application, a plurality of walsh sequences that conform to the technical solution of the present application can be selected, and a part of the sequences can be used for a plurality of environmental backscattering label devices, and the terminal receiving end can select an appropriate sequence, Receive signals from backscattered tag devices in any environment while suppressing self-interference and interference from other tag devices.

The interference signal is one of the determinants that affects whether backscattering is feasible and restricts the reliability and efficiency of backscattering transmission, and has a more decisive influence on whether the system model of backscattering considered in this application is feasible. The solution for eliminating self-interference by using a spread spectrum code provided in this application can ensure the feasibility of backscatter transmission and improve the transmission efficiency and reliability of backscatter transmission.

As shown in FIG. 6 , an embodiment of the present application further provides a communication device 600 , including a processor 601 , a memory 602 , and programs or instructions stored in the memory 602 and executable on the processor 601 . For example, when the communication device 600 is a backscattering device, when the program or instruction is executed by the processor 601, each process of any of the above-mentioned signal sending method embodiments can be realized, and the same technical effect can be achieved. When the communication device 600 is a terminal, when the program or instruction is executed by the processor 601, each process of any of the above signal receiving method embodiments can be realized, and the same technical effect can be achieved. To avoid repetition, details are not described here.

Specifically, FIG. 7 is a schematic diagram of a hardware structure of a communication device implementing an embodiment of the present application. Specifically, the communication device may be an ambient backscatter (ambient backscatter) device, such as a wearable device, and the wearable device may include a wristband, an earphone, and glasses. As shown in FIG. 7 , the communication device 700 includes: a radio frequency device 701 and a baseband device 702 . When receiving the radio frequency signal, the radio frequency device 701 receives the information, and sends the received information to the baseband device 702 for processing. When the signal is reflected, the baseband device 702 processes the information to be sent and sends it to the radio frequency device 701 , and the radio frequency device 701 processes the received information and sends it out.

Those skilled in the art can understand that the structure of the environmental backscattering device shown in FIG. 7 does not constitute a limitation on the environmental backscattering device of the present application, and the environmental backscattering device of the present application may include more or less than the one shown in the figure. components, or a combination of certain components, or different component arrangements, which will not be repeated here.

The above signal sending apparatus may be located in the baseband apparatus 702 , and the method performed by the ambient backscattering device in the above embodiments may be implemented in the baseband apparatus 702 , where the baseband apparatus 702 includes a processor 703 and a memory 704 .

The baseband device 702 may include, for example, at least one baseband board on which multiple chips are arranged. As shown in FIG. 7 , one of the chips is, for example, the processor 703 , which is connected to the memory 704 to call the program in the memory 704 to execute Operation of the ambient backscatter apparatus shown in the above method embodiments.

Memory 704 may be used to store software programs or instructions as well as various data. The memory 704 may mainly include a storage program or instruction area and a storage data area, wherein the storage program or instruction area may store an operating system, an application program or instruction required for at least one function (such as a sound playback function, an image playback function, etc.) and the like. In addition, the memory 704 may include a high-speed random access memory, and may also include a non-volatile memory, wherein the non-volatile memory may be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM) , PROM), erasable programmable read-only memory (Erasable PROM, EPROM), electrically erasable programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. For example at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device.

The processor 703 may include one or more processing units; optionally, the processor 703 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, application programs or instructions, etc., Modem processors mainly deal with wireless communications, such as baseband processors. It can be understood that, the above-mentioned modulation and demodulation processor may not be integrated into the processor 703 .

A processor 703, configured to: receive a first signal, where the first signal is obtained by spreading based on the first spreading sequence; superimpose the local signal on the first signal based on the second spreading sequence, and perform backscatter transmission; The product of the first spreading sequence and the second spreading sequence is the third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.

In this embodiment of the present application, the radio frequency device 701 processes the first signal to the processor 703; in addition, sends the reflected signal. Typically, the radio frequency device 701 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like.

The baseband device 702 may further include a network interface 705 for exchanging information with the radio frequency device 701, and the interface is, for example, a common public radio interface (CPRI for short).

In the embodiment of the present application, the first spreading sequence and the second spreading sequence are respectively used to perform spread spectrum processing on the signal of the transmitting end and the reflected signal of the environmental scattering device, and a third spreading sequence is obtained based on the two spreading sequences for The despreading of the received signal at the receiving end can effectively eliminate the interference signal and improve the signal reliability.

Specifically, the environmental backscattering device of the embodiment of the present application further includes: an instruction or program stored in the memory 704 and executable on the processor 703, and the processor 703 invokes the instruction or program in the memory 704 to execute the instruction or program shown in FIG. 3 . The method executed by each module achieves the same technical effect. To avoid repetition, it is not repeated here.

