标题: | 广义的机会式通讯---无线行动网路中之竞争、合作与感知---子计画一:感知无线行动网路之频谱侦测与管理 Spectrum Sensing and Management in Cognitive Wireless Mobile Notworks |
作者: | 苏育德 SU YU TED 国立交通大学电信工程学系(所) |
关键字: | 无线通讯;频谱侦测;协力通讯;感知无线电;无线电资源管理;cognitive radio;cooperative communications;radio resource management;spectrum estimation;wireless communication |
公开日期: | 2008 |
摘要: | 近年来兴起的感知无线电开启许多新的无线通讯可能性,一般认为将是下一代无线 行动网路的新技术典范。感知无线电技术之所以被广泛的研究是因为其具有侦测周围环 境无线通讯资源现况(即那些资源如频段等是可供信号的传送或接收)的能力,并可因 应现况作最适当的波形调整(例如: 调整讯号频宽、讯号波形、载波频率、调变种类、功 率及传输方向等)以达到有效率的使用无线通讯资源并同时获致最佳的效能表现。另一 新兴的无线传输技术则是所谓的协力式通讯(Cooperative Communications)。这种通讯 方式藉由周遭暂时闲置的通讯传收机的协助来合力一起传收信号,因此可视为另外一种 机会式(opportunistic)无线通讯空间资源的感知与利用。事实上,除了信号的传收之外, 感知无线电对环境的感测与瞭解也可透过多个在不同位置传收机的合作来提升其感测 与瞭解的能力。我们可以说,感知无线电与协力式通讯是广义机会式通讯不同面貌的呈 现。这种广义机会式通讯的具体实现之一就是所谓的感知(无线电为基础的)无线行动 网路(cognitive radio based wireless mobile networks, or cognitive wireless mobile networks)。在现有无线通讯资源有限传输需求却日增的情形下,广义机会式通讯能争取 新的资源并有效的动态运用所有资源,的确是十分值得且需要深入探讨的新领域。 本子计画目的即在开发(一)各式感知无线电技术中的频谱感测(spectrum sensing) 机制与其性能评析,(二)感知无线电系统的无线电资源管理(radio resource managements) 演算法、规约与性能分析-让无线电资源的分配与管理,能因时因地因装置的不同而有 效地管理调整。尽量排除局部性(local)的最佳解,寻求全域(global)的最佳解,以及(三) 感知无线电系统的感知无线电传输(cognitive radio transmission)。同时我们亦将搭配其 他子计画的研究成果,以跨层(cross layer)设计的方式,达到整体系统性能最佳化。 以下,我们分别简述未来三年的研究重点。 第一年重点为频谱感测(spectrum sensing)机制与其性能评比分析。由于频谱感测部 分的性能是影响到感知无线电系统性能表现的主要关键,与其他子计画所探讨的感知协 力通讯等议题息息相关。在此子计画中,我们将针对频谱感测部分提出新型的软式协力 侦测演算法,其中我们将对因主用户不使用、或主用户无法使用所造成的闲置频谱提出 低复杂度且侦测准确机率高的频谱感测机制。这里“频谱”包含了广义信号空间的所有 维度,而不只是传统的频域分布而已。 第二年的重心将是感知无线电系统的无线电资源管理(radio resource managements) 演算法、规约之设计与性能分析。我们延续第一年的研发成果,在计画的第二年着手对 频谱感测获得的无线电资源进行特性分析,提出合理的竞争机制,并进一步研究资源分 配,建议最佳或次佳但低复杂度的频谱资源分配演算法。这些资源包含频段、功率(能 量)、协力传收点等。我们将同时引进赛局理论(game theory)的概念以分析这种既协力又 竞争的通讯规约之理论容量、能量或功率使用效率等相关性能。此部分将需与子计画二 与子计画四相互配合。 第三年 -感知无线电传输技术 在此计画的最后一年,我们将完成感知无线电网路中之感知无线传收子系统设计。 我们的重点是各个感知无线电装置在得知周遭环境的资讯,并被分配到一定的无线电资 源之后如何设计实际的实体层传输波形(基频波形、调变、编码、天线波束等)及接收 技术作深入的研发与探讨。此部分亦将需与子计画二的研发技术相互配合。 Cognitive radio (CR) technology has in recent years emerged as a new communication paradigm for next generation wireless mobile networks. It promises much more efficient radio resource (especially electromagnetic spectrum) utilization, improved system performance and novel new functionalities. The main theme of CR is the capability of a radio to sense and adapt to its environment, constantly making spectrum, transmission and networking decisions that optimize radio resources (energy/power, spectrum, cooperative nodes etc.) opportunistically. Another rising paradigm is the so-called cooperative communications. In a cooperative communication network, a terminal would solicit cooperation from surrounding terminals for transmitting or receiving signals, which means it exploits additional spatial radio resources (in this case, temporary idled terminals) to enhance system performance. Note that a CR can also improve its environmental (spectrum in particular) sensing capability through cooperation with other terminals. Hence both CR and cooperative communications can be regarded as parts of the generalized opportunistic communications and one of its realizations is the class of cognitive (radio-based) wireless mobile networks. The purpose of this subproject is to analyze and develop spectrum sensing schemes in various operation scenarios and investigate key elements of the other two phases of a cognitive cycle, namely spectrum analysis and spectrum (management decisions). We refer to the term “spectrum” in a generalized sense so that it includes all (generalized) signal dimensions, e.g., conventional frequency spectrum, available time slots, non-interfering antenna direction, cooperative nodes, etc. We shall study radio resource management decisions that maximize network capacity with minimum energy consumption and perhaps with certain delay bound constraint. Reasonable or near optimal competition and cooperation mechanisms shall be suggested and their behaviors and effectiveness be evaluated. Finally, based on the given radio resource, we shall design practical cognitive communication waveforms and detection schemes that achieve or approach the theoretical performance limits. These efforts shall need inputs from and will collaborate with other subprojects. We expect very close interactions amongst all subprojects, as has been stated in the main project. |
官方说明文件#: | NSC96-2221-E009-076-MY3 |
URI: | http://hdl.handle.net/11536/102201 https://www.grb.gov.tw/search/planDetail?id=1598698&docId=274590 |
显示于类别: | Research Plans |