DME Interference Mitigation Research Based On Bayesian Compressive Sensing

As one of the communication technologies that the new generation air traffic management system relies on,L-band digital aviation communication system 1(L-DACS1)works between the adjacent channels of distance measure equipment(DME)system.The signal transmitted by the DME system will seriously interfere with the performance of the OFDM receiver of L-DACS1 system,resulting in the reduction of the overall transmission performance of the system.In order to solve this problem,this paper focuses on bayesian compressed sensing(BCS)algorithm to study the interference suppression method of DME.The main research work is as follows:1)Firstly,the interference suppression principles of two conventional methods are given,which are pulse blanking and pulse cliping.Then,based on the simulation platform of the forward link of L-DACS1 system,the effectiveness of the above two methods is verified.Simulation results show that the two conventional interference suppression methods can eliminate some DME interference signals,and the effect of pulse cliping interference suppression method is relatively good,but neither can significantly improve the performance of L-DACS1 system.2)On the basis of BCS theory,a DME interference suppression method based on support agnostic bayesian matching pursuit(SABMP)algorithm is proposed.Firstly,considering that the empty subcarriers of OFDM receiver never transmit useful signals,a compressed sensing model for DME interference signal is established.Then the DME interference signal is recovered based on the SABMP reconstruction algorithm,and finally the interference signal is eliminated in the time domain.Simulation results show that the interference suppression effect of this method is remarkable,which can effectively improve the transmission reliability of the forward link of L-DACS1 system.3)In order to improve the reconstruction accuracy of DME interference signal,a method of DME interference suppression based on block sparse bayesian learning-the bound optimization(BSBL-BO)algorithm is proposed.Simulation results show that,compared with the existing DME interference suppression methods,the proposed method is more effective.This method,which has higher reconstruction accuracy and faster operation speed,can further reduce the bit error rate of OFDM receiver and improve the forward link transmission performance of L-DACS1 system significantly.