Digital-analog hybrid signal modulation method and demodulation method based on polar coordinate system

Abstract

The invention discloses a digital-analog hybrid signal modulation method based on a polar coordinate system, and the method comprises the following steps: S1, collecting a plurality of wireless signals, and aggregating the plurality of signals into one signal through a frequency division multiplexing mode; s2, respectively solving amplitude information and phase information of the aggregated signals; s3, calculating a polar coordinate system signal quantization codebook based on the amplitude information and the phase information; s4, performing quantization calculation on the aggregated signal based on a quantization codebook to obtain a digital part signal; s5, based on the digital part signal and the aggregated signal, obtaining an analog part signal through subtraction operation; s6, performing power regulation on the digital part signal and the analog part signal; and S7, aggregating the digital signal and the analog signal after power regulation into a final modulation output signal by adopting a time division multiplexing mode. The invention further discloses a digital-analog hybrid signal modulation method based on the polar coordinate system. The digital-analog hybrid signal modulation method comprises the inverse process of the modulation method.

Description

Technical Field

[0001] This invention relates to the field of signal modulation and modulation technology, and in particular to a digital-analog hybrid signal modulation method and modulation method based on polar coordinates. Background Technology

[0002] Mobile fronthaul is a critical fiber optic component in centralized wireless access networks. To meet the anticipated 10 to 100-fold capacity growth, Radio over Optical (RoF) technology has gained attention, aiming to optimize the performance balance between signal-to-noise ratio and spectral efficiency. Based on cascaded digital probabilistic shaping orthogonal amplitude modulation and analog pulse code modulation, a Cartesian coordinate-based hybrid digital-analog RoF (CDA-RoF) solution has been proposed. CDA-RoF technology has been extended to dual-polarization coherent systems with multiple coding dimensions, including phase, polarization, and spatial diversity, achieving a Tb / s CPRI equivalent rate.

[0003] For frequency-domain aggregated uplink wireless signals, mathematically they can be represented as a combination of the real and imaginary parts in a Cartesian coordinate system (i.e., a rectangular coordinate system). Traditional CDA-RoF schemes use rounding in the Cartesian coordinate system.

[0004] The arithmetic function rounds the real and imaginary parts of the complex signal to the nearest Gaussian integer, creating digital probabilistic constellation shaping (PCS) quadrature amplitude modulation (QAM). It is worth noting that, mathematically, the aforementioned wireless signal can be equivalently represented as a combination of its amplitude and phase in polar coordinates.

[0005] Therefore, this invention proposes a digital-analog hybrid signal modulation method and modulation method based on polar coordinates. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a digital-analog hybrid signal modulation and modulation method based on polar coordinates.

[0007] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0008] A digital-analog hybrid signal modulation and modulation method based on polar coordinates includes the following steps:

[0009] Step S1: Collect multiple wireless signals from the antenna and aggregate them into one signal through frequency division multiplexing, which facilitates unified processing and improves algorithm efficiency.

[0010] In this embodiment, the signal aggregation method includes, but is not limited to, frequency domain aggregation and time domain aggregation. Preferably, the signal aggregation method using frequency division multiplexing is represented as follows:

[0011] S O =CF(S1,S2,…,S) N )

[0012] Among them, S O This represents the aggregated signal, S1 / S2 / … / S N Let represent the digital signals from the antenna, and CF(·) represent the frequency domain aggregation function.

[0013] Step S2, for the aggregated signal S O The amplitude and phase information are obtained respectively:

[0014] A(t) = AF(S) O )

[0015]

[0016] Where AF(·) represents the amplitude information acquisition function and FF(·) represents the phase information acquisition function.

[0017] Step S3, based on the obtained amplitude A(t) and phase Perform the following signal quantization codebook C p Calculation operations

[0018]

[0019] Among them, C A Represents the magnitude vector. Represents the phase vector, and C A and It can be obtained through the following formula:

[0020] C A =[min(A(t)):Δ d ∶max(A(t))] T

[0021]

[0022]

[0023] Where, min(·) represents the function for finding the maximum value, and max(·) represents the function for finding the minimum value, while Δ d and It can be obtained through the following formula:

[0024] Δ d =(max(A)-min(A)) / n r

[0025]

[0026] Where, n r Indicates the target order of the amplitude to be quantized. This indicates the target order of the phase to be quantized when the amplitude takes the i-th order value.

[0027] Step S4, based on the calculated signal codebook C p In the polar coordinate domain, for the aggregate signal S O Quantization calculations are performed to obtain the digital part S. D Signal:

[0028] S D =Q p (S O C p )

[0029] Among them, Q p (·) denotes the quantization function in the polar coordinates domain. It differs from the rounding operation in existing digital-analog hybrid signal modulation methods.

