Modelling and Optimising Cognitive Radio Networks

在过去的十年中，无线通信服务出现了前所未有的增长，这导致了频谱严重短缺，并对可用的无线电频谱造成了越来越大的压力。然而，许多研究人员报告的实际频率使用测量表明，一些获得许可的无线电频谱极未得到充分利用。传统的静态频谱分配可以有效地减少不同无线业务之间的干扰，但存在严重的频谱稀缺和授权频谱利用率低的问题。频谱共享是缓解这一困境的潜在解决方案。应谷歌、摩托罗拉、微软、EarthLink和戴尔等科技公司的要求，美国联邦通信委员会(FCC)发布了一份关于制定推进认知无线电(CR)技术的拟议规则的通知，作为实施频谱共享的候选方案。认知无线电是一种无线电系统，它不断地感知频谱以识别频谱空白，然后在获得许可的用户的主用户不活动时在频谱中运行。为了使CR节点在不影响许可用户的情况下接入特定许可频谱，CR用户必须准确地检测未使用的频谱，选择最佳可用信道来接入，并协调CR用户之间对该信道的接入。在许可频谱中操作的CR用户必须保持对频谱的感知，并在检测到主用户后立即释放该信道。这些要求使CR网络设计极具挑战性。本研究的目标是研究认知无线电网络的建模和设计，以改进频谱检测和优化频谱共享。建议的研究完成后，将大大改善领有牌照的频谱的使用率，并纾缓迫在眉睫的频谱短缺情况。主要发现将获得专利，并授权给各行业。此外，该项目将通过培训更多的高素质人员(HQF)来帮助建设加拿大的研究能力。

The last decade has seen unprecedented growth in wireless communication services, which has consequently resulted in severe scarcity of spectrum bands and imposed increasing pressure on the available radio spectrum bands. However, actual frequency usage measurements reported by many researchers indicate some licensed radio spectrums are extremely underutilized. The conventional static spectrum assignment is effective to reduce interference between different wireless services but results in severe spectrum scarcity and low utilization of licensed spectrum. Spectrum sharing is a potential solution to alleviate this dilemma. In response to request from technology companies like Google, Motorola, Microsoft, Earthlink and Dell, to open the unused spectrum known as 'white space' for unlicensed use, the American Federal Communications Commission (FCC) has issued a Notice of Proposed Rule Making advancing cognitive radio (CR) technology as a candidate to implement spectrum sharing. Cognitive radios are radio systems that continuously sense spectrum to identify spectrum white space, and then operate in spectrums whenever the licensed users 'primary users' are not active. In order for a CR node to access certain licensed spectrum without affecting the licensed users, the CR user must accurately detect unused spectrum, select the best available channel to access, and coordinate access to this channel among CR users. The CR users that are operating in licensed spectrum must keep sensing the spectrum and immediately release the channel once a primary user is detected. These requirements make CR network design extremely challenging. The goal of the proposed research is to study CR network modeling and design in order to improve spectrum detection and optimize spectrum sharing. Completion of the proposed research will greatly improve the utilization of licensed spectrum bands and alleviate the pressing spectrum scarcity. The main findings will be patented and licensed to industries. Furthermore, this project will help building Canada research capacity by training additional Highly Qualified Personnel (HQF).