Reconfigurable intelligent surface assisted backscattering signal coding method and system

Abstract

The invention discloses a reconfigurable intelligent surface assisted backscattering signal coding method and system, and solves the problems of low multi-signal superposition processing efficiency, low signal identification degree and low transmission efficiency in the prior art. Each quantized signal is input into one RIS unit; the method comprises the following steps: preprocessing an input quantized signal, dividing signals of K channels into two equalization subsets, and distributing different weights for the quantized signal of each channel; calculating the phase shift and backscattering information of each channel quantized signal in the subset by using the weight and the channel number K and combining the opening and closing condition of each RIS unit, and carrying out backscattering signal coding; and based on the obtained coded signal, combining gain in a signal transmission process to obtain a superposed signal. The problem of signal superposition in air computing is solved, the signal identification degree and the transmission efficiency are improved, and the complexity and the cost of an air computing system are reduced.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a reconfigurable smart surface-assisted backscatter signal encoding method and system. Background Technology

[0002] With the rapid development of wireless communication technology, over-the-air computing, as an emerging computing paradigm, transmits and processes data via wireless signals in the air, providing strong support for applications such as the Internet of Things (IoT) and the Internet of Vehicles (IoV). However, in practical applications, over-the-air computing faces the problem of destructive overlap of constellation points caused by signal superposition, which seriously affects the reliability and effectiveness of communication.

[0003] In traditional over-the-air computing systems, multi-channel signals inevitably overlap during transmission, often resulting in destructive overlap of constellation points at the receiver. This means that signals from multiple different channels combine to form the same received signal, making it impossible for the receiver to accurately distinguish between different channels, leading to decoding errors. This problem is particularly pronounced in multi-user, highly dynamic communication environments. Although existing technologies have made some progress in signal processing and modulation / demodulation, most methods still suffer from inefficiency, high cost, or poor compatibility when dealing with signal overlap. Furthermore, existing technologies often struggle to guarantee signal accuracy and stability when handling high-speed movement and complex channel environments. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of low efficiency, low signal identification and low transmission efficiency in the existing technology of multi-signal superposition processing. It provides a reconfigurable smart surface-assisted backscatter signal encoding method and system, which effectively solves the signal superposition problem in air computing, improves signal identification and transmission efficiency, and reduces the complexity and cost of air computing system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A reconfigurable smart surface-assisted backscattering signal encoding method, characterized by comprising the following steps: The signals from K channels at the transmitting end are quantized, and each quantized signal is input into a RIS unit; The input quantized signal is preprocessed by dividing the K channels into two equal subsets and assigning different weights to the quantized signal of each channel. Using the weights and the number of channels K, combined with the on / off state of each RIS unit, the phase shift and backscatter information of the quantized signal of each channel in the subset are calculated, and the backscatter signal is encoded. Based on the obtained coded signal, and combined with the gain during signal transmission, the superimposed signal is obtained.

[0006] The method of this invention divides the input signal into two balanced subsets and assigns unique weights to the quantized signal of each channel, ensuring that the receiver can clearly distinguish each signal even when signals are superimposed. This effectively solves the destructive overlap problem that occurs after multi-channel signal superposition, reduces decoding errors, and improves the overall performance and reliability of the communication system. Encoding based on the on / off state of the RIS unit dynamically adjusts the phase and amplitude of the reflected signal, significantly reducing imperfect superposition of signals in the channel and computational errors. With the help of RIS, the phase and amplitude of the signal can be adjusted in real time during transmission, maximizing signal transmission efficiency and enhancing the adaptability of the communication system in complex communication environments.

[0007] As a preferred option, the weight of the Kth channel is 2 to the power of m, where m is the index of the Kth channel signal in the corresponding subset.

[0008] Preferably, if K is even, the quantized signals of the K channels are divided into an α set and a β set, each containing K / 2 channels; if K is odd, the quantized signals of the first (K+1) / 2 channels are assigned to the α set, and the quantized signals of the last (K-1) / 2 channels are assigned to the β set; each subset is represented using two different dimensions: amplitude and phase.

