Research On The Detection Of PSS And Interference Alignment Technology

Long Term Evolution Advanced (LTE-A) system uses OFDM technology to transmit signals. OFDM signal is highly sensitive to frequency offset and time delay, therefore cell search and synchronization are extremely important. In this process,we must detect the Primary Synchronization Signal(PSS)at first,to get the group ID and basic information.This is the basis for all operations after this.On the other hand,in the multiple cells system, the inter-cell interference can not be avoided,so this requires interference management to improve spectrum efficiency for the edge users in the cells.Interference Alignment is an effective method of interference management,which greatly improved the degree of freedom.In detection of PSS in LTE-A system, PSS uses Zadoff-chu(ZC)sequence. Firstly,this thesis given description and proved the characteristic of ZC sequence,and given its advantages as the PSS. Secondly,this thesis makes a comprehensive analysis and evaluation of the detection accuracy of low signal to noise ratio, resistance to the carrier frequency offset and anti-multipath fading capability using these four methods.Analysis and simulation results show that the performances of four methods under different environments are various.In the study of Interference Alignment,firstly,this thesis analyzed the detailed process of the classic interference alignment algorithms, including three district Single Input Single Output(SISO) interference alignment and Multiple Input Multiple Output (MIMO) interference alignment algorithm.And then expand the existing algorithm,analyzed the distributed interference alignment algorithm and interference alignment in heterogeneous network,researched on time domain,frequency domain and space domain interference alignment,and proposed interference alignment algorithm using in three-dimensional, time domain,frequency domain and space domain.Interference signals can align not only on space domain but also on time domain and frequency domain,this thesis combined time domain, frequency domain and space domain for interference alignment. Three-dimensional interference alignment algorithm is the traditional extended from one-dimensional to three-dimensional domain. Its provided more flexible means of time-frequency-space resource to allocation.