针对认知MIMO系统设计一种空频域机会接入策略。当存在频谱空洞时,认知业务以交叉共享方式实现传输;当无空闲频谱资源可用时,利用授权通信模式信息与系统间干扰信道信息,以重叠共享方式实现认知业务传输。该方法综合利用空间相关度与特征模式传输增益进行空域资源质量评价,实现授权频道与认知特征模式的选择分集。并且,基于授权通信模式信息的信号处理降低了认知系统天线配置要求以及认知信号的功率损失。仿真结果表明,所提策略能够在不影响授权业务的前提下显著改善认知业务性能,获得接近最佳的认知吞吐率。
An opportunistic spatio-frequency access (OSFA) strategy for CR-MIMO system was designed. When spec- trum holes exist, cognitive service was implemented applying overlay approach. While there was no idle spectrum avail- able, primary transmission mode information (PTMI) and inter-system interference channel information were exploited. And cognitive service was implemented using underlay approach. The method utilizes both spatial correlation and ei- genmode transmission gain in spatial resource quality evaluation. Consequently, selection diversity of both authorized channel and cognitive eigenmode was achieved. Moreover, PTMI based signal processing reduced the antenna require- ment for cognitive system as well as the power loss of cognitive signal. Simulation results indicate that the proposed method could achieve significant improvement of cognitive service and near-optimal cognitive throughput on the premise that no interference is imposed on the primary.