[0009] Preferably, the weights satisfy the constraint that each combination of the K channel signals has a unique channel superposition result.

[0010] Preferably, if K is even, the signal modulation in the α set satisfies: if the quantized signal is 0, the backscattering information carried by the encoder is the weight w of the channel where the quantized signal is located. k Subtracting from 2 / K The difference, if the quantization signal is 1, means the backscattered information carried by the encoder is 2 / K minus 2 / K. The opposite of the β set; the signal modulation in the β set satisfies: if the quantized signal is 0, then the phase shift of the quantized signal is the weight w. k The difference between the quantized signal and the power of K / 2 minus 1 is such that if the quantized signal is 1, then the phase shift of the quantized signal is the opposite of the power of K / 2 minus 1.

[0011] Preferably, if K is odd, the signal modulation in the α set satisfies: if the quantized signal is 0, the backscattering information carried by the encoder is the weight w of the channel containing the quantized signal. k Subtracting (K+1) from 2 / 2 The difference, if the quantization signal is 1, means the backscattered information carried by the encoder is (K+1) / 2 minus (K+1) / 2. The opposite of the β set; the signal modulation in the β set satisfies: if the quantized signal is 0, then the phase shift of the quantized signal is the weight w. k Subtracting (K-1) from 2 / 2 The difference, if the quantized signal is 1, then the phase shift of the quantized signal is (K-1) / 2 minus (K-1) / 2. The opposite number.

[0012] As a preferred method, the encoded signals of each channel are superimposed to obtain the received signal. The receiver uses the maximum likelihood estimation method to reconstruct the original information of the transmitter and estimates the transmitted signal based on the Euclidean distance minimization constraint in the signal space.

[0013] A reconfigurable smart surface-assisted backscattering signal encoding system, comprising: The transmitter unit includes K nodes, each node generates an input signal, and processes the input signal to obtain a quantized signal; The RIS (Radio-Integrated Modulation Encoder) performs integrated modulation encoding on the quantized signal by adjusting the phase and amplitude. The receiver receives the superimposed signals from all nodes, processes the superimposed signals, and recovers the signals through the decoder.

[0014] Preferably, the signal transmission includes a direct transmission path and a reflection path. In the reflection path, the quantized signal is sent to the RIS integrated modulation encoder at a preset transmission power.

[0015] Preferably, the RIS integrated modulation encoder includes RIS units. When performing integrated modulation encoding on the signal, the first Na RIS units are turned on. The amplitude coefficient of the turned-on RIS units is 1, and the amplitude coefficient of the turned-off RIS units is 0. Na represents the backscattered signal carried by the RIS integrated modulation encoder.

[0016] Therefore, the present invention has the following beneficial effects: 1. By dividing the input signal into two balanced subsets and assigning unique weights to the quantized signal of each channel, the receiver can clearly distinguish each signal even when signals are superimposed. This effectively solves the destructive overlap problem that occurs after multi-channel signal superposition, reduces decoding errors, and improves the overall performance and reliability of the communication system.

[0017] 2. Encoding is based on the on / off state of the RIS unit, dynamically adjusting the phase and amplitude of the reflected signal, significantly reducing imperfect superposition of signals in the channel and computational errors. With the help of RIS, the phase and amplitude of the signal can be adjusted in real time during transmission, maximizing signal transmission efficiency and enhancing the adaptability of the communication system in complex communication environments. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the overall steps of the reconfigurable smart surface-assisted backscattering signal encoding method in this invention.

[0019] Figure 2 This is a flowchart illustrating the technical process of the reconfigurable smart surface-assisted backscattering signal encoding method in this invention.

[0020] Figure 3 This is a schematic diagram of the architecture of the reconfigurable smart surface-assisted backscatter signal encoding system in this invention.

