Efficient resource allocation schemes for cognitive radio networks: agile spectrum sharing and enabling technologies

近年来，无线应用已经变得越来越重要，而无线用户的数量一直在不断增长。然而，无线电频谱是一种稀缺的自然资源;其大部分被分配给身份明确的许可用户。通常，许可用户不愿意与其他未知用户共享其频谱，并且许可频谱的大部分未被充分利用。认知无线电（CR）技术（基于软件定义无线电）为解决频谱稀缺及其利用不足提供了一种实用方法。这是通过实施动态频谱接入的概念来实现的，使得未授权CR用户可以动态接入授权频谱，而不会对授权用户造成有害干扰。该研究计划的重点是开发原创和创新的高效资源分配方案，以将CR技术集成到新兴的无线网络技术中。首先，我们将研究CR节点与合作通信-建立一个虚拟的多天线系统，通过利用相邻节点中可用的天线。这种集成创建了一个认知合作系统，其中有效的资源分配算法是至关重要的提取认知和合作的好处。其次，我们将研究动态频谱接入到毫微微蜂窝系统的集成。毫微微蜂窝系统提供高吞吐量、高移动性服务，以满足新无线应用更具挑战性的要求。每个毫微微小区包含一个通过可靠的高速连接连接到广域蜂窝网络的低功率、低成本、高吞吐量基站。如果没有有效的资源分配、频谱接入和干扰控制方案，毫微微小区的益处可能会显著减少。

In recent years, wireless applications have become increasingly crucial while the number of wireless users has constantly been growing. However, the radio spectrum is a scarce natural resource; and its majority is allocated to well-identified licensed users. In general, licensed users are unwilling to share their spectrum with other unknown users and a large part of the licensed spectrum is not fully utilised. Cognitive Radio (CR) technology (based on software defined radio) presents a practical approach to spectrum scarcity and to its underutilisation. This is achieved by implementing the concept of dynamic spectrum access such that unlicensed CR users can dynamically access the licensed spectrum, without causing harmful interference to licensed users. This research program focuses on developing original and innovative efficient resource allocation schemes for the integration of CR technology in emerging wireless networking techniques. First, we will investigate CR nodes operating with cooperative communication - that builds a virtual multi-antenna system by making use of the antennas available in the neighbour nodes. This integration creates a cognitive cooperative system where efficient resource allocation algorithms are critical for extracting the benefits of both the cognition and the cooperation. Second, we will study the integration of dynamic spectrum access into femtocell cellular systems. Femtocell systems provide a high-throughput high-mobility service to answer the more-challenging requirements of new wireless applications. Each femtocell contains one low-power low-cost high-throughput base station connected to the wide cellular network through a reliable high speed connection. Femtocell benefits can be significantly curtailed without efficient resource allocation, spectrum access and interference control schemes.