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Study On Adaptive Interference Cancellation Technology For 4G LTE Relay System

Posted on:2017-06-26Degree:MasterType:Thesis
Country:ChinaCandidate:Q RongFull Text:PDF
GTID:2428330596456817Subject:Communication and Information System
Abstract/Summary:PDF Full Text Request
With the growing demand for mobile Internet applications,mobile communication technology has continuously achieved development and innovation.As a new generation of communication technology,4G LTE greatly enhance the transmission rate and system capacity of mobile network.To further enhance network coverage,higher capacity and flexibility link networking,3GPP introduces relay technology in LTE-A?4G?.However,due to the closer distance between the relay device transmitting and receiving antennas without complete isolation,the relay suffers from the self-interference.Especially when the relay deploys in 4G LTE system applying the MIMO technology,due to the use of multiple transmitting and receiving antennas,MIMO relay has a more complex self interference problem.To deal with the problem of the complex self-interference,this subject studys and discusses the self-interference suppression technology of MIMO relay,and is mainly divided into the following three parts.?1?The background and significance of the topic and the development status at home and abroad are briefly introduced;the 4G LTE relay system,relay type and the internal structure of relay is introduced.A detailed description of the self interference problem of the relay is given,and the self-interference characteristics of SISO relay and MIMO relay is analysed?2?For the self-interference problem of SISO relay,the SISO adaptive interference cancellation scheme is presented and analyzed,including system structure,the basic method of elimination and the principle of adaptive algorithms.Though simulation,the performance of interference cancellation system is analyzed,and the performance of LMS?NLMS?RLS algorithms is compared with verifying the effectiveness of the self interference suppression.?3?For the self-interference problem of MIMO relay,based on adaptive steepest descent algorithm,a kind of the self-interference cancellation scheme is proposed.The algorithm is extended from the single channel LMS to the multichannel LMS algorithm.In response to the limited order for the adaptive filter and ensure the performance of interference cancellation,the LMS algorithm is modified according to the adaptive criterion.Through simulation,comparison and analysis of the influence of different echo channel,step factor and the order of the filter and the antenna number of the system is given.The simulation results show that the scheme has good performance of self-interference suppression in 4G LTE relay system,and MSE convergence can be kept under 10-3.
Keywords/Search Tags:LTE, relay, MIMO, self-interference, adaptive interference algorithm
PDF Full Text Request
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