基于动态反馈与功率分配的干扰对齐方法

Novel Interference Alignment Scheme Based on Dynamic Feedback and Power Allocation

在多用户MIMO系统中,信道状态的精确性严重影响干扰对齐技术的性能。该文针对信道状态信息(CSI)有限反馈导致的干扰泄露问题,提出一种基于动态反馈与功率分配的干扰对齐方法。首先从理论上分析了系统和速率与信道状态反馈比特分配和功率分配之间的关系,得到了在动态反馈和功率分配条件下系统和速率的解析表达式;在此基础上,以系统容量提升为目标,对反馈比特分配和功率分配优化问题进行建模;并根据信道的准静态特性利用库恩塔克条件(KKT)对该问题进行求解,得到功率和反馈比特分配方案。仿真结果表明,与单独考虑信道状态动态反馈条件下的干扰对齐技术相比,提出的方法能够有效减少干扰泄漏强度,提高系统和速率。

In multi-user MIMO systems, the accuracy of the Channel State Information（CSI） has a sufficient effect on performance of interference alignment scheme. To solve the problem of interference leakage caused by limited feedback of CSI, a novel method for interference alignment based on dynamic feedback and power allocation is proposed. First, the relationship between system sum rate and the allocation for channel state feedback bits and transmitting power is analyzed theoretically, and the formula of sum rate of the system considering dynamic feedback and power allocation is derived. Based on the above analysis, the model of optimizing allocation for feedback bits and power problem is set to improve the throughput of system. Then, a low-complexity solution to the problem is raised on the basis of channel quasi-static characteristic, and the feedback bit and power allocation scheme are obtained by the Karush-Kuhn-Tucker（KKT） condition. Simulation results show that the proposed method can effectively reduce the interference leakage and improve the system sum rate compared with the interference alignment scheme that just dynamically feedback＇s channel state.