协作通信系统中的中继选择与功率分配算法研究
发布时间：2019-01-20 12:33
【摘要】：1.引言 与有线通信网络相比，无线通信中的多径衰落及节点的移动会导致通信环境较差，从而严重影响了通信质量和传输速率。此外无线通信中的用户（实体/节点）很多（以我国为例，目前为止无线网络用户大约为有线网络用户的4倍），然而有限的宽带资源和丰富的无线网络业务对传输速率和通信质量都有较高的要求。所以，无线通信技术目前正面临着前所未有的巨大挑战。 传统的点到点无线通信技术已经接近香浓极限，必须探索超越传统点到点通信技术的新技术和新方案。由于无线通信信道具有的开放性（空域）和广播特性（信息传输），可以充分借助这两个特点来解决目前技术中出现的问题。在这个过程中协作通信技术应运而生，协作通信技术通过合作伙伴共享天线资源，形成虚拟的天线阵列，从而获得空间分集，它可以有效的抵抗信道衰落，成为无线通信领域的研究热点，本文以国家自然科学基金“基于控制论和矩阵摄动理论的认知无线电系统动态资源分配问题研究(61171079)”为研究背景，作为延伸课题探究协作通信技术应用到无线通信网络的巨大潜力。 本文针对当前协作通信的发展趋势以及多中继协作通信的中继选择算法存在的问题，提出了一种基于中断概率的中继选择与功率分配算法。该算法在总功率受限情况下，完成了中继选择和功率优化，优化系统中断性能的同时提升了功率效率。尽管已有一些多中继协作网络的中继选择算法，但是这些算法都是基于等功率分配AF协作系统的中继选择，忽略了在等功率分配的假设下选择出的中继集合对系统性能的影响。基于上述考虑，本文深入研究了功率优化后的中继选择技术在AF协作网络中的应用，提出了一种新颖的、低复杂度的快速中继选择与功率分配算法。 2.基于中断概率的中继选择与功率分配算法 本文提出一种在功率受限条件下，AF协作系统中基于中断概率的低复杂度的快速中继选择与功率分配算法，第一步进行全局功率优化，通过对源节点和所有潜在的中继节点进行功率优化，使信道条件好的中继节点更快的被选择出来，得到充分利用；第二步完成中继选择，结合当前的信噪比选择最优的中继节点集合；第三步进行功率分配，这是一个求解具有限制条件的凸优化问题，通过最速下降法和拉格朗日乘子法求出使系统中断概率最小的功率分配因子，从而实现系统中断概率的最小化，，同时提高了功率效率。 3.仿真结果及性能分析 仿真结果表明，本文所提出的快速中继选择和功率分配算法突破了等功率条件下中继选择的局限，排除了其对系统性能的影响，明显优化了系统中断性能，提升了功率效率。为多中继协作通信系统中的中继选择提供了创新的思维。
[Abstract]:1. Compared with wired communication networks, multipath fading and node mobility in wireless communication will lead to poor communication environment, which will seriously affect the communication quality and transmission rate. In addition, there are many users (entities / nodes) in wireless communications (take our country as an example, the number of wireless network users so far is about four times that of wired network users), However, limited broadband resources and abundant wireless network services require high transmission rate and communication quality. Therefore, wireless communication technology is facing unprecedented challenges. The traditional point-to-point wireless communication technology is close to the limit of fragrance, so it is necessary to explore new technologies and schemes beyond the traditional point-to-point communication technology. Due to the openness (airspace) and broadcast (information transmission) of wireless communication channel, these two characteristics can be fully used to solve the problems in the current technology. In this process, the cooperative communication technology emerges as the times require. The cooperative communication technology forms virtual antenna array by sharing antenna resources with partners, thus obtaining spatial diversity, which can effectively resist channel fading. It has become a hot topic in the field of wireless communication. In this paper, the National Natural Science Foundation of China, "Research on dynamic Resource allocation in Cognitive Radio Systems based on Cybernetics and Matrix perturbation Theory (61171079)", is the background of the research. As an extension of the topic, explore the great potential of cooperative communication technology in wireless communication networks. In this paper, a relay selection and power allocation algorithm based on outage probability is proposed to solve the problems of the current development trend of cooperative communication and the problems of relay selection algorithm for multi-relay cooperative communication. The algorithm achieves relay selection and power optimization in the case of total power constraints, and improves power efficiency while optimizing system interrupt performance. Although there are some relay selection algorithms for multi-relay cooperative networks, these algorithms are based on the relay selection of AF cooperative systems with equal power allocation, ignoring the influence of the relay set selected under the assumption of equal power allocation on the system performance. Based on the above considerations, this paper studies the application of power optimized relay selection technology in AF cooperative networks, and proposes a novel, low-complexity fast relay selection and power allocation algorithm. 2. Relay selection and Power allocation algorithm based on interrupt probability this paper presents a fast relay selection and power allocation algorithm based on interrupt probability in AF collaboration system with low complexity. The first step is to optimize the global power by optimizing the power of the source node and all the potential relay nodes so that the relay nodes with good channel conditions can be selected more quickly and fully utilized. The second step is to complete relay selection and select the optimal set of relay nodes combined with the current signal-to-noise ratio (SNR). The third step is power allocation, which is a convex optimization problem with limited conditions. By using the steepest descent method and Lagrange multiplier method, the power distribution factor with the minimum interruption probability of the system is obtained. Thus the system interrupt probability is minimized and power efficiency is improved. 3. The simulation results and performance analysis show that the proposed fast relay selection and power allocation algorithms break through the limitation of relay selection under the condition of equal power and exclude the influence on system performance. The system interrupt performance is obviously optimized and power efficiency is improved. It provides innovative thinking for relay selection in multi-relay cooperative communication systems.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN92
