【作者】 刘娟；

【导师】 赵成林；

【作者基本信息】 北京邮电大学 ， 电子与通信工程， 2016， 硕士

【摘要】 随着无线通信技术的迅猛发展,无线通信新系统和无线通信新业务越来越多,所面临的电磁环境越来越复杂,无线频谱资源的匮乏和无线频谱资源的监管已经成为一项重要的问题。射频信号的参数估计作为WCDMA测试仪器和仪表的核心技术,在频谱管理、防止非法电台的使用和频谱的非法占用、保证合法用户的正常通信和频谱资源的有效利用等方面具有非常重要的意义。因此,对信号参数估计进行研究仍具有重要的意义,本文针对WCDMA系统的参数估计主要做了以下几方面的研究。首先介绍WCDMA系统平台,包括信道编码、扩频、加扰、基带调制、射频调制等,平台仿真得到的WCDMA信号,为接下来的算法仿真提供基础。然后介绍WCDMA通信系统中待估计的几个信号参数的定义,如载频、带宽、功率以及杂散功率、邻道功率,并对这几个参数的估计方法进行了详细介绍,从仿真性能方面重点对载频和带宽的估计算法进行比较。其次在上述研究下提出了改进的参数估计方法,在载频估计方面,提出了基于对称拟合的估计算法,该算法首先利用频谱重心法,从功率谱中粗略得到载频估计值,并挑选平滑后的功率谱中间段对称性更好的区间,根据最小均方误差法评估粗估计误差范围内的局部对称性,求取对称性最好的位置作为载频精估计值;在带宽估计方面,提出基于线性拟合的估计算法,减小噪声的干扰。通过仿真验证,新算法对相应参数的估计精度均有提高。本文不但给出了载频和带宽估计算法的设计思路和性能分析,还根据算法之间的依赖关系提出了一个参数估计总体设计方案,该方案包括了功率估计、带宽估计和载频估计。除此之外,根据该实现方案完成了基于C语言的详细代码编写和调试过程,借助FFTW开源函数库实现了功率谱估计,使得整体方案的运算速度大大加快。更多还原

【Abstract】 With the rapid development of wireless communication technology,wireless communication system and wireless communication services are more and more,the electromagnetic environment is becoming more and more complex,the shortage of radio spectrum resources and the management of spectrum resources have become an important issue.Parameter estimation of radio frequency signal is the core technology of WCDMA test instrument and instrument,which has very important significance in the spectrum management,preventing illegal use of illegal radio,and the effective utilization of spectrum resource.Therefore,it is of great significance to study the estimation of signal parameters.The parameters of WCDMA system are studied in this paper.Firstly,the WCDMA system is introduced,which includes channel encoding,spread spectrum,scrambling,baseband modulation,RF modulation,etc.,and the WCDMA signal is obtained.The definition then introduces several parameters signal in a WCDMA communication system to be estimated,such as carrier frequency,bandwidth,power and stray power,adjacent channel power,and the parameters estimation method is introduced in detail,comparing the simulation performance of carrier frequency and bandwidth estimation method.In the second study presents an improved parameter estimation method in frequency estimation,the estimation algorithm based on symmetrical fitting,using the algorithm of spectrum centroid method,the power spectrum obtained from coarse frequency estimation value,interval power and pick the smoothed spectrum of middle segment symmetry better,according to minimum mean square error method evaluation the local symmetry of the coarse estimation error range,calculate the symmetry of the best position as carrier estimation in the estimation precision;bandwidth estimation algorithm is proposed based on linear fitting,smaller interference noise.The simulation results show that the new algorithm can improve the accuracy of the corresponding parameters.This paper not only gives the carrier frequency and bandwidth estimation algorithm design and performance analysis,and also according to algorithm between dependence presents a parameter estimation scheme.The scheme includes the power estimation,bandwidth estimation and carrier frequency estimation.In addition,according to the implementation of the program,this paper completes the C language based on the detailed code writing and debugging process,with the FFTW open source library to achieve the power spectrum estimation,making the overall program operation speed greatly accelerated.更多还原