Spatial modulation method and system assisted by double intelligent reflecting surfaces

Abstract

The invention discloses a spatial modulation method and system assisted by double intelligent reflecting surfaces, and particularly relates to the technical field of wireless communication, and the method comprises the steps: dividing a to-be-transmitted information bit into two parts of data blocks; the sending end modulates a constellation symbol according to the first data block, and assigns a receiving antenna index according to the second data block input bit information; the two intelligent reflecting surfaces adjust the phases of all reflecting units in the intelligent reflecting surfaces, so that the signal power on the target receiving antenna corresponding to the two intelligent reflecting surfaces is maximized; and the receiving end detects the receiving antenna index and the sent data symbol in a maximum likelihood detection mode according to the received signal, and recovers the information bit. According to the invention, communication is carried out through the double intelligent reflecting surfaces, so that the error rate of the system is reduced, the signal receiving quality is improved, and the system performance is improved.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and specifically to a spatial modulation method and system assisted by dual intelligent reflectors. Background Technology

[0002] Spatial modulation (SM) technology maps a portion of information onto active antennas, reducing hardware costs and overcoming the problems of inter-antenna interference and symbol interference in multiple-input multiple-output (MIMO) transmission. Based on spatial modulation technology, many index modulation (IM) technologies have been developed, further improving capability and transmission efficiency.

[0003] A Reconfigurable Intelligent Surface (RIS) is an artificial planar array composed of many low-cost passive components. To realize the enticing potential of RIS, researchers have conducted in-depth studies on its characteristics. Although a RIS does not transform the incident signal, it can enhance the reflected signal by optimizing and controlling its phase.

[0004] Combining RIS and SM technologies can meet the green communication requirements of next-generation communication networks. However, most current RIS-SM systems only consider the case of a single smart reflector and do not comprehensively consider the case of multiple smart reflectors; both smart reflectors are activated when communicating with each other. Summary of the Invention

[0005] The purpose of this invention is to provide a spatial modulation method and system assisted by dual intelligent reflectors, in order to solve the technical problems in the prior art that only considers the case of a single intelligent reflector and does not comprehensively consider the case of multiple antennas at the transceiver end and the increase in the number of intelligent reflector blocks.

[0006] To achieve the above objectives, embodiments of the present invention provide a spatial modulation method assisted by dual intelligent reflectors, the spatial modulation method assisted by dual intelligent reflectors comprising:

[0007] The information bits to be sent are divided into a first data block and a second data block using a bit splitter.

[0008] The transmitting end modulates constellation symbols according to the first data block;

[0009] The intelligent reflector obtains the receiving antenna index based on the second data block, in N rOne of the receiving antennas is selected, and the signal transmitted by the transmitting end is reflected by two smart reflectors. Each smart reflector adjusts the phase of all the reflecting elements in its block to maximize the signal power on the two corresponding target receiving antennas.

[0010] The receiver detects the receiving antenna index and the transmitted data symbols using the maximum likelihood detection method based on the received signal, and then recovers the information bits.

[0011] Preferably, the step of using a bit splitter to divide the information bits to be transmitted into a first data block and a second data block includes:

[0012] The number of transmit antennas is 1, and the number of receive antennas is N. r The order of the constellation diagram is M;

[0013] Based on the number of transmitting antennas, the number of receiving antennas, and the constellation order, the information bit L to be transmitted is divided into a first data block L1 and a second data block L2, with lengths of log2(M) and log2(N), respectively. r ).

[0014] Preferably, the transmitting end modulates constellation symbols according to the first data block, including:

[0015] The first data block L1 is processed based on the signal constellation mapping bits to obtain the constellation symbol x.

[0016] Preferably, the smart reflector obtains the receiving antenna index based on the second data block, in N r One receiving antenna is selected, and the signal transmitted by the transmitting end is reflected by two intelligent reflectors. Each intelligent reflector adjusts the phase of all reflecting elements within its block to maximize the signal power on the two corresponding target receiving antennas, including:

[0017] Convert the second data block L2 into a decimal number and add 1 to obtain the receiving antenna index m, m∈{1,...,N}. r}, N r This indicates the number of all indices in the receiving antenna;

[0018] The expression for the received signal of the receiving antenna is as follows:

[0019]

[0020] In the above formula, and These represent the wireless fading channels between the transmitter and the first and second smart reflectors, respectively. and Let N represent the wireless fading channels between the i-th reflective element of the first and second smart reflective surfaces and the l-th receiving antenna of the receiver, respectively; and let N represent the total number of reflective elements of each smart reflective surface.

