【作者】 李欣；

【导师】 忻向军；

【作者基本信息】 北京邮电大学 ， 电子科学与技术， 2017， 硕士

【摘要】 卫星通信系统具有通信业务覆盖范围广、系统不受地面环境状态限制等优势,成为近几年的研究热点,且卫星通信系统可以在偏远地区、地震灾区等恶劣环境中进行通信,大大提高了通信的传播范围。但是,随着互联网技术的不断发展,卫星通信需求的不断提高,对卫星通信系统性能的要求也不断提高,但是卫星通信在空间传输过程中会受信道中各种衰落的影响,从而降低卫星通信系统的误码性能,利用功率控制方法解决卫星通信系统中信道衰落问题,因此功率控制方法已成为了国内外的研究热点。论文在研究卫星通信系统传输理论和实现方法的基础上,重点研究了卫星通信系统的信道估计算法和卫星通信系统中功率控制方法。论文的主要研究工作如下:(1)在研究Ka波段卫星通信系统信道衰落的基础上,对Ka波段卫星信道模型和卫星移动通信信道模型进行了仿真验证。并对卫星移动信道中的衰落和Ka波段中的卫星信道衰落进行了仿真分析。(2)在分析Ka波段卫星通信系统信道特性基础上,设计一种基于LS估计的卫星通信系统判决反馈信道估计方案,提出了基于LS估计的卫星通信系统判决反馈信道估计算法,并对所提的判决反馈信道估计算法进行了仿真研究,研究结果表明:在卫星通信系统中,基于LS估计的反馈信道估计算法的卫星通信系统判决的误码性能优于基于LS估计的卫星通信系统的误码性能。然后针对所提的判决反馈信道估计算法,设计了基于判决反馈信道估计技术自适应编码方案,并对其进行了仿真研究,研究结果表明:基于判决反馈信道估计技术自适应编码算法的卫星通信系统的误码性能要优于基于LS信道估计算法的自适应编码算法的卫星通信系统的误码性能。(3)在研究功率放大器的非线性特性及预失真方法的基础上,设计了一种基于预失真的卫星通信系统功率控制方案,并且进行了仿真研究。研究结果表明在功率放大器中,不同的功率回退值对卫星通信系统的误码性能的影响有所不同,且功率回退法可以改善功率放大器的非线性失真情况,提高Ka波段卫星通信系统的通信质量。更多还原

【Abstract】 The satellite communication system has the advantages of wide range of communication services, the system is not limited by the state of the ground environment, and the satellite communication system has become a hotspot in recent years. The satellite communication system can communicate in harsh environments such as remote areas and earthquake-stricken areas, greatly improving the communication the scope of the spread. However, with the continuous development of Internet technology,satellite communications needs continue to improve, the satellite communications system performance requirements are also rising, but the satellite communication in the space transmission process will be affected by various fading in the channel, thereby reducing the satellite communications system And the power control method has been used to solve the problem of channel fading in satellite communication system.Therefore, the power control method has become a hot research topic both at home and abroad.On the basis of studying the transmission theory and realization method of satellite communication system, this paper focuses on the channel estimation algorithm of satellite communication system and the power control method in satellite communication system. The main work of this paper is as follows:(1) Based on the study of Ka-band satellite communication system channel fading, Ka-band satellite channel model and satellite mobile communication channel model were simulated and verified. And the fading in satellite mobile channel and the satellite channel fading in Ka-band are simulated and analyzed.(2) Based on the analysis of the channel characteristics of Ka-band satellite communication system, a scheme of satellite communication system decision feedback channel estimation based on LS estimation is proposed. A satellite communication system based on LS estimation is proposed to estimate the feedback channel estimation algorithm. The results show that the error performance of satellite communication system based on LS estimation based on LS estimation is better than that of LS -based satellite communication system based on LS estimation. The results show that the error estimation performance of satellite communication system based on LS estimation is better than that of LS - based satellite communication system. Then, an adaptive coding scheme based on decision feedback channel estimation is designed and simulated. The results show that the satellite communication system based on adaptive feedback channel estimation technique adaptive coding algorithm The bit error performance of the satellite communication system is better than that of the adaptive coding algorithm based on the LS channel estimation algorithm.(3) Based on the study of the nonlinear characteristics and the pre-distortion method of the power amplifier, a power control scheme of the satellite communication system based on pre-distortion is designed and simulated. The results show that different power regressions have different effects on the bit error performance of satellite communication systems in power amplifiers, and the power back-off method can improve the nonlinear distortion of power amplifiers and improve the Ka-band satellite communication system Communication quality.更多还原