CN-122027050-A - Marine wireless propagation path loss hybrid modeling method suitable for evaporation waveguide conditions

Abstract

The invention relates to the technical field of wireless communication, and discloses a marine wireless propagation path loss hybrid modeling method suitable for an evaporation waveguide condition, which comprises the following steps of defining a coherent transition distance And the visual distance limit Dividing a propagation area into a coherent interference dominant region, a transition region and an evaporation waveguide dominant region, constructing a CI-MTR core model for describing the path loss of the coherent interference dominant region, calculating the path loss under the evaporation waveguide condition based on a parabolic method Computing an environmental excess loss term for characterizing path loss variations due to refraction effects Design of transition weighting function And combining the CI-MTR core model, the environment excess loss item and the transition weighting function by adopting a piecewise function to form a unified mixed path loss model CI-MTR-PE. High accuracy, high physical interpretability, and computationally efficient path loss prediction for the full range is achieved.

Inventors

• GAO RUIFENG
• Miao Yanchun
• WANG JUE
• SUN SHU

Assignees

• 南通大学

Dates

Publication Date

20260512

Application Date

20260325

Claims (6)

1. 1. The marine wireless propagation path loss hybrid modeling method suitable for the evaporation waveguide condition is characterized by comprising the following steps of: Step 1, defining a coherent transition distance And the visual distance limit Dividing a propagation region into a coherent interference dominant region, a transition region and an evaporation waveguide dominant region; Step 2, constructing a CI-MTR core model for describing the path loss of the coherent interference dominant region; Step 3, calculating the path loss under the condition of evaporating the waveguide based on a parabolic method Computing an environmental excess loss term for characterizing path loss variations due to refraction effects ; Step 4, designing a transition weighting function The method is used for smoothly predicting the fusion model in the transition zone; And 5, combining the CI-MTR core model, the environment excess loss item and the transition weighting function by adopting a piecewise function to form a unified mixed path loss model CI-MTR-PE.
2. 2. The method for hybrid modeling of marine wireless propagation path loss for an evaporative waveguide environment as defined in claim 1, wherein in step 1, the coherent transition distance is the same as the coherent transition distance The visual range limit distance Middle (a) 、 The heights of the transmitting antenna and the receiving antenna are respectively expressed in meters, And In km, lambda is the carrier wavelength.
3. 3. The method of modeling a hybrid propagation path loss of an offshore wireless system adapted for use in an evaporative waveguide environment as defined in claim 1, wherein in step 2, the path loss of the CI-MTR core model: , Wherein the method comprises the steps of , The path loss index of the different regions respectively, Is the effective Fresnel reflection coefficient of sea surface and the emission coefficient The physical meaning and the calculation mode of each parameter are as follows: Representing the equivalent radius of the earth, Representing the propagation distance from the emitting end to the reflecting point, Representing the propagation distance between the reflection point and the receiving end, wherein the reflection point is the specular reflection point of the electromagnetic wave on the sea surface or the equivalent reflection surface, the position of the reflection point can be determined by a geometric optical method, the fixed point tracking factor of the electromagnetic shielding effect of the wave under the grazing incidence condition is considered, Is the angle of incidence, erfc represents the complementary error function, the root mean square slope of the sea surface , Represents wind speed in m/S and sea surface roughness coefficient The first Bessel function being zero order correction, the standard deviation of sea surface height 。
4. 4. The method for hybrid modeling of marine wireless propagation path loss for an evaporative waveguide environment as defined in claim 1, wherein in step 3, the environmental excess loss term is used Wherein In order to be a free-space path loss, When electromagnetic waves propagate under ideal free space conditions, the power attenuation caused by spherical expansion of wave fronts in space is represented, environmental factors such as reflection, scattering, atmospheric refraction and the like are not considered, the basic characteristics of electromagnetic wave energy along with square attenuation of propagation distance are reflected, and the expression is as follows: , wherein, the propagation distance between the transmitting end and the receiving end is represented, Representing the wavelength of electromagnetic waves, the above formula derives from the propagation law of electromagnetic waves in free space, in particular, the electromagnetic waves radiated by the transmitting antenna propagate outwards in space, the energy of which is uniformly distributed on a sphere centered on the transmitting point, with the propagation distance Increase in spherical surface area per Increasing, resulting in a power density per unit area Attenuation, since path loss is expressed in logarithmic form of power ratio, is expressed in decibel domain In the form of (a).
5. 5. The method of modeling a hybrid propagation path loss for an offshore wireless system, as defined in claim 1, wherein in step 4, the transition weight function is a weighted function 。
6. 6. A method for hybrid modeling of marine wireless propagation path loss for an evaporative waveguide environment as defined in claim 1, wherein said unified hybrid path loss model The method comprises the following steps: 。

