Modelling and Optimising Cognitive Radio Networks

在过去十年中，无线通信业务出现了前所未有的增长，这导致了频谱频带的严重短缺，并对可用的无线电频谱频带施加了越来越大的压力。然而，许多研究人员报告的实际频率使用测量表明，一些许可的无线电频谱没有得到充分利用。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，但会导致频谱严重短缺和许可频谱利用率低。频谱共享是缓解这一困境的一个潜在解决方案。为了响应b谷歌、摩托罗拉、微软、Earthlink和戴尔等科技公司的要求，开放未使用的频谱，即“空白区域”供未经许可的使用，美国联邦通信委员会（FCC）发布了一份拟议规则制定通知，将推进认知无线电（CR）技术作为实施频谱共享的候选技术。认知无线电是连续感知频谱以识别频谱空白的无线电系统，然后在许可用户的主用户不活跃时在频谱中运行。为了使CR节点能够在不影响已授权用户的情况下访问某些已授权频谱，CR用户必须准确地检测到未使用的频谱，选择可用的最佳通道，并协调CR用户对该通道的访问。在许可频谱内运行的CR用户必须保持频谱感知，一旦检测到主用户，立即释放信道。这些要求使得CR网络设计极具挑战性。本研究的目标是研究CR网络的建模和设计，以提高频谱检测和优化频谱共享。本研究的完成将大大提高许可频段的利用率，缓解频谱短缺的压力。主要研究成果将获得专利，并授权给各行业使用。此外，该项目将通过培训额外的高素质人才（HQF）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).