Research On Short Packet Transmission Technology Of Multi-antenna Energy Harvesting System

Ultra-reliable and low-latency communication(URLLC)needs to accurately transmit information with short packets under stringent latency requirement.Moreover,due to the limited packet length,The maximum mutual information algorithm of Shannon’s theorem is on longer appropriate in a short-packet scenario.And the maximum achievable rate(MAR)is not only related to channel distribution,but also related to the packet error probability(PEP).At the same time,since the transceivers are mostly energy-constrained under URLLC,energy harvesting is needed to obtain energy for data transmission.Multi-antenna technology realizes multiplexing gain and diversity gain by utilizing space resources,thereby reducing the system PEP,improving MAR,enhancing the energy transfer efficiency and reducing the transmission latency.Therefore,we propose to integrate MIMO in the short-packet transmission system of wireless energy harvesting,and investigate the PEP and delay performance.First,the packet error probability of multiuser MIMO-WET system with shortpacket transmission is studied.In the short-packet scenario,we obtain an approximate closed-form expression of the packet error probability by utilizing the cumulative distribution function of the signal-to-noise ratio for each user and the Gaussian function approximation method.Then we jointly optimize the number of channel uses in WET phase and the power allocation factors in the WIT phase for minimizing the sum-PEP of all users.The simulation results validate the correctness of the closed expression of the packet error probability.And the numerical results show that there are optimum numbers of channels uses for WET and WIT for given packet length of information transmission and the number of antennas.Next,based on the approximate closed-form expression of PEP for each user,we use the stochastic network calculus theory to study the queuing delay performance when a PEP constraint is enforced.We first analyze the cumulative service capacity of the service process to obtain delay bound,and considers the delay caused by the inaccurate transmission of information.Finally,the delay violation probability is derived for a given target delay.Theoretical analysis shows that the delay violation probability is closely related to the packet length of the information transmission,the number of antennas,and the target delay.The simulation results validate the correctness of the closed expression of the delay violation probability,and the relationship between the maximum PEP and delay.