Research On Full-duplex Two-way Communication Systems In Ultra-reliable And Low-latency Communications

Full-duplex(FD)technology has been extensively studied by academia and industry due to its great potential to improve the spectrum efficiency of communication systems.Most of the existing researches are based on the ideal assumption of arbitrary reliable communication(error rate tends to zero)under Shannon channel capacity,that is,assuming that the encoding is performed on the infinite blocklength.Emerging communication scenarios in the 5G era,such as vehicle to everything(V2X)communication,factory automation,telemedicine,etc.,due to their business' s strict requirements for information delay and reliability,short data packets are needed for information transmission,that is,they need to be performed on the finite blocklength.In the finite blocklength regime,the error rate of information transmission can no longer approach zero infinitely,the Shannon channel capacity can no longer accurately describe the system performance.In order to better guide the analysis and design of short data packet communication systems,Yury Polyanskiy et al.developed a new channel capacity basic framework under the finite blocklength regime in 2010,and gave an approximate analytical expression for the maximum coding rate.The thesis focuses on the performance analysis and optimization of a FD two-way communication system with finite blocklength,and its content and innovative work mainly include:(1)Analysing the overall performance of a FD two-way communication system with finite blocklength from two dimensions of energy efficiency(EE)and effective throughput(ET),and respectively deriving a discriminant containing the parameters(channel gain,bandwidth,average transmit power,self-interference cancellation capability and noise power spectral density)of the communication system which can be used to efficiently select the optimal duplex mode in the two-way communication system and guide the design of the FD two-way communication system;(2)Converting the multivariate non-convex problem of optimizing the EE and ET of the FD two-way communication system into a univariate t convex optimization problem,and the optimal average transmit power is solved by a convex optimization algorithm which maximizes the EE and ET;(3)Due to the existence of residual self-interference,optimizing the EE of a single communication node in a full-duplex two-way communication system has become a game problem.This thesis considers the optimization problem in the two cases of cooperative game and non-cooperative game.For cooperative game case,the game problem is transformed into a convex optimization problem.For non-cooperative game case,designing an iterative algorithm to find a stable approximate solution of Nash equilibrium,and the convergence of the iterative algorithm is proved;(4)Through computer simulations,the conclusions and the convergence of the iterative algorithm are verified,and the trade-offs and dependence relationships between the parameters of the communication system are analyzed.A guide method for the design of the FD two-way communication system with practical value is obtained.