A stokes space quantization type digital-analog hybrid signal modulation method and demodulation method for physical layer security transmission

Abstract

This invention discloses a Stokes space quantization-based mixed-signal modulation method for physical layer secure transmission, comprising the following steps: Step S1, acquiring multiple wireless signals from an antenna and aggregating them into a single signal using signal aggregation; Step S2, constructing a known encryption key signal and encrypting the signal waveform; Step S3, converting the aggregated signal and key signal binary into a three-dimensional Stokes vector signal based on the conversion relationship between Jones vectors and Stokes vectors; Step S4, constructing a three-dimensional vector quantization codebook using a spherical Fibonacci mapping relationship; Step S5, quantizing the Stokes vector signal based on the three-dimensional quantization codebook to obtain a digital signal in the Stokes domain; Step S6, converting the Stokes domain digital signal into a two-dimensional signal containing real and imaginary parts; Step S7, obtaining an analog signal by subtraction between the two-dimensional digital signal and the original aggregated signal; Step S8, adjusting the power of the obtained digital and analog signals using two power adjustment coefficients; Step S9, aggregating the adjusted digital and analog signals into a final modulated output signal using time-division multiplexing. The present invention also discloses a Stokes space quantization-based mixed-signal demodulation method for physical layer secure transmission, the steps of which are the reverse process of the above modulation method.

Description

Technical Field

[0001] This invention relates to the field of signal modulation and demodulation technology, and in particular to a Stokes space quantization mixed-signal modulation and demodulation method for physical layer secure transmission. Background Technology

[0002] Mobile fronthaul serves as a crucial fiber optic backbone connecting centralized and distributed units in cloud wireless access networks. To accommodate the anticipated 10-100 times capacity expansion from 6G networks, RoF (Royal Fiber over Fire) architecture has been extensively studied to balance the inherent trade-off between signal-to-noise ratio and spectral efficiency. Based on cascaded digital probabilistic shaping orthogonal amplitude modulation and analog pulse code modulation, Xiang Liu proposed a digital-analog hybrid optical-over-radio (DA-RoF) signal modulation and demodulation scheme based on Cartesian coordinate quantization.

[0003] For uplink wireless signals aggregated in the frequency domain, mathematically they can be represented as a combination of the real and imaginary parts in a two-dimensional Cartesian coordinate system (i.e., a rectangular coordinate system). Using a priori auxiliary signals, traditional two-dimensional frequency-domain aggregated signals can be converted into a three-dimensional representation in Stokes space. The a priori auxiliary signals can be used as encryption keys to perform waveform-level encryption on the target signal, achieving secure transmission at the physical layer.

[0004] Therefore, this invention proposes a Stokes space quantization-based mixed-signal modulation and demodulation method for physical layer secure transmission. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a Stokes space quantization-based mixed-signal modulation and demodulation method for secure physical layer transmission.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0007] A Stokes spatial quantization-based mixed-signal modulation and demodulation method for physical layer secure transmission includes the following steps:

[0008] Step S1: Collect multiple wireless signals from the antenna and aggregate them into one signal through signal aggregation to facilitate unified processing and improve algorithm efficiency.

[0009] In this embodiment, the signal aggregation method includes, but is not limited to, frequency domain aggregation and time domain aggregation. Preferably, frequency division multiplexing is used, and this process can be represented as follows:

[0010]

[0011] in, This represents the aggregated signal. / These represent the wireless signals collected from the antenna, This represents the signal aggregation function.

[0012] Step S2, construct prior auxiliary signals , can be represented as ,in and Represents a priori time-varying signals The amplitude and phase are used to carry the encryption key, facilitating the analysis of the target signal. Perform waveform-level signal encryption.

[0013] Step S3, based on the Jones vector With Stokes vector The transformation relationship between the aggregated signal and the prior auxiliary signal binary will be used to transform the aggregated signal and the prior auxiliary signal binary. Convert to the corresponding three-dimensional Stokes vector The conversion process can be represented as:

[0014]

[0015] in Represents the conjugate operator. This indicates the operator that retrieves the real part of the signal. This indicates the operator for retrieving the imaginary part of the signal. This represents the matrix transpose operator.

