降雨测试数据和参量引入雨衰时间序列EMB模型,模拟了海口、青岛和北京雨区的斜径降雨衰减时间序列,进行功率谱估计,与文献中测试得到的结果有好的一致性.通过对模拟海口、青岛和北京12.5GHz雨衰序列的衰落持续时间的统计,并与观测统计结果及ITU-R预测结果比较,在海口雨区有好的一致性;在青岛和北京雨区,当衰落时间较短,约小于100 s时,模拟与测试的统计结果一致性好,而对于长衰落时间的结果存在偏差,与ITU-R预测结果有一定差异.30/20GHz模拟统计与ITU-R预测结果的比较,对于较小衰落门限和较短衰落持续时间均有好的一致性,但衰落门限较高的较长衰落时间时的一致性较差.结果表明该模拟统计方法可应用于降雨量较大的雨区,然而,对于某些雨区,模拟序列的长衰落持续时间的统计或ITU-R预测模型还需修正.论文工作为更高频段无线电系统中雨衰落储备技术的研究奠定基础.
The rain attenuation time series are simulated by the EMB model based on rain measured data and parameters at Haikou ,Qingdao and Beijing .The power spectra estimated with simulative series are in good agreement with the measured result in references .The probability of fade exceeding a given fade duration value are calculated based on simulative attenuation time series , and compared with ITU-R predictive and measured values at 12.5GHz ,in Haikou ,Qingdao and Beijing .At Haikon ,the statistics a-gree with predicted and measured results .At Beijing and Qingdao ,as fade duration is less than about 100s ,the simulative statistics are in agreement with measured results .As fade duration is more than about 100s ,there are the difference among them .At 30/20GHz ,for the smaller fade threshold and duration ,the statistics based on simulation approach to the results predicted by ITU-R .As the larger fade threshold and duration ,the statistical results by simulation are different to the prediction statistics by ITU-R .The re-sults show that the simulation method is available for the rain region of abundant rainfall .However ,at insufficient rainfall region ,the method or ITU-R prediction may be modified as longer fade duration .It is significant groundwork for rain fade mitigation techniques development in higher frequency wireless systems .