基于LTE系统的传播模型及模型校正算法研究

发布时间：2018-04-17 13:42

本文选题：LTE + 网络规划与优化　；参考：《东华大学》2014年硕士论文

【摘要】：现代通信技术随着科技的进步飞速发展,中国的无线网络已成功由3G迈入4G,进入LTE时代。传播模型是蜂窝无线网络规划的基础,传播模型的准确性直接影响到无线网络规划和优化的合理性,最终影响通信质量,所以对传播模型及模型校正算法的研究显得极其重要。传播模型是对无线电波传播过程中的路径损耗进行预测,不同的传播模型有不同的路径损耗公式,经典传播模型虽具有相当大的普遍适用性,但是对于具体环境需具体分析。本文对经典传播模型原理进行阐述并总结对比其传播特性,对Okumura-Hata模型、COST-231Hata模型、SPM模型进行了仿真分析,结果表明在密集城区的传播环境下SPM模型是最适合LTE系统的传播模型。随着城市的迅速发展,密集城区的地貌环境趋向多元化和复杂化,导致传播模型校正的准确性降低,难度增加。为了提高密集城区模型校准的准确性,得到与本地传播环境相匹配的传播模型,本文采用拟合校正法、一元校正法以及改进的传播模型校正法分别进行实测数据的传播模型校正。改进的传播模型校正方法基于WLS算法,消除了采样点信号的异方差性,提高了采样数据的有效性,另外考虑了地貌损耗的变化加入了计算获得的变化的clutter (i)值,使得传播模型能够反映当地传播环境的地貌变化,匹配度得到提升。根据改进的模型校正算法,本文在matlab/GUI平台上进行模型校正软件的开发,该软件能够实现CW数据的导入、模型校正公式系数的输出以及误差分析功能。通过校正后的传播模型路损公式,本文进行链路预算分析,根据收发端的参数信息得到上下行的链路预算表,为后期覆盖分析奠定基础。论文采用的实测数据是在上海某密集城区采集到的CW数据,数据包含了采样点的有效GIS信息以及电平信息等,数据处理过程是在matlab平台实现的,其中使用到的2维GIS软件也是在matlab/GUI平台上开发的。本文对LTE系统的实测CW数据分别进行模型校正,校正结果表明,在地貌环境复杂的密集城区进行大尺度传播模型校正时,改进算法使得预测数据的误差最低,校正后的传播模型准确性大幅提高,结果表明改进算法更能够有效反映当地的传播环境。
[Abstract]:With the rapid development of modern communication technology, the progress of science and technology, the wireless network Chinese successfully by 3G into 4G, into the LTE era. Propagation model is based on wireless network planning cellular propagation model's accuracy directly affects the rationality of wireless network planning and optimization, and ultimately affect the quality of communication, so the propagation model and model calibration algorithm the research is extremely important.
The propagation model is to predict the path loss of radio wave propagation in the process, there are different propagation path loss formula of different models, the classical propagation model has considerable general applicability, but need a detailed analysis for the specific environment. This paper describes the principle of the classical propagation model and summarizes the comparison of the propagation characteristics of the Okumura-Hata model, COST-231Hata model, SPM model is simulated. The results show that in the dense urban propagation environment SPM model is the most suitable model for the propagation of the LTE system.
With the rapid development of the city, the dense urban geomorphic environment become more diversified and complicated, resulting in lower accuracy of propagation model calibration more difficult. In order to improve the accuracy of the calibration model of dense urban area, spread model matched with the local propagation environment, this paper uses the fitting correction method, propagation model correction method and the improved one yuan correction method of propagation model were measured data correction. Improved propagation model calibration method based on WLS algorithm, eliminates the heteroscedasticity of the sampling signal, improves the effectiveness of the sampling data, in addition to considering the landform change loss joined the calculated changes of clutter (I) value, so that the propagation model can reflect the the topographical changes the local propagation environment, improve the matching degree obtained. According to the improved calibration algorithm model based on the matlab/GUI platform for model calibration software Development, this software can realize the CW data input, the output coefficient of model correction formula and error analysis. The corrected propagation model path loss formula, this paper link budget analysis, according to the parameter information transceiver get down the link budget for later covered to lay the foundation for the analysis of measured data used in this paper. Shanghai is in a dense urban area to collect CW data, including data sampling point information and effective GIS level information, the data processing is implemented in the MATLAB platform, including the use of the 2 dimensional GIS software is developed on the matlab/GUI platform.
The measured CW data of LTE system were model correction, correction results show that the correction of large scale propagation model in complex geomorphic environment of dense urban area, the improved algorithm makes the minimum prediction error data, the corrected propagation model accuracy is greatly improved, and the results show that the improved algorithm can effectively reflect the local propagation environment.

【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

【参考文献】