【摘要】 认知无线电技术源于频谱资源的短缺,并极大提高了无线通信网络的频谱效率。针对经典的多天线认知网络的容量上界问题,从自由度角度出发,提出了新的自由度上界,并设计实现方法达到这一上界。该方法基于干扰对齐方法,通过主用户对认知用户采取主动频谱共享实现了认知网络自由度上界的提高。结果表明,利用新的方法,自由度上界远远优于之前的研究。更多还原

【Abstract】 Cognitive radio emerges out of the spectrum shortage,and it increases spectrum efficiency in wireless communication networks. Given that traditional problem of the maximal capacity in MIMO cognitive networks,from the perspective of degree of freedom( DoF),this paper proposes a new DoF outer bound,and also gives out the method to achieve it. The method is based on interference alignment,the primary user accepts active spectrum sharing for the secondary users to improve the outer bound of DoF in MIMO cognitive networks. The result shows,the new DoF outer bound is much better than previous one.更多还原