Research On Robust Beamforming And Channel Disturbance Coefficient In Wireless Relay Networks

In recent years,with the development of wireless relay network technology,people have put forward higher requirements for information security under the premise of meeting their own communication needs.The traditional wireless eavesdropping relay network technology improves the user information security rate,while the relay power distribution is unreasonable,and the traditional research method will not be applicable when the external environment changes rapidly.In addition,in the MIMO multi-multicast wireless relay network,the user communication quality is positively correlated with the channel disturbance and positively correlated with the relay transmission power.Under certain channel disturbances,it is extremely urgent to make a reasonable resource allocation for the energy at the relay.Therefore,in order to solve the above problems,this paper makes the following improvements based on the traditional wireless relay network algorithm:For the SIMO wireless eavesdropping relay network,the traditional method of channel known,the power distribution of the relay is unreasonable,and when the external environment changes quickly,it will not be applicable,the relay power optimal allocation algorithm and the random beamforming algorithm are proposed respectively.(1)In the relay power optimal allocation algorithm,to maximize the user information security rate as the objective function,with the relay's transmit power as the constraint,variable relaxation technique,semi-definite programming technique and Charnes-Cooper transform are used to target The non-convex form in the function and constraint is transformed into the standard convex form,and then the one-dimensional search method and the dichotomy algorithm are used to find the optimal allocation strategy of the relay power and the optimal weight vector.(2)In the random beamforming algorithm,the state distribution law of the channel is known,and the time-varying weight vector is introduced to maximize the user's information security rate as the objective function,and the power expectation of the weight vector is used as the constraint condition.The variable relaxation technique,semi-definite programming technique and Charnes-Cooper transformation transform the non-convex form of the objective function and the constraint into a standard convex form,then,based on the above convex problem,the weight vector is discussed in the complex Gaussian distribution and ellipse,the maximum information security rate of users under distribution.Finally,the numerical results of the study show the effectiveness of the above two algorithms.Aiming at the uncertainty of external channel interference coefficients in MIMO multi-multicast wireless relay networks,an evaluation algorithm based on external channel interference coefficients is proposed.First,the external channel interference coefficient is set to maximize the user's signal-to-noise ratio as an objective function,and the original model is constructed with the relay's transmission power as a constraint;Second,the non-convex shape in the original model is transformed by the semi-definite relaxation technique,for standard convexity,the dichotomy algorithm is used to find the user's maximum signal-to-noise ratio;Then,the correlation between the user's signal-to-noise ratio and the external channel's interference coefficient is used to estimate the current external channel interference coefficient;Finally,the numerical results of the study the effectiveness of the above algorithm is shown.