一种基于RLS算法的XPIC技术研究

Research on cross plarization interference cancelation based on RLS

采用双极化复用技术能使传输速率和信道容量加倍,但同时因为环境影响或天线的极化隔离度有限等原因,两个极化方向上的信号不再完全正交,两个方向上的信号相互影响,产生交叉极化干扰。分析了进行交叉极化干扰抵消的原理,提出了一种基于最小二乘算法的交叉极化干扰抵消方法,将递推最小二乘（RLS）算法进行改进,在大幅降低RLS算法计算复杂度的基础上实现了干扰抵消,并进行了仿真,比较了3种XPIC算法的计算复杂度和性能。结果表明,采用NIRLS算法的计算复杂度与抵消器抽头系数成线性关系,且能获得更快的收敛速度和更好的跟踪性能。基于NIRLS的XPIC算法更适合快速变化的信道。

Co-channel dual-polarization technology can double transmission rate and channel capacity. Meanwhile, the antennas are not ideal and environment influence induced cross-polarization interference（XPI）, two cross-polarized signals will be not orthogonal and independent completely. According to the principle of XPIC, a new method based on RLS algorithm is proposed. The interference is eliminated while the computation complexity is reduced sharply. The simulation results show that the novel method can improve the convergence speed and the computation complexity is linearly related to the canceller＇s tap coefficient, and the tracking performance is better than LMS. The proposed method has little performance loss and huge computation reduction compared to RLS. NIRLS algorithm is more suited to the Fast-changing channels.