[0021] Figure 4 This is the constellation diagram after the coding channels are superimposed in Example 2.

[0022] In the diagram: 1. Transmitter unit; 2. RIS integrated modulation encoder; 3. Receiver. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1: This embodiment provides a reconfigurable smart surface-assisted backscattering signal encoding method, such as... Figure 1 As shown, the operation process is as follows: Step 1, quantize the signals from K channels at the transmitter, and input each quantized signal into a RIS unit; Step 2, preprocess the input quantized signals, divide the signals from K channels into two equalized subsets, and assign different weights to the quantized signals of each channel; Step 3, using the weights and the number of channels K, combined with the on / off state of each RIS unit, calculate the phase shift and backscatter information of the quantized signals of each channel in the subset, and encode the backscatter signal; Step 4, based on the obtained encoded signal and combined with the gain during signal transmission, obtain the superimposed signal.

[0024] Reconfigurable Intelligence Surfaces (RIS) can define new wireless transmission and propagation modes and control communication channels (reshaping the wireless channel). A RIS is a metasurface containing electronically controllable and low-power analog processing elements. It can adjust the absorption, reflection, refraction, and phase of passive reflective elements in real time to guide incident electromagnetic signals in the desired direction. The phase and amplitude of the reflected signal maximize the effective channel gain.

[0025] RIS can be deployed in various locations and attached to surfaces such as buildings, vehicles, and interior walls with minimal cost and effort. Another advantage is its compatibility with current radio technologies and its support for advanced wireless waveforms and full-duplex and half-duplex communication across a wide bandwidth and frequency range.

[0026] RIS (Radio Frequency Identification) encoding involves real-time programmable control of the amplitude, phase, frequency, and polarization characteristics of electromagnetic waves by loading specific control devices, such as PIN diodes, varactors, and microelectromechanical systems (MEMS) switches. This control enables RIS to regulate the propagation behavior of electromagnetic waves in free space, overcoming the limitations of traditional wireless channels that cannot be actively controlled, thus constructing a new paradigm for intelligent programmable wireless environments. This embodiment mainly utilizes RIS to dynamically adjust the signal phase and amplitude.

[0027] The reconfigurable smart surface-assisted backscatter signal encoding method provided in this embodiment ensures that the receiver can clearly distinguish individual signals even when multiple channels are superimposed, by optimizing the signal transmission path and quantization processing. A unique encoding strategy and weight allocation are employed to avoid destructive overlap after signal superposition. Encoding the signal based on RIS optimizes the signal transmission path and phase and amplitude adjustment, reducing imperfect superposition and computational errors in the channel. RIS technology can dynamically adjust the phase and amplitude of the signal during transmission, thereby maximizing signal transmission efficiency, significantly reducing redundancy in signal processing, and thus improving the overall performance of the communication system, ensuring smooth and efficient communication.

[0028] The following examples and specific application scenarios further illustrate the technical solution and effects of the present invention. The following examples are explanations of the present invention, but the present invention is not limited to the following examples.

[0029] like Figure 2 As shown, the reconfigurable smart surface-assisted backscatter signal encoding method provided in this embodiment mainly includes two parts: the APCompCode encoding method and the RIS integrated modulation and coding technology. The APCompCode encoding backscatter technology is mainly used to solve the problem of destructive overlap of constellation points caused by signal superposition in aerial computing. It divides multiple signals into two-dimensional balanced subsets and performs non-interleaving weight allocation on all signals. The RIS integrated modulation and coding technology is responsible for optimizing the signal transmission path and dynamically adjusting the phase amplitude.

[0030] Specifically, a reconfigurable smart surface-assisted backscattering signal encoding method includes the following steps: Step 1: Quantize the signals from the K channels at the transmitter, and input each quantized signal into a RIS unit.

[0031] The input signal for each channel is x. k For each input signal (k = 1, 2, ..., K), quantization is performed to obtain the quantized signal.

