Distributed Opportunistic Channel Access in Wireless Networks

为了满足未来高速无线通信的需求，需要大幅度提高频谱利用率。一种公认的方式是机会性信道接入（OCA），其已经在文献中针对信道感知机会性调度（或简而言之，机会性调度）和针对认知介质接入进行。主动调度意味着在多用户网络中，在任何时刻，只有具有最佳信道质量的用户被调度来进行发送。认知介质接入意味着，如果授权用户（称为主用户）在某个时间和位置不活动，则未授权用户（称为次用户）可以利用频谱机会。 该研究由三个部分组成：最优分布式机会调度与服务质量（QoS）保证，分布式认知OCA与时间/频率相关性和顺序感知，和多用户认知OCA与机会调度。预计所提出的研究将提供工程的见解，如何共同处理多用户分集，时间分集，合作，学习和竞争在实际的无线网络。研究成果将有助于加拿大电信公司开发和部署低复杂度、高效率的无线网络。

To meet the high-speed wireless communications requirement in the near future, we need to significantly improve the spectrum utilization efficiency. One well-recognized way is opportunistic channel access (OCA), which has been conducted in the literature for channel-aware opportunistic scheduling (or in short from, opportunistic scheduling) and for cognitive medium access. Opportunistic scheduling means that, in a multiple-user network, at any moment only the user with the best channel quality is scheduled to transmit. Cognitive medium access means that, if licensed users (called primary users) are not active at a time and a location, then unlicensed users (called secondary users) can utilize the spectrum opportunity. The proposed research consists of three components: optimal distributed opportunistic scheduling with quality-of-service (QoS) guarantee, distributed cognitive OCA with time/frequency correlations and sequential sensing, and multiple-user cognitive OCA with opportunistic scheduling. It is expected that the proposed research will provide engineering insights regarding how to jointly deal with multiple-user diversity, time diversity, cooperation, learning, and competition in practical wireless networks. And the research outcomes will help Canadian telecommunications companies develop and deploy low-complexity high-efficiency wireless networks.