宽带准正交时分复用传输系统研究
发布时间：2018-10-10 13:45
【摘要】：作为时分复用技术的一种实现方式,准正交时分复用(QOTDM)技术应用于星上透明转发系统中,具有操作简单易行、星上处理复杂度较低等优点。因此,其在卫星通信中具有很大的应用价值。本文主要对QOTDM技术进行了系统的理论研究,并结合Ka波段卫星通信信道的特点,搭建了基于Ka波段通信的宽带QOTDM信息传输系统,且对该传输系统进行了性能仿真分析及FPGA实现。本论文的主要工作及所取得的研究成果如下:1、对宽带QOTDM传输方式进行了详细的理论研究。分析了采用直接交织方式的基本QOTDM信息传输系统的原理,并给出基本实现方法;提出了一种基于多载波调制的改进QOTDM传输方法,提高了系统的抗多径、抗频率选择性衰落的能力。2、对Ka波段GEO卫星通信的信道特性进行分析。建立了一个针对Ka波段GEO卫星通信的信道仿真模型;分析了不同天气条件对基本QOTDM信息传输系统性能的影响。仿真结果表明:包络衰落对系统性能的影响比较严重,而由相位畸变带来的影响相对于包络衰落可忽略不计。3、对宽带QOTDM传输系统的同步方法进行研究。分析了采样偏差对系统性能的影响,提出基于固定门限算法和群时延匹配滤波器组的系统同步方案。由性能仿真分析可得:该同步方案能够实现接收信号的精确样点同步和帧同步,且保证系统的同步精度达到采样间隔的5%。4、完成了基于多载波调制的宽带QOTDM传输系统的FPGA实现。对整个传输系统进行模块化,分别对各个模块进行FPGA设计,并对其进行了硬件仿真分析。
[Abstract]:As a realization of time division multiplexing (TDM), Quasi-orthogonal TDM (QOTDM) technology is applied to the onboard transparent forwarding system, which has the advantages of simple operation and low onboard processing complexity. Therefore, it has great application value in satellite communication. In this paper, the theory of QOTDM technology is studied, and combining the characteristics of Ka band satellite communication channel, a broadband QOTDM information transmission system based on Ka band communication is built, and the performance simulation analysis and FPGA implementation of the system are carried out. The main work and results of this thesis are as follows: 1. The theory of broadband QOTDM transmission is studied in detail. The principle of the basic QOTDM information transmission system with direct interleaving is analyzed, and the basic realization method is given, and an improved QOTDM transmission method based on multicarrier modulation is proposed, which improves the anti-multipath of the system. Second, the channel characteristics of Ka band GEO satellite communication are analyzed. A channel simulation model for Ka band GEO satellite communication is established, and the influence of different weather conditions on the performance of the basic QOTDM information transmission system is analyzed. The simulation results show that the influence of envelope fading on system performance is serious, while the effect of phase distortion is negligible relative to envelope fading. 3. The synchronization method of broadband QOTDM transmission system is studied. The influence of sampling deviation on system performance is analyzed. A synchronization scheme based on fixed threshold algorithm and group delay matched filter bank is proposed. The simulation results show that the synchronization scheme can realize the precise sample synchronization and frame synchronization of the received signal, and ensure the synchronization accuracy of the system to reach 5.4 of the sampling interval. The FPGA implementation of the broadband QOTDM transmission system based on multi-carrier modulation is completed. The whole transmission system is modularized, each module is designed by FPGA, and the hardware simulation is carried out.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN927.2
本文编号：2262007
[Abstract]:As a realization of time division multiplexing (TDM), Quasi-orthogonal TDM (QOTDM) technology is applied to the onboard transparent forwarding system, which has the advantages of simple operation and low onboard processing complexity. Therefore, it has great application value in satellite communication. In this paper, the theory of QOTDM technology is studied, and combining the characteristics of Ka band satellite communication channel, a broadband QOTDM information transmission system based on Ka band communication is built, and the performance simulation analysis and FPGA implementation of the system are carried out. The main work and results of this thesis are as follows: 1. The theory of broadband QOTDM transmission is studied in detail. The principle of the basic QOTDM information transmission system with direct interleaving is analyzed, and the basic realization method is given, and an improved QOTDM transmission method based on multicarrier modulation is proposed, which improves the anti-multipath of the system. Second, the channel characteristics of Ka band GEO satellite communication are analyzed. A channel simulation model for Ka band GEO satellite communication is established, and the influence of different weather conditions on the performance of the basic QOTDM information transmission system is analyzed. The simulation results show that the influence of envelope fading on system performance is serious, while the effect of phase distortion is negligible relative to envelope fading. 3. The synchronization method of broadband QOTDM transmission system is studied. The influence of sampling deviation on system performance is analyzed. A synchronization scheme based on fixed threshold algorithm and group delay matched filter bank is proposed. The simulation results show that the synchronization scheme can realize the precise sample synchronization and frame synchronization of the received signal, and ensure the synchronization accuracy of the system to reach 5.4 of the sampling interval. The FPGA implementation of the broadband QOTDM transmission system based on multi-carrier modulation is completed. The whole transmission system is modularized, each module is designed by FPGA, and the hardware simulation is carried out.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN927.2
【参考文献】
相关硕士学位论文 前1条
1 胥鹤;Ka频段卫星通信系统的OFDM信道性能分析[D];吉林大学;2013年
，本文编号：2262007
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