Specifically, FIG. 8 is a schematic diagram of a hardware structure of a terminal implementing an embodiment of the present application. The terminal 800 includes but is not limited to: a radio frequency unit 801, a network module 802, an audio output unit 803, an input unit 804, a sensor 805, a display unit 806, a user input unit 807, an interface unit 808, a memory 809, a processor 810 and other components .

Those skilled in the art can understand that the terminal 800 may also include a power supply (such as a battery) for supplying power to various components, and the power supply may be logically connected to the processor 810 through a power management system, so as to manage charging, discharging, and power consumption through the power management system management and other functions. The terminal structure shown in FIG. 8 does not constitute a limitation on the terminal, and the terminal may include more or less components than shown, or combine some components, or arrange different components, which will not be repeated here.

It should be understood that, in this embodiment of the present application, the input unit 804 may include a graphics processor (Graphics Processing Unit, GPU) 8041 and a microphone 8042. Such as camera) to obtain still pictures or video image data for processing. The display unit 806 may include a display panel 8061, which may be configured in the form of a liquid crystal display, an organic light emitting diode, or the like. The user input unit 807 includes a touch panel 8071 and other input devices 8072 . The touch panel 8071 is also called a touch screen. The touch panel 8071 may include two parts, a touch detection device and a touch controller. Other input devices 8072 may include, but are not limited to, physical keyboards, function keys (such as volume control keys, switch keys, etc.), trackballs, mice, and joysticks, which will not be repeated here.

The radio frequency unit 801 is used for sending a first signal or receiving a second signal. The first signal is obtained by spread spectrum processing based on the first spread spectrum sequence, and the second signal is obtained by the backscatter tag superimposing the local signal on the first signal based on the second spread spectrum sequence after receiving the first signal, and Sent by backscatter.

In this embodiment of the present application, the radio frequency unit 801 processes the reflected signal to the processor 810 after receiving the reflected signal; in addition, sends the first signal to the backscattering device. Generally, the radio frequency unit 801 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like.

Memory 809 may be used to store software programs or instructions as well as various data. The memory 809 may mainly include a storage program or instruction area and a storage data area, wherein the storage program or instruction area may store an operating system, an application program or instruction required for at least one function (such as a sound playback function, an image playback function, etc.) and the like. In addition, the memory 809 may include a high-speed random access memory, and may also include a non-volatile memory, wherein the non-volatile memory may be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM) , PROM), erasable programmable read-only memory (Erasable PROM, EPROM), electrically erasable programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. For example at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device.

Processor 810 may include one or more processing units. Optionally, the processor 810 may integrate an application processor and a modem processor, wherein the application processor mainly handles the operating system, user interface, and application programs or instructions, and the modem processor mainly handles wireless communications, such as baseband. processor. It can be understood that, the above-mentioned modulation and demodulation processor may not be integrated into the processor 810.

The processor 810 is configured to: send a first signal, where the first signal is obtained by spreading based on the first spreading sequence; receive a second signal, where the second signal is obtained by the backscatter tag based on the second signal after receiving the first signal The spreading sequence superimposes the local signal on the first signal and performs backscatter transmission; based on the third spreading sequence, the second signal is despread; wherein the first spreading sequence and the second spreading sequence The result of the product of is the third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.

Optionally, the processor 810 is further configured to: determine the second spreading sequence used by the backscattered tag, and multiply each symbol in the first spreading sequence and the second spreading sequence two by two to obtain the first spreading sequence. Triple spreading sequence.

An embodiment of the present application further provides a readable storage medium, where a program or an instruction is stored on the readable storage medium, and when the program or instruction is executed by a processor, any one of the foregoing signal sending method embodiments or signal receiving method is implemented. In order to avoid repetition, the details are not repeated here.

Wherein, the processor is the processor in the environmental backscattering device or the terminal described in the foregoing embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, and the like.

An embodiment of the present application further provides a chip, where the chip includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used to run a program or instruction of an environmental backscattering device or a terminal, Corresponding to each process of implementing any of the above-mentioned embodiments of the signal sending method or the signal receiving method, and can achieve the same technical effect, to avoid repetition, details are not described here.

It should be understood that the chip mentioned in the embodiments of the present application may also be referred to as a system-on-chip, a system-on-chip, a system-on-a-chip, or a system-on-a-chip, or the like.

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of the present application is not limited to performing the functions in the order shown or discussed, but may also include performing the functions in a substantially simultaneous manner or in the reverse order depending on the functions involved. To perform functions, for example, the described methods may be performed in an order different from that described, and various steps may also be added, omitted, or combined. Additionally, features described with reference to some examples may be combined in other examples.

From the description of the above embodiments, those skilled in the art can clearly understand that the method of the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is better implementation. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product in essence or in a part that contributes to the prior art, and the computer software product is stored in a storage medium (such as ROM/RAM, magnetic disk, CD-ROM), including several instructions to make a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) execute the methods described in the various embodiments of this application.

