基于松弛时延的真空管高速飞车uRLLC贪心复用机制

A Greedy Multiplexing Mechanism of uRLLC for Hyperloops Based on Relaxation Latency

真空管高速飞车的安全运行需要多种车地通信业务的有效支撑,包括超高可靠低时延通信(uRLLC)业务和增强移动带宽(eMBB)通信业务,异质业务资源共存时可通过临时抢占eMBB业务的时频域资源优先保障uRLLC业务的传输。根据误码率和时延指标将uRLLC业务划分为5个等级,并将uRLLC业务复用时延范围进行松弛,在考虑uRLLC业务误比特率和复用时频域范围约束条件下,构建以最小化uRLLC业务总功率为目标的优化问题;提出一种贪心策略,在指定步骤内得到次优解以应对高速变化的环境。仿真结果表明:在信道状态较差或噪声功率谱密度较高的情况下,本复用策略能显著降低uRLLC业务复用所消耗的功率,提升车地无线通信的可靠性。

The safe operation of the vacuum tube high-speed flying train requires multi-types of train-ground communication services,including both ultra-Reliable Low Latency Communications(uRLLC)and Enhanced Mobile Broadband(eMBB)traffics.When heterogeneous services coexist,the transmission of the uRLLC service can be preferentially guaranteed by temporarily preempting the time-frequency physical resources of the eMBB traffics.Specifically,the uRLLC traffics were divided into 5 levels based on the Bit Error Rate(BER)and delay metrics,and then the multiplexing delay range of the uRLLC service was relaxed.Furthermore,an optimization problem was formulated aiming at minimizing the total power of uRLLC traffics under the constraints of the BER and multiplexing time-frequency domain range.A greedy multiplexing strategy was proposed to obtain suboptimal solutions efficiently within finite steps to cope with the drastic time-varying scenario.The simulation results show that the proposal can significantly reduce the power consumed by multiplexing uRLLC traffics especially in the case of poor channel conditions or high noise power spectral density,which enhances the safety and reliability of train-ground wireless communication.