[0032] In the reflection path, each quantized signal transmits at power p. k The signal is sent to a corresponding RIS unit, and the gain of the signal from transmission to arrival at the RIS unit is g. k The RIS unit encodes the quantized signal by adjusting its phase and amplitude to avoid calculation errors caused by imperfect signal superposition in the channel.

[0033] According to the signal encoding rules, the first Na RIS units are in the open state. The amplitude coefficient of the RIS unit in the open state is 1, and the amplitude coefficient of the RIS unit in the closed state is 0. Na represents the backscatter information carried by the encoder.

[0034] The second step is to preprocess the input quantized signal by dividing the K channels into two equalized subsets and assigning different weights to the quantized signal of each channel.

[0035] The division method is as follows: (1) K is an even number.

[0036] If K is even, the quantized signals of the K channels are divided into an α set and a β set, each containing K / 2 channels. Each subset is represented using two different dimensions: amplitude and phase. The first K / 2 channels are assigned to the α set, and the last K / 2 channels are assigned to the β set.

[0037] (2) K is an odd number.

[0038] If K is odd, for a quantized signal with K channels, the first (K+1) / 2 channels of quantized signal are assigned to the α set, and the last (K-1) / 2 channels of quantized signal are assigned to the β set.

[0039] After subset partitioning, the quantized signal of each channel A unique weight w will be assigned k This is used to maintain the recognizability of superimposed signals, ensuring that individual signals can be clearly distinguished even when signals are mixed.

[0040] The selection of weights follows a principle: the weights of adjacent signals must have significant differences to avoid uncertainties in the superposition process. That is, it satisfies the constraint that each combination of the K channel signals has a unique channel superposition result.

[0041] Therefore, in this embodiment, the weight is w k =2 m , where m represents the index of the signal in the corresponding subset. This weighting method ensures the uniqueness of the signal superposition result; different permutations and combinations of the input signals have their unique superposition value.

[0042] Step 3: Using the weights and the number of channels K, combined with the on / off state of each RIS unit, calculate the phase shift and backscatter information of the quantized signal of each channel in the subset, and encode the backscatter signal.

[0043] In this embodiment, for a signal transmission system containing K channels, the following modulation and coding strategy is formulated based on the parity of K: (1) K is an even number.

[0044] For the α set (k≤K / 2), the signal modulation satisfies: 1) If the quantization signal is 0 (i.e., the RIS unit is off), the backscatter information Na carried by the encoder is the weight of the channel containing the quantization signal and the power of the second power of K of 2 minus 1 (i.e., The difference between the two values ​​is expressed by the following formula:

[0045] 2) If the quantization signal is 1 (i.e., the RIS unit is enabled), the backscattered information Na carried by the encoder is 2 / K^2 - 1 (i.e., ... The opposite of ) is expressed by the following formula:

[0046] For the β set (k≥K / 2), the signal modulation satisfies: 1) If the quantized signal is 0, then the phase shift of the quantized signal is... For weight w k =2 / K raised to the power of 2 minus 1 (i.e. The difference between the two values ​​is expressed by the following formula:

[0047] 2) If the quantized signal is 1, then the phase shift of the quantized signal is... It is 2 / 2^K minus 1 (i.e. The opposite of )

[0048] A signal consists of a real part and an imaginary part. The real part represents the amplitude information of the signal, and the imaginary part represents the phase information of the signal.

[0049] (2) K is an odd number.

[0050] For the set α (k≤K+1 / 2), the signal modulation satisfies: 1) If the quantized signal is 0, the backscatter information carried by the encoder is the weight w of the channel containing the quantized signal. k (K+1) / 2 minus 1 is... The difference is expressed by the formula:

[0051] 2) If the quantization signal is 1, the backscatter information carried by the encoder is the negative of (K+1) / 2 raised to the power of (K+1) minus 1, expressed by the formula:

[0052] For the β set (k≥K+1 / 2) , the signal modulation satisfies: 1) If the quantized signal is 0, then the phase shift of the quantized signal is the weight w. k The difference between (K-1) / 2 and (K-1) / 2 raised to the power of (K-1) minus 1 can be expressed by the formula:

[0053] 2) If the quantized signal is 1, then the phase shift of the quantized signal is the negative of (K-1) / 2 raised to the power of (K-1) minus 1, expressed by the formula:

[0054] Step 4: Based on the obtained coded signal, and combined with the gain during signal transmission, the superimposed signal is obtained.