[0021] In an uncorrelated flat Rayleigh fading channel

[0022]

[0023] Where, l∈{1,...,N r}, where n represents additive white Gaussian noise with power equal to N0, following a complex Gaussian distribution. and Let represent the reflection coefficients of the first and second smart reflective surfaces, respectively. and These represent the phases of the i-th reflecting unit of the first and second smart reflective surfaces, respectively.

[0024] Preferably, the maximum likelihood detection method includes:

[0025] Maximum likelihood detection is achieved using the following formula:

[0026]

[0027] In the above formula, and Representing the estimated transmit antenna index and constellation symbol, respectively, y l This represents the expression for the received signal at the receiving end.

[0028] In addition, the present invention also provides a modulation system for a dual-intelligent reflector-assisted spatial modulation method, comprising:

[0029] The transmitting end is configured with one transmitting antenna;

[0030] Receiver, configured N r Root receiving antenna;

[0031] Two intelligent reflective surfaces are each configured with N reflective units. The phase of each reflective unit is adjusted by the controller of the intelligent reflective surface to assist in the transmission of information from the transmitting end to the receiving end, and to perform the aforementioned dual intelligent reflective surface assisted spatial modulation method.

[0032] Preferably, the controller of the two smart reflectors is used to adjust the phase of all reflective elements within each smart reflector to eliminate the influence of the channel phase from the transmitting antenna to the smart reflector and from the smart reflector to the target receiving antenna, thereby maximizing the signal power on the corresponding target receiving antenna. The phase of the i-th reflective element of the smart reflector is expressed as: m∈{1,...,N r}

[0033] In addition, the present invention provides a machine-readable storage medium storing instructions for causing a machine to perform the above-described dual-intelligent reflector-assisted spatial modulation method.

[0034] In addition, the present invention also provides a processor for running a program, wherein the program is executed to perform: the dual-intelligent reflector-assisted spatial modulation method as described above.

[0035] This invention deploys two intelligent reflective surfaces to assist in the transmission of information from the transmitter to the receiver. The transmitter is configured with a transmitting antenna, and the receiver randomly activates a receiving antenna. Both intelligent reflective surfaces correspond to the same receiving antenna. The phase of all reflective elements within each intelligent reflective surface is adjusted to maximize the signal power on the target receiving antenna corresponding to that surface. Communication is achieved through the two intelligent reflective surfaces. Adjusting the angle of the intelligent reflective surfaces improves the quality of the received signal, reduces the bit error rate, and thus improves system performance.

[0036] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 This is a schematic flowchart of a spatial modulation method assisted by dual intelligent reflectors provided in an embodiment of the present invention.

[0039] Figure 2 This is a flowchart illustrating a spatial modulation method assisted by dual intelligent reflectors according to the present invention.

[0040] Figure 3 The specific embodiments of the present invention describe the bit error rate performance of the dual intelligent reflector system with different numbers of reflective elements, different modulation orders, and different numbers of receiving antennas. Detailed Implementation

[0041] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0042] like Figure 1As shown, this invention provides a dual-intelligent reflector-assisted spatial modulation system, including a transmitter with one transmitting antenna, two intelligent reflectors each configured with N reflector elements, and N... r The receiving end of the antenna; due to the obstruction between the transmitting end and the antenna receiving end, smart reflectors are deployed to assist the transmission of information from the transmitting end and the receiving end, with one smart reflector near the transmitting end and one smart reflector near the receiving end, and the phase of each reflector element of the two smart reflectors is adjusted by the controller of the smart reflector.

[0043] The working principle of the entire dual-intelligent reflector-assisted spatial modulation system is as follows: the transmitting end activates one transmitting antenna, two intelligent reflectors correspond to one receiving antenna, and the phase of all reflecting elements in each intelligent reflector is adjusted to maximize the signal power on the target receiving antenna corresponding to that reflector.

[0044] In addition, such as Figure 2 As shown, this embodiment also provides a spatial modulation method assisted by dual intelligent reflectors, including the following steps:

[0045] Step 100: Use a bit splitter to divide the information bits to be sent into two data blocks;

[0046] Step 200: The transmitting end modulates the constellation symbol according to the first data block;

[0047] Step 300: The smart reflector obtains the receiving antenna index based on the second data block, in N... r One of the receiving antennas is selected, and the signal transmitted by the transmitting end is reflected by two smart reflectors. Each smart reflector adjusts the phase of all the reflecting elements in that block to maximize the signal power on the two corresponding target receiving antennas.

[0048] Step 400: The receiver detects the receiving antenna index and the transmitted data symbols using the maximum likelihood detection method based on the received signal, and recovers the information bits.

[0049] Specifically, in step 100, the number of transmitting antennas is 1, and the number of receiving antennas is N. r The constellation order M, the bit separator, based on the above parameters, separates the input information bits L into a first data block L1 and a second data block L2, with lengths log2(M) and log2(N) respectively. r ).

