基于全双工的认知MIMO系统性能研究

发布时间：2018-11-08 15:05

【摘要】：无线通信业务和应用的快速发展导致有限的频谱资源与急剧增加的需求量之间的矛盾日益突出,认知无线电是解决频谱资源不足和频谱利用率低等问题的一条有效途径。认知无线电系统通常需要解决频谱感知、认知用户的通信机制等问题。针对上述问题,本文将多输入多输出(MIMO)技术、协作中继技术和全双工技术等引入到认知无线电系统设计中,以提高系统的频谱检测性能和吞吐量。本文提出三种不同的认知无线电系统解决方案,研究了这些方案设计下的系统性能,主要工作和创新如下:(1)研究全双工单次用户下的认知MIMO系统,提出联合优化机会式频谱接入和最佳功率分配方案,在总的发送功率受限下,采用三分法获取最佳的感知时间,利用凸优化算法获得系统的最佳功率分配。仿真结果表明,该方案能够比基于可变矩阵规划序列凸近似的最佳功率分配方案以及半双工模式下的等功率分配方案获得更高的系统平均吞吐量。(2)研究全双工中继协作下的认知MIMO系统,由全双工中继同时协助认知用户源节点进行多天线频谱感知和发送数据,提出最佳帧结构设计、联合天线选择和最佳功率分配方案。仿真结果表明,与传统的双工等功率分配方案、多天线半双工方案以及单天线半双工解码转发优化方案,该方案能够在干扰门限和总的发送功率增加时显著提高系统的平均吞吐量。(3)研究基于干扰感知的机会式频谱接入下多中继协作认知MIMO系统的性能,考虑了不完美报告信道对频谱检测性能的影响,提出一种新的帧结构设计以及最佳全双工中继选择和功率分配联合优化方案。仿真结果表明,该方案能够获得更好的协作频谱感知检测性能,以及更大的系统平均吞吐量。
[Abstract]:With the rapid development of wireless communication services and applications, the contradiction between the limited spectrum resources and the rapidly increasing demand is becoming increasingly prominent. Cognitive radio is an effective way to solve the problems of insufficient spectrum resources and low spectrum efficiency. Cognitive radio systems usually need to solve spectrum sensing and communication mechanism of cognitive users. In order to improve the spectrum detection performance and throughput of cognitive radio systems, this paper introduces multi-input and multi-output (MIMO) technology, cooperative relay technology and full-duplex technology into the design of cognitive radio systems. In this paper, three different cognitive radio system solutions are proposed, and the system performance under these schemes is studied. The main work and innovations are as follows: (1) the cognitive MIMO system based on full-duplex single-user is studied. A joint optimal opportunistic spectrum access scheme and an optimal power allocation scheme are proposed. Under the total transmission power constraints, the optimal perceptual time is obtained by using the three-point method and the optimal power allocation is obtained by the convex optimization algorithm. The simulation results show that, The proposed scheme can achieve higher average throughput than the optimal power allocation scheme based on the convex approximation of variable matrix programming sequences and the equal-power allocation scheme in semi-duplex mode. (2) the cognitive MIMO system with full duplex relay cooperation is studied. The full duplex relay can simultaneously assist the cognitive user source node in multi-antenna spectrum sensing and data transmission. The optimal frame structure design joint antenna selection and optimal power allocation scheme are proposed. The simulation results show that, compared with the traditional duplex equal-power allocation scheme, the multi-antenna half-duplex scheme and the single-antenna half-duplex decoding and forwarding scheme are optimized. The proposed scheme can significantly improve the average throughput of the system when the interference threshold and total transmission power increase. (3) the performance of multi-relay cooperative cognitive MIMO systems based on interference sensing is studied. Considering the effect of imperfect reporting channel on spectrum detection performance, a new frame structure design and optimal full-duplex relay selection and power allocation joint optimization scheme are proposed. Simulation results show that the proposed scheme can achieve better cooperative spectrum sensing performance and greater system average throughput.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN919.3

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