MIMO系统的统计型QoS保障技术研究

发布时间：2018-03-10 05:16

本文选题：MIMO系统　切入点：统计型QoS保障　出处：《西安电子科技大学》2014年博士论文　论文类型：学位论文

【摘要】：在当今移动互联网蓬勃发展的时代，，人们对无线通信系统的服务质量(QoS)提出了更高的要求。如何利用日益紧张的频谱资源来保障不断增长的多媒体业务，成为了无线通信领域的研究热点。多输入多输出(MIMO)技术通过在收发两端配置多根天线获得了额外的空间自由度增益，能够在不增加带宽和发射功率的条件下，极大的提升通信系统的信道容量和可靠性，该技术也成为第四代移动通信(4G)的主要物理层传输技术之一。然而，由于无线信道的随机时变特性，在无线通信系统中为多媒体业务提供确定型QoS保障(Deterministic QoS Guarantees)是难以实现的，因此本文基于有效容量理论研究了MIMO系统中的统计型QoS保障(StatisticalQoS Guarantees)技术。论文的主要贡献概括为以下几个方面： 1.针对存在信道相关性的MISO系统，分别在Nakagami-m衰落和Rician衰落下推导得出了系统有效容量的闭合表达式。通过蒙特卡罗仿真验证了理论分析的结论，并分析了收发天线配置、空间相关程度、QoS需求以及信道衰落强度对有效容量的影响。 2.针对采用MRT/MRC传输方案的MIMO系统，首先推导得出了固定功率分配策略下系统有效容量的闭合表达式；随后在可变功率分配策略下，给出了最优的功率分配策略并推导得出了该策略下系统中断概率和有效容量的闭合表达式。蒙特卡罗仿真验证了理论分析的结论，并表明最优功率分配策略可以显著的提高系统的统计型QoS保障能力。 3.针对采用TAS/MRC传输方案的MIMO系统，首先给出了系统接收信噪比的概率密度函数表达式，并据此推导得出了固定功率分配策略下系统有效容量的闭合表达式；接着在发射功率可变的情况下，给出了最优的功率分配策略并推导得出了该策略下系统中断概率和有效容量的闭合表达式；理论分析和蒙特卡罗仿真表明最优功率分配策略显著的提升了系统的统计型QoS保障能力。 4.针对采用MRT/MRC传输方案的MIMO双跳译码转发中继系统，首先给出了最优接收信噪比的表达式，并在此基础之上推导得出了系统中断概率的闭合表达式；随后分别推导得出了系统在M-PAM、M-QAM、M-PSK和M-PSK调制下的平均误比特率的闭合表达式；最后推导得出了未调制系统的有效容量的闭合表达式。通过蒙特卡罗仿真验证了理论分析的结论，仿真结果表明MRT/MRC传输方案在中断概率、平均误比特率以及统计型QoS保障等方面都极大的提升了系统的性能。
[Abstract]:In the vigorous development of the mobile Internet era, people on the quality of service of wireless communication system (QoS) has put forward higher requirements. How to make use of increasingly scarce spectrum resources to protect the growing multimedia services, has become a research hotspot in the field of wireless communication. Multi input multi output (MIMO) technology can obtain space gain additional degrees of freedom in the transmitter with multiple antennas, can not increase the bandwidth and transmitting power conditions, channel capacity and enhance the reliability of communication system greatly, this technology has become the fourth generation mobile communication (4G) is one of the main physical layer transmission technology. However, due to the time-varying characteristics of wireless channel and for multimedia services in wireless communication systems to provide deterministic QoS guarantee (Deterministic QoS Guarantees) is difficult to achieve, so this paper based on the theory of effective capacity of MIMO The statistical QoS support (StatisticalQoS Guarantees) technology in the system. The main contributions of this paper are summarized in the following aspects:
1. for MISO systems with channel correlation, fading derived the closed form expressions of the effective capacity of the system in Nakagami-m fading and Rician. Through Monte Carlo simulation to verify the theoretical results, and the analysis of the antenna configuration, the spatial correlation degree, the effect of fading intensity on the effective capacity of the QoS channel and demand.
2. for MIMO systems using MRT/MRC transmission scheme, firstly deduces the fixed power allocation strategy under the closed expression of the effective capacity of the system; then the variable power distribution strategy, gives the optimal power allocation strategy and derive the closed form expressions of the outage probability and effective capacity strategy system. Monte Carlo simulation to verify the theoretical analysis the conclusion, and statistics show that QoS can significantly improve the protection ability of system optimal power allocation strategy.
3. for MIMO systems using TAS/MRC transmission scheme, the system signal-to-noise probability density function expression ratio is given first, and then deduces the fixed power allocation strategy under the closed expression of the effective capacity of the system; then the transmit power is variable, gives the optimal power allocation strategy and derive the closed form expressions the outage probability and effective capacity of the system; theoretical analysis and Monte Carlo simulation shows that the optimal power allocation strategy is significant to improve the statistical QoS guarantee system.
4. for the MRT/MRC transmission scheme of MIMO dual hop decode and forward relay system, the expression of the optimal reception SNR is given first, and based on the derived closed form expressions of probability of system outage; then deduces the system in M-PAM, M-QAM, M-PSK and M-PSK modulation of the average bit error rate of the closed expression finally; derived the closed form expressions of effective capacity without modulation system. Through Monte Carlo simulation to verify the theoretical results, the simulation results show that the MRT/MRC transmission scheme in the outage probability, average bit error rate and the statistical QoS guarantee greatly enhance the performance of the system.

【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN919.3

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