Given the proliferation of the massive machine type communication devices (MTCDs) in beyond 5G (B5G) wireless networks, energy harvesting (EH) aided next generation multiple access (NGMA) systems have drawn substantial attention in the context of energy-efficient data sensing and transmission. However, without adaptive time slot (TS) and power allocation schemes, NGMA systems relying on stochastic sampling instants might lead to tardy actions associated both with high age of information (AoI) as well as high power consumption. For mitigating the energy consumption, we exploit a pair of sleep-scheduling policies, namely the multiple vacation (MV) policy and start-up threshold (ST) policy, which are characterized in the context of three typical multiple access protocols, including time-division multiple access (TDMA), frequency-division multiple access (FDMA) and non-orthogonal multiple access (NOMA). Furthermore, we derive closed-form expressions for the MTCD system's peak AoI, which are formulated as the optimization objective under the constraints of EH power, status update rate and stability conditions. An exact linear search based algorithm is proposed for finding the optimal solution by fixing the status update rate. As a design alternative, a low complexity concave-convex procedure (CCP) is also formulated for finding a near-optimal solution relying on the original problem's transformation into a form represented by the difference of two convex problems. Our simulation results show that the proposed algorithms are beneficial in terms of yielding a lower peak AoI at a low power consumption in the context of the multiple access protocols considered.
翻译:鉴于在5G(B5G)无线网络之外大规模机器型通信装置(MTCD)的扩散,能源收获(EH)帮助下一代多重接入(NGMA)系统在节能数据遥感和传输方面引起了大量注意,然而,如果没有适应性的时间档和电力分配办法,依赖随机抽样的NGMA系统可能会导致与信息年龄高(AoI)和高电耗有关的延迟行动。为了减少能源消耗,我们利用了一套睡眠固定时间缩放政策,即多度休假(MV)政策和启动门槛(ST)政策,这体现在三种典型的多种接入协议中,包括时视多接入(TDMA)、频率分散多重接入(FDMA)和非振动性多重接入(NOMA)系统。此外,我们为MTCD系统峰值AoI(AoI)提供了封闭式的表达方式,这是在EH能力限制下,低延迟状态更新状态和稳定性起始门槛值(ST)政策,这是在快速搜索状态设计过程中提出的一种最佳搜索状态状态状态,这是为稳定(C) 快速搜索状态设计一种最精确的状态,这是为稳定状态设计一个最佳搜索状态的状态,这是为稳定状态设计一个最佳搜索状态的状态,在选择状态中的一种状态,一种状态的状态,这是为稳定状态定位状态,一种状态,一种状态的状态定位定位状态,在确定一种状态定位状态的状态的状态定位状态定位状态定位状态的状态,这是一种状态的定位状态的定位状态。