认知无线电系统中干扰对齐的自由度分析

Analysis on the degree of freedom of interference alignment in cognitive radio

在信号空间维度有限的情况下,大部分认知无线电系统(主用户个数大于1)中干扰对齐的可行性条件是不明确的。针对这一问题,把有多个主用户和多个次用户的认知系统中的干扰对齐问题分成主用户干扰对齐问题和次用户干扰对齐问题的2个子问题,给出了一种实现次用户网络干扰对齐的必要性条件(主用户网络干扰对齐的必要性条件在之前的研究中已存在)。根据必要性条件,给出了次用户网络的平均自由度上界,提出了一种改进的最小干扰泄露算法,并以此验证了必要性条件结果。

The feasibility conditions were still unclear in the case of finite number of signal dimension for most cognitive radio systems. The IA problem of CR system with multiple primary users and multiple secondary users was divided into two sub-problems： the IA problem of primary network and the IA problem of secondary network, based on the cognitive mind. Then, the necessary IA conditions of secondary network were presented （good IA conditions of primary network have been proposed in previous research）. Through the necessary conditions, it can obtain the upper bound of the average Dof of the secondary users. An improved minimum interference leakage algorithm was proposed, with which the conclu- sion was verified.