Description

Marine wireless propagation path loss hybrid modeling method suitable for evaporation waveguide conditions Technical Field The invention relates to the field of wireless communication, in particular to a marine wireless propagation path loss hybrid modeling method suitable for an evaporation waveguide condition. Background With the rapid development of offshore activities, there is an increasing demand for reliable offshore wireless communications, such as shore-to-ship links, offshore platform connections, maritime safety emergency services, etc. Unlike terrestrial scenarios, offshore propagation is co-dominated by a variety of distance and altitude dependent physical mechanisms, which makes it difficult for a single model to maintain accuracy and physical consistency throughout the coverage area at the same time. In particular, in short-range offshore line-of-sight links, the received signal is dominated by the coherent superposition of the direct path and the sea surface reflection path, resulting in a significantly oscillating path loss, which is not compatible with conventional monotonic decay models. At greater distances, the refractive effects caused by the evaporation waveguide effect are increasingly pronounced, slowly changing propagation channels, and supporting beyond-the-horizon communication under favorable conditions. Thus, the offshore path loss is co-molded by fast-varying coherent geometrical interference and slow-varying refractive environmental effects. Existing offshore propagation models are largely divided into empirical/semi-empirical models and deterministic physical models. The empirical model has few parameters, stable fitting and easy engineering realization, but generally assumes that the path loss changes monotonically or piecewise linearly with distance, the oscillation fading observed in short-distance measurement cannot be reproduced, and the processing of the evaporation waveguide effect lacks clear physical basis. Deterministic models, particularly parabolic methods, while able to explicitly incorporate highly dependent refractive index profiles and capture waveguide and refractive effects with strong physical interpretability, are computationally intensive and costly to deploy in practical system designs. Furthermore, most narrow angle PE formulas rely on small angle approximations, the effectiveness of which in short-range line-of-sight areas where the propagation elevation is large may be affected. The patent application of publication number CN119094061a discloses an advanced propagation model improvement method that takes into account free space propagation in an evaporative waveguide environment. The method comprises the steps of calculating electric wave propagation loss by using a free space propagation model in an offshore apparent distance range, translating the advanced propagation model based on an electric wave propagation attenuation difference value to obtain an improved advanced propagation model, and substituting the electric wave propagation target distance into the improved advanced propagation model when the electric wave propagation target distance is greater than an electric wave propagation limit distance under the offshore apparent distance condition to obtain the electric wave propagation loss corresponding to the electric wave propagation target distance. The invention solves the technical problem that the existing APM model in the evaporation waveguide environment does not fully consider free space propagation in the offshore line-of-sight range, so that the predicted path loss is larger than the actually measured path loss. When the prior art method is used, the experimental model parameters are few, the fitting is stable, the engineering implementation is easy, and the effectiveness of a short-distance viewing range region with a large propagation elevation angle can be influenced during operation. For this reason, a new technical solution is needed to solve the above technical problems. Disclosure of Invention The invention aims to provide a marine wireless propagation path loss hybrid modeling method suitable for an evaporation waveguide condition, which is used for realizing high-precision, high-physical interpretability and high-efficiency calculation path loss prediction in a full-distance range by organically fusing a near-reference coherent double-ray interference model and a remote parabolic square Cheng Sheshe model and designing a smooth transition mechanism. The technical scheme adopted by the invention is as follows: An offshore wireless propagation path loss hybrid modeling method suitable for an evaporative waveguide condition, comprising the steps of: First, two distance thresholds, namely a coherence transition distance, are defined based on a propagation physical mechanism And the visual distance limitThe propagation region is divided into a coherent interference dominant region, a transition region and an evaporation waveguide