[0016] Step S4: Using the spherical Fibonacci mapping relationship, construct a three-dimensional vector quantization codebook in Stokes space. This process can be represented as:

[0017]

[0018] in, , ,in Represents a three-dimensional quantization codebook The number of quantization points This represents the modulo operator.

[0019] Step S5, based on the above three-dimensional vector quantization codebook For three-dimensional Stokes vectors Quantization is performed to obtain a three-dimensional digital signal in the Stokes domain. This process can be represented as:

[0020]

[0021] in The vector quantization function represents the three-dimensional Stokes space.

[0022] Step S6, convert the three-dimensional Stokes space domain digital signal Transformed into a two-dimensional signal containing real and imaginary parts. This process can be represented as:

[0023]

[0024] in Represented by natural constant An exponential function with base , i.e. , This represents the arctangent function.

[0025] Step S7, based on the above two-dimensional digital signal With the aggregated signal The corresponding analog signal is obtained by subtraction. This process can be represented as:

[0026]

[0027] Step S8, using two power regulation coefficients and Regarding the digital signals obtained above and analog signals Adjust the power:

[0028]

[0029]

[0030] Step S9, for the digital signal after power adjustment mentioned above and analog signals The signals are aggregated into a final "Stokes spatial quantization mixed-signal modulation for physical layer secure transmission" output signal using time-division multiplexing. .

[0031] Step S10: The present invention also provides a Stokes space quantization-based mixed-signal demodulation method for physical layer secure transmission, wherein the demodulation method and its steps are the reverse process of the above modulation method and its steps.

[0032] The Stokes space quantization mixed-signal modulation and demodulation method for physical layer secure transmission provided by this invention has the following advantages compared with the prior art:

[0033] (1) The Stokes space quantization mixed-signal modulation and demodulation method for physical layer secure transmission proposed in this invention differs from existing methods by incorporating prior key information. This is introduced into the signal conversion process to achieve waveform-level encryption, thereby enabling secure transmission at the physical layer.

[0034] (2) (1) The Stokes space quantization mixed-signal modulation and demodulation method for physical layer secure transmission proposed in this invention differs from existing methods in that key information can be loaded into the prior time-varying signal. The amplitude or phase dimension provides a richer degree of freedom for encryption.

[0035] (3) The Stokes space quantization mixed-signal modulation and demodulation method for physical layer secure transmission proposed in this invention differs from existing methods by constructing a three-dimensional vector quantization codebook in Stokes space. The target signal is quantized. Attached Figure Description

[0036] Figure 1 This is a flowchart of the Stokes space quantization mixed-signal modulation method for physical layer secure transmission proposed in this invention.

[0037] Figure 2 This is a flowchart of the Stokes space quantization mixed-signal demodulation method for physical layer secure transmission proposed in this invention.

[0038] Figure 3 The Stokes space quantization mixed-signal modulation and demodulation method for physical layer secure transmission proposed in this invention uses a priori auxiliary signals. This is a schematic diagram of the signal encryption process, that is, a schematic diagram of the transformation of a two-dimensional signal into a three-dimensional Stokes vector signal.

[0039] Figure 4 This is the three-dimensional vector quantization codebook constructed in the Stokes spatial quantization mixed-signal modulation and demodulation method for physical layer secure transmission proposed in this invention. Schematic diagram.

[0040] Figure 5 This figure shows the performance comparison of the signal-to-noise ratio (SNR) as a function of received optical power (ROP) between the Stokes spatial quantization mixed-signal modulation and demodulation method (S-DARoF) proposed in this invention for physical layer secure transmission and the traditional analog optical over-the-air (A-RoF) method, under different degrees of nonlinear impairment (BO).