本文编号：2412044
[Abstract]:1. Compared with wired communication networks, multipath fading and node mobility in wireless communication will lead to poor communication environment, which will seriously affect the communication quality and transmission rate. In addition, there are many users (entities / nodes) in wireless communications (take our country as an example, the number of wireless network users so far is about four times that of wired network users), However, limited broadband resources and abundant wireless network services require high transmission rate and communication quality. Therefore, wireless communication technology is facing unprecedented challenges. The traditional point-to-point wireless communication technology is close to the limit of fragrance, so it is necessary to explore new technologies and schemes beyond the traditional point-to-point communication technology. Due to the openness (airspace) and broadcast (information transmission) of wireless communication channel, these two characteristics can be fully used to solve the problems in the current technology. In this process, the cooperative communication technology emerges as the times require. The cooperative communication technology forms virtual antenna array by sharing antenna resources with partners, thus obtaining spatial diversity, which can effectively resist channel fading. It has become a hot topic in the field of wireless communication. In this paper, the National Natural Science Foundation of China, "Research on dynamic Resource allocation in Cognitive Radio Systems based on Cybernetics and Matrix perturbation Theory (61171079)", is the background of the research. As an extension of the topic, explore the great potential of cooperative communication technology in wireless communication networks. In this paper, a relay selection and power allocation algorithm based on outage probability is proposed to solve the problems of the current development trend of cooperative communication and the problems of relay selection algorithm for multi-relay cooperative communication. The algorithm achieves relay selection and power optimization in the case of total power constraints, and improves power efficiency while optimizing system interrupt performance. Although there are some relay selection algorithms for multi-relay cooperative networks, these algorithms are based on the relay selection of AF cooperative systems with equal power allocation, ignoring the influence of the relay set selected under the assumption of equal power allocation on the system performance. Based on the above considerations, this paper studies the application of power optimized relay selection technology in AF cooperative networks, and proposes a novel, low-complexity fast relay selection and power allocation algorithm. 2. Relay selection and Power allocation algorithm based on interrupt probability this paper presents a fast relay selection and power allocation algorithm based on interrupt probability in AF collaboration system with low complexity. The first step is to optimize the global power by optimizing the power of the source node and all the potential relay nodes so that the relay nodes with good channel conditions can be selected more quickly and fully utilized. The second step is to complete relay selection and select the optimal set of relay nodes combined with the current signal-to-noise ratio (SNR). The third step is power allocation, which is a convex optimization problem with limited conditions. By using the steepest descent method and Lagrange multiplier method, the power distribution factor with the minimum interruption probability of the system is obtained. Thus the system interrupt probability is minimized and power efficiency is improved. 3. The simulation results and performance analysis show that the proposed fast relay selection and power allocation algorithms break through the limitation of relay selection under the condition of equal power and exclude the influence on system performance. The system interrupt performance is obviously optimized and power efficiency is improved. It provides innovative thinking for relay selection in multi-relay cooperative communication systems.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN92
【参考文献】
相关期刊论文 前1条
1 王昭然;谢显中;赵鼎新;;车载自组织网络关键技术[J];电信科学;2011年01期
本文编号：2412044
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