Research On XPIC Technology In Wideband Microwave Communication

In the rapid development of communication technology,how to make full use of the limited resources is a problem which is needed to solve by people.Except the method of developing new grequency bands,Co-channel dual-polarization technology can also double transmission rate and channel capacity.In practical application,the antennas are not ideal and environment influence induced cross-polarization interference(XPI),two cross-polarized signals will be not orthogonal and independent completely.The paper summarizes and analyzes the development of XPIC and current challenges,collates the depolarization effect and XPIC algorithm in use.Cross Polarization Interference is closely associated with the channel characteristics.Cross-polarization interference canceller should be adaptive,which can capture the channel characteristics and track the changes of information channel.Adaptive cross-polarization interference cancellation technology is mainly done by the adaptive iterative algorithm.It introduces the structure and algorithms of cross-polarization interference canceller.First,it introduces two algorithms,including the LMS-XPIC algorithm and the RLS-XPIC algorithm.Then discusses the advangtages and disadvangtages of the two algorithms.The existing XPIC technology is based on LMS algorithm has inferior performance in convergence and tracking performence,the RLS-XPIC algorithm has high computing complexity.According to the principle of XPIC,a new method based on RLS algorithm is proposed.RLS-XPIC has high computation complexity,a new mathod is proposed to overcome this shortage.The interference is eliminated while the computation complexity is reduced sharply.The method:LMS-XPIC?RLS-XPIC and NIRLS-XPIC are simulated and compared.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.The simulation results indicate that the new method can improve the performance of the XPIC.