[0055] The superimposed signal is:

[0056] Therefore, the encoding of the received signal consists of the backscattered information Na carried by the encoder and the phase shift of the i-th RIS unit. To be determined jointly.

[0057] Based on the above, this embodiment provides a reconfigurable smart surface-assisted backscattering signal encoding method, offering a solution to the signal superposition problem in aerial computing, and has the following beneficial effects: 1. Unique signal preprocessing and weighting methods. Significantly improves signal recognition accuracy and communication reliability. APCompCode technology divides the input signal into two balanced subsets and assigns unique weights to the quantized signal of each channel to ensure that the receiver can clearly distinguish each signal even when signals are superimposed. This weighting configuration follows the principle of significant difference, avoiding recognition errors caused by signal permutations and combinations. In this way, APCompCode technology can effectively solve the destructive overlap problem that occurs after multi-channel signal superposition, reduce decoding errors, and improve the overall performance and reliability of the communication system.

[0058] 2. RIS (Reinforced Interchange and Coding) technology. APCompCode significantly reduces imperfect superposition of signals and computational errors in the channel by dynamically adjusting the phase and amplitude of the reflected signal. With the help of RIS, the signal transmission system can adjust the phase and amplitude of the signal in real time during transmission, maximizing signal transmission efficiency and enhancing the adaptability of the signal transmission system in complex communication environments.

[0059] 3. By employing innovative APCompCode and RIS (Radio Synthetic Modulation and Coding) technologies, the signal superposition problem in over-the-air computing is effectively solved. APCompCode technology, through unique preprocessing and weight allocation, improves signal recognition and communication reliability, while RIS technology optimizes the transmission path by dynamically adjusting signal phase and amplitude, thereby improving transmission efficiency and simplifying system design. This not only enhances the performance of the signal transmission system but also strengthens its adaptability in complex communication environments, providing a more reliable and efficient solution for over-the-air computing and wireless communication.

[0060] Example 2: This embodiment provides a reconfigurable smart surface-assisted backscattering signal encoding system for implementing the reconfigurable smart surface-assisted backscattering signal encoding method provided in Embodiment 1.

[0061] like Figure 3 As shown in the figure, this embodiment provides a reconfigurable smart surface-assisted backscatter signal encoding system, including a transmitter unit 1 (containing multiple transmitters), a RIS synthesized modulation encoder 2 (containing multiple RIS units, each transmitter transmitting a signal corresponding to one RIS unit), and a receiver 3; the transmitter is used to generate an input signal, process the input signal to obtain a quantized signal; the RIS synthesized modulation encoder performs synthesized modulation encoding on the quantized signal by adjusting the phase and amplitude; the receiver receives the superimposed signal of all nodes, processes the superposition, and recovers the signal through the decoder.

[0062] Specifically: There are two main transmission paths for signals during transmission: direct transmission path and reflection path.

[0063] In this embodiment, there are K transmitters, i.e., K nodes, and each node generates an input signal x. k (k = 1, 2, ..., K). These nodes are processed by the quantizer in the transmitter to obtain the quantized signal.

[0064] In the reflection path, the quantized signal With transmission power p k The signal is sent to the RIS synthesized modulation encoder, and the quantized signal gains g from the k-th transmitter to the synthesized modulation encoder. k .

[0065] The RIS integrated modulation encoder encodes signals by adjusting the phase and amplitude to avoid calculation errors caused by imperfect signal superposition in the channel.

