Research On Cross-layer Algorithm Of Joint Physical Layer And MAC Layer In Power Line Communication

Power Line Communication(PLC)is a key link to solve the "last mile" information transmission and ubiquitous Io T access.The Media Access Control(MAC)layer algorithm is mainly used to solve how nodes can efficiently share limited channel resources,and its algorithm analysis and improvement are the focus of PLC research.The existing MAC layer algorithm of PLC is based on the ideal channel model,and rarely considers the influence of Physical(PHY)layer channel fading,etc.It is necessary to study the crosslayer performance analysis theory and algorithm design of the joint PHY layer and MAC layer in PLC to further improve the overall performance of communication.Considering the influence of power line channel fading and decision threshold in multi-node parallel transmission,this paper proposes a cross-layer performance analysis model of PLC based on capture effect.Firstly,the probability density function parameters of the signal-to-interference ratio in multi-node concurrent transmission are deduced by using the variable sum approximation algorithm of lognormal distribution.Then,a crosslayer performance analysis model based on the reward update theorem and combined transmission probability is established,and the theoretical performance indicators,such as system throughput,packet loss rate,delay and energy consumption are derived.Finally,the validity and reliability of the model are verified by simulation,and the mechanism of PHY layer and MAC layer parameters affecting the performance of the cross-layer system is analyzed.Aiming at the cooperative communication network of power line and wireless,this paper proposes an enhanced time mirroring improved algorithm of MAC layer based on two-hop relay.Firstly,based on the existing MAC layer algorithm,a general MAC layer algorithm suitable for two-hop relay transmission is proposed;secondly,in order to improve the delay performance of the system,the general MAC layer algorithm of twohop relay transmission is improved,and an improved MAC layer algorithm of enhanced time mirroring is proposed.Secondly,in order to improve the delay performance of the system,the general MAC layer algorithm of two-hop relay transmission is improved,and an improved MAC layer algorithm of enhanced time mirroring is proposed.Then,considering the PHY layer channel parameters and the MAC layer,a PHY-MAC crosslayer mathematical model based on two-hop transmission is established,and the performance indicators,such as saturation throughput,delay and energy consumption based on the above two algorithms are deduced.Finally,the simulation results verify that the enhanced time mirroring MAC layer algorithm based on the dual-media cooperative communication network can effectively improve the system performance and resource utilization.