Optimal Transmission Strategy Of P2P Real-time Communication In Fading Channel

With the rapid development of Internet and information technology,wireless transmission communication has become one of the main ways of communication.In wireless transmission communication,point-to-point(P2P)wireless communication makes the communication,sharing and interaction on the network easier and more direct.P2P wireless communication refers to the communication connection between two communication nodes,and the base station macro regulates the data transmission between them.For example,in a telephone call,one telephone is connected to another,and what one caller says can only be heard by the other.P2P wireless communication is widely used in wireless transmission communication.In wireless communication,Due to the effect of shadowing,multi-path propagation,multiuser interference,and mobility,wireless communication channels are typically correlated fading.Using wireless network optimization to improve channel utilization for cross layer optimization is an important problem.In wireless networks with time-dependent fading channels,the technology of quantifying Channel State Information(CSI)in physical layer is used for optimal transmission scheduling in Media Access Control(MAC)layer.In other words,both CSI and the channel memory residing in the fading process are used for the optimal transmission scheduling of cross layer single user(i.e.P2P).In the P2P wireless communication over the fading channel,the data packets that failed to be transmitted in the communication node are allowed to be retransmitted.That is,when the data packet fails to transmit due to the influence of channel,it can enter the transmission queue and wait for retransmission.In discrete time systems,Finite State Markov Chain(FSMC)channel model can be used for modeling.This paper studies the transmission scheduling problem of P2P real-time communication in fading channel.Specifically,we assume each transmission task with a strict time delay arrives into the system randomly,we consider the transmission scheduling strategy under the time delay constraint of the communication system so as to maximize the total discounted expected reward of the system.The communication model can be constructed as a Markov Decision Process(MDP).With the increase of data packets transmitted by communication nodes and the number of communication users,the dimension disaster of MDP architecture will be caused.In order to solve this problem,MDP based on single user data transmission model and MDP based on multi-user data transmission model are reconstructed into Restless Bandit Process(RBP)and Restless Mult-Arm Bandit(MRAB)to optimize the transmission scheduling model.This paper proves the existence of whittle index in P2P wireless transmission communication,and obtains the closed solution of transmission scheduling strategy based on whittle index.Finally,numerical experiments verify the effectiveness of the transmission scheduling algorithm based on whittle index.At the same time,it also shows that the transmission scheduling algorithm proposed in this paper has low computational complexity and greatly reduces the time loss compared with MDP method.Simultaneously,in the face of MDP dimension disaster,the algorithm can also effectively obtain the optimal transmission scheduling strategy.