[0041] Figure 6The figure shows a comparison of the performance of the Stokes spatial quantization-based mixed-signal modulation and demodulation method (S-DARoF) proposed in this invention for secure physical layer transmission with that of traditional analog optical radio over a wireless channel (A-RoF), under different degrees of nonlinear impairment (BO), regarding the signal-to-noise ratio (SNR) as a function of noise power in a white Gaussian noise (AWGN) channel.

[0042] Figure 7 This figure shows the performance comparison of the bit error rate (BER) as a function of received optical power (ROP) for the Stokes spatial quantization mixed-signal modulation and demodulation method for physical layer secure transmission proposed in this invention, targeting legitimate users (Bob) and eavesdroppers (Eve). Detailed Implementation

[0043] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0044] like Figures 1 to 7 As shown, the Stokes space quantization mixed-signal modulation and demodulation method for physical layer secure transmission proposed in this invention includes the following steps:

[0045] Step S1: Collect multiple wireless signals from the antenna and aggregate them into one signal through signal aggregation to facilitate unified processing and improve algorithm efficiency.

[0046] In this embodiment, the signal aggregation method includes, but is not limited to, frequency domain aggregation and time domain aggregation. Preferably, frequency division multiplexing is used, and this process can be represented as follows:

[0047]

[0048] in, This represents the aggregated signal. / These represent the wireless signals collected from the antenna, This represents the signal aggregation function.

[0049] Step S2, construct prior auxiliary signals , can be represented as ,in and Represents a priori time-varying signals The amplitude and phase are used to carry the encryption key, facilitating the analysis of the target signal. Perform waveform-level signal encryption.

[0050] Step S3, based on the Jones vector With Stokes vector The transformation relationship between the aggregated signal and the prior auxiliary signal binary will be used to transform the aggregated signal and the prior auxiliary signal binary. Convert to the corresponding three-dimensional Stokes vector The conversion process can be represented as:

[0051]

[0052] in Represents the conjugate operator. This indicates the operator that retrieves the real part of the signal. This indicates the operator for retrieving the imaginary part of the signal. This represents the matrix transpose operator.

[0053] Step S4: Using the spherical Fibonacci mapping relationship, construct a three-dimensional vector quantization codebook in Stokes space. This process can be represented as:

[0054]

[0055] in, , ,in Represents a three-dimensional quantization codebook The number of quantization points This represents the modulo operator.

[0056] Step S5, based on the above three-dimensional vector quantization codebook For three-dimensional Stokes vectors Quantization is performed to obtain a three-dimensional digital signal in the Stokes domain. This process can be represented as:

[0057]

[0058] in The vector quantization function represents the three-dimensional Stokes space.

[0059] Step S6, convert the three-dimensional Stokes space domain digital signal Transformed into a two-dimensional signal containing real and imaginary parts. This process can be represented as:

[0060]

[0061] in Represented by natural constant An exponential function with base , i.e. , This represents the arctangent function.

[0062] Step S7, based on the above two-dimensional digital signal With the aggregated signal The corresponding analog signal is obtained by subtraction. This process can be represented as:

[0063]

[0064] Step S8, using two power regulation coefficients and Regarding the above-mentioned acquisitions Signals and Signal power adjustment:

[0065]

[0066]

[0067] Step S9, regarding the signal after power adjustment... and The signals are aggregated into a final "Stokes spatial quantization mixed-signal modulation for physical layer secure transmission" output signal using time-division multiplexing. .

[0068] Step S10: The present invention also provides a Stokes space quantization-based mixed-signal demodulation method for physical layer secure transmission, wherein the demodulation method and its steps are the reverse process of the above modulation method and its steps.