[0066] The reflection matrix is: Where γ i ∈{0,1} is the amplitude coefficient of the i-th RIS unit. It is the phase shift of the i-th RIS unit, i = 1, 2, ..., N, where N represents the total number of RIS units.

[0067] Therefore, the final receiver receives the superimposed signal from all nodes as follows: Among them, h k denoted by , where represents the channel gain of each channel during signal transmission, 'n' represents the additive noise of the channel, and 'w' represents the direct link transmission from the quantized signal to the receiver.

[0068] The receiver processes the superimposed signals and uses a decoder to recover the original transmitter signal f(x1,...,x) K ).

[0069] Further explanation of the encoding process: During the synthesis and modulation encoding of quantized signals using a RIS synthesized modulator-encoder, not all RIS units within the RIS synthesized modulator-encoder are in the active state. According to the signal encoding rules, the first Na RIS units are designated as active, with their amplitude coefficients set to 1, while those in the inactive state have their amplitude coefficients set to 0.

[0070] Therefore, the received signal is re-expressed as: Therefore, it can be deduced that the encoding of the received signal consists of the backscatter information Na carried by the RIS integrated modulation encoder and the phase shift of the RIS integrated modulation encoder. To be determined jointly.

[0071] In over-the-air computing, signals from multiple channels can overlap during transmission. This overlap often leads to destructive overlap of constellation points at the receiver, meaning that signals from multiple different channels combine to form the same received signal after transmission. This overlap makes it impossible for the receiver to accurately distinguish between signals from different channels, resulting in decoding errors and severely impacting the reliability and effectiveness of communication.

[0072] During channel transmission, multiple channel signals are superimposed, and the superimposed signal is:

[0073] Where b (i) Let b be a set of all 0s and 1s of length K, describing the possible permutations of K channel signals at the same time. (i) ∈{0,1} K And it satisfies ∑p(b)=1.

[0074] To achieve effective channel superposition, the following constraints must be met: That is, each combination of K channel signals has its unique channel superposition result.

[0075] The RIS synthesized modulation encoder uses the following encoding method: At the beginning of the signal transmission process, the input signal is first preprocessed, and the signals of the K channels are divided into two equalized subsets.

[0076] After the set allocation is completed, the quantized signal of each channel A unique weight w will be assigned k This is used to maintain the recognizability of superimposed signals, ensuring that individual signals can be clearly distinguished even when signals are mixed.

[0077] The selection of weights follows a principle: the weights of adjacent signals must have significant differences in order to avoid uncertainties in the superposition process.

[0078] Therefore, in this embodiment, the weight w is defined. k =2 m , where m represents the index of the signal in the corresponding subset. This weighting strategy is extremely important because it ensures the uniqueness of the signal superposition result; different permutations and combinations of the input signals have their unique corresponding superposition value.

[0079] Furthermore, if the signal is divided into two groups, each represented by two different dimensions of amplitude and phase, then a clear, non-intersecting constellation diagram can be formed in two-dimensional space.

[0080] In this embodiment, assuming channel K=4, there are 16 possible signal combinations. The signals from the four channels are encoded separately using a RIS-based integrated modulation encoder. The four signals are then superimposed and interleaved in the channel to form a signal as shown below. Figure 4 The constellation diagram shown. Each point in the constellation diagram represents a specific combination of input signals, reflecting the mapping relationship in the tabular function.

[0081] The bit error rate performance of a RIS synthesized modulation encoder can be characterized by the Euclidean distance between adjacent points in a 16-QAM constellation diagram, i.e.: Among them, A M This indicates the maximum amplitude.

[0082] This relationship can be generalized to the general case, that is:

[0083] Therefore, for a signal transmission system with K channels, the following modulation and coding strategy can be formulated based on the parity of K: (1) If K is even, the K channels are divided into two sets, α and β, with each set containing K / 2 channels.

