大规模天线系统混合预编码算法研究

发布时间：2018-10-14 08:39

【摘要】：为满足不断增长的无线通信数据传输需求,利用尚未开发的毫米波频段的频谱成为解决传输速率与有限频谱资源瓶颈的有效方式。目前,配置大规模天线阵列的毫米波MIMO系统引起了学术界和工业界的广泛关注,它能同时提供更宽的传输带宽和更高的频谱效率。结合毫米波传播特性和大规模天线阵列的特性,混合预编码技术成为毫米波MIMO系统中重要的信号处理方法,它能有效抵抗多径衰落,减少传输数据流之间干扰,从而提高频谱效率。传统的MIMO系统为每一根天线配置一条射频链,预编码处理仅在数字基带进行。随着天线数目的增加,这将产生巨大的硬件开销和能耗,因而传统预编码方案已不再适用于毫米波MIMO系统。为降低毫米波MIMO系统射频复杂度,混合预编码方案将信号处理分为两个阶段,分别是模拟预编码和数字基带预编码处理。通过模拟预编器的处理,能有效降低射频链数目,从而降低了射频开销和能耗,再利用低维度数字预编码器,能实现逼近传统全数字预编码方案的良好传输性能。本文首先回顾了毫米波通信系统中MIMO结构,分析了传统MIMO结构特点,重点关注毫米波系统中模拟数字混合MIMO结构和透镜天线阵列结构。在此基础上,针对不同结构进行预编码算法研究。其中,对于模拟数字混合结构,研究了单用户与多用户情形下几种混合预编码算法。另外,针对混合结构中具有较低复杂度的部分连接结构,首先介绍了现有的典型算法,分析其性能与算法复杂度,在此基础上提出了改进的混合预编码算法,仿真表明改进后的算法能以较低复杂度实现良好的性能。最后,对于透镜天线阵列结构,详细分析了系统结构,建模过程和预编码算法设计,提出了改进型算法,并与模数混合MIMO结构的算法进行性能仿真对比,进一步体现了该结构能有效降低毫米波MIMO系统射频复杂度的特点。
[Abstract]:In order to meet the increasing demand of wireless communication data transmission, the spectrum of millimeter wave band which has not been developed has become an effective way to solve the bottleneck of transmission rate and limited spectrum resources. At present, millimeter-wave MIMO systems with large antenna arrays have attracted much attention in both academia and industry. It can provide both wider transmission bandwidth and higher spectral efficiency. Combined with the characteristics of millimeter wave propagation and large antenna array, hybrid precoding technology has become an important signal processing method in millimeter wave MIMO systems. It can effectively resist multipath fading and reduce interference between transmission data streams. Thus, the spectral efficiency is improved. The conventional MIMO system has a RF chain for each antenna, and precoding is performed only in the digital baseband. With the increase in the number of antennas, this will result in huge hardware overhead and energy consumption, so the traditional precoding scheme is no longer suitable for millimeter-wave MIMO systems. In order to reduce the RF complexity of millimeter-wave MIMO systems, the hybrid precoding scheme divides the signal processing into two stages: analog precoding and digital baseband precoding. The processing of analog preprocessor can effectively reduce the number of RF chains, thus reducing the RF overhead and energy consumption. Using the low-dimensional digital precoder, it can achieve good transmission performance of approaching the traditional full-digital precoding scheme. This paper first reviews the MIMO structure in millimeter wave communication system, analyzes the characteristics of traditional MIMO structure, and focuses on the analog digital hybrid MIMO structure and lens antenna array structure in millimeter wave communication system. On this basis, the precoding algorithm for different structures is studied. Among them, several hybrid precoding algorithms are studied in the case of single user and multi-user for analog-digital hybrid structure. In addition, for the partial connection structure with low complexity in the hybrid structure, this paper first introduces the existing typical algorithms, analyzes the performance and complexity of the algorithm, and then proposes an improved hybrid precoding algorithm. Simulation results show that the improved algorithm can achieve good performance with low complexity. Finally, for the lens antenna array structure, the system structure, modeling process and precoding algorithm design are analyzed in detail. The improved algorithm is proposed and compared with the analog-to-digital hybrid MIMO structure. Furthermore, this structure can effectively reduce the RF complexity of millimeter wave MIMO system.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN919.3

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