[0069] The above embodiments are merely preferred examples of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A Stokes spatial quantization mixed-signal modulation method for physical layer secure transmission, characterized in that, Includes the following steps: Step S1: Collect multiple wireless signals from the antenna and aggregate the multiple signals into one signal through signal aggregation. Step S2: Construct a priori auxiliary signal, the amplitude and phase of which are used to carry the encryption key and perform waveform-level signal encryption on the target signal. Step S3: Based on the conversion relationship between the Jones vector and the Stokes vector, the aggregated signal and the prior auxiliary signal tuple are converted into the corresponding three-dimensional Stokes vector signal. Step S4: Using the spherical Fibonacci mapping relationship, a three-dimensional vector quantization codebook is constructed in Stokes space. Step S5: Based on the above three-dimensional vector quantization codebook, perform quantization operation on the three-dimensional Stokes vector signal to obtain the three-dimensional digital signal in the Stokes domain. Step S6: Convert the three-dimensional Stokes space domain digital signal into a two-dimensional signal containing real and imaginary parts. Step S7: Based on the above two-dimensional digital signal and the aggregated signal, a subtraction operation is performed to obtain the corresponding analog signal. Step S8: Use two power adjustment coefficients to adjust the power of the digital and analog signals obtained above. Step S9: The digital and analog signals after power adjustment are aggregated into a final output signal of "Stokes spatial quantization mixed-signal modulation for physical layer secure transmission" using time-division multiplexing.

2. The Stokes spatial quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S1, multiple wireless signals from the antenna are collected and aggregated into one signal using a signal aggregation method. This facilitates unified processing and improves algorithm efficiency. The signal aggregation method includes, but is not limited to, frequency domain aggregation and time domain aggregation. Preferably, frequency division multiplexing is used. This process can be represented as follows: in, This represents the aggregated signal. / These represent the wireless signals collected from the antenna. This represents the signal aggregation function.

3. The Stokes spatial quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S2, a priori auxiliary signals are constructed. , can be represented as ,in and Represents a priori time-varying signals The amplitude and phase are used to carry the encryption key, facilitating the analysis of the target signal. Perform waveform-level signal encryption.

4. The Stokes space quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S3, according to the Jones vector With Stokes vector The transformation relationship between the aggregated signal and the prior auxiliary signal binary will be used to transform the aggregated signal and the prior auxiliary signal binary. Convert to the corresponding three-dimensional Stokes vector The conversion process can be represented as: in Represents the conjugate operator. This indicates the operator that retrieves the real part of the signal. This indicates the operator for retrieving the imaginary part of the signal. This represents the matrix transpose operator.

5. The Stokes spatial quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S4, a three-dimensional vector quantization codebook is constructed in Stokes space using the spherical Fibonacci mapping relationship. This process can be represented as: in, , ,in Represents a three-dimensional quantization codebook The number of quantization points This represents the modulo operator.

6. The Stokes space quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S5, based on the above-mentioned three-dimensional vector quantization codebook For three-dimensional Stokes vectors Quantization is performed to obtain a three-dimensional digital signal in the Stokes domain. This process can be represented as: in The vector quantization function represents the three-dimensional Stokes space.

7. The Stokes spatial quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S6, the three-dimensional Stokes space domain digital signal Transformed into a two-dimensional signal containing real and imaginary parts. This process can be represented as: in Represented by natural constant An exponential function with base , i.e. , This represents the arctangent function.

8. The Stokes spatial quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S7, based on the above two-dimensional digital signal With the aggregated signal The corresponding analog signal is obtained by subtraction. This process can be represented as:

9. The Stokes spatial quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S8, two power adjustment coefficients are used. and Regarding the digital signals obtained above and analog signals Adjust the power:

10. The Stokes space quantization mixed-signal modulation method for physical layer secure transmission according to claim 1, characterized in that, In step S9, the digital signal after power adjustment is... and analog signals The signals are aggregated into a final "Stokes spatial quantization mixed-signal modulation for physical layer secure transmission" output signal using time-division multiplexing. .

11. A Stokes spatial quantization-based mixed-signal demodulation method for physical layer secure transmission, characterized in that, The modulation method and its steps are the reverse process of the modulation method described in any one of claims 1 to 10.

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