多端口及其应用中的校准技术研究

发布时间：2018-02-27 06:13

本文关键词： 多端口技术校准方法直接变频接收机误差分析　出处：《杭州电子科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：当今是一个无线通信技术快速发展的时代,无线通信技术使得信息的传送方式和传播范围发生了极大的变化,整个世界可以通过无线通信技术连接形成一个整体。无线通信在不同的业务和不同的使用场景中,往往需要使用不同的通信协议与标准,而且在频带范围和调制的方式上也存在差异。移动通信从当今的4G普及,逐渐向传输速度更高的5G推进,新的信号协议标准与原有的硬件设备无法兼容的问题也随之而来,如果直接更换原有的通信设备,势必会花费极大的费用。而多端口的众多应用,如多端口直接变频接收机和多端口反射计可以兼容不同标准,适应不同频带。其中,多端口接收机在未改变通信硬件设备的基础上,仅调节相应的软件参数便可实现射频信号直接转化为低频的基带信号,完成对不同频带和不同调制方式的信号的接收和解调;多端口反射计结构简单,能实现宽频带参数的精确测量。然而,在直接使用多端口接收机或反射计等应用时,由于硬件电路的加工误差及信号传输过程中信号泄露及偏移等造成的误差,会使多端口的性能大大降低,使其精度下降和速度减慢。因此,需要对多端口进行校准,补偿信号和电路的误差,才能实现信号更高精度地解调。多端口的众多应用离不开多端口校准技术,这也正是多端口及其应用中的校准技术研究价值所在。论文首先对多端口的微波基础结构和原理进行了分析,分别计算和研究了不同端口数的微波网络结构和网络参数,并分别对六端口和五端口直接变频接收机的基本分类、电路组成和解调过程进行了阐述。介绍了微波电路的误差来源和常用的校准件,并分析了不同端口数的微波网络的误差模型和校准方式。其次对多端口网络的主要参数进行了研究,并提出了一种多端口反射计的校准方法,该方法可以拓展至任意多端口网络。通过对微波理论的分析和计算,确定多端口网络的校准方程,提出了含有权重因子的最小二乘法的误差校准方案,同时为了减少匹配负载引起的失配误差,使用误差盒对多端口网络进行二次校准,实验结果表明校准后多端口反射计具有良好的幅度特性和相位特性。最后分析了多端口直接变频接收机的误差来源和校准技术,并结合神经网络的基本理论,提出了一种基于实值时延和遗传算法的六端口接收机的校准方法,该校准方式属于软件校准,实现了对六端口接收机系统的整体校准,实验结果显示基于该校准方法的接收机信号解调精度得到了一定提升,使系统误差矢量幅度(Error Vector Magnitude,EVM)得到降低,且对不同调制信号均具有较好的性能。
[Abstract]:Today is an era of rapid development of wireless communication technology. Wireless communication technology has greatly changed the way and scope of information transmission. The whole world can be connected by wireless communication technology to form a whole. Wireless communication often needs to use different communication protocols and standards in different business and different usage scenarios. In addition, there are differences in frequency band and modulation mode. Mobile communication is popularized from 4G to 5G with higher transmission speed, and the new signal protocol standard is not compatible with the original hardware equipment. If the original communication equipment is replaced directly, it will cost a great deal of money. And many applications of multi-port, such as multi-port direct frequency conversion receiver and multi-port reflectometer, can be compatible with different standards and adapt to different frequency bands. On the basis of not changing the communication hardware equipment, the multi-port receiver can directly convert RF signal into low frequency baseband signal by adjusting the corresponding software parameters, and complete the reception and demodulation of signals with different frequency bands and different modulation modes. Multiport reflectometer is simple in structure and can be used for accurate measurement of broadband parameters. However, in applications such as direct use of multi-port receivers or reflectometers, Because of the processing error of hardware circuit and the error caused by signal leakage and deviation in the process of signal transmission, the performance of multi-port will be greatly reduced, and the precision and speed will be slowed down. Therefore, it is necessary to calibrate the multi-port. Only by compensating the error between the signal and the circuit can the signal be demodulated with higher accuracy. Many applications of multi-ports can not be separated from the multi-port calibration technology. This is precisely the research value of multi-port and its application calibration technology. Firstly, the microwave infrastructure and principle of multi-port are analyzed, and the microwave network structure and network parameters with different ports are calculated and studied respectively. The basic classification, circuit composition and demodulation process of six-port and five-port direct frequency conversion receivers are described respectively. The error sources of microwave circuits and the commonly used calibrators are introduced. The error model and calibration method of microwave network with different ports are analyzed. Secondly, the main parameters of multi-port network are studied, and a calibration method of multi-port reflectometer is proposed. This method can be extended to any multi-port network. Through the analysis and calculation of microwave theory, the calibration equation of multi-port network is determined, and the error calibration scheme of least square method with weight factor is proposed. At the same time, in order to reduce the mismatch error caused by the matching load, the error box is used for the secondary calibration of the multi-port network. The experimental results show that the multiport reflectometer has good amplitude and phase characteristics after calibration. Finally, the error source and calibration technology of the multiport direct frequency converter receiver are analyzed, and the basic theory of neural network is combined. This paper presents a calibration method for a six-port receiver based on real time delay and genetic algorithm. The calibration method belongs to software calibration and realizes the overall calibration of the six-port receiver system. The experimental results show that the demodulation accuracy of the receiver signal based on the calibration method has been improved to a certain extent, and the error Vector error Vector EVM) has been reduced, and it has better performance for different modulation signals.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92

【相似文献】