The embodiments of the present application have been described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the inspiration of this application, without departing from the scope of protection of the purpose of this application and the claims, many forms can be made, which all fall within the protection of this application.

Claims

A signaling method, comprising:

The communication device receives a first signal, where the first signal is obtained by spreading based on a first spreading sequence;

The communication device superimposes the local signal on the first signal based on the second spreading sequence, and performs backscatter transmission;

Wherein, the product of the first spreading sequence and the second spreading sequence is a third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.
The signal transmission method according to claim 1, wherein the first spreading sequence and the second spreading sequence belong to the same walsh-hadamard matrix.
The signal transmission method according to claim 2, wherein none of the first spreading sequence, the second spreading sequence and the third spreading sequence is an all-ones sequence.
A signal transmission device, comprising:

a receiving module, configured to receive a first signal, where the first signal is obtained by spreading based on a first spreading sequence;

a processing module, configured to superimpose the local signal on the first signal based on the second spreading sequence, and perform backscatter transmission;

Wherein, the product of the first spreading sequence and the second spreading sequence is a third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.
The signal transmission apparatus according to claim 4, wherein the first spreading sequence and the second spreading sequence belong to the same walsh-hadamard matrix.
The signal transmission apparatus according to claim 5, wherein none of the first spreading sequence, the second spreading sequence and the third spreading sequence is an all-ones sequence.
A signal receiving method, comprising:

The terminal sends a first signal, where the first signal is obtained by spreading based on the first spreading sequence;

The terminal receives a second signal, and the second signal is that after receiving the first signal, the backscatter tag superimposes the local signal on the first signal based on the second spreading sequence, and reverses the sent by scattering;

The terminal despreads the second signal based on the third spreading sequence;

Wherein, the product of the first spreading sequence and the second spreading sequence is a third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.
The signal receiving method according to claim 7, wherein the first spreading sequence and the second spreading sequence belong to the same walsh-hadamard matrix.
The signal receiving method according to claim 8, wherein none of the first spreading sequence, the second spreading sequence and the third spreading sequence is an all-1 sequence.
The signal receiving method according to claim 7 or 8 or 9, wherein before the step of despreading the second signal by the terminal based on the third spreading sequence, the method further comprises:

determining, by the terminal, the second spreading sequence used by the backscatter tag;

The terminal multiplies each symbol in the first spreading sequence and the second spreading sequence two by two to obtain the third spreading sequence.
A signal receiving device, comprising:

a sending module, configured to send a first signal, where the first signal is obtained by spreading based on a first spreading sequence;

The receiving module is configured to receive a second signal, and the second signal is that after receiving the first signal, the backscattering tag superimposes the local signal on the first signal based on the second spreading sequence, and performs sent by backscatter;

a processing module, configured to despread the second signal based on the third spreading sequence;

Wherein, the product of the first spreading sequence and the second spreading sequence is a third spreading sequence, and the inner product of the third spreading sequence and the first spreading sequence is 0.
The signal receiving apparatus according to claim 11, wherein the first spreading sequence and the second spreading sequence belong to the same walsh-hadamard matrix.
The signal receiving apparatus according to claim 12, wherein none of the first spreading sequence, the second spreading sequence and the third spreading sequence is an all-ones sequence.
The signal receiving device according to claim 11 or 12 or 13, wherein the processing module is further used for:

determining the second spreading sequence used by the backscatter tag;

Each symbol in the first spreading sequence and the second spreading sequence is multiplied two by two to obtain the third spreading sequence.
A communication device, comprising a processor, a memory, and a program or instruction stored on the memory and executable on the processor, when the program or instruction is executed by the processor, the implementation of claims 1- 3. The steps of any one of the signal transmission methods.
A terminal, comprising a processor, a memory, and a program or instruction stored on the memory and executable on the processor, when the program or instruction is executed by the processor, the implementation of claims 7-10 The steps of any one of the signal receiving methods.
A readable storage medium, on which a program or an instruction is stored, and when the program or instruction is executed by a processor, the signal transmission method according to any one of claims 1-3 is realized, or the method as claimed in claim 1 is realized. Steps of the signal receiving method according to any one of requirements 7-10.
A chip, the chip includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used to run a program or an instruction to implement the signal transmission according to any one of claims 1-3 method, or implement the signal receiving method according to any one of claims 7-10.
A computer program product, the program product being executed by at least one processor to implement the signal transmission method as claimed in any one of claims 1-3, or to implement the signal reception as claimed in any one of claims 7-10 method.
A communication device comprising the communication device configured to perform the signalling method of any one of claims 1-3.
A terminal, comprising the terminal configured to perform the signal receiving method of any one of claims 7-10.