[0030] Step S5, based on the quantized digital portion S D Signal and aggregated signal S O The simulation part S is obtained by subtraction. A Signal:

[0031] S A =S O -S D

[0032] Step S6, for the obtained S D Signal and S A The signal is adjusted with appropriate power:

[0033] S′ D =α d ·S D

[0034] S′ A ′=α a ·S A

[0035] Where, α d α represents the power regulation coefficient of the digital section. a This represents the power adjustment factor in the analog section.

[0036] Step S7, convert the digital signal S′ generated in the above steps into digital signals. D and analog signal S′ A The signals are aggregated into a final modulated output signal S through time-division multiplexing. PDA .

[0037] Step S8, the present invention also provides a digital-analog hybrid signal modulation method based on polar coordinates, wherein the modulation method and its steps are the reverse process of the modulation method and its steps described above.

[0038] The digital-analog hybrid signal modulation and modulation method based on polar coordinates provided by this invention has the following advantages compared with the prior art:

[0039] (1) The digital-analog hybrid signal modulation and modulation method based on polar coordinates provided by this invention enables the digital signal to simultaneously possess the advantages of geometric constellation shaping and probabilistic constellation shaping, such as... Figure 5 As shown.

[0040] (2) The digital-analog hybrid signal modulation method and modulation method based on polar coordinate system provided by the present invention are more flexible in the signal modulation process, have amplitude and phase degrees of freedom, and can be cascaded to optimize the signal modulation and demodulation process.

[0041] (3) The digital-analog hybrid signal modulation and modulation method based on polar coordinates provided by this invention more effectively approximates the original signal waveform, such as... Figure 4 , Figure 5 and Figure 6 As shown. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the digital-analog hybrid modulation signal modulation scheme based on polar coordinates according to the present invention.

[0043] Figure 2 This is a schematic diagram of the digital-analog hybrid modulation signal demodulation scheme based on polar coordinates according to the present invention.

[0044] Figure 3 This is a schematic diagram of the multi-signal aggregation scheme of the present invention.

[0045] Figure 4 The modulated signal S after multi-signal aggregation in this invention O A diagram of a constellation.

[0046] Figure 5 The digital portion S before demodulation in this invention D A schematic diagram of the signal constellation.

[0047] Figure 6 The simulation part S before demodulation in this invention A A schematic diagram of the signal constellation.

[0048] Figure 7 The demodulated and restored S′ of this invention O A schematic diagram of the signal constellation. Detailed Implementation

[0049] 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.

[0050] like Figures 1 to 6 As shown, the digital-analog hybrid signal modulation and modulation method based on polar coordinates of the present invention includes the following steps:

[0051] Step S1: Collect multiple wireless signals from the antenna and aggregate them into one signal through frequency division multiplexing, which facilitates unified processing and improves algorithm efficiency.

[0052] In this embodiment, the signal aggregation method includes, but is not limited to, frequency domain aggregation and time domain aggregation. Preferably, the signal aggregation method using frequency division multiplexing is represented as follows:

[0053] S O =CF(S1,S2,…,S) N )

[0054] Among them, S O This represents the aggregated signal, S1 / S2 / … / S N Let represent the digital signals from the antenna, and CF(·) represent the frequency domain aggregation function.

[0055] Step S2, for the aggregated signal S O The amplitude and phase information are obtained respectively:

[0056] A(t) = AF(S) O )

[0057]

[0058] Where AF(·) represents the amplitude information acquisition function and FF(·) represents the phase information acquisition function.

[0059] Step S3, based on the obtained amplitude A(t) and phase Perform the following signal quantization codebook C p Calculation operations

[0060]

[0061] Among them, C A Represents the magnitude vector. Represents the phase vector, and C A and It can be obtained through the following formula:

[0062] C A=[min(A(t)):Δ d ∶max(A(t))] T

[0063]

[0064] Where, min(·) represents the function for finding the maximum value, and max(·) represents the function for finding the minimum value, while Δ d and It can be obtained through the following formula:

[0065] Δ d =(max(A)-min(A)) / n r

[0066]

[0067] Where, n r Indicates the target order of the amplitude to be quantized. This indicates the target order of the phase to be quantized when the amplitude takes the i-th order value.

[0068] Step S4, based on the calculated signal codebook C p In the polar coordinate domain, for the aggregate signal S O Quantization calculations are performed to obtain the digital part S. D Signal:

[0069] S D =Q p (S O C p )

[0070] Among them, Q p (·) denotes the quantization function in the polar coordinates domain. It is different from the rounding operation under the existing Cartesian coordinate system (i.e., rectangular coordinate system).