[0050] The bit splitter separates the input L bit stream into two data blocks, L1 and L2. Data block L1 is used to map a QAM constellation symbol x; data block L2 is used to select an antenna index from the receive antenna indices.

[0051] Step 200: The transmitting end modulates the constellation symbol according to the first data block, and activates a transmitting antenna to transmit the signal according to the second data block;

[0052] In step 200, the transmitting end modulates constellation symbols according to the first data block. The specific implementation steps are as follows:

[0053] The first data block L1 is processed based on the signal constellation mapping bits to obtain the constellation symbol x of the M-QAM signal;

[0054] For example, data block L1 contains log2(M) information bits, which are used to map to a constellation point x in the M-QAM signal constellation set S, where M represents the modulation order of the QAM constellation set S. The specific constellation mapping is shown in Table 1.

[0055] Table 1 Zodiac Sign Mapping Table

[0056] Bit symbol 00 -1-j 01 -1+j 10 1-j 11 1+j

[0057] Step 300: The second data block is used for receiving antenna index selection. The smart reflector obtains the receiving antenna index based on the second data block, in N... r One receiving antenna is selected from the root receiving antennas. Two intelligent reflective surfaces adjust the phase of all reflective elements within that block to maximize the signal power on the target antenna receiving antenna corresponding to that block, forming a beam pointing towards the target antenna at the receiving end.

[0058] In step 300, the second data block is used for receiving antenna index selection. Each smart reflector adjusts the phase of all reflective elements within that block to maximize the signal power on the target receiving antenna corresponding to that block. The specific implementation steps are as follows:

[0059] (1) Convert the second data block L2 into a decimal number and add 1 to obtain the receiving antenna index m, m∈{1,...,N}. r};

[0060] (2) Select N based on the receiving antenna index m. r One of the receiving antennas in the block has two intelligent reflective surfaces that adjust the phase of all reflective elements within that block, thereby maximizing the signal power on the target receiving antenna corresponding to that block.

[0061] For example, in a system there are N r =4 receiving antennas, which means that one of the four receiving antennas is selected. The specific receiving antenna mapping is shown in Table 2.

[0062] Table 2 Receiving Antenna Mapping Table

[0063] Bit Selected receiving antenna 00 1 01 2 10 3 11 4

[0064] The system's spectral efficiency is: R = log2(N) r )+log2(M).

[0065] log2(M) represents the constellation mapping bits, log2(N) represents the constellation mapping bits. r ) represents the receive antenna index bit.

[0066] The expression for the received signal of the receiving antenna is as follows:

[0067] In the above formula, and These represent the wireless fading channels between the transmitter and the first and second smart reflectors, respectively. and Let N represent the wireless fading channels between the i-th reflective element of the first and second smart reflective surfaces and the l-th receiving antenna of the receiver, respectively; and let N represent the total number of reflective elements of each smart reflective surface.

[0068] In an uncorrelated flat Rayleigh fading channel Where l∈{1,...,N} r} n represents additive white Gaussian noise with noise power equal to N0, following a complex Gaussian distribution. and Let represent the reflection coefficients of the first and second smart reflective surfaces, respectively. and These represent the phases of the i-th reflecting unit of the first and second smart reflective surfaces, respectively.

[0069] In step 400, the calculation formula for the maximum likelihood detection algorithm is as follows:

[0070]

[0071] In the above formula, and Representing the estimated transmit antenna index and constellation symbol, respectively, y l This represents the expression for the received signal at the receiving end.

[0072] Based on the above, this embodiment conducts a specific simulation experiment. The simulation conditions are as follows: the total transmit power in each transmit vector symbol time slot is 1, the signal-to-noise ratio ranges from -35 to -20 dB, the number of transmit antennas is 1, the fading channel is flat Rayleigh fading, the interference noise is additive white Gaussian noise, the receiver uses maximum likelihood detection, and the channel state information is known.

[0073] like Figure 3As shown, the bit error rate performance of the two smart reflectors is depicted under different numbers of reflective elements, different modulation orders, and different numbers of receiving antennas. For different parameter values, it can be seen that the theoretical results (Theoretical in the figure) are very close to the simulation results, especially in the high signal-to-noise ratio range. Furthermore, the bit error rate performance of the proposed scheme is improved as the number of reflective elements in the smart reflector increases.

[0074] This invention provides a storage medium storing a program that, when executed by a processor, implements the dual-intelligent reflector-assisted spatial modulation method.

[0075] This invention provides a processor for running a program, wherein the program executes the dual-intelligent reflector-assisted spatial modulation method during runtime.

