移动基站远场区功率密度分布和规划控制距离

为掌握畸变条件下移动通讯基站周围功率密度分布,合理确定其规划控制距离,在杭州市主城区选取具有不同网络类型和载波数的2057个移动基站,实测话务高峰期基站周围射频场功率密度.结果表明,畸变条件下GSM基站远场区功率密度S∝r-1.83 (非畸变条件下S∝r-2),决定系数R2=0.80;距基站天线20m内,约85.91%测点功率密度实测值小于非畸变条件下依据天线标称功率和增益计算的理论值.,频数统计结果表明,距天线1~15m范围内,运营商A所属基站S10值(表示有10%的测点功率密度高于该值)比运营商B高10.00%;距天线1~30m内,双网和三网共站基站S10值分别比单网基站高50.31%和57.10%.移动通讯基站规划控制距离以15m为宜,15m外测点功率密度值超过8μW/cm2的基站只占所测基站的0.11%.

Distribution of far-field power density and planning control distance of mobile base stations

In order to investigate power density distribution regularity and determine planning control distance reasonably, 2057 mobile communication base stations with various network types and carrier wave numbers in urban district of Hangzhou were selected, and the radiofrequency field power density around the antenna was measured when mobile phone traffic was in peak period. Results indicated that far-field power density of GSM base stations S∝ under the condition of distortion field (S∝ under the condition of non-distortion field), and the determination coefficient (R2) is 0.80; in the range of 20m away from antenna, about 85.91% of measured power density values around base stations is less than theoretical values, which can be calculated according to antenna nominal power and antenna gain under the condition of non-distortion field. In addition, the frequency statistical results indicated that, in the range of 1~15m away from antenna, S10 (10% of measured values are higher than the value of S10) of base stations which belong to A operator is 10.00% higher than B operator; in the range of 1~30m away from antenna, the statistical power density values S10 of base stations with double and ternate networks are 50.31% and 57.10% higher than base stations with single network respectively. So the planning control distance of mobile communication base stations determined accordingly should be 15m. Out of this range, only 0.11% of base stations power density values are above 8μW/cm2.