| With the rapid development of information network,wireless transmission capability has been enhanced,and the latency of information communication has been greatly reduced.With access to large-scale Internet of Things(Io T)devices,human beings have unprecedented transmission capability.However,the future 6G-based Io T application scenario is more complex,which may face problems such as how to ensure efficient and sustainable access and operation of Io T devices,how to achieve certain communication latency and reliability in heterogeneous network environment,and how to further improve wireless transmission capability.Therefore,this paper aims to solve the above problems,so as to design and research an algorithm configurable by using Intelligent Reconfigurable(IRS)to assist wireless transmission.The main tasks are as follows:First of all,in order to improve the efficiency of Wireless Power Transfer(WPT)and improve service coverage,this paper studies the biggest problems in the energy collection area available to WPT systems based on IRS assistance.In order to overcome the sharp attenuation of the signal during radio propagation,the passive reflection beamforming of IRS and the energy beamforming of Base Station(BS)are jointly optimized under the constant mode constraint of the reflected beamforming vector with the goal of expanding the available energy region.Aiming at the non-convexity of this Optimization problem,the original problem is transformed into two easy to deal with subproblems.An Alternating Optimization algorithm is proposed.Successive Convex Approximation(SCA)method and Successive Convex approximation(SCA)method have been used for iterative optimization of reflection beamforming.Experimental simulation results show that this algorithm can maximize the energy collection target region.Then,aiming at the transmission problem of Ultra-Reliable Low-Latency Communications(URLLC)business in a heterogeneous network scenario,this paper proposes the design problem of a beamforming algorithm based on IRS to assist maximize the users and rates of short-packet communication.Short packet communication technology is used in the micro region of heterogeneous network.On the premise of guaranteeing the communication quality of macro cell users,IRS is used to ensure the latency of micro region users and reduce the decoding error probability.A model for the problem of user and rate maximization in micro region is established by jointly optimizing the beamforming vector and IRS phase shift vector.By alternating optimization variables,the original problem is transformed into a convex optimization problem by SCA method,and the problem is solved by AO optimization algorithm.The simulation results show that the algorithm can effectively reduce the interference of macro station to users in small area under heterogeneous scenarios by deploying IRS,and improve the short packet transmission performance of users in small area by optimizing the beamforming vector effectively.Moreover,the communication enhancement effect of IRS is directly related to the decoding error probability and the number of IRS reflection units.Finally,in order to further improve the transmission rate of short packet communication users in URLLC scenario,this paper studies short packet performance optimization based on irregular active IRS assisted backscatter transmission.Considering that irregular active IRS can further improve the spatial freedom of reflection units and thus improve the system capacity,the system sends information to short packet users through irregular active IRS backscattering communication,which enhances the transmission signal of BS to users.Under the power constraints of BS transmitting power,backscatter signal dry to noise ratio and irregular active IRS,the optimization problem of maximizing backscatter short packet transmission rate was established.The deep reinforcement learning model based on DDPG was adopted to solve the problem,and the maximum neural network feedback under the optimal state was obtained to obtain the highest transmission rate.The simulation results show that the short packet transmission performance of irregularity active IRS assisted backscattering is related to different irregularity scaling coefficients decoding error probability and IRS horizontal position in two-dimensional plane. |
