TD-SCDMA码域参数测量及信号处理方法研究

发布时间：2019-02-28 21:03

【摘要】：TD-SCDMA是由我国首次提出的第三代移动通信标准，在物理层核心技术上具有自主知识产权。TD-SCDMA作为一种新技术标准，相比WCDMA和cdma2000其技术的成熟性和商用经验还不是很成熟，因此需要大量的测试工作来保证其商用的顺利进行，在整个测试过程中终端射频参数的测试是非常重要的环节。需要测试的终端射频参数包括：通道功率、占用带宽、邻道功率泄漏比、误差矢量幅度、码域功率、峰值码域误差、星座图、眼图和比特表等。目前国内外提供TD-SCDMA测试解决方案的公司有安捷伦、泰克、中电41所等，但国内大多是专用的综测仪，，支持对其测量功能的频谱分析仪较少。本文在教研室现有的PXI实时频谱分析模块硬件平台的基础上采用软件编程的方式对中频处理后的基带IQ数据进行处理，得出误差矢量幅度、码域功率、峰值码域误差和比特表等重要参数的测量方法，给出C语言编写参数计算函数接口。在对这些参数进行测量过程中需要用到待测信号和理想参考信号，而理想参考信号的恢复过程则是测量过程中的难点所在，本文对物理层信号处理过程研究后得出理想参考信号的恢复过程，这也是文章的创新之处。本文主要工作如下：（1）首先研究物理层的核心技术传输信道编码复用和解码解复用技术。讨论了各模块的具体实现算法，然后建立了整个系统编码复用以及解码解复用过程仿真模型。模型中各模块算法用C语言S函数实现，最后给出误码率等仿真结果，验证了算法的正确性。（2）数据流经过编码复用后进行调制、扩频和加扰以及插入训练序列码和脉冲成形处理，经频谱搬移后在无线信道中传输。本文对扩频调制环节进行分析，讨论了扩频调制环节各模块的算法，然后给出了仿真模型，产生TD-SCDMA信号。（3）得出了一种由待测信号恢复理想参考信号的方法，并由待测信号和参考信号给出误差矢量幅度、码域功率、峰值码域误差和比特表等重要参数测量方法，用C语言编程实现各参数计算的函数接口，并对参数的测量算法进行了仿真验证，最后将EVM的算法接口嵌入到上层软件中，对其进行测试并和泰克频谱分析仪测试结果进行对比验证。
[Abstract]:TD-SCDMA is the third generation mobile communication standard proposed by our country for the first time, and it has independent intellectual property rights in the core technology of physical layer. As a new technology standard, TD-SCDMA is not very mature compared with WCDMA and cdma2000 in terms of maturity and commercial experience. Therefore, a great deal of testing work is needed to ensure the commercial running smoothly, and the testing of terminal RF parameters is very important in the whole testing process. The terminal RF parameters that need to be tested include: Channel power, bandwidth occupancy, adjacent channel power leakage ratio, error vector amplitude, code domain power, peak code domain error, constellation diagram, eye diagram and bit table, etc. At present, the companies providing TD-SCDMA testing solutions at home and abroad are Agilent, Tecker, CLP 41, etc., but most of them are special integrated instruments in China, and there are few spectrum analyzers supporting their measurement functions. On the basis of the existing hardware platform of PXI real-time spectrum analysis module in the teaching and research office, this paper uses software programming to process the baseband IQ data after intermediate frequency processing, and obtains the error vector amplitude and the power of the code domain. The method of measuring the important parameters such as peak code error and bit table is given, and the function interface of parameter calculation in C language is given. It is necessary to use the signal to be measured and the ideal reference signal to be used in the process of measuring these parameters, and the recovery process of the ideal reference signal is the difficult point in the measurement process. This paper studies the physical layer signal processing process and obtains the ideal reference signal recovery process, which is also the innovation of the paper. The main work of this paper is as follows: (1) the core technology of physical layer, transmission channel coding multiplexing and decode demultiplexing, is studied firstly. The implementation algorithms of each module are discussed, and then the simulation models of code multiplexing and decode demultiplexing process of the whole system are established. The algorithm of each module in the model is implemented by S function in C language. Finally, the simulation results such as bit error rate (BER) are given, and the correctness of the algorithm is verified. (2) the data stream is modulated, spread spectrum and scrambled, inserted training sequence code and pulse shaping after code multiplexing, and transmitted in wireless channel after spectrum shift. In this paper, the spread spectrum modulation link is analyzed, the algorithm of each module in the spread spectrum modulation link is discussed, and then the simulation model is given to generate the TD-SCDMA signal. (3) A method of recovering the ideal reference signal from the signal to be tested is presented. The error vector amplitude, the power of the code domain, the error of the peak code domain and the bit table are given by the signal to be measured and the reference signal. The function interface of each parameter calculation is realized by programming in C language, and the parameter measurement algorithm is simulated and verified. Finally, the algorithm interface of EVM is embedded in the upper software. The test results are compared with those of Tecker spectrum analyzer.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TN929.53

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