[0071] Step S5, based on the quantized digital portion S D Signal and aggregated signal S O The simulation part S is obtained by subtraction. A Signal:

[0072] S A =S O -S D

[0073] Step S6, for the obtained S D Signal and S A The signal is adjusted with appropriate power:

[0074] S′ D =αd ·S D

[0075] S′ A =α a ·S A

[0076] Where, α d α represents the power regulation coefficient of the digital section. a This represents the power adjustment factor in the analog section.

[0077] Step S7, convert the digital signal S′ generated in the above steps into digital signals. D and analog signal S′ A The signals are aggregated into a final modulated output signal S through time-division multiplexing. PDA .

[0078] Step S8, further, the digital-analog hybrid modulation signal modulation method and its steps based on polar coordinates of the present invention are the reverse process of the above modulation method and its steps.

[0079] 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 digital-analog hybrid signal modulation method based on polar coordinates, characterized in that, Includes the following steps: Step S1: Collect multiple wireless signals from the antenna and aggregate the multiple signals into one signal by frequency division multiplexing; Step S2: For the aggregated signal, obtain its amplitude information and phase information respectively; Step S3: Calculate the signal quantization codebook based on the obtained amplitude and phase information; Step S4: Based on the signal quantization codebook, perform quantization calculation on the aggregated signal in polar coordinates to obtain the digital part signal; Step S5: Based on the digital part signal obtained by quantization and the aggregated signal, the analog part signal is obtained by subtraction. Step S6: Perform appropriate power adjustment on the obtained digital and analog signals; Step S7: The power-adjusted digital signal and analog signal are combined into a final modulated output signal by time-division multiplexing.

2. The digital-analog hybrid signal modulation method based on polar coordinates according to claim 1, characterized in that, In step S1, the signal aggregation methods include, but are not limited to, frequency domain aggregation and time domain aggregation. Preferably, the signal aggregation method using frequency division multiplexing is expressed as follows: S O =CF(S1,S2,…,S N ) Among them, S O This represents the aggregated signal, S1 / S2 / … / S N Let represent the digital signals from the antenna, and CF(·) represent the frequency domain aggregation function.

3. The digital-analog hybrid signal modulation method based on polar coordinates according to claim 1, characterized in that, In step S2, the aggregated signal S O The amplitude and phase information obtained separately can be expressed as follows: A(t)=AF(S O ) Where AF(·) represents the amplitude information acquisition function and FF(·) represents the phase information acquisition function.

4. The digital-analog hybrid signal modulation method based on polar coordinates according to claim 1, characterized in that, In step S3, based on the obtained amplitude A(t) and phase... Perform signal quantization codebook C p The calculation operation can be represented as: Among them, C A Represents the magnitude vector. Denotes the phase vector, and CA and It can be obtained through the following formula: C A =[min(A(t)):Δ d :max(A(t))] T Where, min(·) represents the function for finding the maximum value, and max(·) represents the function for finding the minimum value, while Δ d and It can be obtained through the following formula: Where, n r Indicates the target order of the amplitude to be quantized. This indicates the target order of the phase to be quantized when the amplitude takes the i-th order value.

5. The digital-analog hybrid signal modulation method based on polar coordinates according to claim 1, characterized in that, Step S4 is based on the calculated signal codebook C. p In the polar coordinate domain, for the aggregate signal S O Quantization is performed to obtain the digital part S D A signal can be represented as: S D =Q p (S O ,C p ) Among them, Q p (·) denotes the quantization function in the polar coordinates domain. It differs from the rounding operation in existing digital-analog hybrid signal modulation methods.

6. The digital-analog hybrid signal modulation method based on polar coordinates according to claim 1, characterized in that, Step S5, based on the quantized digital portion S D Signal and aggregated signal S O The simulation part S is obtained by subtraction. A A signal can be represented as: S A =S O -S D 7. The digital-analog hybrid signal modulation method based on polar coordinates according to claim 1, characterized in that, In step S6, the obtained S D Signal and S A A signal, after appropriate power adjustment, can be represented as: S′ D =a d ·S D S′ A =a a ·S A Where, α d α represents the power regulation coefficient of the digital section. a This represents the power adjustment factor in the analog section.

8. The digital-analog hybrid signal modulation method based on polar coordinates according to claim 1, characterized in that, In step S7, the digital signal S′ generated in the above steps is... D and analog signal S′ A The signals are aggregated into a final modulated output signal S through time-division multiplexing. PDA .

9. A digital-analog hybrid signal modulation method based on polar coordinates, 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 8.

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