[0084] Then the signal modulation in set α satisfies:

[0085] Signal modulation in the β set satisfies:

[0086] (2) If K is odd, allocate the first (K+1) / 2 channels to the α set and the last (K-1) / 2 channels to the β set.

[0087] At this point, the signal modulation in set α satisfies:

[0088] Signal modulation in the β set satisfies:

[0089] Based on the above, the backscattering information Na and phase shift of each channel signal can be obtained. The backscattering information Na and phase shift are used to encode the channel signal. Then, according to the formula for the superimposed signal mentioned above, the superimposed signal received by the receiver can be obtained.

[0090] For the receiver, this embodiment employs the maximum likelihood estimation method to reconstruct the original information from the transmitter. Based on the principle of minimizing Euclidean distance in the signal space, it ensures that, given the received signal y, the transmitted signal can be accurately estimated with the highest probability.

[0091] Specifically, the receiver estimate The calculation formula is as follows: In the above formula, Indicates the transmission signal The estimate, Represents the RIS synthesized modulation encoder for the transmitted signal The result after encoding and channel superposition.

[0092] The encoding process can be viewed as a tabular function determined by the number of input channels K. Since the encoding method satisfies the constraint that each combination of K channel signals has its unique channel superposition result, the superimposed signal values ​​after transmission can still maintain a one-to-one mapping relationship with the input signals.

[0093] This embodiment proposes a reconfigurable smart surface-assisted backscatter signal encoding system with the following advantages: 1. Avoiding destructive signal overlap. By optimizing the signal transmission path and quantization processing, the receiver can clearly distinguish each signal even when multiple channels are superimposed. A unique encoding strategy and weight allocation are employed to avoid destructive overlap after signal superposition. The weight configuration follows the principle of significant difference, ensuring uniqueness and recognizability after signal superposition, thereby improving the reliability and effectiveness of communication. This enhanced signal recognition is particularly important in multi-user and high-dynamic environments, effectively reducing decoding errors and improving overall communication quality.

[0094] 2. Improved Signal Transmission Efficiency. By encoding the signal using a RIS (Reinforced Interchangeable Signal Encoder) system, the transmission path and phase and amplitude adjustments are optimized, reducing imperfect superposition of signals in the channel and computational errors. RIS technology enables the system to dynamically adjust the signal phase and amplitude during transmission, thereby maximizing signal transmission efficiency. Compared to traditional systems, this optimization significantly reduces redundancy in signal processing and improves the overall system performance. Especially in complex communication environments, the system's high-efficiency transmission capability effectively addresses various challenges, ensuring smooth and efficient communication.

[0095] 3. Reduced System Complexity and Cost. The coding system significantly reduces system construction and maintenance costs by simplifying signal processing and reducing required hardware resources. Traditional methods require complex hardware and algorithm support, leading to high costs. The backscatter coding system provided in this embodiment simplifies system design through innovative coding methods and RIS technology, achieving more cost-effective signal processing, reducing required hardware resources and computational burden, and lowering system construction and maintenance costs. The simplified design of the coding system reduces hardware requirements and dependence on high-performance processors and large amounts of storage resources, thereby reducing overall costs. Compared to traditional methods, APCompCode, combined with RIS technology, not only improves transmission efficiency but also significantly reduces system complexity and cost, making it more economical and practical for large-scale applications. For large-scale applications such as the Internet of Things and the Internet of Vehicles, the low-cost advantage of the coding system makes it more competitive in commercial deployment.

[0096] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A reconfigurable smart surface-assisted backscattering signal encoding method, characterized in that, Includes the following steps: The signals from K channels at the transmitting end are quantized, and each quantized signal is input into a RIS unit; The input quantized signal is preprocessed by dividing the K channels into two equal subsets and assigning different weights to the quantized signal of each channel. By utilizing the parity of the weights and the number of channels K, and combining the on / off state of each RIS unit, the phase shift and backscatter information of the quantized signal of each channel in the subset are calculated, and the backscatter signal is encoded. Based on the obtained coded signal, and combined with the gain during signal transmission, the superimposed signal is obtained.