[0076] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs the following steps: (method claim steps, exclusive claim + subordinate claim). The device described herein can be a server, PC, PAD, mobile phone, etc.

[0077] This application also provides a computer program product that, when executed on a data processing device, is suitable for executing an initialization program having the following method steps: (steps of method claims, exclusive claim + subordinate claim).

[0078] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0079] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0080] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0081] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0082] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0083] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0084] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0085] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0086] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0087] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A spatial modulation method assisted by dual intelligent reflective surfaces, characterized in that, The dual-intelligent reflector-assisted spatial modulation method includes: The information bits to be sent are divided into a first data block and a second data block using a bit splitter. The transmitting end modulates constellation symbols according to the first data block; The intelligent reflector obtains the receiving antenna index based on the second data block, in N r One of the receiving antennas is selected, and the signal transmitted by the transmitting end is reflected by two smart reflectors. Each smart reflector adjusts the phase of all the reflecting elements in its block to maximize the signal power on the two corresponding target receiving antennas. The receiver detects the receiving antenna index and the transmitted data symbols using the maximum likelihood detection method based on the received signal, and then recovers the information bits.

2. The spatial modulation method assisted by dual intelligent reflectors according to claim 1, characterized in that, The step of using a bit splitter to divide the information bits to be transmitted into a first data block and a second data block includes: The number of transmit antennas is 1, and the number of receive antennas is N. r The order of the constellation diagram is M; Based on the number of transmitting antennas, the number of receiving antennas, and the constellation order, the information bit L to be transmitted is divided into a first data block L1 and a second data block L2, with lengths of log2(M) and log2(N), respectively. r ).

3. The spatial modulation method assisted by dual intelligent reflectors according to claim 2, characterized in that, The transmitting end modulates constellation symbols according to the first data block, including: The first data block L1 is processed based on the signal constellation mapping bits to obtain the constellation symbol x.

4. The spatial modulation method assisted by dual intelligent reflectors according to claim 1, characterized in that, The intelligent reflector obtains the receiving antenna index based on the second data block, in N r One receiving antenna is selected, and the signal transmitted by the transmitting end is reflected by two intelligent reflectors. Each intelligent reflector adjusts the phase of all reflecting elements within its block to maximize the signal power on the two corresponding target receiving antennas, including: Convert the second data block L2 into a decimal number and add 1 to obtain the receiving antenna index m, m∈{1,...,N}. r }, N r This indicates the number of all indices in the receiving antenna; The expression for the received signal of the receiving antenna is as follows: In the above formula, and These represent the wireless fading channels between the transmitter and the first and second smart reflectors, respectively. and Let N represent the wireless fading channels between the i-th reflective element of the first and second smart reflective surfaces and the l-th receiving antenna of the receiver, respectively; and let N represent the total number of reflective elements of each smart reflective surface. In an uncorrelated flat Rayleigh fading channel Where, l∈{1,...,N r }, where n represents additive white Gaussian noise with power equal to N0, following a complex Gaussian distribution. and Let represent the reflection coefficients of the first and second smart reflective surfaces, respectively. and These represent the phases of the i-th reflecting unit of the first and second smart reflective surfaces, respectively.

5. The spatial modulation method assisted by dual intelligent reflectors according to claim 4, characterized in that, The maximum likelihood detection method includes: Maximum likelihood detection is achieved using the following formula: In the above formula, and Representing the estimated transmit antenna index and constellation symbol, respectively, y l This represents the expression for the received signal at the receiving end.

6. A modulation system for a spatial modulation method assisted by dual intelligent reflectors, characterized in that, include: The transmitting end is configured with one transmitting antenna; Receiver, configured N r Root receiving antenna; Two intelligent reflective surfaces are each configured with N reflective units. The phase of each reflective unit is adjusted by the controller of the intelligent reflective surface to assist in the transmission of information from the transmitting end to the receiving end, and to perform the spatial modulation method assisted by dual intelligent reflective surfaces as described in any one of claims 1-5.

7. A space modulation system assisted by dual intelligent reflectors according to claim 6, characterized in that, The controllers of the two smart reflectors are used to adjust the phase of all reflective elements within each smart reflector to eliminate the influence of the channel phase from the transmitting antenna to the smart reflector and from the smart reflector to the target receiving antenna, thereby maximizing the signal power on the corresponding target receiving antenna. The phase of the i-th reflective element of the smart reflector is expressed as: m∈{1,...,N r } 8. A machine-readable storage medium storing instructions for causing a machine to perform the dual-intelligent reflector-assisted spatial modulation method according to any one of claims 1-5 of this application.

9. A processor, characterized in that, Used to run a program, wherein the program is run to execute: the dual-intelligent reflector-assisted spatial modulation method as described in any one of claims 1-5.

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