基于能效和谱效的协作频谱共享策略研究

发布时间：2018-05-21 05:54

本文选题：协作频谱共享 + 分数傅里叶变换　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：无线通信网络的高能耗和通信需求的指数性增长对设计具备更高能量效率和频谱效率的绿色通信提出了严峻的挑战,以应对无线资源的稀缺。有效解决办法认知无线电被提出作为提高通信系统频谱效率的关键手段之一。因此,在确保主用户正常通信的条件下,开放已授权频段使次级用户和主用户一同占用频谱的频谱共享技术,成为认知无线电系统的研究热点。本文基于能效和谱效的协作频谱共享平台,从能效和谱效角度出发,研究了协作频谱共享系统性能与次级用户选择、协作模式选择及次级用户功率分配等的关系,设计实现了绿色高效的频谱共享策略。首先,本文研究了认知无线电的关键技术,归纳总结了频谱共享的系统模型和主要技术,并给出了本文的频谱共享平台模型。接着针对协作通信技术中的几种协作模式进行了概括分析。然后给出了分数域处理的概念,并仿真分析了Chirp信号的分数域能量聚集特性。最后针对常见的能效和谱效联合优化算法进行了简单的分析介绍。然后,本文设计了统计信道信息已知模型中基于能效和谱效的协作频谱共享策略。在此策略中,次级用户依据信道状态实时选择协作模式进行协作。然后在主用户中断概率约束条件下,设计了最大化次级用户系统能效的功率分配算法和最大化系统谱效的多次级用户选择算法,给出了优化的协作频谱共享策略。仿真结果表明,所提协作频谱共享策略显著地降低了对主用户的干扰,保证了主用户的通信需求,同时显著提高次级用户系统能量效率和系统频谱效率。此外,次级用户系统的中断性能和数据传输速率随次级用户数的增多都得到了明显提升。最后,针对信道的快速时变性,本文进一步研究了瞬时信道信息已知模型下基于能效和谱效的协作频谱共享策略。此策略中,主用户和次级用户分别采用正弦信号和Chirp信号,在满足主用户速率需求的前提下,以最大化系统频谱效率为目标进行次级用户选择,以最大化次级用户系统能量效率为目标进行所选次级用户的功率分配,最终通过两者的联合优化实现频谱共享性能的提升。仿真结果显示,所提协作频谱共享策略极大地降低了对主用户的干扰,主用户系统和次级用户系统的中断性能明显提高,次级用户系统的能量效率显著提高,系统的频谱效率大幅提升。
[Abstract]:The high energy consumption of wireless communication networks and the exponential growth of communication demand pose a severe challenge to the design of green communications with higher energy efficiency and spectral efficiency in order to cope with the scarcity of wireless resources. Cognitive radio, an effective solution, is proposed as one of the key means to improve the spectral efficiency of communication systems. Therefore, under the condition of ensuring the normal communication of the primary users, opening up the spectrum sharing technology in the authorized frequency band, which allows the secondary users and the primary users to share the spectrum together, has become a hot research topic in cognitive radio systems. Based on the cooperative spectrum sharing platform based on energy efficiency and spectral effect, this paper studies the relationship between the performance of cooperative spectrum sharing system and secondary user selection, cooperation mode selection and secondary user power allocation from the perspective of energy efficiency and spectrum effect. A green and efficient spectrum sharing strategy is designed and implemented. Firstly, this paper studies the key technologies of cognitive radio, summarizes the system model and main technologies of spectrum sharing, and gives the spectrum sharing platform model of this paper. Then, several cooperation modes in the cooperative communication technology are summarized and analyzed. Then, the concept of fractional domain processing is presented, and the fractional energy aggregation characteristics of Chirp signal are simulated and analyzed. Finally, the common energy efficiency and spectral optimization algorithms are analyzed and introduced briefly. Then, a cooperative spectrum sharing strategy based on energy efficiency and spectral effect in the known statistical channel information model is designed. In this strategy, the secondary user selects the cooperation mode according to the channel state in real time. Then, under the constraint of the primary user interrupt probability, the power allocation algorithm for maximizing the energy efficiency of the secondary user system and the multi-stage user selection algorithm for maximizing the spectral efficiency of the system are designed, and an optimized cooperative spectrum sharing strategy is proposed. Simulation results show that the proposed cooperative spectrum sharing strategy can significantly reduce the interference to the primary user, ensure the communication requirements of the primary user, and significantly improve the energy efficiency and spectrum efficiency of the secondary user system. In addition, the interrupt performance and the data transmission rate of the secondary user system are obviously improved with the increase of the number of secondary users. Finally, in view of the fast time-varying of the channel, this paper further studies the cooperative spectrum sharing strategy based on energy efficiency and spectral effect under the known model of instantaneous channel information. In this strategy, the primary user and the secondary user adopt the sinusoidal signal and the Chirp signal respectively. Under the premise of satisfying the demand of the primary user rate, the secondary user is selected in order to maximize the system spectrum efficiency. In order to maximize the energy efficiency of the secondary user system, the power allocation of the selected secondary user is carried out, and the spectrum sharing performance is improved through the joint optimization of the two. The simulation results show that the proposed cooperative spectrum sharing strategy greatly reduces the interference to the primary user, improves the interrupt performance of the primary user system and the secondary user system, and improves the energy efficiency of the secondary user system. The spectral efficiency of the system is greatly improved.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925

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