Research On XPIC Technology In High Speed Data Transmission System

As the development of information technology,the demand of transmission speed of communication link increase highly.While the limit of frequency spectrum is always a problem to the arising of the transmission rate.Thus,it is an important issue to improve the utilization efficiency of frequency spectrum.Co-Channel Dual Polarization(CCDP)and Polarization Modulation(PM)are two effective methods to improve the utilization efficient of frequency spectrum.Due to the depolarization effect of channel,Cross Polarization Interference(XPI)would be introduced in the CCDP system,which need a Cross Polarization Interference Canceler(XPIC)to remove it.For the PM technology,the depolarization effect will be conducted by rain and ice crystal,which will worsen the communication performance.In this paper,we discusses the algorithm of XPIC and the compensation technology of channel depolarization effect.First of all,this paper introduces the based theory of electromagnetic wave,builds models of cross polarization channel and depolarization channel,which are the base of the following study.Then,this paper introduces the theory of XPIC,deduces and simulates these XPIC algorithms based on correlated character,lateral filter and estimation of channel parameter.For the disadvantages of the algorithms existing,the XPIC based on SCS(Soft Constraint Satisfaction)algorithm is bought forth.The innovation of XPIC based on SCS algorithm has advantages in convergence and flexibilities,and is suit for high speed data transmission system.Finally,this paper introduces and deduces the polar channel module,simulates and analyzes the depolarization effect of channel,and puts up a new structure to compensation the depolarization affect.Besides,this paper analyzes the correlations between time probability of several environment factors and depolarization effect based on depolarization theory,and draws the summary that the main factor to exacerbate XPI is the rain.At last,simulations evident the validity of the new compensation structure.