多用户大规模MIMO系统的能量效率研究

发布时间：2018-05-24 02:32

本文选题：大规模MIMO + 频谱效率　；参考：《大连海事大学》2017年硕士论文

【摘要】：作为5G中的关键技术,大规模MIMO技术通过在基站侧配置几十根甚至上百根天线,能够深度挖掘空间的无线资源提高无线通信系统的性能,但是这些性能的提升是以增加硬件成本和能耗为代价的。能量效率作为无线通信中一个重要的衡量指标,被定义为系统和速率与功率之比,能够很好的体现系统速率与功率之间的折中。以此为背景,本论文围绕多用户大规模MIMO系统的频谱效率和能量效率进行研究和分析。首先对多用户大规模MIMO系统下行链路的频谱效率和能量效率进行研究。分析了下行系统频谱效率的近似解表达式,其次依据能效定义建立能效模型,讨论了基站天线数,小区用户数和发送功率分别对系统频谱效率和能量效率的影响。仿真结果表明单小区系统的频谱效率随天线数的增加不断增加,多小区系统的频谱效率随天线数的增加先增加后趋于一定值;多小区由于存在导频污染和小区间干扰,其性能相对单小区较差;系统的能量效率均为天线数、小区用户数和发送功率的凸函数;增加发送功率只能暂时提高系统频谱效率和能量效率,当发送功率超过某一值时,系统频谱效率趋于恒值,能量效率逐渐减小。之后,考虑上行和下行多用户MIMO联合系统和一种更为贴近实际的功耗模型,对系统的能效最大化进行研究。该功耗模型不仅包含了发送和接收端与天线相关的线性消耗功率,还包括了信号检测和预编码、编码和解码、回程和信道估计的消耗功率。理论分析了采用ZF处理时,如何联合选取天线数、用户数以及发送信噪比能够使得系统能量效率达到最大。给出了能量效率与可达速率之间的闭式表达式。仿真结果表明ZF能效和可达速率要比MRT/MRC高的多,最大能效约为MRT/MRC的3倍,相应的可达速率约为MRT/MRC的8倍;系统总发送功率应该随基站天线数的增加而增加以补偿电路功耗增加带来的损失;能量效率和可达速率的趋势并不总能保持一致,而是随可达速率的增加先增加后减小,这是因为当可达速率较低的时候电路功率占据主导地位,而当可达速率较高时发送功率占据主导地位。
[Abstract]:As a key technology in 5G, large-scale MIMO technology can improve the performance of wireless communication system by configuring dozens or even hundreds of antennas on the base station side. But these performance improvements come at the expense of increased hardware costs and energy consumption. As an important measure of wireless communication, energy efficiency is defined as the ratio of system and rate to power, which can well reflect the compromise between system speed and power. Against this background, this thesis focuses on the spectrum efficiency and energy efficiency of multiuser large scale MIMO systems. First, the spectrum efficiency and energy efficiency of multiuser large scale MIMO system downlink are studied. The approximate expression of spectrum efficiency of downlink system is analyzed, and then the energy efficiency model is established according to the definition of energy efficiency. The effects of the number of base station antennas, the number of cell users and the transmission power on the spectrum efficiency and energy efficiency of the system are discussed. The simulation results show that the spectral efficiency of single-cell system increases with the increase of the number of antennas, the spectral efficiency of multi-cell system increases first and then tends to a certain value with the increase of the number of antennas, and the multi-cell system has pilot pollution and inter-cell interference. The energy efficiency of the system is the convex function of the number of antennas, the number of cell users and the transmission power, and the increase of transmission power can only temporarily improve the spectral efficiency and energy efficiency of the system, when the transmission power exceeds a certain value, The spectral efficiency of the system tends to constant and the energy efficiency decreases gradually. Then, considering the uplink and downlink multiuser MIMO system and a more practical power model, the maximum energy efficiency of the system is studied. The power consumption model includes not only the linear power consumption associated with the antenna at the transmitter and receiver, but also the power consumption of signal detection and precoding, coding and decoding, return range and channel estimation. How to select the number of antennas, the number of users and the signal-to-noise ratio can make the energy efficiency of the system maximum when ZF processing is adopted. A closed expression between energy efficiency and reachability rate is given. The simulation results show that the energy efficiency and reachable rate of ZF are much higher than that of MRT/MRC, the maximum energy efficiency is about 3 times of MRT/MRC, and the corresponding reachability rate is about 8 times that of MRT/MRC. The total transmission power of the system should increase with the increase in the number of base station antennas to compensate for the loss caused by the increased power consumption of the circuit; the trend of energy efficiency and reachable rate is not always consistent, but increases first and then decreases with the increase of reachable rate. This is because the circuit power dominates when the reachable rate is low and the transmission power dominates when the reachability rate is high.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN919.3

【参考文献】