长短包混合传输的互惠共生无线电系统资源分配方法研究OA

The internet of things(IoT)aims to map the physical world into the digital world and enable ubiquitous connectivity among people,as well as between people and devices,and among devices themselves through wireless commu⁃nication technologies.As one of the key enablers of the 6G vision of intelligent connection of everything,IoT has been widely adopted across various vertical industries.However,the massive access of IoT nodes has exacerbated the inherent contradiction between the scarcity of available spectrum resources and the surging demand for spectrum from IoT services.On the other hand,constrained by manufacturing costs and physical size,IoT nodes are typically equipped with limited bat⁃tery capacity and are not suitable for frequent battery replacement,making energy limitation a critical challenge.Recently,backscatter-aided mutualistic symbiotic radio(MSR)has been widely recognized as a promising spectrum-and energy-shar⁃ing paradigm to address these challenges.Its core idea is to allow IoT nodes to share both spectrum and energy resources with ambient primary system transmitter(PST).In an MSR network,IoT nodes utilize PST signals as the carrier and energy source for backscatter communication.They not only achieve passive information reflection through signal reuse but also harvest energy from incident radio frequency signals to replenish their energy supply,thereby effectively alleviating energy constraints.Meanwhile,by exploiting the fact that backscattered signals contain PST symbols and leveraging the difference in modulation rates between the primary and backscatter links,the cooperative receiver(CR)can convert the backscattered signals into beneficial multipath components to enhance the capacity of the primary link,thus realizing mutualism between the primary and secondary links.Considering that PSTs typically transmit long-packet data with infinite blocklength,while IoT nodes tend to use short packets for low-data-rate services,this paper investigates an MSR network that supports long-packet communication from a PST and short-packet communication(SPC)from multiple IoT nodes.A resource allocation scheme is studied to minimize the transmit power of the PST.Specifically,given that the error probability of SPC from IoT nodes directly affects the transmission performance of the primary link,a closed-form lower bound expression for the trans⁃mission rate of the primary link is derived.On this basis,an optimization problem is formulated to minimize the PST trans⁃mit power under the constraints of quality of service for each IoT node,energy causality,and guaranteed throughput gain of the primary link.To solve the formulated non-convex optimization problem,a hybrid optimization algorithm based on the bisection method and block coordinate descent(BCD)is proposed.Specifically,the bisection method is employed to itera⁃tively update the PST transmit power and shrink the feasible region,thereby simplifying the original problem.In each itera⁃tion,with the PST transmit power fixed,the BCD method is applied to decouple the simplified problem into two indepen⁃dent subproblems.These subproblems are solved alternately to obtain an approximate optimal solution to the original prob⁃lem.Simulation results demonstrate that the proposed algorithm converges rapidly and verify the superiority of the pro⁃posed scheme in reducing the transmit power of the PST.