基于极化信息处理的认知无线电频谱共享技术研究
发布时间：2018-09-07 14:16
【摘要】：无线频谱是一种不可再生的宝贵资源。提高频谱资源的利用率以满足无线通信业务的需求,是无线通信领域一个永恒的话题。采用认知无线电技术实现认知用户在信号的时域、频域和空域共享授权频谱资源已经成为研究热点,而在信号的极化域实现对授权频谱的共享却尚未得到充分的研究。在对传统时、频、空域频谱机会充分开发利用的基础上,进一步挖掘信号极化域上存在的频谱资源潜力,可以使得认知用户与授权用户在相同的频段上、相同的时间内以及相同的空间资源上共存,从而进一步提高频谱利用率。基于极化信息处理的认知无线电频谱共享技术的研究将为开发新的频谱机会以缓解频谱资源紧缺现状开辟新的途径。 论文选题来源于国家自然科学基金项目“极化域频谱感知理论与技术研究”(项目编号：60902047)、国家重大科技专项项目"TD-LTE系统中认知无线电技术的研究与验证(项目编号：2012ZX03003006)”。论文主要围绕如何利用信号的极化域信息实现认知用户对授权频谱的共享展开研究,主要研究工作及成果如下： (1)对认知无线电频谱共享技术和极化信息处理技术进行了综述和分析。归纳了现有研究中的频谱共享方式并重点分析了认知用户可接入的多域频谱机会；梳理了极化信号处理的研究现状,进而分析了在信号极化域实现频谱共享的可行性。 (2)在一对认知用户与一对授权用户共存的频谱共享方面,目前的频谱共享算法仅能利用时域和空域的频谱机会而导致对频谱效率的提升幅度不高。针对这一问题,提出了以干扰约束和半盲极化适配为特征的变极化算法,来实现认知用户和授权用户的同时同频同空间共存。首先,从不妨碍授权用户正常通信的角度出发,设计了基于干扰约束的极化域频谱共享算法。进一步地,考虑认知用户难以获取信道先验信息的情况,提出了基于半盲极化适配的极化域频谱共享算法。理论和仿真分析表明,与传统基于频谱感知的时域频谱共享算法相比,基于干扰约束和半盲极化适配的频谱共享算法能取得更高的频谱效率。 (3)在多对认知用户与一对授权用户共存的频谱共享方面,针对由于认知用户增加而导致的复杂干扰问题,在利用信号极化维度资源的基础上进一步利用信号空域维度的资源,提出了联合变极化和波束赋形算法,来消除认知用户与授权用户之间、认知用户与认知用户之间的干扰。为适应多对认知用户与授权用户共存场景所特有的授权频谱动态特性,设计了融合授权频谱所有状态的认知用户吞吐量优化模型。分析和仿真结果表明,论文所提出的极化-空域频谱共享算法不仅对动态变化的授权频谱环境具有鲁棒性,而且比传统频谱共享算法对频谱效率的提升幅度更大。 (4)针对极化模式色散作用使得极化状态发生色散而降低认知用户和授权用户接收性能的问题,提出了在更窄的频带上承载极化状态的子载波分簇机制。子载波簇的大小不仅会影响到极化模式色散作用,也会影响到认知用户环境学习开销,而极化模式色散和环境学习开销又最终影响到认知用户的有效吞吐量。因此设计了以最大化认知用户有效吞吐量为目标的约束优化问题并求解。仿真结果表明,通过对子载波进行分簇,可以很好地兼顾认知用户环境学习开销和避免极化模式色散影响两方面的性能,从而在提高认知用户有效吞吐量的基础上改善了对授权频谱的利用。
[Abstract]:Wireless spectrum is a kind of non-renewable precious resource. It is an eternal topic in wireless communication field to improve the utilization ratio of spectrum resources to meet the needs of wireless communication services. However, the sharing of authorized spectrum in polarization domain has not been fully studied. On the basis of fully exploiting and utilizing the traditional time-frequency and space-domain spectrum opportunities, further tapping the potential spectrum resources in polarization domain can make cognitive users and authorized users in the same frequency band, the same time and the same time. Coexistence of spatial resources will further improve the spectral efficiency. The research of spectrum sharing in cognitive radio based on polarization information processing will open up a new way to develop new spectrum opportunities to alleviate the shortage of spectrum resources.
The selected topic of this paper is from the National Natural Science Foundation project "Polarization Domain Spectrum Sensing Theory and Technology Research" (Project Number: 60902047), and the major national science and technology project "Research and Verification of Cognitive Radio Technology in TD-LTE System" (Project Number: 2012 ZX03003006). To achieve cognitive user sharing of authorized spectrum, the main research work and achievements are as follows:
(1) The spectrum sharing technology and polarization information processing technology in cognitive radio are summarized and analyzed. The spectrum sharing methods in existing research are summarized and the multi-domain spectrum opportunities accessible by cognitive users are analyzed emphatically. Sex.
