Research On Self-Interference Suppression Algorithms In Simultaneous Transceiver System

Simultaneous transceiver system is widely applied in the fields of communications,radar,sonar,navigation et al.For communication,the same-frequency full-duplex working mode can double efficiency of spectrum utilization.For continuous wave radar,simultaneous transceiver system is the basic condition for its regular work.There are some bottlenecks in simultaneous transceiver technology,such as self-interference suppression.In order to study the self-interference suppression problem in the simultaneous transceiver system,the fractional order gradient theory is introduced to improve the least mean square adaptive algorithm,so we get the fractional least mean square algorithm(FOLMS).And then the FOLMS algorithm is used to complete the self-interference suppression in the simultaneous transceiver system.The main contents of this paper include the following aspects:1.Established a system model of self-interference suppression in the FMCW radar system.Firstly,the common FMCW radar system structure and self-interference suppression method are introduced.Then the FMCW radar system structure and self-interference suppression scheme used in this paper are established,and the system model of self-interference suppression is established to provide a basis for the following research on self-interference suppression algorithms.2.The self-interference suppression algorithm based on classical adaptive filtering theory is studied,including LMS,NLMS and RLS.Firstly,the self-interference suppression structure of each algorithm is described combined with the self-interference suppression structure.The relevant mathematical models and implementation steps are derived out,and the simulation and performance analysis of each algorithm are completed.3.Combining the fractional order gradient theory and the least mean square adaptive algorithm,we get the fractional least mean square algorithm(FOLMS),and then the FOLMS algorithm is used to complete the self-interference suppression in the simultaneous transceiver system.Firstly,the basic theory of fractional order gradient is given.Combined with the gradient descent method based on LMS criterion,the mathematical model and implementation steps of fractional FOLMS are derived out.Then FOLMS is applied to the self-interference suppression in the simultaneous transceiver system.The convergence conditions,convergence rate and convergence value of the FOLMS algorithm in the selfinterference suppression process are analyzed in detail,so as to improve the self-interference suppression performance by using FOLMS algorithm.the goal of.Finally,the simulation is completed under the background of FMCW radar system.The simulation results verify the correctness and effectiveness of the self-interference suppression algorithm based on FOLMS.And it shows that the self-interference suppression effect of the higher order FOLMS algorithm with high order is better than the LMS algorithm and the NLMS algorithm while using the same step factor.In addition,the stability of the FOLMS algorithm and FONLMS algorithm is better than that of the RLS algorithm.