Energy Efficient Cognitive Radio Networks

随着对无线通信的高要求和快速发展，无线网络的能耗大幅上升，成为环境保护的一大威胁。与此同时，能源成本占移动运营商运营费用的很大一部分。建设节能的无线通信系统已成为无线通信网络和业务可持续发展的迫切需要。在各种无线通信技术中，认知无线电网络(CRN)引起了学术界和工业界的广泛关注。CRN接入由其他网络分配但未完全利用的无线电频谱。认知无线电设备具有感知环境、自适应调整工作模式、有效提供各种服务的能力。预计在不久的将来，CRN将得到非常广泛的部署，以应对无线通信和传统固定无线电频谱分配的高要求带来的频谱稀缺问题。目前，CRN的工作主要集中在如何有效地检测和利用可用的无线资源，并支持各种业务。本项目的目标是设计和分析节能CRN的性能。我们将i)识别CRN的次要性质带来的挑战和复杂性；ii)探索CRN的能效、数据传输性能和CRN实施之间复杂的权衡以实现节能；iii)利用CRN设备的内置认知功能带来的各种多样性和机会来实现高能效。这项研究对于未来无线通信服务的普及和保护我们所处的环境具有至关重要的意义。这项研究的结果将有助于提供既节能又频谱高效的无线通信服务。它将促进加拿大绿色无线通信的进步，并进一步走向绿色电信，这将对加拿大社会的可持续发展产生长期影响。

With the high demands and rapid evolution for wireless communications, energy consumption of wireless networks has escalated significantly, and become a major threat for environmental protection. Meanwhile, energy costs account for a significant portion of a mobile operator's operating expenses. Building energy efficient wireless communication systems has become an urgent need for sustainable development of wireless communication networks and services. Among various wireless communication techniques, cognitive radio networks (CRNs) have attracted a considerable amount of attentions from both the academia and industry. CRNs access the radio spectrum that is allocated but not fully utilized by other networks. Cognitive radio devices have the ability to sense the environment, adaptively adjust their work modes, and effectively provide various services. CRNs are expected to be very widely deployed in the near future to cope with the spectrum scarcity problem caused by the high demands for wireless communications and traditional fixed radio spectrum allocations. Currently, the work on CRNs mainly focuses on how to efficiently detect and utilize the available radio resources and to support various services. The objective of this project is to design and analyze performance of energy efficient CRNs. We will i) identify challenges and complexities raised by the secondary nature of the CRNs, ii) explore the intricate trade-offs between energy efficiency, data transmission performance, and implementations of CRNs for energy saving, and iii) take advantage of various diversities and opportunities brought by the built-in cognitive capabilities of CRN devices to achieve high energy efficiency. This research is of paramount importance for the proliferation of future wireless communication services and for protecting the environment we live in. The outcome of this research will contribute to providing wireless communication services that are both energy efficient and spectrum efficient. It will foster the progress of green wireless communications and further towards green telecommunications in Canada, which will have a long-term impact on the sustainable development of the Canadian society.