Research On Performance Of Hybrid Fading Relay System Based On Mixture Lognormal Approximation

In addition to the basic requirements of reliability and effectiveness,developing a communication technology requires considering construction cost,complexity,and other factors in combination with the current situation.Power line and wireless communication technology have broad application prospects in the fields of intelligent power consumption and home Internet of things.Under the background of multi-media mixed network,the relay cooperation technology based on wireless and power line can complement each other,save construction costs,and improve the overall performance of the system,which becomes a research hotspot.For wireless and power line Amplify and Forward(AF)relay communication system,a unified performance analysis algorithm based on mixture Lognormal(Log N)distribution is proposed.Based on the approximate modeling of optimal mixture Log N and parameter optimization calculation with the minimum difference of probability density distribution,the system performance analysis problem under hybrid fading is transformed into Log N variables sum approximate calculation problem under Log N-Log N identical distribution.Then,based on the mixture Log N approximation,under the condition of two-dimensional Log N distribution model and multi-parameter impulse noise,the Probability Density Function(PDF)of the system Signal-to-Noise Ratio(SNR)is used to solve the theoretical analytic expressions of system performance,such as outage probability,bit error rate and channel capacity.The effectiveness and reliability of the theoretical analysis are verified by Monte Carlo simulation.And the effects of hybrid fading factor,impulse noise parameters and power allocation on system performance are analyzed.The fixed AF and Decode and Forward(DF)relay protocol has its own advantages and disadvantages.If the best mode can be adopted for forwarding when the channel quality is known,the communication quality can be greatly improved.Therefore,for the power line and wireless hybrid communication scenarios,this paper presents an adaptive relaying protocol based on SNR threshold value,and establishes a power line and wireless parallel communication framework based on relay forwarding.Using the approximate algorithm of mixture Log N distribution and the Moment Generation Function(MGF)of SNR,the performance of the system model was analyzed by AF,DF and adaptive relay protocol.Theoretical and simulation results show that compared with AF and DF relay protocols,the adaptive scheme can achieve better communication quality in both low SNR region and high SNR region.