2. The reconfigurable smart surface-assisted backscattering signal encoding method according to claim 1, characterized in that, The weight of the Kth channel is 2 to the power of m, where m is the index of the Kth channel signal in the corresponding subset.

3. The backscattering signal encoding method assisted by a reconfigurable smart surface according to claim 1, characterized in that, If K is even, the quantized signals of the K channels are divided into an α set and a β set, each containing K / 2 channels; if K is odd, the quantized signals of the first (K+1) / 2 channels are assigned to the α set, and the quantized signals of the last (K-1) / 2 channels are assigned to the β set; each subset is represented using two different dimensions: amplitude and phase.

4. A reconfigurable smart surface-assisted backscattering signal encoding method according to claim 1 or 2, characterized in that, The weights satisfy the constraint that each combination of the K channel signals has a unique channel superposition result.

5. The reconfigurable smart surface-assisted backscattering signal encoding method according to claim 3, characterized in that, If K is even, the signal modulation in set α satisfies the following: if the quantization signal is 0, the backscatter information carried by the encoder is the difference between the weight of the channel containing the quantization signal and 2 / 2^K minus 1; if the quantization signal is 1, the backscatter information carried by the encoder is the opposite of 2 / 2^K minus 1. The signal modulation in set β satisfies the following: if the quantization signal is 0, the phase shift of the quantization signal is the difference between the weight and 2 / 2^K minus 1; if the quantization signal is 1, the phase shift of the quantization signal is the opposite of 2 / 2^K minus 1.

6. A reconfigurable smart surface-assisted backscattering signal encoding method according to claim 3 or 5, characterized in that, If K is odd, the signal modulation in set α satisfies the following: if the quantization signal is 0, the backscatter information carried by the encoder is the difference between the weight of the channel containing the quantization signal and (K+1) / 2 power (K+1) minus 1; if the quantization signal is 1, the backscatter information carried by the encoder is the opposite of (K+1) / 2 power (K+1) minus 1. The signal modulation in set β satisfies the following: if the quantization signal is 0, the phase shift of the quantization signal is the difference between the weight and (K-1) / 2 power (K-1) minus 1; if the quantization signal is 1, the phase shift of the quantization signal is the opposite of (K-1) / 2 power (K-1) minus 1.

7. A reconfigurable smart surface-assisted backscattering signal encoding method according to claim 1, 2, 3, or 5, characterized in that, The encoded signals of each channel are superimposed to obtain the received signal. The receiver uses the maximum likelihood estimation method to reconstruct the original information of the transmitter and estimates the transmitted signal based on the Euclidean distance minimization constraint in the signal space.

8. A reconfigurable smart surface-assisted backscattering signal encoding system, employing the reconfigurable smart surface-assisted backscattering signal encoding method according to any one of claims 1-7, characterized in that, include: The transmitter unit includes K nodes, each node generates an input signal, and processes the input signal to obtain a quantized signal; The RIS (Radio-Integrated Modulation Encoder) performs integrated modulation encoding on the quantized signal by adjusting the phase and amplitude. The receiver receives the superimposed signals from all nodes, processes the superimposed signals, and recovers the signals through the decoder.

9. The reconfigurable smart surface-assisted backscattering signal encoding method according to claim 8, characterized in that, Signal transmission includes a direct transmission path and a reflection path. In the reflection path, the quantized signal is sent to the RIS integrated modulation encoder at a preset transmission power.

10. A reconfigurable smart surface-assisted backscattering signal encoding method according to claim 8 or 9, characterized in that, The RIS integrated modulation encoder includes RIS units. When the signal is integrated and modulated, the first Na RIS units are turned on. The amplitude coefficient of the turned-on RIS units is 1, and the amplitude coefficient of the turned-off RIS units is 0. Na represents the backscattered signal carried by the RIS integrated modulation encoder.

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