(2) For spectrum sharing between a pair of cognitive users and a pair of authorized users, the current spectrum sharing algorithm can only take advantage of spectrum opportunities in time and space domains, which leads to a low enhancement of spectrum efficiency. First of all, a polarization domain spectrum sharing algorithm based on interference constraints is designed from the point of view of not interfering with the normal communication of authorized users. Furthermore, considering that it is difficult for cognitive users to obtain channel prior information, a polarization domain spectrum sharing algorithm based on semi-blind polarization adaptation is proposed. Theoretical and simulation results show that the spectrum sharing algorithm based on interference constraints and semi-blind polarization adaptation can achieve higher spectrum efficiency than the traditional spectrum sensing based time domain spectrum sharing algorithm.
(3) For the spectrum sharing of multiple pairs of cognitive users and one pair of authorized users, aiming at the complex interference caused by the increase of cognitive users, a joint variable polarization and beamforming algorithm is proposed to eliminate cognitive users and authorization based on the use of signal polarization dimension resources and the use of signal spatial dimension resources. A throughput optimization model for cognitive users is designed to accommodate the unique dynamic characteristics of authorized spectrum in the scenario where multiple pairs of cognitive users and authorized users coexist. The proposed method is not only robust to the dynamic authorized spectrum environment, but also more efficient than the traditional spectrum sharing algorithm.
(4) Aiming at the problem that polarization mode dispersion causes polarization state dispersion and reduces the reception performance of cognitive users and authorized users, a subcarrier clustering mechanism is proposed to support polarization state in narrower frequency band. Therefore, a constrained optimization problem with the objective of maximizing the effective throughput of cognitive users is designed and solved. The simulation results show that the learning cost and avoidance of cognitive users can be well balanced by clustering subcarriers. Polarization-free mode dispersion affects both aspects of performance, thus improving the utilization of authorized spectrum on the basis of improving the effective throughput of cognitive users.
【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN92
本文编号：2228501
[Abstract]:Wireless spectrum is a kind of non-renewable precious resource. It is an eternal topic in wireless communication field to improve the utilization ratio of spectrum resources to meet the needs of wireless communication services. However, the sharing of authorized spectrum in polarization domain has not been fully studied. On the basis of fully exploiting and utilizing the traditional time-frequency and space-domain spectrum opportunities, further tapping the potential spectrum resources in polarization domain can make cognitive users and authorized users in the same frequency band, the same time and the same time. Coexistence of spatial resources will further improve the spectral efficiency. The research of spectrum sharing in cognitive radio based on polarization information processing will open up a new way to develop new spectrum opportunities to alleviate the shortage of spectrum resources.
The selected topic of this paper is from the National Natural Science Foundation project "Polarization Domain Spectrum Sensing Theory and Technology Research" (Project Number: 60902047), and the major national science and technology project "Research and Verification of Cognitive Radio Technology in TD-LTE System" (Project Number: 2012 ZX03003006). To achieve cognitive user sharing of authorized spectrum, the main research work and achievements are as follows:
(1) The spectrum sharing technology and polarization information processing technology in cognitive radio are summarized and analyzed. The spectrum sharing methods in existing research are summarized and the multi-domain spectrum opportunities accessible by cognitive users are analyzed emphatically. Sex.
(2) For spectrum sharing between a pair of cognitive users and a pair of authorized users, the current spectrum sharing algorithm can only take advantage of spectrum opportunities in time and space domains, which leads to a low enhancement of spectrum efficiency. First of all, a polarization domain spectrum sharing algorithm based on interference constraints is designed from the point of view of not interfering with the normal communication of authorized users. Furthermore, considering that it is difficult for cognitive users to obtain channel prior information, a polarization domain spectrum sharing algorithm based on semi-blind polarization adaptation is proposed. Theoretical and simulation results show that the spectrum sharing algorithm based on interference constraints and semi-blind polarization adaptation can achieve higher spectrum efficiency than the traditional spectrum sensing based time domain spectrum sharing algorithm.
(3) For the spectrum sharing of multiple pairs of cognitive users and one pair of authorized users, aiming at the complex interference caused by the increase of cognitive users, a joint variable polarization and beamforming algorithm is proposed to eliminate cognitive users and authorization based on the use of signal polarization dimension resources and the use of signal spatial dimension resources. A throughput optimization model for cognitive users is designed to accommodate the unique dynamic characteristics of authorized spectrum in the scenario where multiple pairs of cognitive users and authorized users coexist. The proposed method is not only robust to the dynamic authorized spectrum environment, but also more efficient than the traditional spectrum sharing algorithm.
(4) Aiming at the problem that polarization mode dispersion causes polarization state dispersion and reduces the reception performance of cognitive users and authorized users, a subcarrier clustering mechanism is proposed to support polarization state in narrower frequency band. Therefore, a constrained optimization problem with the objective of maximizing the effective throughput of cognitive users is designed and solved. The simulation results show that the learning cost and avoidance of cognitive users can be well balanced by clustering subcarriers. Polarization-free mode dispersion affects both aspects of performance, thus improving the utilization of authorized spectrum on the basis of improving the effective throughput of cognitive users.
【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN92
【参考文献】
相关期刊论文 前2条
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2 ;Improved artificial bee colony algorithm with mutual learning[J];Journal of Systems Engineering and Electronics;2012年02期
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