TD-LTE电力无线专网中射频失配下MIMO功率分配算法

Power allocation of MIMO system with RF mismatch in TD-LTE power wireless private network

随着智能配电网的发展,采用TD-LTE技术的电力无线专网逐渐成为了热门的研究课题。其中,多输入多输出(MIMO)系统是TD-LTE电力无线专网的一项关键技术。在TD-LTE中,常采用时分双工的方式估计信道信息,进行合适的功率分配,使得通信系统的频谱效率最大化。然而由于射频链路的不匹配,在实际的通信系统中完整的上下行信道并不能实现完全的对称。分析了射频不匹配下MIMO系统的性能,给出了次优的功率分配方案,结合近似的容量表达式,对比分析了射频失配和匹配下的系统频谱效率。仿真结果表明,相比于最优功率分配,次优功率分配算法下的系统容量会有一定的损失,但是相对于等功率分配算法仍有一定的性能提升,并且不需要复杂的校准过程,便于操作实现,证明了该次优功率分配算法的有效性。

With the development of smart distribution network, the power wireless private network using TD-LTE technology has gradually become a hot research topic. Among them, multiple-input multiple-output （MIMO） system is a key technology of TD-LTE power wireless private network. In TD-LTE, time-division duplex is often used to es- timate channel information and perform appropriate power allocation to maximize the spectral efficiency of the communication system. However, due to the mismatch of radio frequency link, the complete uplink and downlink channels in the actual communication system can not achieve complete symmetry. The performance of MIMO system under radio frequency mismatch was analyzed and the suboptimal power allocation scheme was given. Combining with the approximate capacity expression, the spectral efficiency of the system under radio frequency mismatch and matching was analyzed. Simulation results show that compared with the optimal power allocation, the system capac- ity will suffer some loss due to the sub-optimal power allocation algorithm, but there is still some performance im- provement compared with the equal power allocation algorithm, and does not require complicated calibration process. The realization of the operation proves the validity of the sub-optimal power allocation algorithm.