一种低复杂度的降低MIMO—OFDM峰平比的CARI方法

天线旋转取反算法(CARI)是降低MIMO-OFDM系统峰平功率比(PAPR)的一种性能较优的算法,不足之处是其迭代次数很大。CARI的次最优算法逐次次最优天线旋转取反(SS-CARI)算法虽然可以减小迭代次数,但性能损失又比较大。针对这一问题,提出了一种用滑动窗搜索旋转取反组合的次最优CARI方法,利用滑动窗搜索局部最优的旋转取反组合,既可以避免整体的遍历搜索大大减小CARI算法的计算复杂度,又可以改善SS-CARI的PAPR减小性能。仿真结果表明,该方法能够在系统复杂度与PAPR降低性能上取得很好的折衷。

A Low Complexity Cross-Antenna Rotation and Inversion (CARI) Method for Reducing Peak-to-Average Power Ratio (PAPR) in MIMO-OFDM Systems

The cross-antenna rotation and inversion(CARI) algorithm,which is used to reduce the peak to average power ratio(PAPR) in MIMO-OFDM systems,has better performance but a large number of iteration.Although the suboptimal scheme of CARI,successive suboptimal CARI(SS-CARI),can reduce the number of iteration,the performance of PAPR reduction is lost largely.For this problem,a suboptimal rotation and inversion combination searching method based on sliding window is proposed.By utilizing sliding windows to search for the local optimal rotation and inversion combinations,not only the whole traversal search can be avoided to reduce the complexity of CARI greatly,but also the performance of PAPR reduction based on SS-CARI can be improved.Simulation result shows that a good tradeoff between the complexity of the system and the capability of PAPR reduction can be obtained through using the presented scheme.