wherein k (h) is the attenuation power when the base station radiates through a peak with height h, the unit is W, h is the peak height, the unit is m, e is a natural constant, and the value is 2.178;

(2) according to the power k (h) attenuated after the base station radiation passes through the peak with the height h obtained in the step (1), counting the number of the peaks between the base station and the point to be measured to obtain a total attenuation power expression P (h);

(3) and (4) obtaining total attenuation power P (h) according to the step (2), and obtaining the electromagnetic radiation intensity S of the base station to be measured by combining a far-field power density expression.

In the step (2), the power expression of the total attenuation is calculated by combining the base station radiation signal obtained in the step (1) through a mountain obstacle propagation model k (h) as follows:

where P (h) is the power of the total attenuation in W, where n₁The number of peaks with the height between the base station and the point to be measured being 40 meters, and h_mIs at n₁The height of the mth mountain peak is m; n is₂The number of peaks with the height between the base station and the point to be measured being higher than or equal to 40 meters, and h_iIs at n₂The height of the ith peak in m.

In the step (3), by combining the total attenuation power expression p (h) obtained in the step (2), a power density expression with a distance r between the point to be measured and the base station is as follows:

wherein S is the total radiation intensity value of the base station to the point to be measured, and the unit is W/m²R is the distance between the point to be measured and the base station, and the unit is m, G is the antenna gain of the base station, and the unit is dB, and P is the transmitting power of the base station, and the unit is W.

The invention has the beneficial effects that: the method comprises the steps of firstly providing a base station radiation signal, obtaining power k (h) attenuated when the base station radiation signal passes through a peak with the height h through a peak obstacle propagation model, then counting the number of peaks between a base station and a point to be measured, calculating to obtain total attenuated power P (h), and finally predicting to obtain a base station electromagnetic radiation value of the point to be measured, wherein the distance from the base station to the point to be measured is r by combining with a base station electromagnetic radiation intensity calculation formula S. According to the method, the radiation attenuation power of the mountain base station is calculated according to the height of the mountain peak in the mountain area, and the electromagnetic radiation intensity of the mountain base station can be accurately predicted.

Detailed Description

The implementation object of the invention is a base station of FDD-LTE, and the working frequency is as follows: 1980MHz, the test site was a mountainous area around the school, the measuring equipment used a portable spectrum analyzer (KEYSIGHT N9918A, measuring maximum frequency 26.5GHz) and a log periodic antenna (HyperLOG 60180, measuring frequency range 680 MHz-18 GHz), the antenna factor AF was 30dB/m, and the cable loss was 3 dB.

The invention discloses a method for predicting electromagnetic radiation of a mountainous area base station, which comprises the following steps:

(2) according to the power k (h) of the attenuation of the base station radiation after the peak height h is obtained in the step (1), counting the number of the peaks between the base station and the point to be measured to obtain a total attenuation power expression P (h);

(3) and (3) obtaining the electromagnetic radiation intensity S of the base station to be measured according to the total attenuation power P (h) obtained in the step (2) and a far-field power density expression.

In the step (2), the number n of buildings less than or equal to 40m is obtained according to the height and the number of the peaks between the mountain area base station and the point to be measured₁Number of buildings n of 1, height 33m, above 40m₂And 2, the heights are 57m and 69m respectively, the power expression P (h) of the total attenuation is calculated according to the propagation model k (h) of the base station radiation passing peak obstacles obtained in the step 1, and the power expression P (h) is as follows:

in the step (3), a power expression p (h) of the total attenuation is calculated according to the step (2), where the antenna gain G of the base station of the FDD-LTE is 13dB 20, the transmission power of the base station is 15W, and the power density expression where the distance between the point to be measured and the base station is 45m is as follows:

the predicted power density s obtained from the above predicted point is 0.015W/m²To demonstrate the effectiveness of the invention, we obtained a measurement of 0.013W/m after field measurements with a spectrometer at a location 45m from the base station^2，；

Through comparison, the predicted value of the electromagnetic radiation intensity of the mountainous area base station is very consistent with the actual measured value, and the validity of the content of the invention is verified.

Claims

Translated fromChinese

1.一种山区基站电磁辐射预测方法，其特征在于，包括以下步骤：1. a mountain base station electromagnetic radiation prediction method, is characterized in that, comprises the following steps:

(1)建立基站辐射信号通过山峰障碍物传播模型：(1) Establish a model for the propagation of base station radiation signals through mountain obstacles:

其中k(h)为基站辐射经过高度为h的山峰时衰减功率，单位为W，h为山峰高度，单位为m，e为自然常数，取值为2.178；Where k(h) is the attenuation power when the base station radiation passes through the peak of height h, the unit is W, h is the height of the mountain peak, the unit is m, and e is the natural constant, the value is 2.178;

(2)根据(1)得到的基站辐射经过高度为h的山峰后衰减的功率k(h)，统计基站与待测点之间的山峰个数后得到总衰减的功率表达式P(h)；(2) The power k(h) attenuated by the base station radiation after passing through a mountain peak with a height of h obtained according to (1), and the total attenuation power expression P(h) is obtained by counting the number of peaks between the base station and the point to be measured. ;

(3)根据(2)得到的总衰减的功率P(h)，结合远场功率密度表达式，得到待测点基站电磁辐射强度S。(3) According to the total attenuation power P(h) obtained in (2), combined with the far-field power density expression, the electromagnetic radiation intensity S of the base station at the point to be measured is obtained.

2.如权利要求1所述的一种山区基站电磁辐射预测方法，所述步骤(2)中，结合根据步骤(1)得到的基站辐射信号通过山峰障碍物传播模型k(h)，计算总衰减的功率表达式如下：2. a kind of mountain base station electromagnetic radiation prediction method as claimed in claim 1, in described step (2), in conjunction with the base station radiation signal obtained according to step (1) through mountain peak obstacle propagation model k (h), calculate total. The power expression for attenuation is as follows:

其中P(h)为总衰减的功率，单位为W，其中n₁为基站与待测点之间高度低40米山峰的数量，并且h_m为在n₁中第m个山峰的高度，单位为m；n₂为基站与待测点之间高度高于或等于40米的山峰数量，并且h_i为在n₂中第i个山峰的高度，单位为m。where P(h) is the total attenuated power in W, where n₁ is the number of peaks with a height of 40 meters lower between the base station and the point to be measured, and h_m is the height of the mth peak in n₁ , in units of is m; n₂ is the number of mountain peaks with a height higher than or equal to 40 meters between the base station and the point to be measured, and hi is the height of the_ith mountain in n₂ , in m.

3.如权利要求1所述的一种山区基站电磁辐射预测方法，所述步骤(3)中，结合步骤(2)得到的总衰减功率表达式P(h)，则待测点与基站距离为r的功率密度表达式为：3. a kind of mountain base station electromagnetic radiation prediction method as claimed in claim 1, in described step (3), in conjunction with the total attenuation power expression P (h) that step (2) obtains, then point to be measured and base station distance The power density expression for r is:

其中S为基站对待测点的辐射强度总值，单位为W/m²，r为待测点与基站的距离，单位为m，G为基站的天线增益，单位为dB，P为基站的发射功率，单位为W。where S is the total radiation intensity of the base station to be measured, in W/m² , r is the distance between the point to be measured and the base station, in m, G is the antenna gain of the base station, in dB, and P is the transmission of the base station Power, in watts.