用于卫星通信中阵列天线的MMSE解码方法
发布时间：2018-09-19 10:07
【摘要】：随着向信息化社会的迈进,移动互联网时代的到来,卫星通信的应用范围正在得到不断地扩展。目前,以互联网、大数据为代表的新一代信息技术正在迅猛的发展。卫星通信系统作为重要的通信基础设施,需积极应对信息技术领域的这一发展方向。然而,面对物联网“万物互联”的需求,基于传统互联网业务的宽带多媒体卫星通信系统将难以满足如此大量的接入需求。因此,需要对卫星的多址接入问题展开进一步的研究,用以在有限的频谱资源内满足尽可能多的物联网信息节点的联网接入要求。大量的科研结果已经证明大规模天线技术不仅可以提供比MIMO(Multiple-Input,Multiple-Output)系统更高的频谱利用率,而且可以提高系统的容量和信道的可靠性,并且简单的线性检测即可达到最优的性能。随着阵列天线技术的日渐成熟,目前已在卫星通信上得到越来越多的应用。基于卫星具有阵列天线及大规模天线系统具有上述优势的事实,卫星通信可以通过将大规模MIMO系统的技术应用于阵列天线系统来有效地支持海量网络信息节点的接入,这与传统的多波束空分多址接入(SDMA)不同。卫星通信信道区别于地面通信信道最重要的特征之一是接收信号中有较强的直射分量的存在。本文针对布置了等距型阵列天线的卫星通信上行系统,首先验证了其信道向量的渐进正交性。基于此正交性,提出了适用于此系统的解码方法,并假设其信道状态信息(CSI)已知的情况下,推导出了其最大可达速率及其对应的一个下界。在这些公式的基础上,首先分析所提出的最大比合并(MRC)解码法和最小均方误差(MMSE)解码法的解码性能。然后比较卫星通信系统采用MRC检测和MMSE检测之后的可达速率,及其对应下界的比较。通过仿真验证了提出的解码方法的可行性,并且MMSE解码法的解码性能要比MRC解码法好很多,但相应的计算复杂度要高些;相同条件下,MMSE检测的可达速率要比MRC检测的高。仿真证实了以上结果。实际情况下,信道状态信息(CSI)一般是未知的,为此就要进行信道的估计。准确的估计出信道信息对系统的解码性能有重要的影响。在本文中,提出了几种新的信道估计方法,并详细分析了所提出的信道估计方法的原理。通过与传统MMSE信道估计方法的仿真比较,验证了所提估计方法的优越性。
[Abstract]:With the development of information society and the arrival of mobile Internet, the application of satellite communication is expanding. At present, the new generation of information technology, represented by the Internet and big data, is developing rapidly. As an important communication infrastructure, satellite communication system should actively deal with this development direction in the field of information technology. However, in the face of the "interconnection of everything" in the Internet of things, the broadband multimedia satellite communication system based on traditional Internet services will be difficult to meet the needs of such a large number of access. Therefore, it is necessary to further study the multiple access problem of satellites in order to meet the requirements of as many Internet of things information nodes as possible in the limited spectrum resources. A large number of scientific results have proved that the large-scale antenna technology can not only provide higher spectral efficiency than MIMO (Multiple-Input,Multiple-Output) system, but also improve the system capacity and channel reliability, and simple linear detection can achieve the optimal performance. With the development of antenna array technology, more and more applications have been made in satellite communication. Based on the fact that satellite has the advantages of array antenna and large-scale antenna system, satellite communication can effectively support the access of massive network information nodes by applying the technology of large-scale MIMO system to array antenna system. This is different from the traditional multiple beam space division multiple access (SDMA). One of the most important characteristics of satellite communication channel is the existence of strong direct-emitting component in the received signal. In this paper, the asymptotic orthogonality of channel vectors is verified for the uplink system of satellite communication with equidistant array antennas. Based on this orthogonality, a decoding method suitable for this system is proposed, and its maximum reachable rate and its corresponding lower bound are derived under the assumption that the channel state information (CSI) is known. Based on these formulas, the decoding performance of the maximum ratio combined (MRC) decoding method and the minimum mean square error (MMSE) decoding method is first analyzed. Then, the reachability rate of satellite communication system using MRC detection and MMSE detection is compared, and the corresponding lower bound is compared. The feasibility of the proposed decoding method is verified by simulation, and the decoding performance of the MMSE decoding method is much better than that of the MRC decoding method, but the corresponding computational complexity is higher, and the reachable rate of the MMSE detection is higher than that of the MRC detection under the same conditions. Simulation results confirm the above results. In practice, channel state information (CSI) is generally unknown, so channel estimation is necessary. Accurate estimation of channel information has an important impact on the decoding performance of the system. In this paper, several new channel estimation methods are proposed, and the principle of the proposed channel estimation methods is analyzed in detail. Compared with the traditional MMSE channel estimation method, the superiority of the proposed method is verified.
【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】：TN927.2
本文编号：2249824
[Abstract]:With the development of information society and the arrival of mobile Internet, the application of satellite communication is expanding. At present, the new generation of information technology, represented by the Internet and big data, is developing rapidly. As an important communication infrastructure, satellite communication system should actively deal with this development direction in the field of information technology. However, in the face of the "interconnection of everything" in the Internet of things, the broadband multimedia satellite communication system based on traditional Internet services will be difficult to meet the needs of such a large number of access. Therefore, it is necessary to further study the multiple access problem of satellites in order to meet the requirements of as many Internet of things information nodes as possible in the limited spectrum resources. A large number of scientific results have proved that the large-scale antenna technology can not only provide higher spectral efficiency than MIMO (Multiple-Input,Multiple-Output) system, but also improve the system capacity and channel reliability, and simple linear detection can achieve the optimal performance. With the development of antenna array technology, more and more applications have been made in satellite communication. Based on the fact that satellite has the advantages of array antenna and large-scale antenna system, satellite communication can effectively support the access of massive network information nodes by applying the technology of large-scale MIMO system to array antenna system. This is different from the traditional multiple beam space division multiple access (SDMA). One of the most important characteristics of satellite communication channel is the existence of strong direct-emitting component in the received signal. In this paper, the asymptotic orthogonality of channel vectors is verified for the uplink system of satellite communication with equidistant array antennas. Based on this orthogonality, a decoding method suitable for this system is proposed, and its maximum reachable rate and its corresponding lower bound are derived under the assumption that the channel state information (CSI) is known. Based on these formulas, the decoding performance of the maximum ratio combined (MRC) decoding method and the minimum mean square error (MMSE) decoding method is first analyzed. Then, the reachability rate of satellite communication system using MRC detection and MMSE detection is compared, and the corresponding lower bound is compared. The feasibility of the proposed decoding method is verified by simulation, and the decoding performance of the MMSE decoding method is much better than that of the MRC decoding method, but the corresponding computational complexity is higher, and the reachable rate of the MMSE detection is higher than that of the MRC detection under the same conditions. Simulation results confirm the above results. In practice, channel state information (CSI) is generally unknown, so channel estimation is necessary. Accurate estimation of channel information has an important impact on the decoding performance of the system. In this paper, several new channel estimation methods are proposed, and the principle of the proposed channel estimation methods is analyzed in detail. Compared with the traditional MMSE channel estimation method, the superiority of the proposed method is verified.
【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】：TN927.2
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